Engineering Design Handbook - Carriages and Mounts Series, Carriages and Mounts - General
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English Pages 49 Year 1964
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UNCLASSIFIED
AD NUMBER AD830276
NEW LIMITATION CHANGE
TO Approved for public release, unlimited
distribution
FROM Distribution authorized to U.S. Gov't. agencies and their contractors; Critical Technology; MAR 1964. Other requests shall be referred to Army Materiel Command, Attn: AMCRD-TV, Washington, DC 20315.
AUTHORITY USAMC ltr,
22 Jul 1971
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'
PAMPHLET
*AMC
AMCP
106-340
RESEARCH AND DEVELOPMENT OF MATERIEL ENGINEERING DESIGN HANDBOOK
CARRIAGES AND MOUNTS SERIES CARRIAGES AND MOUNTS-GENERAL
STATEMENT
#2
UNCLASSIFIED
subject to special expert to foreign made each transflittal controls an(&or nationals may be freiGln goVerdsients
This document
is
to r ArmyWa l of: only with prior appro Washington, D.C. AMCRD-TV, Attn: Command,
O
20315 COMMAND HIEADQUARTERS, U. S. ARMY MATERIEL
MARCH 19F4
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HEADQUARTERS UNITED STATES ARMY MATERIEL COMMAND WASHINGTON 25, D.C.
31 March 1964
AMCP 706-340, Carriages and Mounts--General, forming part of the Carriages and Mounts Series of the Army Materiel Command Engineering Design Handbook Series, is published for the information and guidance of all concerned. (AMCRD) FOR THE COMMANDER:
SELWYN D. SMITH, JR. Major General, USA Chief of Staff
OFFICIAL:
Chief, A
inistrative Office
DISTRIBUTION:
Special
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"PREFACE This Handbook has been prepared as one of a series on Carriages and Mounts and forms part of the Engineering Design Handbook Series of the Army Materiel Command. This, handbook presents introductory' information and prelimirary design procedures for the structures and mechanisms that are embodied in a gun carriage or mount. More detailed design information concerning thes,! items will be found in othh handbooks of the series, published or to be published. Material for this handbook was prepared by The Franklin Institute for the Engineering Handbook Office of Duke University, prime contractor to the Army Research Office-Durham. The Carriages and Mounts Series was under the technical guidance and coordination of a special committee with representation from Rock Island Arsenal and Springfield Armory, of the Weapons Command; Development and Proof Services of the Test and Evaluation Command; Army Tank-Automotive Center of the Mobility Command; Frankford Arsenal of the Munitions Command; and Watertown Arsenal of the Missile Command. Chairman was Mr. K. A. Herbst of Headquarters, Weapons Command. Agencies of the Department of Defense, having need for Handbooks, may submit requisitions or official requests directly to Publications and Reproduction Agency, Letterkenny Army Depot, Chambersburg, Pennsylvania 17201. Contractors should submit such requisitions or requests to their contracting officers.
a "W
Comments and suggestions on this handbook are welcome and should be addressed to Army Research Office-Durham, Box CM, Duke Station, Durham, North Carolina 27706.
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TABLE OF CONTENTS Page ...........................
PREFACE .....................
i iv
LIST OF ILLUSTRATIONS ......................................... ................
LIST OF SYM BOLS .. ............................
v
CHAPTER 1. INTRODUCTION .................................... ................................... A . Purpose .................. B . D efinitior ..................................................... C. F unction ......................................................
I 1 1 I
CHAPTER 2. DISTIN(TION BETWEEN CARRIAGE AND MOUNT ... A. Definition of Carriage and Mount ................................ B. M ount ........................................................ C . Carriage ....... t ..............................................
3 3 3 3
CHAPTER 3. TYPES OF CARRIAGES AND MOUNTS ............... ............. A . M onopod M ount ................................. B. Bipod Mount .................................................. C . Tripod Mount ................................................. D. Antiaircraft "Mount . .......................................... 1. For Machine Gun ........................................... 2. F or A rtillery ............................................... E . A ircraft M ount ................................................ 1. Fixed Mounting ............................................. 2. F lexible Mounting ........................................... F. Mounts for Defense Armaments ot. Transport Vehicles .............. 1. T ruck M ount ............................................... 2. K int Mount ................................................ G. Tank Mounts .................................................. 1. (om bih iation M ount ......................................... ......... ..... 2. B all Mount ................................ 3. Gim bal Mount .. .............................................. II. Field Artillerv Carriage ....................................... 1. let'era ......... .... ...... .... ..... .... ... ....... ........ 2. Single T rail .......... ................................... ............................... :1. S p lit T rail .... ............ I. Self-Pl'ropt lled Uarriag,,e . ...... ................................ I. Tank (Cha ,is ............... ........................... . 2. Dotible Revoil Type ........... ........... ................
4 4 4 4 5 5 5 6 6 6 6 6 6 6 6 7 7 7 7 S 8 9 9 9
3. T rinsportatiou .........
..................
.................
9
10 ....... ..................... 1. Mortar M oiunt ....... ........... ..... ......... .......... j0 K . RIaihk a"y C arriage .................. ... 10 I,. Fixedl Emplacement ('arria . ........ ........................ ...... 10 ................. 31. e•ecoilless Gull M,mint ................. ii
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TABLE OF CONTENTS (Cont.) Page CHAPTER 4. COMPONENTS OF A CARRIAGE OR IMOUNT AND THEIR FUNCTIONS ....................................... ................................... A . C radle ................... B. Reecil M echanism .............................................. C . Top Carriage .................................................. D Bottom Carriage ...................................... E. Equilibrator ............................................ F. Elevating and Traversing Mechanisms ...........................
.......
11 11 11 12 1:1 13 1:
CHAPTER 5. PRELIMINARI APPLIED DESIGN LOADIS ............ A . W eight Estim ates ............................................. B . Recoil Force .................................................. C. B uffer Force .................................................. D . Equilibrator Force ............................................ E. Elevating and Traversing Gear Loads ............................ F. Trunnion Rearing and Traversing Bearing Loads .................. 1. Trunnion Bearing Loads ..................................... 2. Traversing Bearing Loads .................................... G. Applied L.)ads During Transport ......... ........... ..........
15 15 16 17 IS 19 21 21 22 22
HIIAPTER 6. SIZE O STRI'CTI'RE ................................ A . Trunnion Height .............................................. B. Stability Effevts of Structural Size . ............................. CHAPTER 7. PRELIMINARY DESIG;N PI{ROtEI)I'IES FolR MiohTAR MO 'N T S ........................................................ ..................... A. Structural Com ponents ................... ............................... B . Y ou n t ........................ ................ C. Base P late ...................................
24 24 24
CHAPTER S. SAMPLE CAL('AtlI..,rNS ......................... .... ............ A . W eight Estim ates ........................... B. Preliminary Re.oil (Charactvritivs ............................... 1. Singit- Recoil Sy.tem ....................................... .................. 2. Double Re.oil System .................... C. Equilibrator Forct.. .................................... I). Elevating and Traversing Loads ...... .......................... IAXd ........................................ 1. Elevating 2. Traversi,," (,ear IAMAd ..................................... R. Trunnion lM-aring and Traversing Bearing Load s................. 1. Trunnion BearingiL,,ad ....................................
:12 :2 :2 :2 :2 3: 33
toear
2. Travirrinr Bearing L ad .......................... F , S;ize of S"trm 'ur ,'r. ........ . ..... I..................
27 27 2S :10
*:
34 34 :14
....... :14 ........... . 3
5 1. Trnnnion Heigh! ........................................... "2. s ta b ility . . . . . .. . . . . . . . . . . . . .. I. . .. . . . . . . . . . . . . . . . . . . . .. 1 G LO SS)," ,". il{ - - .. . . -... .................... ..... ....... . . . . . .. :17 REFERENCE,. ..............
..................
...............
II.I
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LIST OF ILLUSTRATIONS Title
Page
Figure 1. Gun Carriage With Major Components ....................... Figure 2. Monopod Mount ........................................... Figure 3. Bipod M ount ............................................. Figure 4. Bipod Mortar Mount ....................................... Figure 5. Tripod Mount ............................................. Figure 6. Tripod Antiaircraii Machine Gun Mount ..................... Figure 7. Multiple Machine Gun Mount ............................... Figure 8. Antiaircraft Gun Mount .................................... Figure 9. Ring M ount ............................................... Figure 10. Truck Peiestal Mount .................................... Figure 11. Pedestal Mounts on Landing Vehicle ........................ Figure 12. Combination Gun' Mount .................................. Figure 13. Ball M ount .............................................. Figure 14. Gimbal M ount ............................................ Figure 15. Single Trail Field Carriages ............................... Figure 16. Split Trail Field ('artiage ......................... ....... Figure 17. Firing Base for Carriage .................................. Figure 18. Tank Chassis Carriage .................................... Figure 19. Double Recoil Weapon .................................... Figure 20. Double Recoil Weapon, Detachable Prime Movers ............ Figure 21. Double Recoil Weapon, Semitrailer ....................... Figure 22. Doub'e Recoil Weapon, Attached Prime Mover ............... Figure 23. Cradle Showing Attachments .............................. Figure 24. llydropneumatie Recoil Mechanism ......................... Figure 25. Top Carriage ................................. .......... Figure 26. Bottom Carriage .......................................... Figure 27. Spring Equilibrator ....................................... Figure 28. Elevating Mtechanism .................................. Figure 29. Traversing Mechanism .................................... Figure 30. Muzzle Energy-Reeoiling Parts Weight Ratio ................ Figure 'A1. Muzzle ,nergy-Weapon Weight Ratio ...................... Figure 3?). Equiliiij'stor Geometry .................................... Figur, 33. E'tvator Cear Loading Diagram ............................ -igu : 34. Trav'-rsiig Gea. Loading Diagram ......................... Figur-, 35. Trunnion }--arig Loading Diagram ........................ Figur,' 31. Traversing Bearing Loading Diagram ....................... Figure 37. Side 'lop, ,4tibility . ..................................... Figure 3:4. Stabilit., y inspection-Single Recoil System ............... Figure 39. ',ifii~ y by Inspection-Double Recoil System ............... Figure 40. itability During Firing-Single Recoil System ............... Figure 41. Stability During Firing-Double Recoil System .............. F igure 42. Mortar .................................................. Figure 43. Typical Firing Data .......................... ........... Figure 44. Loading Diagramn of Mortar ............................... Figure 45. Pinned Ball and Socket Joint .............................. Figure 46. lland-lleld Mortar ....................................... Fig!.re 47. Base Plate W ith Spades ................................... Table 1. Muzzle Enew gy.Wr.ight Ratiom .... ........................ iv
1 4 4 4 4 5 5 5 6 6 6 7 7 7 7 8 8 8 9 9 10 10 11 11 12 13 13 14 14 16 16 18 19 21 21 22) 24 24 24 25 25 27 27 28 29 30 30 15
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LIST OF SYMBOLS 'ib =
bore4
Lt = %% hed- spaii lengjtth of t ubi'
arl'a
A.
projee(tsA4 a r4' of miorta r base mpade 0.= mo rt ar 1110 i t avve.leratii a, = aceleerationi of prime mo1ve'r a, = reeoi ack-e'h'ra ti a1 acceleration of sevondary rec(oiling parts C = dlistane,' trumnlion~ to equilibrator pivot Dh=bore (Iiamf't e
E. mizzle ene14rgy'I Er = enel4rgy of free' ref'oiI F', = iert it forcef of r.ecoilhig parts Fa, = bufife r forve. 114'f4'14ralt ing f orce of p rim 114'It mov1e r; rf'si(1 11 forve c11 m1o rt ar ba~se ('It JI Flit = s.'oiitar~v bu ffe r force F'i: m'jitilibrittor f44r',, Fe P ffet-i'vt priwsus1r4' load F,=
prope'llanit gas force average propel'lanlt gas forf'e
F.
L. = eq il ibrator Ie'iigthI when o, L, = lenlgth1 of p ri mat r re'oil L,= ntgth of sii4oiidary recoil ifI.1 = momno~l't abount mo rt ar Ilas( .11, = mims of propellawl gas YV,
=
mass(i5f
.11,
=
itss oif rf'('fli~iig parts momew ui ithimt h t Irael ''ri ng
= V
.I
inertia load4
F.
li, Ila litk 1, .
prim
F'.
side4
Ft I
=iner~t ia fore'' (i
aveeli'ratio i~twitl e' 4ff
iII. lt K
:
radios1
4',
iu
a
iifirlgi n~i.~r11)li
aIxial load(4 , in right lo'g of mofrtar hiomllit fiule to swe-
1?
-
rvrwhaig
od(
fott~
o"
(jut' tomNr
baw plate il
of'ondaIhry rf''ffl~iml~ pairt,;
wf'11p44
J4
4ilratfl
A'..
- Lrfooll rem'a'lo onL
moI(rtar
m~otlint
fimtsil' rafitlls
pit~h raoliii, of *'air1m'ire' tof I ralvir-
f'f'ite.,
of
gra vit.%
zv~ir
iC
.,rwm(! po4iiit multi bfre t-f'ilf'r uhf'e rv'51t141('f
Jff'I
riftjll',
to jlrima~r.%
.'m-r,.gY
if
Ct '
of r,'.oifiilt- part, l'1ippjiili
4'
pt4~rts
1741141iml'
on'. 'I r ra' *'rxiig bi'ariti-1r
rat". ir'rti, fof ,,ynitionl (if tilll~ipz J)ll'.~
.islnvfrom~ ha.
-
Ir
primaliry pa~rts din,4 t4o sev-Jlile71
rtsjsait','e t( ro'.'.ii rosv44ling jis.rt'%
A_slprnii.
I
4,ravi7i:V14,or.1
1
itbfovf
parts
by' tranls-
ax is
wronnil jpri".slLr-f on1 :iioirtar las.'spatlt' t or airio
inert'ii fore o' owlldary llhflim.g
=
P'.
14indw-el
inertia force: of prima.
h
1111
__~
mo.hI4ver
load(4 on1 mounh1t
1(A( Fr =total trulimimi loa 1441ca rriage of rv'4 it fo 1114'rt Fi.' = F', =
project iw
Jpr4.;44'laii gns Jpre'olirf i veragig pro~pe'llant gits pri'551174'
P,
I'
of mlortair mllinlt
"--ke't
wi-ight nionwnlt of t ippinig parts Weiatht mlonlen oC tipping parts at zero igl 4f elfevation1 oi h=Inus of tippinrg parts 111H4.SS (if pr imlarv recoiliing parts toft.'% of %evionflitrv reioiliiig parts ~,inumo orvr.'ire rmi m4 o rt ar hase
=
=
Fon ma.~ 111illm pIrope'llaniit gats for4'e
0.
tulatz'
%twk.'t If, mortar
,
h-f
'4
I",~l~ iJf'.j I -i'
Irihi~tltI
r
off vi O
'4li'1
.iI'4
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T.
-=
actelirating, ti•rue for elevatinig tippl)ing
It', = weight of primary rt.oilinlg parts
parts
it', -
T = d,.sigi; torquie of tipping parts TI =
firinig torque
T,
toirfliio
=
iliidire-td
bly
sev•onwlary
aev~el~ral-
t ioiu
V.., = v,elohity i,f secolinlury r
=
Is'-
to r
to loadl cieiter !ierlr ).rt stroke; primar.y buffer stroke
buffer stroke = distanet, from center of gravity of weapon to front support
trinnion height aibove ground tz .ir a, = ehlvating accleration 2 =t traversiig acceleration
,minterrermoil
imuizzle, vthi(ity
total welight
of eimiplaved
weapon;
uf
=
towled weapon
WAr = weight of bottom .arriage of nmortar base plate w, =-eight 1 lweight of cradle; of propellant charge W "= 11" = weight of propellant gases
8 =
g eiar tooth
pre.slir-, angle; half angular spread betweeii mortar mount legs ujuigll" of elevation
0 = miaxiniiuli angle of elevation b = 11185 I iiniint of inertia of tipping parts
W.
= weight oif mortar mount 11', = weight of proj.ctile; of prime ulovor IV, =
traversing bearing center
diisti{ee fromn
tdesig torql, of trversig svshinir v=ldesign ioffret, re•.oil srs -- loity of frueieitrrieeoil
TI, tI.
weight of se,,nulary revoiling parts
x.=
4)" =
Inas moment of inertia of top carriage
0,, •
mam i nioment of inertia of traversing
weight of recoiling parts
parts
WrC = weight of top carriage I, = weight of tipping parts, of tube aws-mbly W. = weight of towed weapon
vi
o
angular displacement of (G of tipping parts; side slope
i&
coefficient of friction
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CHAPTER 1
INTRODUCTION A. PURPOSE 1.
('arriafys iD~
i is~ th .)Ioii nIt-Grutal
with Ivi
a eisof hanidthook%. dva lhii
first ill
cuat urriages
tutu miotitits. Deutailed ilisvus,';'iis andt des~ignt pro. i~-lie~for the hiiiiviultial comtponents~t that formi moht in appi tjar or tire ti ssoy at tId wiitht a rrianes t (1ian int the other htandbooks of titis seri.'s. These huan(l.
hooks' areN :142
:14:1 3144
3145 3146 : 147
,it-s It), coil Sqf pas Top Cr'la ru~qvs Rottoun ( 'riaqI ~ls Kquilibrators
-
Kill retiail Vf~ i/ianisms. I lls Travi i r ,a .111l i ii
TIhis hadotlIiok jiti rodivists fill- sUibject.
It prov~ides
ili..aaiptivt- narltrial w~hilc s1 wifich tiesigi oata anid witld ses (ii thle vatrilts liiIIpioheils are taki-ii III ini All effort is made' to the sit ivieedinIgai'"iks. draw ;I dist inctioun hetwieniit carriage Iii anit Iaoulat sincie the-se ti~rhis havv bieen
the
pas~t.
The
various
ostit
tpe
mtowits from aI simpile mioaiopod.
rather loo-.etv ill of
carria--ns
ust-dI'mo- at
alatoaitativ rit!. to aI hav~v artille-rY cat;
2.A
iwr
awlt
Ii-0t. arv
tY pical vt riragr %%itht It,, miair vomlljolilt'
;aiothir arv dltwsi~ss'. aI 1 irchimiiiittr .'tL'i
Fiqtue
Ili orl'-r to tiiakr etlilarv -f -I varrlaju. 1t ur-.
1. Gon Carr iage With Ahjor Comnponent~s
111aii. ii' I-. TIw ol~lil.
h
tl,Tlr
ft .1(Ti
jtt,-
'
lti~
I'l!
li't
C. FUNCTION B. DEF1IN1TION sniwtu~ri
that
t.ijqlort,
\11 I!.Il' r t~s:', a %%rapIwn
Th.
l.rrtiaeo
'
l~~l~t
I..lpr'*!a:
111-j u
:
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inCChaIisins ?•oderate t he ftorces inducet d by firing, Oil most field mortars, si•ook absorbers perform a similar function by reduin- the shock on the
vation, but to a degree limited by the type of weapon. The larger caliber weapons have equipnent for loading and ramming ammunition in-
mount. Other functions, iwluding transport, traversing and elevating, dt pnd on the type of weapon. In practically all wcmi.pons, traversing and elevating mechanisms adjust azimuth and ele-
stalled on the mount. Many field artillery weapons are either self-propelled or have their own prime movers for transportation. Others use auxiliary facilities such as trucks or tractors.
2I
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CHAPTER 2
DISTINCTION BETWEEN CARRIAGE AND MOUNT A. DEFINITION OF CARRIAGE AND MOUNT 5. In many weapon, the distinction between the terms carriage and mount has become rather obseure. No doubt this has developed through the years; although there still seems to be some feeling that the term mount has a more general connotation, despite the fact that in some cases the term carriagfe has displaced it. This is particularly evident in the ease of some towed weapons. B. MOUNT 6. The mount may be considered to be the entire structure tiat supports a weapon. It does not, in itself, move in azimuth or elevation or during recoil. In the case of fixed emplacements the mount is usually attached to a large structure, whereas
in field artillery it rests on the grounid. The transportation of the mount may be performed by a separate transporter or, in somp cases, it is a vehi(clh capabhle of being towed. C. CARRIAGE 7. As previously stated, the carriage may be a portion of a mount or may he considered complete in itself. Its fundamental function is to support the weapon during the firing cycle. It contains all the equipment for aiming and for absorbing the recoil frces. Wheels may be attached for travelinv as a towed weapon, or the carriage may be Stl)ported by one or two transporters during travcling.
t
3r
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CHAPTER 3
TYPES OF CARRIAGES AND MOUNTS A. MONOPOD MOUNT 8. The most elementary mount is the soldier's armi which supports his rifle while firing. For light automatic rifles or light machine guns a more stable rest and therefore better accuracy is available with a small monopod (Figure 2) which is attached to the barrel. Since these weapons are often fired from the prone position, the irregularity of the ground and the need to elevate the weapon requires some telescoping adjustment in the monopod.
"RAvErfW MECOAWSM /
-MORTAR
ELEVATIN
1~9
131 O
MECHA 4ISM
PLATE
Figure 4. Bipod Mortar Mount
Figure 2. Monopod Mount B. BIPOD MOUNT 9. Heavier automatic rifles and machine guns, needing more stable support than monopods provide, resort to bipod mounts (Figure 3). The two legs of the mcunt are adjustable to compensate for uneven ground and ehange in elevation. Light feld mortars have bipods and base plates (Figure 4). Screw arrangements provide limited elevation and traverse. The traversing and elevating meclianisms which rotate the tube about the base plate
Figure 3. Bipod Mount
usutally consist of horizontal and vertical screws ho||sed in tubular yokes and aetuated by handwheels or cranks,. C. TRIPOD MOUNT 10, Tril'-d mouats for machine guns support the entire ,.eapon. The gun is aimed directly by the gunner, thus permitting rapid changes in azimuth and elevation, or simpie elevating and traversing mechanisms may be used for more stable and pret,•--
-
-
Figure 5. Tripod Mount
4i ..
-!
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vise aiming CFiguire 5). The tripod mount is used prlimnarily for ground fire.
and~, thierefore, grountd clearanc(es adequate to perjuit tinlintited high elevation and amiple clearancec
for the gulutter when moving with the gun. The mounts for multiple madehine gunls are af the pedestal type. Figuvre 7 shows ai monott equipped with four miachine guns. The mounts may be controll ed matnual ly or power-operated. 1i-I poweroperated mounts, the power plant is self-contained. The multiple machine gun riountt may rest on the groltund or mayv be mounted on a vehicle or trailer. It has t11itiiiited traverse, and the gunls may be elevated to 90") or depressedI below thle horizontal. ~All ac~tivity during firing, is cotntrolled by the guittier seatedl 'entitralIly on the itotimit. A rmor ~~plate miay be loeaiti d ini frotit of the gunnter.
D. ANTIAIRCRAFT MOUNT 1. For Machine Gun 11. Mlaehiine guns for antiaireraft u.,e are moti ted either sinugly or in mnutlt ipie utnits. The pedestal mouint for onec machine gun is suppo,'ted on a three- or four-legged stand (Figure 6). The pedestal extends upward to effeet a high trunniion
N
GUN
2. For Artillery 12. 0
Existitig mtountts for antitiaircraft artillery leofteidstal ty:vw hther teiv installation is
PEDESTAL
~ ~~-'.--LEGS
C
GUN
Figure 6. Tripod Antiaircraft Machine Gun Mount ELE VATNWG AMMO
BEARINGS CETGUNS
/*
PLATFORMOuRGE
ARO PLATE
I-igure S.
Antiaircraft Gun Mount
the frvviloti of immi'ioiid. rt rav-s aitil the high mnttig (isfelf-:,uuioi (,() or bvttvrý niecessary for iutiairctrtfu fite. PFixed iwteillatiottsý forttu-rl v used~ for hairbor dlefeits arsv (.h-.olvt antd have~ b~et-1
1
relplaveet
TRAV[RS#^C
B(A~t9~G('2ilmble The
Figure 7. AMutihpi Maochine Gun M~ount .5
with I rumispotiable or moibiile miurtimitiu. of tbeitii tuumod~ to the site of iltt-tiow Thv5 .
pedestil whitib ri-sts oun Owi tzro.uml lhas foumr
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folding- out tiggers attachedl to its base to provide n~ eeded st abl~i ity. Tliis type in~ount increases the weapons' versatility by being stable at low angles of el eva tion thIiereby rendering the gun effective for0 genieral warfare as well as for dlefense against aircra ft. The mnoun t has the add~lit ionial asset of being eaSilY andl rapidly emplaced.
E. AIRCRAFT MOUNT 1. Fixed Mounting l:3. The mountts of guns and lauinchers in fighter
'ora
Fiur 1O. Truck Pedestal Mount type aircraft are usually attached rigidly to some part of the wing, or in the forward part of the fusetakteeypoiigulmtdtaes Fg lagre. Except for recoil action, no relative motion tirae 9)her leeb povidingd unic tdorversg isFcig-eb e occurs between any) 'oniponent of the weapon and lr ) opeeoeha oeaei civdb raising the track for the necessary ground clearthe aircraft. The gmins are aligned with the axis aiice. This type of installation is used onl landing 'ho planle anol are ailniedyamigteaicat aimig te arcrft. vehicles, light armored cars. uitility cars, personnel 2. Flexible Mounting carriers, half-traeks and m notor c:-rr~ages. If comnplete coverage is not dlesired for these vehicles. 14. ()n large botnber- type aircraft the( gunis and pedestal ioi no ts with li mi ted t ra versi andl elevalii ii deris mnay be in stalIled onl muaneu verable tion are used ( Figure 10i). The pedustal is atiiioints, and turrets. Turrets are, usually powernvye nient pa~rt of th, vehicie 's t ac ed to a% coq opewrated but have imia mmuaoperatingw fa ci lit ies il structure where effective firing can be realized, catse of polwer failure. Firing isi cointrolled by- the giiereither remotely or fromt the proxiniity of 2. Boat Mount the weapon ;but, where unlimited traverse is availI (; ilatlmimie guns onl pedestal miounts are tise(1 able. firing- is interruiptedl auitomatically when any olsalbasadlnigcatfrlmtdpo p~art of the aircraft comaes in the line of fire.onsalbtsndldigcftorimedptec tionl aigrainst groundn forces anmd low flying airF. MOUNTS FOR DEFENSE ARMAMENTS craft. This type of miouiit is comlveniemit for inON TRANSPORT VEHICLES stallation where space is limited (Figure 11).
1. Truck MountKA 15. For swlf-defen-se againis t aircraft and grouiid fire.- tranisport vehicles are equipped with machine gil us moun11 ltedi omi ci reu a r tracks. The wea 1)011 iisually a caliber .30 or caliber .50 macwhine guis attac-hed to, a roller carriage that runs onl a circular
G.TAKM UT
17.
A tconlinmltion mount in the turret of a tank liiiiscs twoi guns, a niiachiiie gun and the primiar~y
Figure 9. Ring Mon 6
Downloaded from http://www.everyspec.com
GtA
9
/
.- 3-.
MOUT!
Figure 12. Con~bnahion Gun Mount1 ELEVAT04GTA
arniarnent weaponl (Fignre 12). The machine gunl. referred to -4 a spotting rifle or a ('oaXnil gun, is fired to a fix on the target before thce iarger caliber weapoil is fired. The mount has limited elevation but the turret provides unlimited traverse.
2. Ball Mount A ball miount is used in tanks to support seconda18ry a rmiament such as niaeh ine guins. This mioiunt is essen tially- a ball ani I socket a rra n geniel it w it h thei(guni attached to and passinug through the Close conintiemuent due to hall unit ( Figunre 13) 18.
AW TAESN
L-
MECHiMS
'CAW
AA(RCTON M:-
Figure 14. C 'I"ol M~unf brfo
ie
riit~
th:1mi 1
iinwlbth
u
u
iatytý
sdb
h i atyt Iinin and laý ied pileces suvii as thle S- inch th min 1iw it zer. ThIiese ear riag-es have single the~ 24(1)1 fr s I lit trail to carry r a rwa rd loadIs a nd to pronvide* the ioiessary stability. L~iaht art Illers pieces bay be firvol with the Im~ia~~ojtic tires. restling on the gromi'ii w he reas t he heaiv r pieve arv fired
(SECTTIONI
Fsgw, Mo0n 3. lo bi
C.Y
ELOTY0
Fiim 13. &Aba Moou atimllr intvrs'ivlsin tk
,irht
t1 !travvi 11e
tof
but.0 r'.
horrts. i
lmation an i
%itl e.ivi-t to the timpir theiutainti-.l
thle wirstiet npoonont.turt
3. General Mount !ight
aItravls
Ieutoi~ wouointtkýirrvts artillery ii
ermut wir~th
Fevaionit
it, tweps timiiugig
Im
o
te
tr
ttk
%vS, I
limitedw
ii
%tie
5.&rg.
t,
F,-
Cro
Downloaded from http://www.everyspec.com
with the carriage splpportied on a firing hase, the whcr ' heing lifted off the ground or removed with
-
2. Single Trail 21. Early field artillery was equipped with single trails (Figure 15a). The single trail is a simple arrangement volhw(ive to rapi:1 emplacement and providing a ready tow bar. Traverse which is limited to only a few degrees is obtained by sliding the unit on its axle. Elevation, because of interfeconce with the trail struneture, is limited to about 20 degrees. Thesie restrictions reduce the4, weapon's effectiveness; to the point that this type is used only for light transportable weapons sui'h as pack howitzers. The recently designed box trail carriage (Figtre 151)) is a modified single trail type (.apable of 360' traverse. The front ends of the earriageiare supported by a circular platform on whivit it pyivots while the rear end of the trail rests on a crawler type traversing mechanisin whi.h v.an position the weapon over the full 3W)° range. Providing ample space inside for the loader to work during flrinit, lolinhinwv the1 the wishbone-shaped box strtucture advantages of simplicity found in| the mingleh trail with the versatility of the split trail and still r,. tains good rigidity-weight characteristic..
"
A
r
L .--
%,Amti
,
thltmith no 'vyar. within the confines of the
frail %pr,.iI
F"or t it',,s, we'almmpus not supported by
3. Split Trail 'sage has made the split trail carriage the 22.
%%h',l.li doril, fIring. a firing base similar to that in Ftcuar'" 17 icrtvide, ,opport at the front of the
Figure 16), Thim standard type for field artillery F type offers several advantagtes )ver the siingle trail
tarriaij,.
type--it permits a longer recoil and therefore lower forces, higher angles of elevation, greater traverse, and greater stability. Angieh of elevation may be as h;g'h as 65° while travers, may
,
OO
\-"-
Sio
Figuro 18. T&k Chammsi Carriage
ripw. 16. Spid Trai F-ivd Cairnago
8
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PRNMY -LNTB
REOI
FEHAigue1.(tbe
shoin i Fiure
8.
esitanc
toreFilur is offere .
by larnk spade hinoe aa amnttatera 23 Tha oi obhinh digthmele iontrmobteiruddultoasityo
eolWao
Relt~l ecoil o
f h heavy
ing firing. No further restriction is offered by this monollt. the limlis being those of the split trait type. Onl the other hand, fine traverse is severely limited to a few degrees. hut coarse traverse, available by %iminply t urniiing the vehicle, is m iin iti-d.
e
~carriage
4
systerns are, invo
-ita. thet
v~iii rttlil 'v b4e j-a'tlteul to sinigle sstel-ins S ' siiiilJO b liveuiji~atling the# wvcondatry recoil alt-fivitv. A It oughl thll recoil forces mill he he samii' as those for the split t riil types (of var!vjuu of strutitmir
ri'vcu
structurem
3. TraUsportAtion
Two recoil
primary svstvoii oif the
25.
directly affeited hi th tilt vimariuis ttf thet round and thlt mseeon-iiry %ystemi ttf tilt- topj c-arria~cwhic conrulsthe- imiipttis of the p)riiiarv
24. 0till arge caliber wenpons. the ouutirt recitil.. tIlw of carriage offers adathaiiiathat an- tif a regl valoe il modern titid wnrfarv- ()tIn-is thecooim siul-rabl-- rw-dtition inI horiztonial grotmnu fonr-t-s ais to thamse uxlsrit-n.-edtlii
the (,tlt r a'lvuitmiges (if tlttijiA- ri-coil t. ptNvil fi- rctaiamt-d.
rig.all of
"gunl Which is
t'0111ltaru-l
lrainer thi ra six is einigtql seriwaons. il hstd'imtag
suich a
to help niode-rate rec'uil for(-,..
weapoti is illustratedl inl Figure 11).
t terctlre of minth fo thrtag ituis va
smgit,
Dol~t~ihcrei
tltit
~a
the- firing bmsr rejuiiire It-,% iuugrotiiitt pri-larftioll. both
4
takimg intI
-
-.
~.
r-.-iiil
little or
-,mtnlivivr to 1erV
t
rlsuit
bvyan til- vonihitittit uif several yiwthfod-. .A dtlible travtor foirms oni., vtnuttdti:;t ill F'ivilru :(,, Anltither I-. silt r-niiI.al-m%%ith bo, Egue 1
gii.Them, low forves andi the $general structutlre of
o
since coar-se traverst, is mmligitted and quickly attaintici. Thet double recoil tipe of cartriage need not he r-st rit-ted tot tlnihle rei..il systemis. T h is-
2. DubleRecil Tpe The principal feat-ure of the tiouble ri. -oil xvapoll is thle ability to utilize thet Ilnivss of thet topl
fWeeaponuly ed
Fgio2.Dul
~i
eo1WcoDth&,pm
Downloaded from http://www.everyspec.com
46i illustrates an ev'ii simpler structure, f(,r a handheld mortar. The mounts for the larger calibers, because of much greater firimg load,;, should be with somie weans of moderating these joadls.
Gor
'j
T1
~
sprovided
-
L. RAILWAY CARRIAGE
CAM&MA(
27.
Figure 21. Double Recoil Weapon, Semitrailer third is a full trailer with bogie and limber, the entire iunit being towed by a prime mover. Other uinits represent a comlbination of these three. The conveyers may be detachable or attachedl to the strueture. Evitn the prime mnover may be attached, Figure 22 being a sketch oi a concept of this type.
Railway-miounted heavy artillery was first used dluring the Civil WVar. Its development continned through and after World War 1, but aircraft bombing assumed the mission of these longrange weapons to the point thAt they are now considered obsolete. However, the use of railway mounts may be revived since the advent of the missile. This is based on the supposition that railroads augment the ivobility aspewcts of transporting launchers to convenient and toetically advanitageouls sites. M. FIXED EMPLACEMENT CARRIAGE
/
The additional miiass of the lprinie miover invreasesi the effectiveness of the secondary recoil systeml. In the-se installa'ions. the (lesigner mutst N-' aware that
2)8. Fixed emplacement carriages, including the (disappearing, barbette. and pedestal types, were used in harbor anmd city defense. They usually mounted large caliber guns, howitzers and mortars. These weapons were located at stra. tegic lo4-ations, always ready for action, and~ well Permanent facilitie~s protectedl by fortmficat iow%: such as comnmunications, fire control equipment, and anmnunitioni storage were used to full advantage. Ample power was available to the site and was used freed" thereby eliminating the veed forextensive auxiliary units. 1However, the mnobile ba s, sofnvlaratad hexnedagef
all parts of bo~gie. limber, or prime mover are subjected to secondary recoil accelerations anoi intist be' designed according1%.
land based aircraft has placed an attacking force beyond the rangn- of these, we.ajsmns. Additionally, modern explosi.ves and design of fort ifica! ion-
PIN 11114011primarily /f MPCAO
~ ~7
-,
7
.-
Figure 22. D"19~Recoil Weapon, Attache Prime Mover
26.
K. OUNTpiercing MOTAR Mortar-, are the simplest formn of art iller' .
usedI prinmsri ly for short range at high angles oIf elevation. There Are two typTes, the fixed and the mobile. T'he fixed molunt mortarsN, now ob-stlete, were usuially of large valib-' usedl for harbor de'fensr- Th~e mo~i Ic mounits. ei-i i g t ravis prt abie.,ci may tw emplaced on any convenient site. Mortars maty range in size as widely as fithrr art illery weap. on-.. For the' sinaller calibers, the tmount is tusually (of simple colnst ruct ion, kcansistint: of a b4se to absorb the firing loadis and asbipedl to lend %tability to the we'apon andl to prov ide Iimntmid elevation andl Fig'uure Figtire -4 ',hl~wN ,tiwh a nionuut ira verr-
bomibs have madle the use of fixed tortifiwaThus the very features which made the permanent oniplacnient highly des~irable have been respciisible for its presetit obsolete statius. t ions impractical.
N. RECOILLESS GUN MOUNT. .~ gunsmiml nev littleI or no ret-,il fork-,-, therefore mnouint anr- nertli-i for l'itoing and posiof -suticfiient mitire t ioning tinly. A nv sitn le %trt stability stich a% at tripodl. or it omvr %addlleto h.-d4 it on the irunner's shoulder, is aihi94uat.- to stnllport a weapoui of this type, When niouumiet on vehivies. be s' igen otigh to so .taiui t hese motn1it shotil by x.cli 'tla r I rr'x,-l. the areetr'.t Ions die
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CHAPTER 4
COMPONENTS OF A CARRIAGE OR MOUNT AND THEIR FUNCTIONS *
~A.
CRADLE -Oi that The vradl~e is oElIe of thle ('4)111 eits 29. make up it carriage or mo11unt ( Figujre 2:). Ani-
who- ther byv (lea raneies hepeI lot i 'a Iili- itivns. e tween mnalin aigsrfavuls or by' --triettiira deflectleions, the fire control vniwiieer sh"Oidl he onilde ''ogilizalit 41f the extenit of t ht-e~ 4le-leeetioiills si) thiiat he van (it.d-
ELA?
~~~~sigil hiis equipiieli t
-,
lEm~tvtYW Weap~onii inn nt rol (lesipio' r.
WCH11114((Eli1
:11
other handhlook" de-als speE'ifiE'aly with the vradle. (iisvils~sillg it ii(lldtaili along" with its voElipoIeEIElit,; anld pertiitie't (lesigni dilat. The ('radliE is onlv of the tipping parts se'rvinig as the' supporahin.- strulefor
P~it
other tijpping, part,.
is to suipport tilt
Imlin
tulbe.
Its
primaOry
It has
gtriiles
or trac'ks Em which the' tulle slidels dlitrilg ri'E'EiI antd couniltfi~t'euli. It anichors the revoEilinrch.ll avisni. It prevenits thle' tubi' from rEotatuio~. It transituits Hil loads iincluiding, thoeE' of roE-old tullE' wihip.
andl~
tor~jli-.
ritliitv
lilarill- tfirwi~gh
thE'
art,
by
traninuitted
iunit,
P
Eimrla1t'
tEE th ilE' toj
tr'iililjEiitis. (Ethrr
iogli.
ae''lt-vt't f 1(1
Till-
toE
ail tiit fir'
niIEEIEIXtE's
the fnirinig
lEE' nvei,''
I
B. RECOIL MECHANISM
Figure 23. Cradle Showing Attachments
funcetion
HECE o'tl
St ritetlire andit v beca list of ii i et er linia tv naol 1meof jIill t 5, alre- not uvvu*iiratvl.% pErI (et able; thl' erfore it
ATAHETT1UH
tlir(
through goodI Iginle'erhi ig p raetjes. Mad i iied ('E H 1( siliali t' iehra nees su rfaces withI low tole rativ are hiel p fui. Symnimet riva I strue tutres geniera Ill de-' fleet sV lininiet rivaliv thle ri' fort' l'ss ',niiJ etisation1 for
IncEidental sonIId' as
loads VH jugal"
rvellil
A
~iEliitilin
Eii
loads oEl iv tiSlj)EErfiig t rui-tuirle i~daguln 1EVpro(lonlging the linit Elf re'sistativeE lEE thuý propoilauit gEl5 f *,q*. As the gals llressulrv prEEwiE tlE- JprEojoct!ie' toward the muitzzlit' viXrts Jall viiiia1 and)1 (EiEp(Eitl' forvo' on the btrvi-ch whitli drive's tilh.e0 'urirl The revo~il int-dEilalisiil vusii5iIIs this force' anli limits thE'
rearward
lilotioni
and~ tlieii
rvt irll-s
quicIklyitEE t1win' l-balttr' vEEI poo11)*n
strellgtil
iitilE A\side' from
wild
jolE'!zEtioal
vieP fimuii aind ri-fiahlo' base for th iret 'tll1)IIItllilt
ril~jit
that
tiit
bs' IfloiEEiIIIE.
Vf i%Epititinultin ht
Most
rl'1EoI
niitehaniiitivs
ilvdrEosjrinlg oEr to tin
h
hydrEE1 EliElluli
avo1( g-is uiider IprE'StrE til'.
rE-E'Eil
enrruv
vEL it hir
ill
til'he laty,,
Stoel
tEom EEointErrEE-il.IIE
stirfae.'' will e'.ilst
'ýonliv
L\
rE'--
~
wnt'rloEIl
luinka-im~lEEivio
ThI'
~
'
n r*
tIrue.-
s~m IMI
toE tiE'
i'Io ,E'
howni
ntl'I~IE'
ilr'2.Atl''OiO1!s-ii
i
(El1 itý.Ah.-1it'.
in''''r .;ittaliilEI.
guin
lloliE-
tiEoli is Ealledl vCEuiterrt'ol'((i.
Illle'ha i stus a 111 et-uliilEraI ors :30.
th.
rilE' 't
"E-itiv Eit
iothtl~t
Downloaded from http://www.everyspec.com
atsmns absorb revoil t'nvirgY by restricting the flow of itytirat iliv flti id wit 1 a regt lat t't orifice. Dourinig o vinig mass is brought to a coil interrecoiii. th m1' stop with bntffers. which at-t oiver n short distantce termnaitintlg ait the in-battery position.* Riecoil systems i'misltt ing of recoil init'h. :12. antistins andu aN.S'viatt'd recoilinug parts cutnprissu' two .ypes. O tti' is the sitiglie r'coi I systt'f whose recoil ttmet'hatistl and recoil jug parts mtove as a sinigle' voortlinat' tinit in onet re'arwardt direct ion. The ot her is at double rt'4'oil system on'lsistinlg of two separate tunits of recoiling parts, with bo~th eosordii miated units moving in the same getieral dliret'ttion but niot "":'. 'arily in parallel paths. Tile ulnit conltainting tile glutl tiube', i'.e. tilt' primiary systt'm, is equ~iivalenlt to th4' single revoil system. C. TOP CARRIAGE The' top carriage is thlt prilmairy stippotrtin.'Wi lle a F igutre 25 1. structulrt' of thlt we'aponl 33.
EOUILIRITOR
front the cradle to the bottlcti carriage or other supporting st ruet tire. It authors the equiiiib rators. It hou se~st he o'ieva tilog antd traversing miecha iiisins and the power units if tieeded for these mechanisnis. lIn traverse, thle top carriage moves with thlt ('radle and81,iii tltiblt' recoil systemiis, these two unlits 4'otstittite the bnlk of the secondary recoilimig matss. l(-sign data, procedures aind requireMierits are discussed in dta'iil ill another handbook.0 314. Triunnion and( traverising bcarings provide the low-friction rotating elemnlmts which are so Either t'sseiutial during elevationl and traverse. sleeve or roller bearings art' tised. Strutu'trally speakitng, the bearings mutlst be--strong enough to stipport the large firing loads. llt addition, they mutst permit the unlits to rotate freely as the weapIf either ball or roller on is elt'vate'd or travt'rm-'(. to nanitfactturers' selected a4teordiilg ty-pe, they art' Bearinigs with rollin~g elements spi'tifications. hlavt' a bamsiv static-load ratiiig de'ttermneitd by' a t olt f rintg and1( c'4ni1billet pe rmtanen'lt de formation rolling element, Sometimnes the stariit load ratilng be greatl v txv'teded withlout tlcleti'riotls effects. this rt'spect, the ratin.g ma1y3 bv doubled for
RSO ATTCHEN -KAW4calt EARHGIn £TTACH~EN -
trntnmiomn and1 traverse bearings withtout imipairili 0
ELEVATIMOG MWCANSM~
It is advisa-ble to 'onisul~t bearing authorities before tht' filnal st'lt'ctiton, part ictilarly if 8lly designt feature rt'miains tquetstionlable.
FRW-0-
stre'ngth of the material for stat it
we'ap)on ac4'tra('v.
FRA~-~
-e'tve beariaigs are de-signed actontlill to tht' loadl but wht'it the bearing pressure shoultd niot exceed
''tutrniitl,
35.
rtecoil and4 the double revoil. Tht' top carriage for re'o iI wt'apoll is a sim11p1le st ruet re -oi-
ELvTIGasin!glet
base plate ,Fgr25,Waevrcmlxtth st ructtre tilt imtati'ly acquiire's is prnimari 13 diii to tit,' provision of ('tilveitont anid admi~tiatt' at tath-
TRAV( RSor GER
-H~s
P tutits for tile meti-haniisnis which it supo
p"
A'
a ri.-ditti
ant
~t~mof
reI-ii--
Y.!,mv art
It in
T 1 lol'riiiItl'(ftpcri hown ii i l'gturs 2'), 21, 2-2., de-spite its lialami It mais- be i% riot reýt ritti-(1 to tminbl' ret-coil Irims ti'i-il for %iiigli ri-ioil wriapons ms '-el1. rr-ltiillair aill itm intherent advtnutages i-l-i-pt thase derived tll.
e0arriage- )klno
tit' fi~re in neled,'I to fxtritt the 6'm basvt r-rjieitinni the rough th cit~i-tinl. it supports the' lippiing part,iring loaoi, b4'arillgs a 114! run'.uni t- al fI 1 tranniont Rec-ioil 20ljt0
rts-
sutpported by the botti-in carriage or requivalellt till whi, h it r-tattes. It ha%, no other nmo-
F~r~Cnog.stniactiuri's 25.Top a reiquisite. rigidl cradle i_%
Top carriages are of twea ty*pes: the single
8is3. Pf-'ne' W.
rumotd in dt'tait iz Reft-ri'oe
12
Downloaded from http://www.everyspec.com
itfr
double recoilI activity.
The comiponients of
pedestaNs, pllatftormis, or supports. all are essentially
this type of top carriaw- have hiisically the same
bottom carriages from ilhe functional point of view%and( the same (Vigil philosophy applies for all.
functions as their couniterpairts in the siiigle recoil wecp~oii. However, its s;ize awld shape and struetural requirements differ materially. W~hi le the toll carriage of a single' recoil weapon only rotateti with re-spect tol the bottom carriage, that of a
double recoil weapon also translates but only duririg the recoil cycle. Its chief assets stemi froiri1 il.Q quick ernpIJnceizient features and its role in the secrwida rv svst cii which, in essence. is equ 1 iva len t to a 'mniger recoil strokc with a colrrespondinig deCcrease in force.
E. EQUILIBRATOR* 37. An equilibrator is a force-producing rnechanisni of a weapon which provides the moment needed to balance the muizzle preponderance of thle tipping paris ( Figure 27). It fmiot bus as a mieYo TUK
D. BOTTOM CARRIAGE*
Roo
:16. The bottom carriage supports the top carriage and provides the, pivot for thle traversing parts. It aiid its comlponieits an, the structural
foundation of the w~eaplon
Figiro 26).
lk
~
...
)4;VP'i
*
-
' T(f
DurirnmgCR
A .1
Figure 27. Spring Equilibrata.
"114141 P
letsehaniiical
vou tit -rivei ght hult 'is r n'id erahlyx-'nial Icr, i.lithter. and miore' ltntel iivihl. in fieldl uise *,han it-ý war sive voi)iiterllrt. E.quilibratirs re eic 's,iital~ for moioltrii weaplon., jarm Lii!dirl sine '. their use enable'. airtiilery- to have it il.''.rabl' Ito\% silliouii'rm wvith lo-w veirttcz- ofga v wiestill 1eing. 111101-
bleof firng, at hizh a,, wv'] t
ofgaivof the Fdthe,
*
it'- lxAV
si4'
Itinitiv
lin.rper gro'liiii! civararive
'Ileva.i vooil is;
ipigprsi%%.!fr\at4
trunrr~iois. 'Thi htj.wi bY- this overhrugiliw..' out '
1w lou it
trmiooi.'r i-val,.. 'il- hi dio
cijuilibrator.
Fig"
26. Soffoam
ang
fi rbig it tranismits. all top carriage loaulsi t, the D~uring t raniir it bwetin ýis.' vhha,.'is fo singier rcilil type Ut'al)(Ils or. as part of a douible ~I r.o-oil S\ ..term. it v; ret raetabte ind hierie, . oif thik !inicti,,in It house'. part i:f the trnv.-rN'.io mrl--hamiini. It anii.'lor- the 5ý--oliary nec.i zniie. iAl'lO1 of d-l.ubb- flvoll l.'.r' iti sing!. r . 1
grouind.
weajk.n'. it may iniliidtc trail or owrijgiers. 5I'l d aol1~~s !hotiol -A~nie strtitturi. an.,
~,'
40,1,.-
F. ELEVATING AND) TRAVERSING MECHANISMS" Tit
INý
-
r'-quiirsi-~i
tgr
inr
a
1st liljin
!
\ be
.
ri-..jtiror
l
*r-
'h
n~
.
N
a±
to.'oio
~j'oli t::
i
'
ai nd -'il-
~-.!-i %k
10
'1i
.Iirti
.~llivit
-1o-I o: rli, --siril
* ~j~ii' ~i~~I.''i.~
7
zir~-
r
i
t-I: 0 o-
~, r.-, "
L
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is too heavy to be aimed directly by hand. Hence, handwhvel or power-opt-rated zmechanisins are providhd to enable gunners to attain precise positions in elevation and azimuth and hold thew during firing. Tihe angle of elevition corresponding to
TOP CARRIAG
the distance between gun and target is obtained by rotating the tipping parts and, therefore, gun tube about the cradle trunnions. The elevating invchanisni is the apparatus which imparts this rotation (Figure 28). Its horizontal counterpart, the traversing niechanismn (Figure 29), rotates the traversing parts whic-h generally consist of the cannon and other tipping parts and the top car-
B-aorroM
-1
cARRIAGE
01
-7
/ HNOWEE
,
riage. n 39. The elevating an( traversing nehi and their controls must be designed for easy opera. tion to the extent that the g,:,,iier can devote most of his attention to the target. These r.echanisms
--
GEAR
PNIONt...
Figure 29. Traversing Merhanism are essentially gear trains or linkages; one terminal at the power source, the other on the tipping or traversing parts. The gear train uses either a selflocking worm and worm-wheel assembly or a mechanical brake to hold the rotating parts in the prescribed position. Manual- and power-operated "types form the two general categories. Manualoperated units alone are installed on those weapons which do not demand activity at high torques, at high speeds, or for prolonged periods. Effort is applied by a handwheel. If elevation or traverse
GUN TUN
ii 4
7
GEM, . STOP
AFIRIA E
.
"-*
is too burdensome, the mechanism must derive power from mechanical or electrical sources. However, these mechanisms are operated by handwheel in the event of power failure.
t1
Figure 28. Elevating Mechanism
14
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CHAPTER 5
PRELIMINARY APPLIED DESIGN LOADS (2a) R".= E, specific energy of weapon ' -Rr E, s E - frr' pecific energy of recoiling parts (2b)
A. WEIGHT ESTIMATES 40. The prelitninary design of gun carriage or mount can be started concurrently with or even before the tube design when the only known data are the muzzle velocity and weight of the projectile. Later, when the design is more detailed, rod pull will be the controlling factor in determining size and therefore weight of structure. whether the recoil mechanism acts alone or in conjunction with a mauzzle brake. These data are all that are needed for a preliminary estimate of the total weight the weapon wlisted and the weight of the rewelingh of orthe coiling parts, P) whereRr where N',--m mass uzloi rojectile "2muzzle velocity
where W = total weight of emplaced weapon 11"r = weight of recoiling parts The two ratios are computed for twelve contemporary weapons consisting of guns and howitzers, ranging in caliber from 57 mm to 240 mmi are
in Table 1. Several other relationships of omnentum-weight and energy-weight were investigated but did not compare favorably with Ri and stati-xtically
t !eoiy Ric, 3856 Ric = -1-
Estimates of th? weights of weapon and recoiling parts are determined from the two ratios
I
r
T?
321 ft-lb/lb
--!tRt12--12601 12 -00f-bl = 1050 ft-lb/lb
TABLE I MUZZLE ENERGY-WEIGHT RATIOS
W Weapon 57 mn G 75 mm G 3.in G 90 mm G 105 mm H 4.5-in G 120 mm G 155 mm 11 1655 mm G 175 nmn G 8-in G 240 mnn 11
IV,
IV,
1000lb 1000 lb 0.8 2.7 3.4 0.9 1.6 5.2 12.5 2.6 4.9 1.1 12.3 4.1 48.0 10.8 12.0 3.9 27.7 9.8 49.9 14.6 69.5 :30.2 64.7 25.5
lb 6.28 14.96 12.87 23.4 33.0 54.9 50.0 94.8 95.6 150.0 240.0 360.0
v ft/sec 2700 2030 2800 2700 1550 2275 3100 1850 2800 285(0 2600 2300
E.
Ric
R,
106 ft-lb ft-lb/lb ft-lb/lb 888 0.71 262 0.96 282 1063 980 301 1.57 2.65 212 1020 1.2:1 251 1115 1075 4.41 358 7.45 155 690 418 1290 5.03 11.63 420 1190 378 1295 18.90 26.20 363 8:35 1160 29.6(0 456
H = Howitzer: G= Gun; I'P = weight of pro.'ectile.
3(0 and 31 whi(,h show the spread of the data in
When based on the average values shown as R,,
This 1;irge spread inhibits tnonsistency
and R,, the estimated weights of weapon and re-
Table 1.
coiling parts are vonservrtively high. A more realisti' approach involves til'e curves of Figaires
and is therefore replaced by one line in each niterirl and new techfigure. Available stron.vr ma 15
r
V
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40
ment. Therefore the straight lines conforming closest to the upper boundaries of the shaded areas should be used for determining the prelimivary weights. The equations based on the straight lines are TV, - 8.2 X 10-4 E. ib (3) W - 22.8 X 10-4 E, lb (4)
V
35
-
30
,25-
J. RECOIL FORCE 41. The recoil force is the principal design load of the gun carriage. The force is proportional to the size of weapon, i.e., heavy artillery has large recoil forces whereas light artillery and small arms have correspondingly smaller recoil forces. The recoil force can be estimated quickly. It is derived from the velocity of free recoil and the length of recoil. Free recoil assumes the gun to recoil horizontally without resistance. The maximum velocity of free recoil IV, v. +t 4700 W, (5a) ft/sec* Vt =-" W
-
•20-
15 10-
O
5
10
15
1 20
251
_J 30
where
WEIGHT OF RECOILING PARTS (1000 Ib)
Wg -- weight of propellant gases, lb weight of projectile, lb W, -- weight of projectile, lb
Figure 30. Muzzle Energy-Recoiling Parts Weight Ratio
1v.
40
35
W_
-- weight of recoiling parts, lb
= muzzle velocity, ft/sec
The energy of free recoil Er =,
VO0
M)
(5b)
where Mr = mass of recoiling parts
25-_
The average required resistance to recoil* E, K +1' Wr sinl = F. + W, sin 8
> 2015-
(6)
where
L = length of recoil F. = inertia force of recoiling parts 8 = angle of elevation
10542.
Of the four factors in Equation 6 which
determine the recoil resistance, the length of rec•oil,
SJ
1 __J MO 20 30 40 50 60 70 WEIGHT OF WEAPON (10W 1b)
L. Appears to be an arbitrary choice, as well it may. However, an estimate of a reasonable length
should be attempted. The first choice of L is seldom accurate and because the correct length is R*Referentte 8. piage 242.
Figure 31. Muzzle Energy-Weapon Weight Ratio design combined with modern design philosophy follow the trend toward lighter equip-
ni,;ues in
__8_
.
16
Refer-,%,
2, Equntion 3b.
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where D,, = bore diameter. Later, when the( carriage design is Ii(j1,f complete, the recoil stroke' may be adjusted to stit finial cotnditions. Tfhe longer the recoil, the lower the recoil force and hence, the lighter the i'arriagre. Iloivever, a desirable low silhouette with vor~'esponding low trunnion height severely limtits the length of recoil, especially at high angles of elevation when
not niecessarily a low one. Since ground clearance is essential, and aniple ground clearance miay mean high trunnions whieh impewde stability at low angh's of elevation, the solution is a variable recoil, i.e., short recoil ait high ailgles with corresponding high, manageable recoil forees, and long "ecoil at low angles of elevation with recoil forces low enough for weapooi stability. 44. The double recoil systi-i in--wbi('h the top carriage r-coils as a secondary mass, is also coniduvive to stabilit 'y at low angles of elevation. Pertinent %%eights are estiinate~l similarly to those of the( single recoil weaponus by Equations 3 and 4.
clearance between ground andl recoiling parts is
But, two add~itional dlata are- needed, the secondary
found by itcrative c'alculationi, the( first approximaA piractical tion should be neur the niaxitnumi. reeoil stroke length L = 1ib(7)
I,
not reredilv realized. For t~iis reason, ivngth of recoil and t rinwion height becomne ('ottproiniisingparameters, each being selected within the conipatibie limits of the other.
recoil *force and the weight of the secondary recoilinge parts. Based onl experience, the secondary re('oilinga parts will weigh about 1.5 t inucs as much10 as the pirimiary recoiling- parts. Therefore the ratio
43. Caliber of gun suggests the general size ofnJ ('arriage or mnount. Large gutns exert large forces. MitPl~_ and supporting struutures, to be capable of suswhr *tamling these forces, w-ll corresp)ond in size to the 11Ws Of primary recoiling parts mas matgnitude oif the applied forc.'s. Siiwe recoil = V~ss of secondlary recoili ng part,. ML foree v'aries inversely with recoil length, a wveap~on 2 having long recoil req(luires a light structure but The primiarY recoil re-sistanve
~2L.,
iv here
1,1 ('058 ± L.
-i
2
The secondarv recoil riesist ance
aeoaeta
LIII
9
~
a iclci g' l tritttr N~'l 0o.'esriwe thelsigit is ilitahizeil.
ie
ti
C. BUFFER FORCE
10)
'Iii
il
e levatijon c hat iges. The sevotloldri rct'oi I force itiiitqIfo tuation 11'for 20' aug 1 '- of elevat iot c lose'ly alpprox inma tes thle ri gt rousl% chinuili ei v-aIuc. Early' ost to t es of ret',oilI forces, whet hr for single or dotuble recoil s'%stt'nis, art' 'oiff~ictietli'
Li length of pirimlary recoil 1.2ý 5/3 Ll, len.tt th of secondla ry recoil 1I~=weight of prjimari recoiIim, pgI arts conipitted ats W, in Equnatioil :1.
111 +
I+I'
~45,
lttiff~im fotrt's, at! the en'ti~,f vounttturr,.i'il are
revttP forret' prnir liffu111l ItIld tIlitLitulttIt R11gles otf elevation whereats, a','ortlitii to Ettoatioti 10. the cttnvt'rs is triue for the secitttlary rectuil force. Although Equataioni 1t indivaltes othcrwi''.
noit lxrgV' enotugh tot affect the get'tral tl'giof the t'arriman' struttelure lbut mtay be viltival with ',ititerro'vil iiIvsoresltect tto weaptotn staihioyt it ' andt buffter Nttiokt' are' ih,sely ;issi.tt,o'iv with iistito, of r.,'voil antI rate' (if fire'. lIn rapid tire- e
no nierical inategra tionts that have bee It 1- r fo rnte I for doutble- recoil s ystenis hitve. shown that: the stv otuiary forces vary ionly slightlY a-, thr ~angle' of
outn ter recoil art- tIe' rliniet by the firn tg cycle. Itn art ill'rvy%u r'her ilt' ik titt v'ruitf-al, rt'-toil tilli,' (t'f r,'cýi,i aiuti a wi j%st,'voridlarvy tit fo~-ve anIlenth i-tttierro'i-,il i,'l1sity (if .1 tt, 4 feet per '.eetd i~s
Maxinuiiuii aad ininintitiuh oectr reslH'ctivelv a tit
*
ferrrc', 2. KMIi2ti
tcfirrrncr
At3ct) utale'
721.
Eiuatioti 7'3. k.
XV101io
i ,rel~'lsivkon
the
17
p
0
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buffer force may be estimated for single recoil systems and for the primary recoiling parts of double recoil systems by assuming constant deceleration for the cointerrecoiling mass. Therefore, buffer force Fb
M v, 2
2. b where parts rcoilng M, :massof prts Mi. = mass of recoiling = velocity of counterrecoil =, .r-= buffer stroke For the first estimate, let the buffer stroke equal 25% of l,,ugth of recoil, whether in single or double recoil guns. 46. The forces in a double recoil system pro-
- 0.25 It', = 0.25 (W, + We) 1,---weight of recoiling parts We = weight of tipping parts
For preliminary estimates, the weights of other items such as the recoil cylinder are relatively small and are considered negligible. for W1,( Collecting terms and tsolving -- % W,.(3b Although the po:'ition of the equilibrator on the mount is a critical design feature, the equilibrator force may be estimated with reasonable ac.curacy by assuming perfect balance and a geometry comparable to those now in use. Figure 32 is
dt!(-ed by buffing the secondary recoiling parts are also found by &ssuming constant deceleration. Since there is no relative motion between primary and secondary recoiling parts during secondary buffing, the kinetic energy of the two masses moving as a unit must be absorbed by the secondary buffer whose force -1. (12a)(,2
(13a)
. I
. 0
b
where m, = mas of primary recoiling parts m2= mass of secondary recoiling parts = velocity of secondary counterrecoil 1 X 12 = secondary buffer stroke The inertia force of the primary" recoiling parts due to secondary buffing F,± 2 =
M m- + -;n
F&2
and that of the secondary recoiling parts F= m2 • m1 + m:
(12by
(12c)
D. EQUILIBRATOR FORCE 47. The eqiltibrator force necessary to pr,%duce a moment sbc.,t the trunnions to balance the weight moment is readily computed once the weight and mass center of the tipping parts are known. For preliminary estimates, assume that the weight of the cradle comnprises 25% of the weight of the tipping parts. Thus, the weight of the crad'r
W
Figure 32. EquiSl*ot
Gometry
typical. Perfect balance is achieved only with a spring equilibrator because of its constant spring rate and only if ', - 900 when 0 = 0 (Figure 3. The weight moment of the tipping pa:ts at any angle of elevation is 1"2 = (12c)cos (14a) =
"O"'n
0
(14b) I= vI'R, The spring rate for v., h of two identical equilibrators .( 2 (. CR .. *
5, parsrapkS :5 S "Refrraev 5. .'.uxrionv 5 and
RtfCT.C,
.
,
Aad es. 5a&
14a.
!
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Althougzh the ej'uilibrator force is maximum at the minimum Rngle of depressionjt the error is small when the maximum force is assumed to be the miore' readily estimated value of
cV0AM Pam CC POAM
(16)
FS = K.L.
a* TIAE
CAL
where =equilibrator length when 0 -0.
'Since perfect balanee is preferred, set 0 ==0, theii from Figure 32 L. =Vc + R7
4~=900 and/ q (17)# I
For preliminary estimates, let R and R, = 5 calibers in length, arid select a convenient value of e between R, and R7 Later, when the design of mount takes on more permanency, the dimensions may~ be adjusted to be more compatible with the Main structure. The typ~e of equilibrator is also Subject to change. Although the initial data are
$
HCSZONT&
fur a spring equilibrator, another type. such as the hydropneumatie, may bo used in the final design
without involving any radical changes in the orig-
)
LA0
inal design concept.
E. ELEVATING AND TRAVERSING GEAR LOADS MEVEATM4 PO4W* Estimates of the preliminary df-:iign loads 48. which are applied to the mount throt~gh the eleFigure 33. Ehvotor Geo toa&g Diagram vating and traversing mechanism a' e computed according to accepted methods avill ine theodoftelmnai tL'3fo t t sa ,3fo ftelmn ?netecnri individual handbooks on these mevh~ainisms t Albase, the miass%moment of inertia though these methods are accurate, rheii t'he availI(19) able design dats. are aveurate, at this early stage in tt=i,[k,2 ± (1:j Lt - 2D,.)^] the design, the coniputed loads are only approximatte because the preliminary data ar- apploxiuniate. One oif these data is the miass moment of
inertia of the tipping part~s about the truanions. For early estimiates a-ss une thtterdu fgrt'ioi of tlhe tippinIg parts is equeivale-nt to that of a triangul.ir lamninai about zh.' ceuetroid.0 axis parallel to its base. (18) A- 0.236 L, wherewhr
1)
"l,
The torque needed to a-velerate 'he tipping prsdrn
prsdrn
4gkeuc5,
f4Referca
paraamspb V~. 6 and 7
lvto
lvto T
03
whr
L,=length of tube
Ass-aining further that the trumnnens ar'- lorate-d two calibers forward of the bre-ech face, and
bore diameter mass of the tipping parts.
2,
vaRinig ite-veleration
F~iguire :13 shw the prrlimiwiory design load,; whii'h affi'v' the elevating ge-ar load. ( Note that P, t'.
Yero for sinegle recoil gunsý.
The firing torque
is. another e'cemponent contributing to the load on
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the elevating are. A preliminary value is computed by assuming a 0.10 ineh offset between trunnion and tube center of gravity. The firing torque (21a) T,-= 0.1(0 F. The general equation for the inertia force of the recoiling parts F.
F, - K + W, sin 0
or maneuvering, otherwise the larger of the two components becomes the design parameter. With T, estimated, the tooth load on the elevating are becomes. R,where . R, = pitch radius of elevating arc A = pressure angle of gear.
(21b)
where DbP, = propellant gas force 4 =D =bore diameter P, =-propellant gas presmure K = total resistance to recoil
F,
The total preliminary design torque of the tipping parts of a single recoil guni T, -- T. + Tf
(27)
T
The gear tooth load on the traversing gear 49. (Figure 34) is determined by a similar procedure. The firing torque is assumed to be the same as that for th,, elevating mechanism but the accelerating torque has a much larger mass to rotate since the traversing parts iin"lude the top carriage in addition to the tipping parts. The mass moment of inertia of the traversing parts about the traversing
(22) torque In double recoil guns, the maximum applied to the elevating mechanism occurs during wecondary recoil acceleration. According to Equations 21a and 21b, when F, = 0, (23a) T1= 0.10 (11, sin 9-k) I, The acceleration of the secondary recoiling parts K cos 9- W, cos 9 sin e - R
axis
(23b) mn-+mm s (See paragraphs 41 and 44 for explination of t,,rms.) The inertia force of the tipping parts due to s•eondary acceleration
For preliminar" estimates, assume that the mass moment of inertia of the top carriage in terms of weight is (28b) t,, = I',1rt. lb-ft-secO
-
_I2
"I F, =
(24)
where 4), = imass moment of inertia of tipping parts about the traver.;ing axis. In this analysis assumed to be the same as that about
the trunnions. See Equation 19. Ot, = mas. moment of inertia of top carriage about traversing axis.
The accelerating torque
9
The resulting torque (Figure 33) T, =F,Rtsin •
qh,+4•,•(28a) =4•t
To = Otr 20
(25)
(29a)
whr Fll = traversing ,teceleration.
Finally T,
- T, + Tf
(26)
The total design torque of the travcrsing system (29b)
T During secondary recoil deceleration, , and T, art- in the same direction. Other components of tornljm are involved in
The two romponents ot the total torque are combilled otily if the gun firms while traversing. If
both doubl" awl single recoil guns but these are of
the two never ,weur simultaneously, the larger is
minor intensity and are not ptrtinent for preliminary design etiniat,-s. T. ad T., appear simniltaneously only if the weapoa fires while elevating
eunsihered for design, load
" Reftrrnee
2,, Equation 88.
TI, =.
+ Tf
The traversing gear tooth T,, R)
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I where t
CC, TIPPING
pitch radius of traversing gear.
R,
F. TRUNNION BEARING AND TRAVERSING BEARING LOADS 1. Trunnion Bearing Loads 50. The recoil force is predominant on the cradle trunnion but additional force components derived *
Ft
from the elevating gear and the equilibrator may influence the total trunnion load to the extent of becoming significant. The equilibrator load was estimated by balancing the weight moment of the tipping parts, while the elevating gear load was
h
o.1
C.G. RECOILLING PARTS
Rv GUN TUBE
CRADLE---
PINION
PITCH CIRCLE0
,
.Figure
35. Trunnion Bearing Loading Diagram
2F,
= inertia force of tipping parts due to sec.oldar".
recoil a.celeraion; zero for single
recoil 5,vtemsl F. = K - It, siii 0. inertia force of re•oiling
/-TRAVERSING
GEAR
parts (Eq. 6) RI, elevating geor tooth load 8 = an he of elovathion.
The vertieai reaction
Fig"re 34. Trcnering Gear Loading Diagram derived fromn balancing the firing torque, i.e.. the momcnts produced by the inertia forces offset from the trunnions. The moments being balIanced, the only values left unknown are the horizontal and vertical reactions. According to the direction of forces shown it: Figure 35, the horizontal renttio -
"€
W' T he total tranni-, 'oad bev.nies " :
h+
3-13b)
,'H2)
3i4
AIth.tarh tiht fer.e' for he ccmejhe , ratge of R++vhatio-n must event0;lly he inv eti gat ed to deteri-inie the aiaxinaaane trllullien4 loa1l, the loads at zerolvro and maxiunmn anhle' of elevation are seemice.t
(31a)
where
f,,r pr,,liminary
F, = equilibrator force
selection. 21
etirnates
for trunte-n he'aring
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ing the expressions for ýi. of Equation 1 9 0 and for of Equation 170 into Equation 33b and solving for p, the maximum pressure. Applying p over the bearing surface, the effective pressure load is now assumed to be uniformily distributed.
TRUNNIONR
M11 I
~~where
T Wt Xtr
R-
(33e)
,
R,= inside radius of bearing
R. - outsidle radius of bearing.
T
The radii are obtained from catdlogs for bearcompatible with anticipated loads and structural requirements. The total effective load on the traversing bearing R, =F, + !-V (33d) + Wrc (3Ke) V =F. sin 0 + 11' where 1VTc = weight of top carriage, assumed to be on center line of bearing.
- fieings Figure 36. Traversing Bearing Loading Diagram 2. Traversing Bearing Loads 51. Early estimates of traversing bearing loads are likewise bas~ed op. firing ait zero and maximum angles of elevation. In single recoil systems, the major externally applied loads and moments inelude weights of tipping parts and top carriage, the recoil force and the firing torque (Figure 36). Taking moments about the center of the traversing
G. APPLIED LOADS DURING TRANSPORT 52. Loads produced in carriages or miounts by
bearing
accelerations during transport seldom exceed those ]fr= -
T, ± F.(yt, cos 8 + .ri, sin 9) II (Rt cos 9 - .r,,.
(luring firing except for the local structural umembers to which the conveying components are at-
(33a)
tached. However, the total structure should be inivest igated geni'rally to dletect any- critical Icads which may apptcar while traveiing. Smooth terrain offers no design problems other thanm side slopes which geýnerally affect only stability. On the other
where
F. =K
-
We sin 9, inertia force of recoiling
parts Tf=firing torque (Equation 21)
Wt= weight of tipping parts.
hand, the effects. of rough terrain on design are significant. particularly on towing structures and conveossc as bogies and limbers. resign proce-
To balance the applied moment, assumne a bearing load distributed triangularly whose mnoment about the center
Mr,=2I?,b 7.
(lures for these three structures (10 now fall within
the scope of the Carriages and Mounts Series of handbooks but their capacity for t ransinit t iug loads to the carriage structure is involved. The size of those loads depends on svveral factorsi including
( :33b)
where Rt.=react ion on each s~le of the (diameter
towing acceleration. speied ano. the type- of suispen:wi011. Givon load factors determine the design loads cniinwenmlile by the weigt of the various carriage 'oomjw'nemmts.
1.=distance front bearing venter to loadfrec c-enter The eftr't-ive load on the bearing is the load obtamied by applying the maximumn pre-isure of the triangulatr (distribuition over the cnt ire bes rinig surface. The effective load is found b% suKstitut-
):I, The unaxitnmum towing avt'celrat ion (lepends on the icwfficient of friction betwern tires anid running so rfrn-c and nn the weights of priue umover
22
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is the towed and towed i vehicle. During braking, thc vehicle is assumed capable of stoppiiig itself with its own brakes. The maximum accelerating force which the prime mover can exert is
F,
--
ttW,
(34a)
The resulting acceleration
•:
where
( (
S55.
S54.
Since the towed unit is capable of stopping itself, the maximum acceleration during braking for both weapon and prime mover is a
&,W•
:
--
--
0.65 g
(34c)
11,W SUnless direction has special significance, the decelerating force becomes the horizontal design force. It combines with the vertical forces which
,i.
4. 12.0 g's for maximum speeds of 30 or more mph The weapon must bi- capable of being transported along a side slope of :307, without over-
towed weapon.
-
mph 2. 5.0 g"s for maximum speeds of 30 or more mph Load factors for unsprung chas.sis a3.5.0 g's for niaxiniu||| speeds of less than 30 mph
where W, = weight of prime mover ;L = 0.65, coefficient of friction of tire.
0.65 WP -F Ij g = i-- , + Iv,
o~ involving 1ffu(oni for one of four condition4 estimated fovr are etiatedt vel but rougi. terrain. transportatiot oe Loa(l factors for a sprung khassis 1. :30 g'.. for maximum speeds of less than 30
loading any of its structural components. Such a steep slope must be nieg-tiatcd at slow spec !s to preserve stability and hence. ; load factor of 1.0 g seeims reasonable. Local areas near attacnhments may be critically loaded and should be investigated for side loads but the general carriage structure will not suffer under the sa•me conditions. Other than from a stability viewpoint, the side slope condition does not influence preliminary design.
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CHAPTER 6
SIZE OF STRUCTURE tiot: whidh spevifies stability while moving along a 30'/; slope. Accordiioz to Figure 37, stability is
A. TRUNNION HEIGHT Required ground clearance at the end of 56. elevation estabrecoil when firing ai -naxinimu lishes the trunnion height and hence, the height of weapon. After the preliminary length of recoil has been found (Equation 7c). the trutnion height may be coriputed by allowing a !,ngth of three calibers which is ample for the distance between trunnion and rear of breech ring. Adopting such a measure quickly e,-tablisheq the preliminary trunnion height of (:a) YT -- (L -- 3D 1 ) sin O
achieved when the .ent,-r of gravity lies inside the wheel span,. i.e., when the span (35b) Lt It tan 0 where h1 distance of C(6 above ground tan p ==0.30, maximuitm side slope Thus a symmetrical transvwrs, distribution of rather tha.. ,e weight and a low center of •ravi actual weight are the criteria foi ;tability during !iting lesitransport. The 30'4 side slopi, is a
where D= bore diameter L ih'.gth of recoil 0. = maximum angle of elevation.
B. STABILITY EFFECTS OF STRUCTURAL SIZE Under ordinary cir, amnstances, a weapon 57. should be stable at all titres, whether firing or in transport. During transl ort, stabil;!y is seldom a vital design factor c:xcept for the side slope condi-
,
Figrm* 38. Stabilty i-y inspection.-SingI. Recoil System
Figure 39. Stobiliy by mspe•xw--OoubJv Recod Syste
Figure 37. Side SJope Skdoal•y
24
-
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Ito~
I'lev;ilioll is low wmiogh for the resultant to intersevt Hthe grolalnl oaitside the rvar stipports. stability lii Aholit the interis v h inAd1 vy voli poit ii a olone rt inr xi0 section of re-ar suipport and grounad. stabiI-tY is assuired dlriiror recoil whent Fit = 0, if Wý
Ito
Kv(315C)
-.
Sim il~arly. durin-g hullimng. wh ruiK
= 0. ,4tabilitV is
;ljvdwheuu Wit 1.-
.
FIRING JACK
Figure 40. Stability During Firing-Singite Recoil System cond~itionl. uleveessrv
rvvoil if K, > IV
-IDurimg
A valuie of
tan
li1 reater than 0.30 is
to assu rt stabilitYVoil tlti.. slope,
tv;1vo t Ii -rounduunldll
(35ld
".1
11,
flithe froiif suppor* will
iv totbe will move-i fro
ORzt
ainied Jpo~itioi?_ thert-hv uinlltuuae som uinaeiiracv. th This~ moveiO~t-lit 1% .Jinupt." Most 01 lithe, iitileZ!. bent i)4Iilrs ýiflv r tfli 11r44.jv.t iit 141's the
On the other hadll, wi-,iht vilt rihut's appr.. 58. viably to the stabilityVEf a weaponl whenl firing., Slabifltv partiviularlyt at low agll"es of viewali iu.
is still EIject ioulable beallse. it gradl [)it .Jttinp staI inpriA'v P'~inil. IiuaUY vilaig"' tilt-u the (listaill.t Ilrui Dilitv Irax. bei nh.llb
stbl if th:' resultant of the revoil forvv initersects the groundl within the ouiter limits of the sup;ports thet e-nds of trails or otierof F igulre :J;
1
sltim!E
rear suppor-t of dou1bt v U If til t,z le Of lFipirt T?!
rI
ari~s
brhrx
Th uu
tilt, till.tilli- 'tilloltitv
~lii
hesollst
too"t
l~lgro i rit itdI
l
Itrl
'jilI,
Ip~li' )wu' .
oi~e t, .Avvleiiti
lzlili-llli
toI satkbvI
ret Iil tpe-s, or the
r''Ii t"ý1
1
Idb~ix
lt!II1I ti arttr
lprolI'IlEilt
Yf
Figuw* 4;. S.*o6irty Duin
Fr>*g -- Oooublv R-Cof SY1x*ftn
_-~iiý
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pressures are no longer effective and when both
pedestal mounts equipped with four outriggers
primary and secondary recoiling masses are deceleratijig ,,,iultaneously. With the forces and dimensioihs in Figure 41 shown positive, a stable weapon it: assured when
equally spaced, stability is assured traverse. With recoil forces being buffing forces and with a virtually fir' base, stability during buffing is
x1lri + x1,2r +-C xJIi y Fa - y2Frc - ytFt
ability of double recoil weapons during ecoil generaliy includes two conditions. st occurs during buffing of the primary system while the secondary system is still recoiling or is in the process of counter:ceoifing. In either event, the inertia force of the secondary recoiling mass is opposite to that of the primary mass and therefore helps to balance the nosing o-:er moment. The first endition is seldom critical but should be investigated. The second condition occurs during buffing of the secondary recoiling mass, with the
(35e)
w,here inertia .%3rce of primary parts induced by primary acceieration F, = inertia force of tipping parts induced by secondary acceleration FTc = inertia force of top carriage ind.wed by secondary acceleration Ii = weight of bottom carriage WrTC = weight of tor. carriage I,=weight of tipping parts F,
-
primary parts fully returned to battery. The weapon will be stable when, in Figure 41, the moments about the front support y,'Fb + ytF 12 5'WVc + X12rc + x xO't (35f) + y2 FT2
Forces which do not appe.er in Eiaation 35e have diminished to zera by tbe time the present condition prevails. Stability also becomes a problem during 60. counterrecoil, _speciall; during buffing when prevailing forces tending to nose over the weapon are
maximum.
for 360' of larger than symmetrical also assured.
where Fh = inertia force of primary parts induced by
Although not as critical as during
primary buffing F 1 2 = inertia force of tipping parts induced by secondary buffing Fr2 -=inertia force of top carriage induced by secondary buffing
recoil, since projectile flight is not disturbed, a disturbanee of this nature may shift the original position of carriage or mount tc displace the aiming refeence. Rapid fire, single recoil guns need a longer firing base for buffing stability since counterrecoil must be rapid, and with more energy to be absorbed ever a short distance, buffer forces are correspondingly higher. Bat, since these guns have
The inertia forces F., Ft and FTC are i.eneral terms shown positive in Figure 41. During buffing, these terms are replaced, respectively by Fb, Ft. and F78 .
26
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CHAPTER 7
PRELIMINARY DESIGN PROCEDURES FOR MORTAR MOUNTS component, base, mount, or tube assembly, should not weigh more than 25 pounds. If the tube is much heavier, it may be long enough for two men to carry. 1Ieavier'eomponents may still be portaIle but longer periods of time will be required to reach the area of emplacement.
A. STRUCTURAL COMPONENTS A mortar is basically a short-tubed, light62. weight weapon capable of firing at very high elevations with low muzzle velocities. This velocityelevation conibination offers the advantage of being able to reach nearby targets and to clear high barriers that shelter these targets fior direct fire. The weapon consists of three primary con.ponents: the tube assembly (mortar), the mount, and the base plate which -ire shown in Figure 42. Base
10,000 PSI
"40C"
MEC~
'.' 400R
BASE
I
ASHOA
RLATE
-
~200 LB
' wOUNT
C
tc200
L
L
L
4F
au
Figure 42. Mortar
SG
plate and mount support and position the ilabe during, firing, Each component is essentially a simple stru-ture, readily attachable to the others,
F•
thereby providing for (luiek enllplacenient and~ dis-
lI0
e0
#
8
G 0 0 I 0 e0
emplacement.' 63
ihns
s h
udmna
dsg
rtro
thpfndretabldesignhereby wh63ichtrnders motas
•; hic •!the
Sreadily
re~des
ortrs
crido ortble terey poviin
infantry with large caliber weapons.
A
CHAMBER
8
SIGHT ACCLN, TRANs
D
LEFT LEG LOADS
PRESSURE
C SIGHT ACCLN, LONG
To be
portable by one man, each major weapoi
E
RIGHT
F
EJE'CTION
G
TIME -MILLISECONDS
Figure 43. Typical Firing Data
27
LEG LOADS
a
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hm
tn (8-#)
LEG RIGHT LEG
Figure 44. Loading Diagram of Mortar 20% to 35% of the recoil acceleration. Thus (36) 0.20 a, Z a, Z 0.35 ar
B. MOUNT 64. The mount is tbt- stabi!izing and positioning component of the weapon. It supports the elevating and traversin- mechanisms and the sight. Both elevating ard traversing mechanisms are generally of the screw and nut type. Elevation ranges from 45 to 85 degrees whereas traverse is limited to about ± 5 degrees. Direct support of the tube is achieved through a flexible linkage coiprised of one or two shock absorbers mounted parallel to the bore. The piston rod of the shock absorber is clamped to the tube; the cylinder is attached to the mount to p~ermit motion between tube and mount. This motion moderates the shock of recoil on the mount by absorbing the -nergy of vibration, Under the influence of the shock absorbers, the acceleration induced on the mount is reduced to
where am -= mount acceleration ar = recoil acceleration The limits of Equation 36 are substantiated ly test results similar to those of Figure 43. 65. To obtain static loading conditians, the mass center of the mount is conservatively assumed to be located at the tube attachment. Figure 44 shows the loads, reactions and the dimensions pertinent to the loading analysis. The symbols appearing in the analysis are defined A- = bore area F,-= inertia force on mount in plane of mount 28
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All the information needed to compute the loads and reations are available except for recoil acceleration which determines the inertial load of the
residual avcelerating force on base cap average propellant gas fore maximum propelh, nt gas force inertia load of mount applied to tube side load oni mount in(luted by transverse aeccleration ., - distanve from mount attachment to bore center line. L1g =-distance from base plate socket to mass center of tube L. = distan'e from base plate socket to mount attachment average propella8lt f,4 p',,e4urP Pg P,. maximum propellant gas pressure B. -- axial load in left leg axial load in right leg Rb horizontal reaction on base plate Rh reaction on momnit in elevation plane R. vertical reaction on base plate R, lVb weight of base plate Fb
Fga Fgm/ , .F. -
W,.
:
mount. An approximate acceleration can be obtained from the average propwllant gas force and lhe known or estimated weight of tube assembly and base. The average propellant gas force
Th. average recoil acceleration Fg4 a.+
9
weight J.f mount
weight of tube assembly - aillle of elevation 0= angle between mount and the vertical in
The ground reaction oi the mount beeomcs 66, available by balancing the moments from Figure
elevation plane
m
',L,= cos 0
44. Equating the moments about B to zero
+
r',,,I., -
WtL, cos 0 + F,,, hI, L. cos (0 -
0) +
m IR.L.
eos (0
-
0) + h,,, sin (0 - 0)1
0
(38a)
Furthermore, the rig.ht leg cannot be loaded when
(38b)
F)'. • F. tan
s(0 sin
,. a condition which becomes obvious
by inspecting Figure 44. When F. exceeds F. tan •. a balanced system deniands that the right leg be put in tension. However. since it merely rests on the ground, tension cannot exist in this memn:'r
A bipod mount will have components of the around rfiction distributed to each of the two legs. Since appreciable transverse accelerations are present (Figure 43) the legs are not loaded equally.
ADAPTOR SALL
SOCKET Figure 45. Pinned Ball and Socket Joint
2n
.1t
(
After obtaining the limits of mount acceleration from Equation 36, compute the mount inertial force Wr t (37c) F,,,
WVt
1
(37a)
F'a = PgaIl
SECTION
A-A
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hence a static condition no longer prevails. The residual side load in this case has a tendency to tilt the weapon. The rapid periodic change in direction of the transverse acceleration prevents the weapon from falling. On this basis, the assumption can be made that one leg of a bipod should be capable of supporting the entire vertical load. Thus, the maximum axial load in the leg R.
F. cos
C. BASE PLATE 66. Base plate and tube are connected by a ball and socket joint. The ball of the adapter base cap rests in the socket located in the ctnter of the base plate and is retained by a snap ring. On some arrangements, the ball has a pin which passes through it on a transverse diameter and enters into corresponding s;lots in the socket. This ar-
(38e)
where F. = -R, from 30 to 408.
Svaries
load from the tube to the ground. The components of these loads are found by completing the static load distribution of Figure 44. The vertical reac-
R. completes the design data needed for the stress analysis of the mount structure which may be coMputed by established procedures for columns. R,,
W6 + W, + (Fb + F.) sinG
-
rangement which permits elevating rotation between adapter ball and socket, and azimuth rotation between socket and base plate is schematically illustrated in Figure 45. 67. The base plate transmits most of the firing
tion R. cos 0
(39a)
The horizontal reaction on the spades R", = (Fb + F.) cos 8 + R. sin 0
(39b)
Although base plates have been made rectangular and may still be useful for hand-supported firing (Figure 46), the trend is toward circular construetion. The size of the contacting surfaces is determined from an allowable ground pressure of 190 psi. For a circular base, P.
190 lb/in-'
(40a)
where = radius of base, in.
-r&
The spade area is determined from an allowable maximum ground pressure of 770 psi although one of 500 psi is more desirable
Figt.e 46. Handhold h
Figure 47. B.Pkft. With Spodgs
30
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P-'-
,
770 lb/ie"
nor the shape of spades. The design is decidedly empirical in approach. Forged aluminum alloy
(40b)
top plates ranging from 1/4 to 5 plates Ribs and spades range from 1,42to 1 thick. have is ur al patapo spades The thick. The shape of spades is usually patthick. terned after those which have been used successbase inch inch inch
where A, -total projected spade area in direction of Rh.
fully, an example is sketched in Figure 47. Final acceptance always depends on experimental firings.
68. No analytic procedure has been established to determine the thickness of top plate and spades
4J
3
311
€.
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CHAPTER 8
SAMPLE CALCULATIONS A. WEIGHT ESTIMATES A 165 mm gun is selected as the hypothetical weapon to illustrate the procedures ",olved in finding the preliminary design data needed for its (carriage and associated components•. The given data I Db = 6.5 in., bore diameter (165 mam) l) = 45,000 lb/in2, maximum propellant gas pressure 111ft 2850 ft/sec, muzzle velocity ;Vp 126 Ib, weight of projectile :37 Ib, weight of propellant gas lU* 9 = 65*, maximum angle of elevation,
Wle
B. PRELIMINARY RECOIL CHARACTERISTICS 1. Single Recoil System Both weights represent minimal values which recognizes design philosophy of minimum structural weights. These weights are assigned to sing!e or double recoil type weapons. Equation 5a provides the velocity of free recoil lWptm + 4700 W0 126 X< 2850 + 4700 X 37 3,0 00 1 W, .. V1-= -4 IV, 13,000 41 ft/sec Froi4 Equation 5b, the energy of free recoil
A..ordiig to Equation 1, the muzzle energy =
/./
,r,
2
= 1/2 X
eluding the cradle and other secondary recoiling parts W - I,,Wr, = 3,700 lb, weight of bottom carriage.
S•6 - .2 28502
-32.2
15,9(3),0004 ft-lb
2
X 13000
1/2 X3.
412
-339,000 ft-lb
Frrom Eqpliatioin :3,the minimum weight of the re-
Er
v'iling partii
The length of recoil, according to Equation 7
W, = 8.2 X 10-
4
En = 13,000 lb
1/2.
Mr,
L 1Db=10X6.5=65in
From Equation 4, the minimum weight of the emplaced weapon W -=22.8 X 10-1 E. = 36,200 lb
Based on this distance, the recoil force, according to Equation 6 K E E,ý •I• Sin a K L + s339,000 5.42
Weights asigned to other components are based on proportions generally found applicable to the type weapon. For the single recoil gun Wc--= 10,000 Ib, weight of top carriage Wlle = 8,800 lb, weight of bottom carriage, ineluding trails.
2. Double Recoil System For a doulble recoil weapon, assume a primary recoil stroke of 65 in., the same as for the single recoil weapon and a secondary recoil stroke of 4 ft. According to Equation 9, the primary recoil re-
WTc = 19,500 lb, weight of top carriage, in___________________________________________
instance
K M, =i=/2 1 K FL;_ K
COS 2,.0 ni0 eo
L, cos 0 +
L2
12+
)
tSl
W sim
13,000 X 412 1 4 X 0.4232 6 64.4 X 5.42 ý 5.42 X 0.423 + 4 X 2.5) + 13,000 < 0.906 = 62,500 X C.942 + 11,800 = 70,600 32
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where, according to Equation 8 tn
+ ?i-,
-
Fv - K., = 2 X 133 X 72.7 - 19,400 lb If a pneumatic or hydropneumatic equilibrator is desired, its maximum operating pressure deter-
2.5
nil The suggested angle of elevation for computing the secondary recoil force is 200. From Equation 10, this force m v.12 cos2 0
R =
D. ELEVATING AND TRAVERSING LOADS 1. Elevating Gear Load
L, eos 0 + L2 )?1 + n 2
til 339,000 X 0.94 2 5.42 X 0.94 + 4 X 2.
19,900 lb
On the surface, the difference in reeoil forces between single and the pl-inary recoil force of double
recoil systems is slight but past experience has shown that for similar weights, the double recoil weapon can sustain greater loads and, therefore, can tolerate a shorter recoil stroke which in turn tends towards a lower silhouette. The large contrast between single knd double recoil systems is in the horizontal loads which becomes evident at horizontal firing where the spade reaction for the single recoil weapon is 62.500 lb while for the double recoil weapon, according to Equation 10 when 0 equals zero, it is only 22,000 lb. C. EQUILIBRATOR FORCE Paragraph 47 deals with equilibrator param-
eters which are obtained from Equations 13b to 17. The weight of the tipping parts =
IV,
4/
W IV, =
To estimate the elevating gear load, assume a tube length of 45 calibers. Other assumed parameters which appear practical are R, a,.
:38 in., pitch radius of elevating gear 0.15 rad/sec.2, elevating aeceleration 20*, gear pressure angle 45 Lib = 292 in.
Lt
According to Equation 18, the radius of gyration kt - 0.236 Lt - 0.236 X 292 =- 69 in The mass monient of inertia by virtue of Equation 19 wn, 1kAY! +-2- L( - 2D) -( 17,:00 12 X :12.2 16!' + (97.- 1:)21 '5310H)lb-in-see: -
From Equation 20
T, = 4 2=, = 0.15 X 5:31,000 = 79,800 lb-in From Equation 21b
X 13,000 = 17,300 lb
Conforming to the geometry suggested in para-
graph 47
44
"I'
-x 6.5• \ 45.000
--
I,493.000 lb
From Equation 21b
Rt = R = 5 Db= 32.5 in. c = 2 R - 6.5 in. (First trial value, see paragraph 47.) = V' 6 5- + 32.5` = 72.7 in. The weight moment from Equation 14b =/.= .I7her3for), 0conies bat The spring rate, for each of two equilibrators,
according to Equation 15) o 562,00OO __
K,
mines the piston area to conform with the maximum force.
---
F,,
-F, - K + W1 sil a 1,49:3,000 - 74,:10() +- I,,00 -_ 1,430.500 lb T A0.1F. = 14:3,0(00 Ib-imi
Since the gull does not elevate whihl firii-g. T, ithe maximuim torque !, ion 27 ,:rovides the prehlimwimaryN "ar tth dbesieigu load R,
14_ 143T,0
-
R,•o s
:iS X I0.94
4 ,101011
4.t)IH
_
2 X65 X
-- 2.--
1=:11lb/in
The maxinminm force for two cquilibrators, according to Equation 16
Isff,,ts of sc,,.For . . d1e revoil w -a o i. hlt,e onlar" i32.5 recoil acceleratmion lm.ust he in'vestigated. As T4 and Tt do mitt appear simulim omsly and since setiondary avelbratio, appears aft'r pro-
f
E
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pellant gas force cease, Equation 21a involves only the primary recoil itertia force, therefore, - 0.10 F. = 0.10 X58,800 = 5,880 ib-in =T a=--
Equation 23 when an angle of elevation 0 K c - I c Osi 8 - R 2 a= 2 + W1 Sil 8
70,600 X 0.423 - 13,000 X 0.423 X 0.906 - 19,900 19,500 + 13,000 X 0.906 2
Based Equation 24, the inertia force of the tilping on parts F1 =
To determine the trunnion bearing loads the assigned values to the angles and loads of Figure for the single recoil weapon are
Ih Equation 25, 0 - 700 with the resulting torque Tt = PR, sin 0 -- 2,S00 X 32.5 X 0.94 = s5,500bin 28 3 035 -- 85,500 lb-in From Equation 26 T, = Tt + T1 - 85,500 + 5,880 = 91,380 lb-in From Equation 27 T,
"-Rp cos •
0.162 g's
E. TRUNNION BEARING AND TRAVERSING BEARING LOADS 1. Trunnion Bearing Load
a. = 17,300 X 0.162 = 2,800 lb
RP=
5000 30,200
65*
0 = 20* 7 = 60*
FE =
0 = 650
P. = 62,500 lb
),-- 25'
R, = 4,000 lb
19,400 lb
F. = 0
The horizontal reaction of the trunpion, according to Equation 31a
= 2,560 lb _ 91.380 38 X 0.94 - ,
This load is less than that produced by the firing torque which remains as the design condition for the elevating gear.
Rh-= PFcos 6 - Rg sin (7--) + FE Cos Ft= 26,500 - 2,600 + 17,600 - 0 = 41,500 lb From Equation 31b, the vertical reaction
2. Traversing Gear Load
R,. = F. sin 0 - R, cos (y--) 4- FE sinlX + Wt = 56,600 - 3,100 + 8,200 + 17,300
For the traversing gear load analyses, the pitch radius and angular acceleration for' the single recoil weapon are assumed to be, respectively, R, 40 in. 0.15 rad/sec" =,, 0
79,000 lb The total trunnion load as compitltd from Equation 32 FT =,\IR' -+ R.ý'2
Now, according to Equations 28a to 30 inclusive, b"=
VTWrc
10,000) X 12 = :10,000 lb-in-sec2
- 4ý, - 531,000 + 30,000 - 561,000 lb-in-see" T. = 7=- 0.15 X 561,000 = S4,100 lb-in
tan 0 = Yt The values in paragral)h 51 assignoid for this anglysis are K 74,300 lb T- 143,000 lb-inl Rt 32.5 in Wt', 17,300 lb R, 12 in I" 18 in y,, 48 in &R 14 in 13° 8 0 07••5 = -- 035 tan t13580 i
The firing torque, T' = 143,000 lb-in, is also as.,suled to apply to the traversing unit an(1. since it has the larger value, it becomnes the design loading. The traversing gear tooth load 14:31,•9) 40
89,300 lb
2. Traversing Bearing Load The traverse bearing design load is based on the maximum loading conditions. This happens with a negative firing torque and where
where the top carriage unit is assumed to weigh 10,000 lb
R" -
=
-
lb.
34
4
"
"
q
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BIased onl Equation 6 F. = K
= 143.00M +- 69,700(4419 + 6-32) 17,3(X)(30.4 - 18) = 14:3,000 + 31,570,000 -- 215,000 - :1,49S,000 lb-in
It',sin 0 = 74,300 - 4,600 =69,700 lb
-
Equation 33a has -T, + F. (!I, cos 0
Ml,
-
, A
9
es
-
+ x, sin 91)
According to Equation 3&!, the effective presisure load
Xt,)
F,= 24& R, +R,
2
M0 .1,=4 X 14 3,498.000 = 576,M() lb 340
The total effective lohd onl the traversing hearing obtanedfromEqution 33 and33ethe P, F,.± F. sinii + IV,+ 11'Tc =576,000 + 24,400 + 17,300 + 10,000 =627,700 lb The task reniairting fin the selection of bearing, the roller type being recomnmended, which wl support the trunnion and traversing h~earing loads,. Sizc's and
load capacities are available
Nosing-oyer tendeneies prevail during buffing, latter part of the counterrevoil stroke. Early estimates has the buffer stroke eqjual to 257c of the recoil stroke (paragraph 45) .~=.5~j=.5f
A.%;umhing avtnerv h ufn ocefo V~,2
in coni-
Practive permits 100 percent inercial witalogs. overloads for firing conditions, therefore a bearing with a static rating of :314,000 lb would be ade(luate.
=________ -____
2
Th'orona itrt.beenfotsuptan center of gravity of the weapon to balance it duiring counterrevoil is comnpu ted from Equation 35d
F. SIZE OF STRUCTURE 1. Trunnion Height Equatioi, 35a e!;tablishes the p~relinminary trunnion height as
yr = (L. +- 3Db) sin ,., =(65 + 3 X 6.5) sin F5' = 84.5 X 0.906 = 76.:i in. 2. Stability The weapon is stabilized by locatintg the vertical 'round reaction with. respect to the center of gravity. For the single recoil weapon, mssnime horizonta' tiring. Thus inl Equations 35c and 35f
x= -~y
Th,, lrojeeted length of the enzp'tved trail ini the vertical) plane of the tube iobtainedl from Eiloation 315v by solving for x x_-
yr -
74,311x - 7ti4 - b.P)leontv
If this length is considered Ito) long, the ueapon imust be rest rietedl to a minininum aiir.'l of e'Wlemion large'r thbant zero if weaptil itump is to 1w pr'ýk Iuded.
-.--
i'
3,-
y
6.
7.77 ill
The stability oif a douible revoil iveapon dependsN on secoindary revoil .t-aractt'risties inl addition to the locations of ground 5ibtt.trunn~tionis, and (enter of gravity. Tvintative Im-ations are testiLatee,, mated first for firing at zero Aelvation. %.~hen.design data i'ý comnplete for the enttire revoil cycle. the critical eie-,atiot ritay be lowier, The asli1giied data are K = 70,600 lb R = 19),(KX lb
IV, It',
-~17,3W
lb lb
362X 1b
lln.
P
05(~ Ib l
11
Y =Y6b-- Yr = 76.5) in.ý 11 = 36,21X) lb K = 74,30W lb
-
veloeity of 5 It prso qain1 l _ 13.000X) 25 3. 20 1 2 X :12.2 X 1.355
13,M()
Accordingi to Equationi 35x, prelimniiary truzinion 1wigbits of single and .lnble rectil gnus ar -equal. Assiume that the tia~im-esnter of I h. fiql, varrin; l~,Is at half th, ironiini i.'h mill. frimi 'x~perleiene. u~t h-fn w l~r irt;rl. wti .is-.I Ohe h,,lon *Nrog teitaierso grvar%%aro4 wli.thin tpq .'R1riA$:r1 losautl '11.1~h the 1.mw, l~orizitn~ll a;L7il.tt the vibel- of th r.'~isr;oe t . .... i-itlarb
revoil jmust he eoiis!(lr -1 t. oif gra 'it of 11w' we atlý'1 -
-F-
n
o
lo.;utlzit .f ,hv ý-ei~r bf~;i i a mni~ltifi"
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K.
RI
, r =! 70.1;i0)
X 76.5 -+-19.900 X 3S25
W The values asi,,,nvd to the secondary buffer are
F•
1-(1, + 1112)
)0.
:12SO Y 105.9 + 4920
- 1.0 ft = 4 ft p e r s e e
)otal secondharv The Eiluation 12a
6.162,0 :3fi,2t()
36,200
36.70M 14 .6
-
00.
bnffing force aivording tG
-:36,700
X :38.25
--
The farthest forward location of the trunnions with W01 2 X .I)
.durinlg
Front Equatiions 12b and 12c the inertial forces of the primary and secondarv recoiling parts due to secondary buffing
respect to the front su:oport to insure stability secondary buffing is found by balancing the weight mometuts of the .onpou|us with that of the
total weight about the fron, mipport.
X.. = 2D, = '2 X 6.5 = 1:3 in. = (R, os 6.-0 -- x') It'. WI', I, .r._'19.100 X 1:1 - 13.75 X 17,600 + 17,600 -zr'
S-
F,1
-=
MI + 11-
2
X
S1tK)
= *3_'2X lb
1.5-~X SII IO )O = 4,9(X) ,90lIb ± The critical forward tipping action occurs at maximum elhvation. The hoation of the weapon -center of gravity from the front support F"
=
"12
MI' 1
F,
Faa:
11-12
at
2.5
(!r ± R,sin 8) I'W
i Fr.-y,
= 336,000 5:60017,600 xrr' =---530.000 7,600.rr' 530.10 = 30.1 the trutnniohn distanie to the rear of the front support. The actual location of the final deign as
iineated by past experience would have a distance approximately twice this length.
9.i
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GLOSSARY base plate, mortar.
The structure of a mortar
pelanit gas force and tilc inertial force of the
that holdIs the breec-h end (;f the tube and trarismits the recoil force to thle ground.
recojhing parts cau'w,-d by their nonli! :ýar lines of actioni, i.# the renter of grav;'* of the re-
buffer. A invclmnismi that absorbs thle tueriy ol -otniterrevoil and brings thle recoihing pari.s, t, a stop mwithout shock,
Mobile or fired support of a weap-
carriage, gun.
coiling parts d -s not lie ol thle N!,e axis. Upright gi'ired are attachel to the tipping parts or carriage i'Y whichv~ the weap-
gear, elevatarg. lvtf
oli
gear, traversing.
011,
carriage, bottom. The secondlary supporting Otrueture of a gunt. It supports tle top earriagt, and transmits firing forces to the grunod. carriage, top. Primary supporting st ructure of at gun- It supports thle tipping parts and moves with the cradle in traverse. In double recoil systems, it comprises the bulk if t he stccoriarY rt~oilng ties.mount, The moot ion of the recoilingl parts
counterrecoil.
as tflev return to the i:i-batterv posit ion.
cradle.
The noiireeoilir'g structure of it %vapon that houses the recoiling- parts anid rotatcs about thle trnintionis to eleytite the gliit
The- last gear it, the traversing gear train that is attaichmi Ito the t r.. ;ers'ing parts.
moment, weight. The moment about thle truinn ion axis caused by the wei-lht of the tippinig parts. mount, ball. Smnall armis or lilght ar1 ývni.uit havit..r the tipping par~s pivoted hIf. a ball midi socket joint. bipod. sitigotw
Small arums oir mi rtar mounti sporn g.
con-t
mount, combination. A tanik miount Niupporting, art art illt-ry wvcajsn -ido at machine guni. mut
lxbe
ml rsmutfo hc ml ni oi. rr hc a maclihinle g-1ut (-ll lie ainish over at lai ge range.
onfeile
elevating mechanism.
Mechanism oil a guin carSby which the tiplping- parts arci elevated or depressedl.
A rigidl miount fijr snial I armis
mount, fixed.
ti x-,i Ai~niitgl is alviiveil hv ihiri. ,Ing, th.'
Vi aircraft.
craft. Tb.' preparedi site- of it -gun iii tiring"
emplacement. pi'sitioln.
armis glu
energy, muzzle.
Thle cortililiicI energy tile anid provellanti gas at the riuzyle.
energy, specific, of weapen.
mcunt, gun.
The ratio of
i'trzzle
muilizlc ricrg'
firiag
torque.
Tlhc
n;!it
.
sut metir
ntftnt
A.sal .Itmi,'n
mýi!
n that
that
tvs
-nount,
'111io~-. int.!.!
ire.
~r
r.'ofhr .
i
iu:;' l~lo- 1'r--
'n~ n,~r
,tuoTi-1H
trzinion% th
~ lb'......
mount, mortar.
paoll 'j~rt,
Tbhe ffore,', pr-bthikiML wt-chawt
a
ut
The' ratito -if
to wki,-gut of
a itoiquet atsiit tI. e-qual -.111d .psst" to
The ectiratl lern
supports at g.un. mount, monopod.
"-nergy, specific, of recoiling p&ALt
small
iti
projecv-
oif
ý'apwnt en *rgy to wr-ight of %%
equilibrator.
A mount which sts fniinv60-11s tm
mount, ginbai,.
tripod .. 'al A
t;:
rf!!.:tl! 1.s1N01!. !iO
ý
bee
preponderance. "!Pi~v r .t;
:
~
f~ rf
Ti
.v
Ir-ili
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prime mover. A vehicle capable of providing its own means of loccmotion. propellant gas force, Thic force prbduced by the propellant gas acting over the bore area. recoil. The movement of a gun opposite to the direction of projectile travel,
recoil, single. The recoil associated with a weapon when only the gun tube and its attached parts move in recoil.
recoil, double. A systum in which the gun recoils on the top carriage and the top carriage rtcoils on the bottom carriage.
tipping parts. The cradle, gun tube and associated parts which rotate about the trunmdons. trail, single. A single rearward thrust member of
recoil, energy of. The kinetic energý of the recoiling parts,
v'eapon. It stabilizes the weapon during firing and serves as a liik between weapon and pr'ime
recoil, free. Recoil of a gun, uninhibited by resistance.
mover during transport. trail, split. Two members serving the same pur-
spade. The , ertical member of a mount which is buried in wte ground to transmit lateral loads into the ground.
pose as the single trail.
recoiling parts. All parts that move in recoil, recoil, length of. The distarce that the recoiling parts move.
traversing mechanism., The mechanis' 1 that transmits power TO the traversing parts.
recoil mechanism. The unit that absorbs most of the energy of recoil aid stores dhi rest for returning the recoiling parts to battery. recoil, primary. The recoiling of the gun tube and its associatryd parts in a double recoil weapon.
traversing parts. traverse.
Aui the units which move in
trunnion. One of the two pivots supporting a weapon on its mount and forming the horizontal axis about which the weepon elevates.
recoil resistance. The resistance to recoil ennsistipg of the force developed by the recoil mechanism and the frictional resistance to the moving recoiling parts.
velocity, muzzle. The velocity of the projectile as it leaves the muzzle. velocity of free recoil. The rearward velocity that
recoil, secondary. The recoiling activity associated with the top carriage in a double recoil weapon.
a weapon would attain if no resistance were offered.
38
t, oj
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REFERENCES 1. Engineering Designl Handbook, 341, Carriages and Mounts Series, Cradles.* 2. Engineering Design Handbook, 342, Carriages and Mounts Series, Recoil Systems.* 3. Engineering Design Handbook, 343, Carriages and Mounts Series, Top Carriages.' 4. Engineering Design Handbook, 344, Carriages and Mounts Series, Bottom Carriages.* 5. Engineering Design Handbook, 345, Carriages and Mounts Series, Equilibrators.0 6. Engineering Design Handbook, 346, Carriages and Mounts Series, Elevating Mechanisms.* 7. Engineering Design Handbook, 347, Carriages and Mounts Series, Traversing Mechanisms.* 8. T. J. Hayes, Elements of Ordnance, John Wiley and Sons, New York, 1938. See inside back cover for information on handbook designation.
S$
339
4i,
I'3
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ENGINEERING DESIGN HANDBOOK SERIES The Engineering Design Handbook Series is intended to provide a compilation of principles &4dfundamental data to supplement experience in assisting engineers in the evolution of new designs which will meet tactical and technical neede while also embodying satisfactory producibility and maintainability. Listed below are the Handbooks which have been published or submitted for publication. Handbooks with publication dates prior to I August 1962 were published as 20-series Ordnance Corps pamphlets. AMC Circular 310-38, 19 July 1963, redesignated those publications as 706-series AMC pamphlets (i.e., ORDP 20-138 was redesignated AMCP 706-138). All new, reprinted, or revised Handbooks are being published as 706-series AMC pamphlets. General and Miscellaneous Subjects Number 106
Title Elements of Armament Engineering, Part One, Sources of Energy 107 Elements of Armament Engineering, Part Two, Ballistics 108 Elements of Armament Engineering, Part Three, Weapon Systems and Components 110 Experimental Statistics, Section 1, Basic Concepts and Analysis of Measurement Data ill Experimental Statistics, Section 2. Analysis ot Enumerative and Classificatory Data 112 Experimental Statistics, Section 3, Planningand Analysis of Comparative Experiments 113 Experimental Statistics, Section 4, Special Topics 114 Experimental Statistics, Section 5, Tables 134 M.intenance Engineering Guide for Ordnance .; Design 135 rventions, Patents, and Related Matters 136 •ervomechanisms. Section 1, Theory 137 /Servomechanisms, Section 2, Measurement I and Signal Converters 138 Servomechanisms, Section 3, Amplification 139 . Servomechanisms, Section 4, Power Elements and System Design 170(C Armor and Its Application to Vehicles (U) 252 Gun Tubes (Guns Series) 270 Propellant Actuated Devices 290(C) Warheads--General (U) 331 Compensating Elements (Fire Control Series) 355 The Automotive Assembly (Automotive Series) Ammumition and Explosives Series 175 Solid Propellants, Part One 176(C) Solid Propellants, Part Two (U) 177 Properties of Explosives of Military Interest, Section 1 178(C) Properties of Explosive- of Military Interest, Section 2 (U) Z10 Fuzes, General and Mechanical ZI(C) Fuzes, Proximity, Electrical, Part One (U) 212(S) Fuzes, Proximity, Electrical, Part Two (U) 213(S) Fuzes, Proximity, Electrical, Part Three (U) 214(S) Fuzes, Proximity, Electrical, Part Four (U) 215(C) Fuzca., Proximity, Electrical, Part Five (U) 244 Section 1, Artillery Ammunition--General, with Table of Contents, Glossary and Index for Series 245(C) Section 2, Design for Terminal Effects (U) 246 Section 3, Design for Control of Flight Characteristics 247(C) Section 4, Design for Projection (U) 248 249(C)
(C0
Section 5. Inspection Aspects of Artillery Ammunition Design Section 6, Manufacture of Metallic Components of Artillery Ammunition (U)
Ballistic Missile Series Number 281(S-RD) 282 284(C) 286
Title Weapon System Effectiveness (U) Propulsion and Propellants Trajectories (U) Structures
Ballistics Series 140 Trajectories, Differential Effects, and Data for Projectiles 160(S) Elements of Terminal Ballistics, Part One, Introduction, Kill Mechanisms, and Vulnerability (U) 161(S) Elements of Te'rminal Ballistics, Part Two. Collection and Analysis of Data Concerning Targets (U) 16Z(S-RD) Elements of Terminal Ballistics, Part Three, Application to Missile and Spi'c Targets (U) Carriages 340 341 342 343 344 345 346 347
and Mounts Series Carriages and Mounts--General Cradles Recoil Systems Top Carriages Bottom Carriages Equilibrators Elevating Mechanisms Traversing Mec:hanisms
Materials 301 302 303 305 306 307 308 309 310 311
Handbooks Aluminum and Aluminum Alloys Copper and Copper Alloys Magnesium and Magnesium Alloys Titanium and Titanium Alloys Adhesives Gasket Materials (Nonmetallic) Glass Plastics Rubber and Rubber-Like Materials Corrosion and Corrosion Protection of Metals
Military Pyrotechnics Series 186 Part Twu, Safety, Procedures and Glossary 187 Part Three, Properties of Materials Used in Pyrotechnic Compositions Surface-to-Air Missile Series 291 Part One, System Integration 292 Part Two, Weapon Control 293 Part Threes Computers 294(S) Part Four, Missile Armament (Us 295(S) 296 Z97(S)
Part Five, Countermeasures (U) Part Six, Structures and Power Sources Part Seven, Sample Problem (U)
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