Golden Gate Bridge 1620316994, 9781620316993

Table of contents :
1 Modern Marvel
2 Bridging The Gap
3 Design And Construction

Citation preview

ENGINEERING MARVELS

GOLDEN GATE

BRIDGE by Nikole Brooks Bethea

Ideas for Parents and Teachers

Pogo Books are published by Jump! 5357 Penn Avenue South Minneapolis, MN 55419 www.jumplibrary.com

Pogo Books let children practice reading informational text while introducing them to nonfiction features such as headings, labels, sidebars, maps, and diagrams, as well as a table of contents, glossary, and index.

Library of Congress Cataloging-in-Publication Data

Carefully leveled text with a strong photo match offers early fluent readers the support they need to succeed. Before Reading • “Walk” through the book and point out the various nonfiction features. Ask the student what purpose each feature serves. • Look at the glossary together. Read and discuss the words. Read the Book • Have the child read the book independently. • Invite him or her to list questions that arise from reading. After Reading •D  iscuss the child’s questions. Talk about how he or she might find answers to those questions. • P rompt the child to think more. Ask: Have you ever seen the Golden Gate Bridge, either in person or in a photograph?

Copyright © 2018 Jump! International copyright reserved in all countries. No part of this book may be reproduced in any form without written permission from the publisher.

Names: Bethea, Nikole Brooks, author. Title: Golden Gate Bridge / by Nikole B. Bethea. Description: Minneapolis, MN: Jump!, Inc., [2018] Series: Engineering marvels | Includes index. Identifiers: LCCN 2017000803 (print) LCCN 2017003425 (ebook) ISBN 9781620316993 (hard cover: alk. paper) ISBN 9781624965760 (e-book) Subjects: LCSH: Golden Gate Bridge (San Francisco, Calif.)—Juvenile literature. | Golden Gate Bridge (San Francisco, Calif.)—History—Juvenile literature. Suspension bridges—California—San Francisco—Design and construction—History—Juvenile literature. Classification: LCC TG25.S225 B435 2018 (print) LCC TG25.S225 (ebook) | DDC 624.2/30979461—dc23 LC record available at https://lccn.loc.gov/2017000803 Editor: Kirsten Chang Book Designer: Leah Sanders Photo Researcher: Leah Sanders Photo Credits: Bruce L Crandall/Shutterstock, cover; Andrew Zarivny/Shutterstock, 1, 23; ChameleonsEye/ Shutterstock, 3; Spondylolithesis/Getty, 4; dibrova/ Shutterstock, 5; Alessandro Colle/Shutterstock, 6–7; Flugklick/Shutterstock, 8; Underwood Archives/Getty, 9, 16–17; Peter Burnett/iStock, 10–11; Maly Designer/ Shutterstock, 12; SAN FRANCISCO HISTORY CENTER, SAN FRANCISCO PUBLIC LIBRARY, 12; George Rinhart/ Getty, 13; Albo/Shutterstock, 14–15; ventdusud/ Shutterstock, 18–19; Pung/Shutterstock, 20–21. Printed in the United States of America at Corporate Graphics in North Mankato, Minnesota.

CHAPTER 1

Modern Marvel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 CHAPTER 2

Bridging the Gap. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 CHAPTER 3

Design and Construction . . . . . . . . . . . . . . . . . . . . . . 12 ACTIVITIES & TOOLS

Try This!. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 To Learn More. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

MODERN MARVEL Imagine you are riding up the California coast. Fog surrounds you. Something rises above the haze.

It is a tower. Sunlight hits it. Orange shines through the fog. You know where you are. You are at the Golden Gate Bridge!

The bridge is a modern marvel. It set world records when it was built. It was the longest suspension bridge in the world. Its towers were the world’s tallest. It also proved to be strong and stable. In 1989 the Loma Prieta earthquake hit. Some bridges fell. The Golden Gate Bridge stood.

The Golden Gate Bridge is painted in “International Orange.” The strait is often foggy. The color makes it easier for ships to see.

BRIDGING THE GAP In 1848 gold was found in California. San Francisco’s population exploded with people seeking wealth.

Highway 101 ran north and south through California. But it ended at the strait. Crossing required a long ferry trip. Docks became crowded. There needed to be another way to cross.

Golden Gate Strait, 1900

Some engineers thought a bridge across the strait was impossible. The Pacific Ocean rushes into the strait. Currents and waves are strong. Fog is heavy, and winds are fierce. Earthquakes are possible. Foundations would need to be built deep into the ocean floor. Joseph B. Strauss said the bridge was possible. He became the chief engineer in 1921.

DESIGN AND CONSTRUCTION Strauss’s original design did not look like today’s bridge. It was a hybrid. The center was a suspension bridge. On each end was a cantilever bridge. But people complained. They called it ugly.

anchorage

Strauss redesigned the bridge. It would have two towers. They would support two main cables. The cable ends would be anchored in concrete on each side of the strait.

Vertical cables would hold the roadway. The truss underneath would support its weight.

Many parts work together to make the Golden Gate Bridge strong. towers anchorage

anchorage

truss

cables

cables

truss

tower

Construction was a dangerous process. But Strauss made sure to take safety measures. Men were required to wear hard hats. This was a new standard for construction workers. A large safety net was strung under the bridge in case men fell. The net saved 19 lives.

During construction, it took workers 20 minutes to climb the ladders to work on the bridge towers.

The bridge opened to vehicles on May 28, 1937. Six traffic lanes stretch across it. The distance between its towers is as long as 14 football fields. It is as tall as 129 men. It weighs as much as 127,000 elephants!

How big is the Golden Gate Bridge?

■ = total length of bridge: 1.7 miles (2.7 kilometers) ■ = distance between towers: 4,200 feet (1,280 meters) ■ = tower height: 746 feet (227 meters)

Today, about 40 million vehicles cross the bridge each year. Engineers named it one of the Seven Wonders of the Modern World. Maybe one day you will see this marvel for yourself!

BUILD A BRIDGE Now, you are the engineer. You will read a design plan and build a truss bridge. Truss bridges are formed by a series of triangles. What You Need: • 18 gumdrops • 39 toothpicks • small books • two chairs

Build a gumdrop bridge by following the design plan pictured. Build the two sides first. Then, connect the sides together horizontally with toothpicks. Slide two chairs together facing each other, leaving a gap between the seats. Lay your bridge across the gap. The chairs should support each end of the bridge.

Gently place a small book on top of your bridge. Stack books one at a time until the bridge falls. Count how many books your bridge supports before it falls. If you have extra gumdrops and toothpicks, experiment with different bridge designs. Test to see if the new design holds more or fewer books. SIDE:

TOP:

cantilever bridge: A bridge built from horizontal beams supported only on one end. currents: Continuous movements of water in a river, lake, or sea. engineers: People who use math and science to solve problems and create things that humans use. ferry: A boat that carries passengers and goods, usually over a short stretch of water. hybrid: Something that combines two different elements.

stable: Steady and unlikely to move or change. strait: A narrow waterway connecting two larger bodies of water. suspension bridge: A bridge in which the roadway is supported by cables that stretch over towers and are anchored to the shore. truss: A metal framework that supports a bridge.

cables 13, 14

orange 5, 6

cantilever bridge 12

roadway 14

California 4, 8, 9 concrete 13 currents 11

earthquakes 6, 11 engineers 11, 21 ferry 9

fog 4, 5, 6, 11 gold 8

height 6, 18, 19 hybrid 12

length 6, 18, 19

Pacific Ocean 11 safety measures 17 San Francisco 8

strait 6, 9, 11, 13

Strauss, Joseph B. 11, 12, 13, 17 suspension bridge 6, 12 towers 5, 6, 13, 17, 18 truss 14

vehicles 18, 21 weight 14, 18

world records 6

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