REAU5043 About Ready-Ed Publications Ready-Ed Publications Was Established in 1984 with the Purpose of Creating Practical Classroom Blackline Master Activities

Ebook code: REAU5043 About Ready-Ed Publications Ready-Ed Publications was established in 1984 with the purpose of creating practical classroom blackline master activities. At the time, the role of the Ready-Ed teacher was becoming ever more diverse with an increasing range of duties and Publications responsibilities within the school and school community. Since then, the role of the teacher has continued to evolve with an escalating range of tasks and obligations, ensuring a reduction in time available to prepare work for the daily instructional program. Throughout these past 24 years, Ready-Ed Publications has built a reputation as publishers of Australian made, high quality, innovative, timesaving materials for teachers of primary and lower secondary levels. In addition, all materials are based on state or national curriculum guidelines or specific age-related interest areas and subjects. Ready-Ed Publications aims to assist busy professionals by making available contemporary classroom materials that contain relevant and stimulating work to support the requirements of the curriculum.

Cover image: Clip art images have been obtained from Microsoft Design Gallery Live and are used under the terms of the End User License Agreement for Microsoft Word 2000. Please refer to www.microsoft.com/permission. Acknowledgements i. I-stock Photos. ii. Clip art images have been obtained from Microsoft Design Gallery Live and are used under the terms of the End User License Agreement for Microsoft Word 2000. Please refer to www.microsoft.com/permission. iii. Corel Corporation collection, 1600 Carling Ave., Ottawa, Ontario, Canada K1Z 8R7. iv. Wikimedia Commons. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.

Published by: Ready-Ed Publications PO Box 276 Greenwood WA 6024 www.readyed.com.au [email protected]

ISBN: 978 1 86397 775 3

COPYRIGHT NOTICE Permission is granted for the purchaser to photocopy sufficient copies for non- commercial educational purposes. However, this permission is not transferable and applies only to the purchasing individual or institution.

2 Contents

Tell Me About Bridges 1 6 How Bridges are Made Safe 1 26 Tell Me About Bridges 2 7 How Bridges are Made Safe 2 27 Tell Me About Bridges 3 8 How Bridges are Made Safe 3 28 Tell Me About Bridges 4 9 Geronimo! 1 29 Claim to Fame 1 10 Geronimo! 2 30 Claim to Fame 2 11 Geronimo! 3 31 Claim to Fame 3 12 Famous Bridge Mishaps and Collapses 1 32 Stronger Bridges 13 Famous Bridge Mishaps and Collapses 2 33 Famous Bridge Mishaps and Collapses 3 34 The Four Bridge Designs 1 14 The Four Bridge Designs 2 15 Opening a Bridge 35 It’s Opening Day 36 Beam Bridge 1 16 Beam Bridge 2 17 Bridges in Film 37 Bridges in Film 38 The Arch Bridge 1 18 Bridges in Song 39 The Arch Bridge 2 19 Bridges in Tales and Rhymes 40 The Arch Bridge 3 20 Bridge Activities 41 The Suspension Bridge 1 21 The Suspension Bridge 2 22 Answers 47 For the Teacher - Lessons in Suspension 23

The Cable-Stayed Bridge 1 24 The Cable-Stayed Bridge 2 25

3 Teachers’ Notes

Bridges is written primarily for teachers of Students are encouraged to test their own Design and Technology, but it can also be used engineering skills by making their own bridges in English and Information Technology lessons. from a number of materials for a range of It can be taught to Years 5, 6, 7 and 8, as the purposes. activities can be easily adapted to suit different age groups. They are also encouraged to explore how bridges have played a main role in popular This book explores how engineers have, over culture because they are so often viewed as time, planned, designed and constructed a strong symbols and metaphors. range of bridges and learned from their mistakes and discoveries. It looks at the first and most More bridge activities are provided at the back recent bridges and examines the materials of the book and can be used for early finishers or that have been tried and tested over the years. to extend more able students. This book will help students appreciate why bridges stay up as well as understand why they sometimes tragically fall down.

Curriculum Links

• WA (Technology and Enterprise) • NSW (Design and Technology) Materials (2) Knowledge and understanding of design Enterprise (5) concepts and processes (1) Technology Skills (6) Understanding and appreciation of the impact of past, current and emerging • VIC (Design, Creativity and Technology) technologies on the individual, society and Investigating and Designing - Levels 4 & 5 environment (2) Producing - Levels 4 & 5 Knowledge and understanding of skills in managing resources and producing quality • ACT (Technology) design solutions. (6) ELA 25 - The student designs, makes and appraises using technology. 25.EA.1, 25.EA.5, • SA (Design and Technology) 25.EA.8 Making – 3.5, 4.5

• TAS (Vocational and Applied Learning) • Q/LAND (Technology) Innovation and Design – Standards 3 & 4 Technology Practice - Levels 4 & 5

• NT (Design and Technology) Designing – Bands 3 & 4

4 Tell Me About Bridges 1

Listen to the Bridges Bigger, Better Bridges The advancement of bridges has parallelled the advancement and spread of people Deep valleys and vast water around the globe. Bridges have helped millions of people every day go about expanses are becoming worthy their ordinary daily lives. Each bridge has a challenges for engineers who are unique story to tell about the people whose now capable of building longer and lives are linked with its success or failure. bigger bridges than ever before. Bridges tell the stories of the people who have designed, built and used them. They There may come a time when no tell the stories of the people who have distance or object will be enough to damaged and destroyed them. They tell the stop the building of a bridge. stories of the people who have then re- Bridges stand as proof of built, celebrated and strengthened them. humankind’s incredible ingenuity.

Research  Record Breaker!

Research bridges that have broken world records. Look up the longest bridge, the oldest bridge, the widest bridge, the highest bridge, the most expensive bridge, the busiest bridge and the longest main span bridge. Record your findings below.

The Longest Bridge:

The Oldest Bridge:

The Widest Bridge:

The Highest Bridge:

The Most Expensive Bridge:

The Busiest Bridge:

The Longest Main Span Bridge:

5 Tell Me About Bridges 2

What Exactly Do Bridges Do? I Declare This A Bridge! Bridges are in every place where people want to cross and are such a natural part A bridge is a structure, either of our every day life that we often take human-made or natural, that allows them for granted. They are born out of a necessity to achieve a more direct, efficient for transportation over a physical route. Generally, we think of bridges obstacle. Although bridges differ in carrying people in cars as they hurry to the way that they look, they have work. However, they serve many other many things in common. Typically, useful purposes, carrying such things as a bridge consists of a deck that is trains, trucks, buses, motorcyclists, push- adequately supported for traffic bikes, pedestrians, power cables, water to pass over. Bridges are readily pipes, telephone cables and livestock. recognisable because of this With continuing urbanisation, bridges purpose, and if they achieve it, we are becoming increasingly important as can declare the object as a bridge. governments seek ways to improve trade links, help us save time and minimise the costs of living.

Comprehension Helpful Bridges Answer the questions below. 1. How do bridges improve trade links? ______

______

2. How do bridges save us time? ______

______

3. How do bridges reduce the costs of living? ______

______Brainstorm  What If? What if an important bridge like the Sydney Harbour Bridge or the San Francisco Bridge (or a bridge in your city) was closed for a month? Suggest how people could still safely get from one place to another without the bridge. Have fun and include some more unusual ways – like an air balloon service. ______

6 Tell Me About Bridges 3

Group Activity How Do Bridges Work? Lean On Me 1 A bridge can be as simple as a log or Get organised into groups of as sophisticated as the engineering three. Two members of the marvel of the world’s highest road group should stand facing bridge over the Tarn Valley in France. each other and grasp each For any bridge to work successfully, other’s forearms, then gently no matter what its size, it must be lean back. The third member able to deal with two competing of the group should place a forces; compression and tension. book where the arms meet. Tension Compression shortens the things The book represents a load on a bridge and it acts on, while tension acts in the will cause the arms to stretch a little further opposite way; it expands the things apart. This is tension. it acts on. These forces appear every time someone or something (even Lean On Me 2 wind or water) come in to contact To demonstrate with a bridge. The design of a bridge compression, have will try to spread or transfer these two members of the forces in different ways. If it is unable group face each other to do so, the forces will act to either again. This time they break or weaken the bridge. should place their palms together and Compression gently lean toward Compression each other. The third member of the group should place a book where the arms meet.   The book represents a load on a bridge and will cause the arms to push together a little. This is compression. Tension 

 Bridge to Nowhere Your Task My Silly Bridge On the North Island in New Where do you think would be the silliest Zealand there is a bridge in the place to build a bridge? Scout your local Whanganui National Park that has area and find a place where you think a been built with no roads leading bridge would be a waste of time. to or from it! It has since become a popular tourist attraction. Draw your bridge on a separate piece of paper and state its location and why it’s a silly place to have a bridge.

7 Tell Me About Bridges 4 Write a letter to the government stating your case for a new bridge to be built over a river in your city. Include drawings and diagrams to support your argument. Research the best type of bridge to be built and outline the benefits of the bridge to the local community. Present your argument to the class pretending that they are the government authorities. Use the space below to plan your letter.

8 Claim to Fame 1

when the very first human- would have been mainly made bridge was built. made from wood because Primitive men and women there was lots of it and it would have begun to use is an easy material to work nature’s bridges before with. The Egyptians and discovering a way to make Babylonians were known bridges themselves. These to be early bridge builders. would have been very The Chinese and Indians are simple bridges, made by thought to have built the placing slab stones over earliest types of suspension a stream or strategically bridges. No single person can claim moving fallen logs between to have invented bridges. river banks. The world’s first The earliest recorded bridge The very first bridges would bridge engineer was the ever built, was across the have been naturally made first person to rearranged Euphrates River at Babylon from erosion or fallen trees a log or try to make a place around 784 BC. It was made or rocks forming overpasses. sturdy enough to cross. from timber planks and with Said to be 500 millions years stone supporting columns old, The Natural Bridge in Later, people would have and was held together by Virginia USA is an example learnt how to make bridges iron cramps. The planks of a bridge formed from using combinations of were removed at night to natural erosions. materials such as placing stop criminals using the branches end to end on bridge. It’s impossible to say exactly stone piers. The first bridges

The Enraged King Your Task  Acrostic Poem In 480 BC, the Persian King Xerxes constructed a Write an acrostic poem using the letters that spell the remarkable pontoon bridge word bridges to tell the story of the enraged King. made up of over 600 of his war ships tied together! It B ______stretched 3.2 kilometres R ______across the Hellespont in the Dardanelles. Unfortunately for I ______the King, the bridge collapsed after a storm tore the ships D ______apart. Enraged, the King G ______ordered the waters of the E ______Dardanelles to be whipped! S ______

9 Claim to Fame 2

It was the Romans though, who were the first to be recognised for their superior bridge building techniques and beautiful designs. The most famous of the Roman bridges is the Pons Sublicius. The Pons Sublicius was originally built from wood, “Pons Sublicius” Wikimedia commons before it was later rebuilt from stone. It was not unusual for early bridges to be destroyed and then rebuilt, sometimes many times. Over the course of 2000 years, London Bridge, for example, was built and re-built several times after being washed away, destroyed by invading Norwegians and levelled by fire.

The Romans are most noted for their clever stone arch bridge designs, which they constructed all over their vast empire to help open up trade routes and move troops quickly. In 55 BC the Roman Emperor Julius Caesar built two famous bridges considered masterpieces of military engineering to help his 40,000 strong army cross the Rhine River. Historians claim that the strength of the Roman Empire during this time was largely due to the roads and the bridges that they constructed. “London Bridge” Wikimedia commons

Comprehension  Reread the passage above and answer these questions. 1. Bridges often fell down in the early days of bridge building. Why?______

______

2. How did bridges help the Romans in times of war? ______

______

Your Task  Think about Famous Bridges Just about every city has bridges, but why do certain bridges become associated with cities, while other bridges go unnoticed? What bridges do you associate with the following cities:

New York ______London ______

San Francisco ______Bath (UK) ______

Sydney ______Venice (Italy) ______

Give one more example of a famous bridge and the city it is associated with:

10 Claim to Fame 3 Draw three different bridges – one that reflects the ancient past, one that reflects a bridge from today, and one that you think could represent a bridge of the future. Label and explain each of your three pictures. What is each bridge made from? What purpose does each bridge serve?

11 Stronger Bridges

By the 20th century four major types of bridges had emerged. They were: the beam bridge, the arch bridge, the suspension bridge and the cable-stayed bridge (the most recent design). Each type was developed over the course of human history from trial and error and from the environmental conditions which dictated to engineers what was possible. Improved technology and the refinement of building materials has enabled engineers “Iron Bridge” Wikimedia commons to build bridges Up until about 200 years ago, most bridges that were once were still made from timber or stone and impossible. the stone masonry arch was very popular. However, things have changed. The first book Bridges have been written about bridges was by the French built from almost engineer Hubert Gautier in 1717. This was an every known important book because it documented a more substance: wood, analytical and calculated approach to bridge stone, iron, steel, construction. The world’s first iron bridge was concrete and even built over the Severn River in Telford in 1779, ice. Today, most “Steel wire rope” Wikimedia commons by Abraham Darby. This opened the way for bridges are built from combinations of steel engineers to build much stronger and larger and reinforced concrete. The future in bridge bridges to carry heavy steam locomotive trains. design is linked to what types of building During the 19th century, more stable bridges materials are developed. New composite evolved, as new and better building materials materials are being developed and some became available. Increasingly, bridges became bridges are already made from special plastics. cheaper to build as iron reinforced concrete Bridges of the future will be environmentally and low cost steel were used. Later, steel, as a friendlier, lighter, stronger and constructed cheaper, stronger material began replacing iron from more durable and cheaper materials. as the material of choice for bridge designers.

Your Task  Looking at Bridge Materials List six materials that bridges can be built from.

Creative Challenge  Draw some of the materials on a separate piece of paper.

12 The Four Bridge Designs 1

Every bridge is unique because no two bridges are built under exactly the same The Arch Bridge circumstances. They are all built in different As its name suggests, an arch bridge is places, in different times, using different identified by its arch shape. Built over materials, spanning different distances and short distances, these types of bridges they all serve different purposes. are constantly under compression and Engineers have developed bridges that fall so are constructed from materials into one of four basic categories: strong enough to withstand pressure. • The beam bridge • The arch bridge • The suspension bridge • The cable-stayed bridge Each of these bridge types can be described in more detail according to their type of span (e.g. continuous, cantilever, simple), the material that they are predominately made from (e.g. stone, concrete, steel) and where their road deck appears (e.g. The Suspension Bridge deck, half-through, through). Sometimes Suspension bridges bridges are a combination of bridge are strong and designs (hybrids) and cannot be identified as exclusively belonging to one particular flexible and are category. designed to be built over long distances. They have their The Beam Bridge disadvantages The beam though. Read on. bridge (also known as a girder) is the oldest, The Cable-Stayed Bridge cheapest and Cable-stayed bridges are recognisable most common by their unique A, Y or diamond shaped of the bridge towers. The towers are always in designs. It is also the most simple. A compression. Cable-stayed bridges beam bridge is a horizontal platform are cheaper and easier to build than placed over two end piers. The first suspension bridges. beam bridges were just logs placed over streams. Early beam bridges were built from wood, but today they are typically made from reinforced concrete and steel that is needed to carry the weight of heavy trucks and trains.

13 The Four Bridge Designs 2

Answer these Questions

1. In what order do you think the four bridges were invented? Explain your answer.

______

2. If you only had a tree trunk to use, which bridge design would you build?

______

3. Which bridge do you think is better suited to be built over longer distances? Explain why.

______

4. Describe what an arch bridge looks like. ______

5. Which bridge do you think is the most popular bridge in the world? Explain your answer. ______

6. What are some materials bridges can be made from? ______

______

Extra  Test Your Skills Act It Out Use your body (no talking) to Website Challenge demonstrate the four different Log onto this website: types of bridges – arch, beam, www.pbs.org/wgbh/nova/bridge/ suspension and cable-stayed. and test your engineering skills. Perform by yourself (or in a small group) in front of the class. You may Match the right bridge to the right use a limited number of props. location.

14 Beam Bridge 1

How strong is the Beam Bridge? Strengthening the Beam Bridge To make beam bridges as strong as possible a When a car drives over a beam bridge, it supporting lattice construction called a truss causes the two edges of the beam to can be added to the design, although this will slightly push together. This is compression. only help to a point. As the beam distance increases, so must the size of the truss until In the meantime, the lower edges of the the bridge will not be able to support the bridge become stretched. This is tension. extra weight of the traffic and the truss itself. The beam bridge works by moving the weight For this reason, a beam bridge span must of the load vertically through the piers be less than around 75 metres. If engineers and to the ground. A beam bridge must need the bridge to cover a distance greater be built strong enough to resist twisting than this, they must use a technique called and crumpling under the weight that it is a continuous span. This is where a series of beam bridges are more or less joined together. carrying. The further apart the piers are This works successfully and in fact, the longest built, the weaker the beam becomes. This is bridge in the world is a continuous span beam an inherent weakness of a beam bridge. bridge; the Lake Pontchartrain Causeway in Compression Louisiana (38.4 km).

To increase the span size of beam bridges, a cantilever can also be used. The simplest Pier Pier way to understand the cantilever is to think Tension of it as three separate spans joined together. supports in supports in Two spans are anchored and built from compression compression the shore towards each other – like diving platforms. These spans are joined together by a third span. Cantilever bridges are often Your Task Test It! supported (but not always) by trusses and the best known example of this design is Scotland’s Forth Bridge. Apart from a greater Create a beam bridge by supporting span capacity, cantilevers are useful when the each end with a stack of books. Press terrain is difficult to build on, because they down on the centre of the bridge. need little supporting structures (known as What happens? Keep adding weight falsework), during their construction. to the middle of the beam. What eventually happens? Explain why.

Make a List  The Good and The Bad Example of a cantilever in the a cantilever of Example Reread the information about Beam

Bridges. List the ADVANTAGES and commons Wikimedia ForthBridgeEdinburgh. DISADVANTAGES of these types of bridges on the back of this sheet.

15 Beam Bridge 2

comprehension  Read page 16 and answer the questions below. 1. How do engineers make beam bridges as strong as possible? ______

______

2. Explain how beam bridges work. ______

______

3. Beam bridges are more suited to shorter distances, but how can they be used for longer distances? ______

4. How can engineers safely increase the span size of a beam bridge?______

______

______Where to Build Beam Bridges Given what you know about beam bridges, where do you think they should be built? Draw pictures to illustrate the types of terrain and places where beam bridges should be built.

Create a Venn Diagram  Cantilever and Beam Bridge On a separate piece of paper, complete a Venn diagram which lists the similarities and differences between a cantilever and a beam bridge design.

16 The Arch Bridge 1

Arch bridges are identified by a semicircular arch with supports (known as abutments) at Arch diagram each end. There are three basic variations to Arrows suggest forces acting on the structure the way the arch appears. In a deck-arch, the road sits on top of the arch. These were very common from the times of Ancient Rome and D are still popular today. In the half-through arch, the road is built through the middle of the arch. The third variation is the through-arch (or B tied arch) bridge and has the road suspended A  C C  A from the arch. The through-arch design has the advantage of allowing boats to travel unheeded underneath. The Sydney Harbour A - Abutments C - Footers Bridge, the Fort Pitt Bridge (USA) and the Tyne B - Voussoirs D - Key Stone Bridge (UK) are examples of this type of bridge.

Sydney Harbour Fort Pitt Bridge Tyne Bridge Bridge

Your Task  Understanding the different types of arches Find an example of a deck-arch and a half-through arch bridge. Draw and paste a picture of these types of arch bridges in the space below. Fort Pitt Bridge (Pittsburgh) Tyne Bridge (Newcastle) Sydney Harbour Bridge (Sydney)

17 The Arch Bridge 2

Arch bridges are most often used for shorter distances (60 to 240 metres), particularly where a centre pier is difficult to build, such as over deep valleys or freeways. It is the shape of the arch that gives the bridge its strength. Arch bridges work because the weight from the deck is distributed outward along the curve to the abutments at the bridge ends. This gives them a natural strength that allows them to be built without the need for additional supports or cables.

Group Activity  Test It!  Research Demonstrate how arch bridges work. Cut out a 30 to 50 cm piece of firm cardboard. Make an Stone Arch Bridge arch shape from the cardboard and then gently place your hand or a weight on the arch centre. Building a Roman arch 1. What do you notice happens? bridge requires a certain degree of skill and patience ______because during construction, ______the arch remains unstable until the last brick, called a keystone, is put in place.

• Do some research then explain how to build a stone arch bridge. Now place an even stack of books either end of the • Draw diagrams cardboard arch. Place your to support your hand (or the weight) on the explanation and clearly centre of the arch again. show the bridge building process.

2. What do you notice this time? ______3. How does the stack of books affect the strength of the arch? ______

Paying toll on a stone arch bridge, Wikimedia commons

18 The Arch Bridge 3 Arch bridges are always Sydney is an example of a under compression and modern arch bridge built so most modern arch from concrete. The Sydney bridges are made of steel Harbour Bridge is built or reinforced, prestressed from steel. The William concrete. Ancient Jolly Bridge in Brisbane is Roman engineers used made from a steel frame stone to build their arch with a concrete veneer. bridges. The Iron Bridge The oldest and longest on the River Severn at known one-arch stone Coalbrookdale, England Anji Bridge China, Wikimedia commons bridge in the world is the built in 1779 is made from cast iron. The Anji Bridge in China’s Hebei Province, built Gladesville Bridge on the Parramatta River in 1400 years ago in 605.

Comprehension  Answer the questions below. 1. How do arch bridges work? ______2. If you were to build an arch bridge today what materials might you use? ______3. Why do you think that so many people visit the Pont du Gard Bridge each year? ______4. Why do you think that the Anji bridge in China has lasted so long? ______5. View the the next largest arch bridge ever built by logging on to this site: http:// hawtaction.com/2008/02/dubais-insane-new-bridge.html. On the back of this sheet, write a paragraph about what you see and write down two questions that you want to ask about the bridge.

The arch bridge is one of the oldest and most successful designs. The most famous arch bridge in the world would have to be the World Heritage listed Pont du Gard aqueduct near Nîmes in France. It was built around 2000 years ago by the Romans to carry water across the Gardon River Valley. Incredibly, this three level 50 metre high stone bridge was constructed without mortar and held together by the force of its own weight. Pont du Gard is visited by over a million tourists every year. Pont Du Gard Aqueduct, Wikimedia commons

Research  Find out more about bridge aqueducts. What are they? Are they still being built today?

19 The Suspension Bridge 1

Like the name suggests, the deck of a suspension bridge is suspended from cables hanging from towers and secured at each end by anchorages. This allows the span to cover much greater distances than either a beam or arch bridge can. For this reason, you will see suspension bridges built over greater distances, particularly where central supports are too difficult or not practicable to build. Some of the world’s most famous, longest and spectacular bridges are suspension Photograph of Golden Gate Bridge by Rich designs. The Golden Gate Bridge and New Niewiroski Jr., Wikimedia Commons York’s Brooklyn Bridge are two examples that you may know about. The world’s longest single span bridge is the Akashi Building Suspension Bridges Kaiyo Bridge in Japan.

The suspension bridge, however, did cables under compression not start out in such a memorable way. It began as a simple rope that people used to swing over a chasm or river. Later, a deck made from wooden planks was added by securing it to suspended anchorages ropes. Suspension footbridges are quite under towers under Deck common today and you may have even tension compression walked on one yourself. To build a suspension bridge, engineers The father of the modern-day suspension bridge was American inventor James begin with two strong towers. To keep the Finley. Finley built his famous Jacob’s bridge balanced, steel cables are hung Creek Bridge in 1801 to connect the between them and secured to the ground towns of Uniontown and Greensburg in solid concrete blocks, called anchorages. in Pennsylvania. His innovative design The anchorages are positioned at each secured the bridge with wrought end of the bridge and absorb the tension iron chains fastened like anchors in the main cables. Unlike arch and beam into the ground at each end. Further bridges, where the road rests on piers and advancements came when iron chains abutments, suspension bridges hang the were replaced with steel wire woven road from suspender cables (called hanger ropes. By using these stronger and more cables) attached to the main cables. flexible cables, stronger and longer Suspension bridges work by transferring bridges could be built. weight to the towers and then to the ground.

20 The Suspension Bridge 2

Although suspension bridges are very strong and flexible, they are also Comprehension  susceptible to wind currents. Engineers have to take extra precautions to stabilise Answer the questions below. these type of bridges. The use of trusses 1. How do suspension bridges work? make the decks sturdy and stop them from excessive swinging and swaying. ______This is what happened to the Tacoma ______Narrows Bridge just before it collapsed. To view this collapse go to 2. How would you help prevent www.youtube.com. suspension bridges from excessive Trusses are an effective way of swinging and swaying? strengthening bridges. Trusses are stiff framed triangular configurations. ______3. Where are suspension bridges most likely to be built? ______

 Suspension bridges remain at the pinnacle Research Trusses of engineer achievements. They are a Do some research and answer the testament to humans’ ability to build questions below. structures over almost impossible terrains 1. What are trusses made from? and distances. The future of bridge design 2. Of these materials, what do you think remains full of exciting possibilities, with is most commonly used on bridges suspension bridges at the forefront of today and why? designs.

Make a List  List all the advantages and disadvantages of suspension bridges in the table below.

Advantages Disadvantages

21 For the Teacher Lessons in Suspension

Classroom Activity GrouP Activity

Make a Class Make a Suspension Bridge This exercise will demonstrate the value Suspension Bridge and need for anchorages in suspension designed bridges. • You will need sixteen students to • For this activity, you will need make the bridge, plus the remainder books of fairly equal size and of the class to act as vehicles. weight and two pieces of string. • Four class members should hold a piece of rope parallel, about a metre • Stand two books upright and or so apart and about a metre from about 30 cm apart. the end. (The rope will act as the • Connect the books by tying a cables and the students holding the piece of string around the top rope will be the towers.) portion of the books. • Four students should sit on the floor, holding the very end of each rope. • Now put pressure on the cable by (This will be the anchorage.) resting your finger at the centre of the rope construction. • Ten students should kneel on the floor and gently grab the rope to act • Push down until the books as the hanger cables. (The ground is collapse. Note the degree of the deck.) resistance.

• The remainder of the students can • Rebuild the design, but this time, walk up and down the bridge as add anchorages by placing a vehicles. stack of books at each end next to the upright books. • To explore how suspension bridges work, remove the anchorages and • Tie the string around the upright ask the students if the bridge still books and secure it to the feels as strong. anchorages. Push down again until the books collapse.

What do you notice this time?

22 The Cable-Stayed Bridge 1 A cable-stayed bridge can be thought of as the suspension bridge’s cousin. They both have their decks suspended from tall towers, making them a suspense structure. From a distance, the two bridges look similar, but there are some important differences. The suspension bridge has its deck hung from cables that are strung from tower to tower, whereas the cable-stayed road deck is suspended directly from cables hung from the tower itself. The cable-stayed bridge works by transferring the weight to the towers and then to the ground. The towers themselves are always in compression because the deck is pulled towards it. Engineers need to take precautions to ensure the deck doesn’t The Rio-Antirrio bridge, Wikimedia Commons buckle. Most suspension bridges are typically built with two towers, but cable-stayed bridges can be built using one, two or more towers. The world’s tallest road bridge, the Viaduct de Millau, is built using seven towers. A Popular Design

Cable-stayed bridges have rapidly found acceptance and are now built all around the world. In Australia, the ANZAC Bridge in Sydney and Melbourne’s Westgate Bridge are well known cable-stayed bridges. The four towered 2.9 kilometre Rio-Antirio Bridge in Greece is considered The cable-stayed bridge is considered a 20th a great engineering achievement. Cable- century bridge, but its origin can be traced stayed bridges are ideally, medium back to a famous book published in 1615 spanned bridges, but engineers are now called the Machinae Novae where sketches designing long spanned cable-stays as of both suspension and cable-stayed bridges well. Up until 2009, the world’s longest are clearly recognisable. Cable-stayed designs cable-stayed bridge was the Tatara began showing up in the early 1800s but Bridge in Japan, with a record span of quickly faded after a number of collapses. The 890 metres. It was eclipsed by 200 metres design did not really become popular until when China’s Sutong Bridge opened in the construction of the Stromsund Bridge in 2009. Sweden in 1955. Engineers discovered that cable-stayed bridges were well-balanced, Cable-stayed bridges are an attractive and offered a more rigid design and didn’t require increasingly popular design. They have an the large ground anchorages that suspension aesthetic appeal and as they continue to bridges needed. push engineering boundaries, we will see a lot more of them around our cities and towns in the future.

23 The Cable-Stayed Bridge 2

Read about Cable-Stayed Bridges on page 24 and answer the questions below. Your Task 

Comprehension  You may want to work in pairs.

1. What is the main similarity between a suspension and a cable-stayed bridge? ______2. What is the main difference between a Demonstrating a suspension and a cable-stayed bridge? Cable-Stayed Bridge ______This exercise will demonstrate how a cable-stayed bridge ______works. ______• Tie a piece of rope at your elbows and position the rope over your head. Your elbows 3. List three famous cable-stayed bridges. should be propped up like cable- • ______stays. • ______• Now stretch your arms out and • ______tie another rope from wrist to wrist and run the rope over 4. What is the future of cable-stayed bridges? your head again. Where do you ______feel the pressure? ______• Your arms will now be horizontal and act as the road ______to carry the traffic (the load is ______transferred from your arms to your head).

Make a List  List all the advantages and disadvantages of cable-stayed bridges in the table below. Advantages Disadvantages

24 How Bridges are Made Safe 1

Bridges have to be built to work properly. No- Today, engineers use special computer designed one is going to use bridges that are unstable or software to help them build safe structures. fall down all the time. To build a bridge that will The conditions of the area (e.g. the wind, carry cars, trucks and trains, requires technical soil or water) are carefully analysed and the expertise and know how. Civil engineers are proposed bridge design is tested for strength people who study for many years to understand using computer simulations. Engineers also the laws of physics and material science that use models and devices like wind-tunnels to apply to bridge construction. They can design test bridge strength. For a number of decades bridges and make them as safe as possible by now, engineers have been building bridges taking into account the many things that can using a fail-safe design feature referred to as go wrong. Bridge designers can learn from the redundancy. The engineer designs the bridge mistakes of the past, to develop better, safer to be so strong that if one element of the bridge designs for the future. fails, other elements can cover the weakness until it has been properly repaired.

Inspecting Bridges

Once a bridge is built, it is continually examined by qualified bridge inspectors and structural and corrosion engineers. These experts are certified by the government and are required to keep updating their qualifications so that they can apply the latest technology and understandings to bridge inspections. Depending on the type and age of a bridge, it is usually inspected every one or two years. Bridge inspection involves carefully looking all over a bridge. Inspectors will walk over a bridge as well as under it. They have both high-tech and low-tech tools. Using a checklist, inspectors will look for things such as cracks, rust, general wear and tear and the condition of the bolts and rivets. Inspectors uses a ‘tap, look and listen’ technique that involves tapping a hammer against the metal and concrete to listen out for a hollow sound. A hollow sound indicates a crack or weakness. If inspectors suspect that something is wrong, they may have to use sophisticated equipment such as an ultrasound or X-ray to get a more accurate reading. After inspections, the inspectors write up reports that are compared with previous reports. Inspectors are looking for any signs of change in the bridge, big or small, that shows flaws or potential problems that need to be attended to. If a bridge is deemed to be unsafe by inspectors, it is referred to as either ‘functionally obsolete’ or ‘structurally deficient’. A structurally deficient bridge means that the bridge can no longer carry the load it was originally designed for. Officials have the power to only let lighter vehicles use a structurally deficient bridge to reduce the risk of any further damage to the bridge or risk to the users. For example, as part of their regular maintenance, the inspectors of the Auckland Harbour Bridge in New Zealand discovered evidence of material fatigue. They have since restricted usage of the bridge. However, if a bridge is deemed functionally obsolete, inspectors believe that the bridge has a significant design problem and it is torn down and replaced.

25 How Bridges are Made Safe 2

Answer these Questions Read page 26 and answer the questions below. 1. Explain how redundancy could save people’s lives. ______2. What is the advantage of being able to test bridge designs in wind-tunnels and on the computer before they are built? ______3. Why aren’t bridges normally inspected more often than once every one or two years? ______4. Do you think that it is a good idea to use trained and qualified bridge inspectors to examine bridges for safety? Explain your answer. ______5. Which bridge do you think is safer to cross - one that is declared ‘functionally obsolete’ or one that is declared ‘structurally deficient’? ______

Extra  Make a List Role Play Bridge Safety Inspection Time Act out the role of a Bridge inspectors have a checklist of things that they bridge inspector as he/ need to look at. Below, list some important items that you she walks up and down a think a bridge inspector might check in a typical routine bridge, tapping, looking inspection. and listening for flaws •______and weaknesses. Set it •______to music. •______•______

26 How Bridges are Made Safe 3

Task 1  What Would You Do?

Fact Imagine that you are the mayor of Bright Light If bridges are well designed City and that you have just been given a report and regularly maintained, that says, they can last a very long time. “A recent analysis of bridges in our city, shows Many of the Roman bridges that nearly 20% of Bright Light City bridges are built 2000 years ago are not structurally deficient and are showing signs of only still standing, but are in deterioration.” perfect working order and are • In pairs discuss what you would do next. still being used today.

Task 2 What Shape is the Strongest?

Fact To test their strength against other shapes, Triangles are • Make a triangle, square and pentagonal shape from the strongest cardboard strips held together with pins. geometrical • Gauge the strength of each shape by pushing the sides shapes and are together. commonly used in • Record which shape offers the most resistance and why. bridge design and ______construction. ______

Task 3  Test the Strength of aTube

Fact In pairs discuss what other everyday items As well as triangles, tubes are constructed from tube shapes. are also remarkably strong. To test the strength of a tube, The Chinese built bridges • Take two sheets of newspaper and make from bamboo shoots a bridge that will successfully hold up a because their shape made book. the bridges strong. (The secret to this challenge is to roll the paper into a tube shape.)

27 Geronimo! 1

Why Do Bridges Maintenance Fall Down? At the core of many bridge failures is the lack of proper care Despite all the checks and careful planning, and attention to maintenance. bridges still fall down. For a bridge to Many bridges have needlessly remain standing, it needs to withstand fallen down because not enough due diligence was taken to look a combination of forces and pressures after them. In August 2007 the from things like: bending, tension, torsion, Minnesota Bridge collapsed vibration, contraction, corrosion, erosion, into the Mississippi River during expansion, fatigue, friction, rain, water peak hour, killing 13 people. flow, salt, temperature changes and wind You can see this collapse at turbulences. Even though a bridge may have www.youtube.com. It was later even been designed to withstand these revealed that problems with the sorts of pressures, it can still fall down. Minnesota Bridge had surfaced How does this happen? Let’s look at the ten years earlier when inspectors main reasons why. identified fatigue cracks and corrosion around the steel joints.

The Minnesota Bridge fell down because the load that it continually carried was too heavy and the connections between the bridge’s structural elements were too weak. Sometimes inspectors make mistakes or do not check bridges often enough to pick up a weakness in time. These terrible accidents serve as a constant reminder of the need for thorough and regular inspections.

Minnesota Bridge collapse 2007, Wikimedia Commons Miscalculation Bridges can fall down because the engineer misjudged or made a miscalculation that created a weakness in the design. Melbourne’s Westgate Bridge collapse is an example of what can go wrong when proper construction decisions are not made. However, it may not always be the engineer’s fault. The Tacoma Narrows Bridge collapse in 1940 was a result of the phenomenon called resonance, which was not properly understood Tacoma Narrows Bridge collapse 1940, Wikimedia Commons until later.

28 Geronimo! 2

Bridges Fall Down On Purpose Excessive Force Some bridges are too old or no longer suitable and are pulled down to make way for new and Extreme naturally occurring events like better designs. Sometimes bridges earthquakes, cyclonic winds, monsoons, heat, are sabotaged, when they become floods or freezing temperatures can damage military targets during conflicts, to bridges. A section of the San Francisco Bay stop troop or supply movement. Bridge double-decker span, collapsed during Throughout history, bridges have the Loma Prieta earthquake on October 17th, been attacked and fought over. Armies 1989. An even worse accident occurred in New in Ancient Rome and armies today, Zealand in 1953 when a steam locomotive have targeted bridges. In 2003 the US fell into the Whangaehu River after the military deliberately bombed bridges bridge became damaged and weakened from throughout Baghdad during the Iraq invasion. The Israeli air force did the lahar spewing from nearby Mount Ruapehu. same when they invaded Lebanon Engineers have not yet been able to build in 2006. They bombed bridges bridges to withstand every natural force that surrounding Beirut in an attempt to the Earth experiences. seal off the city from the enemy.

Bridge Misuse and Accidents Bridges are designed for a specific purpose and can come under serious pressure if they are not used in the way that they were intended to be used. Heavy trucks that cross bridges that are designed to carry only light cars, can cause structural damage. Accidents could cause weaknesses to bridges. This was the case when a barge collided with one of the piers on the I-40 Bridge in Okalahoma in 2002. This caused part of the span to collapse on top of the barge. A dozen cars and trucks plunged into the Arkansas River, tragically taking the lives of four people. The Golden Gate Bridge in San Francisco is painted ‘international orange’ so that it is more visible to shipping during fogs. Australia’s worst bridge accident occurred in 1977, when a crowded commuter train travelling into Sydney derailed at Granville Station. It crashed into the supporting pillars of the Bold Street Bridge. The four lane overbridge then collapsed onto the train, killing 83 passengers and injuring 213.

29 Geronimo! 3

Your Task Interview an Eyewitness

Imagine that you are a TV or a newspaper reporter interviewing an eyewitness to a bridge collapse. Create a list of interesting questions. Details of Bridge Collapse Time______Name of Bridge______City______Name of Eyewitness______

Question 1______qus on p37-38 Question 2______

Question 3______

Question 4______

Extra  Questions Read pages 29 and 30 and answer the questions below. Cross in Safety 1. What naturally occurring events can damage bridges? In small groups, come up ______with a way to get people across a dangerous, 2. List four other reasons why bridges weaken or are raging river. Explain what destroyed. bridge design you have ______chosen and why. You may ______want to draw and label ______your final design. ______

30 Famous Bridge Mishaps and Collapses 1

Tacoma Narrows Bridge Dangerous and Disruptive (USA) Tacoma Narrows Bridge collapse is one of the world’s most When a bridge falls down, it’s usually news famous bridge disasters, most worthy. Apart from being spectacular to notably because it was actually witness and dangerous to the people on filmed! In fact, you can see this the bridge at the time, it can be extremely amazing footage on You Tube disruptive to people’s lives. In recent times, (www.youtube.com). So, what happened? The Tacoma Narrows the most famous bridge mishaps have been Bridge was built to link the city the ones in which video footage of them of Tacoma with Gig Harbor in collapsing has been available. Although any Washington State. Even before bridge collapsing is a very serious incident, it the bridge was finished, engineers can serve a useful purpose for engineers to noticed that when a breeze learn from mistakes in future construction blew, the road bridge rolled up and maintenance. and down. Even after making modifications, they were unable to fix the problem. The local residents nicknamed the bridge ‘Galloping Gertie’. Normally, you would expect that this would scare people away, but in fact, the opposite was true. The centre road span rolled and twisted and thousands of people flocked to experience the bridge ride of a lifetime. Although the authorities remained confident that the bridge was safe, on November 7th, 1940, just four months after opening, it collapsed. Before the bridge collapsed, the police became concerned about its increasing violent and constant motions and closed the bridge. An hour after it was closed, the bridge began to fall apart and then plunged into the Puget Sound waters below, where Your Task Describe the Last Moments it remains today. In 1950, a new Tacoma Narrows Bridge was built in its place. The Have a look at the breathtaking footage of the local residents named this Tacoma Narrows Bridge collapse bridge ‘Sturdy Gertie’. The  Tacoma Narrows Bridge www.youtube.com/watch?v=HxTZ446tbzE collapse taught engineers Imagine that you are the last person on the bridge. an invaluable lesson about bridge aerodynamics, that Describe this moment as you scramble to safety was not properly understood before the bridge finally collapses. before.

31 Famous Bridge Mishaps and Collapses 2

Westgate Bridge (Australia)

The Westgate Bridge provides a link over the banks of the Yarra River Natural bridge collapse between Melbourne’s sprawling western suburbs and downtown Melbourne. It stretches over two and a half kilometres, making it the third longest bridge in Australia. Completed in 1978 at a cost of $202 million, it now carries 190 0000 cars a day. As proud as Victorians are of this magnificent bridge, it also has a sad place in history; as the site of one of Australia's worst industrial accidents. Two years into construction, at

precisely 11.50 am on 15th October London Bridge on the Great Ocean Road in Victoria 1970, a span between piers ten Wikimedia Commons and eleven of the West Gate Bridge collapsed. Two thousand tonnes of In 1990, a natural arch bridge collapsed. steel and concrete crashed 50 metres Known as the London Bridge, it could be into the Yarra below, taking with it seen along the shoreline on the Great the lives of 35 workers. Soon after, Ocean Road in Victoria. At the time, two the government announced a Royal tourists were trapped on the second Commission into the accident. After eight months of investigation, the natural arch that remained. A helicopter Commission concluded that the cause was called to air-lift them to safety. Use of the accident was a structural failure, the website below to help explain why the brought on by the removal of bolts in bridge collapsed. Present an oral report to an attempt to line up sections of the a Safety Board recommending what to do bridge. It was an accident that could with the bridge next to make it safe. well have been avoided but the lessons learnt from this disaster are taught to www.ga.gov.au/urban/factsheets/shore_ engineers today. The accident delayed safety_arches.jsp the construction of the bridge by four years. A memorial has been built at the bridge to remember the workers who were injured and lost their lives.

32 Famous Bridge Mishaps and Collapses 3 Millennium Bridge (England)

The Millennium Bridge in London was opened on the 10th of June 2000. In a blaze of publicity, 160 000 people walked across the bridge on the opening weekend. It was the first new Thames crossing in more than 100 years and linked the City of London at St Paul's Cathedral with the new Tate Gallery at Bankside. At a cost of £18.2 million (approximately A$42 million), the 320 metre long suspension footbridge bridge design was considered an engineering innovation. It used a "lateral suspension" which meant that it could be built without the tall supporting columns that suspension bridges usually need. However, the bridge swayed badly and users complained of feeling sea-sick and had to steady themselves against the rails. The bridge was nicknamed the ‘Wobbly Bridge’ and just three days later it closed – causing much embarrassment to the engineers and City of London officials. Fortunately, no-one was hurt and most importantly, after an investigation, the engineers discovered the reason for the swaying. With 2000 people on the bridge at the same time, the small vibrations that each step generated, encouraged people to walk in step with each other. This caused the bridge to sway. It took another 18 months and £5 million (approximately A$12 million) worth of repairs and modifications before the Millennium Bridge was declared safe again and could re-open. Footbridges built today are safer, thanks to the lessons learnt from the ‘Wobbly Bridge’.

Your Task Select a Bridge Collapse or Mishap of your Choice There have been many, well documented bridge collapses. Select one to investigate further. Find out the reasons for the collapse (there are usually many contributing factors), the damage it caused and discuss the investigation into the collapse. You may wish to include diagrams and pictures. A list of bridge collapses can be found on the wikipedia site at http://en.wikipedia.org/wiki/Listofbridgedisasters Bridge: ______Year of collapse/mishap______City______

Mishap and damaged caused: ______

Reasons for mishap:______Include a diagram or picture with your report.

33 Opening a Bridge

Opening of the Your Task Sydney HArbour Bridge What if you were put in charge of organising a bridge opening? On March 19th, 1932, nearly half of Sydney’s 1.2 million people attended There are many things to the opening of the Harbour Bridge. consider that require careful and The opening of a bridge is an exciting event. It attracts thousands of sight- thoughtful planning. seers and well-wishers and is often Write up your proposal of ideas, covered widely by the media. Openings are in the papers the next day and on detailing what will happen and the news the same night. when in the planner below.

Planner List the people who you will invite. What activities will you have for them to do to join in the festivities? ______Who will officially cut the ribbon to open Design a special commemorative the bridge? token for this bridge opening. Choose from a coin, medal or postage stamp. ______What media will you invite to be there to cover the event? ______How many people are you expecting? ______

34 It’s Opening Day You are a reporter for the opening day of a selected bridge. Write a recount of the day’s ceremonies and present your work in the form of a newspaper article. You may want to include a headline banner to make it look as authentic as possible. As a reporter, you will need to include such details as who, what, when and why. Include quotations from people at the opening and factual details about the bridge itself.

______

35 Bridges in Film 1

Bridges in Bridge on the River Kwai (Movie) Popular culture This film is based on a true story. During WWII, the Japanese captured many Americans, British and Australians and forced them to build a railway bridge over the river Kwai in Bridges often appear the Burma-Thailand jungle. The railway bridge was to help in popular culture. They the Japanese defeat the British, Americans and Australians. Essentially then, the prisoners were being forced to help their are used as strong enemy win the war against their own countries. At first the symbols and metaphors. prisoners did their best to sabotage the building of the bridge There have been movies, by working slowly and purposely making mistakes. However, documentaries, songs, the British officer in charge, Colonel Nicholson, reached nursery rhymes, stories an agreement with the Japanese commander to build the and plays based around best bridge they could. The film climaxes when the British, bridge themes. Australian and American troops blow the bridge up, killing their own men. Bridge on the River Kwai was released in 1957 and won 7 Academy Awards, including Best Picture.

Write a Diary Entry Choose fom the two points of view below 1. Put yourself in the position of a Japanese solider. Write a diary entry detailing a typical day for you supervising the prisoners of war. Remember that your country expects you to force the prisoners to build the bridge. 2. Write a diary entry from an Australian prisoner’s point of view. Think about the conditions in which you have to work (long hours, humidity, poor diet). Think about the friends that you have lost, your family and friends at home and the reasons for and against sabotaging the building of the bridge.

______

36 Bridges in Film 2

Write A plot Write a plot outline for a movie based on a bridge theme. Use the headings below to help you with your outline.

Title: ______Main character: ______Villain: ______Other characters: ______Setting: ______

Beginning: ______

Middle (complication and problem occurs): ______

Ending (resolution occurs – usually problem is solved): ______

Significance of bridge in movie: ______

37 Bridges in Song

Bridges are often used in songs because they are powerful symbols. There are many artists, who, over time, have used bridge themes in song. Bridge Over Troubled Water is a popular tune by the American singing duo Simon and Garfunkel. It was released in 1970 and became a number one hit song, winning 5 Grammy Awards, including Song Of The Year. Simon and Garfunkel also released another bridge title song called 59th Street Bridge Song. The Red Hot Chili Peppers had a hit with their most successful song, Under a Bridge.

Bridge Over Questions Troubled Water Read the first two verses of Bridge Over Troubled Water. When you’re weary 1. What does the bridge represent in this song? Feeling small When tears are in your ______eyes ______I will dry them all ______

I’m on your side 2. List other popular tunes that have a bridge theme or title here. When times get rough And friends just can’t be ______found ______Like a bridge over Photocopy or write out the lyrics of one of the popular troubled water tunes that you have mentioned above. I will lay me down Like a bridge over Look at the lyrics that you have written out again. troubled water 3. What does the bridge represent in the lyrics? I will lay me down ______

4. On the back of this sheet, write a two or three verse song about a bridge of your choice (e.g. Sydney Harbour Bridge). You might want to use an original song with your own lyrics or take an existing song and re-write it with your own lyrics. Try performing it as a rap tune to the class.

38 Bridges in Tales and Rhymes

Your Task  Three Billy Goats Gruff (Fairy Tale)

Three Billy Goats Gruff is 1. What does the bridge represent for the Billy Goats? a traditional fairy tale. ______It’s about three goats of different stature who need ______to cross a bridge in order to ______access greener pastures on the other side. However, they 2. What does the bridge represent for the Troll? are stopped by a troll who ______lives under the bridge and ______threatens to eat them. Read the fairy tale at www.pitt. ______edu/~dash/type0122e.html Activity: Act out Three Billy Goats Gruff. Re-write the and answer the questions. setting and plot to put a more modern slant on it.

Your Task  London Bridge is Falling Down London Bridge is Falling Down is a catchy nursery rhyme tune. It describes some of the problems experienced during early attempts at building a bridge on the Thames River in London. Read through the lyrics. Write down what materials were used to build London bridge, what problems the builders experienced with each material and which material was used to finally construct the bridge.

London Bridge is Falling Down Material:______London Bridge is falling down, falling down, falling down. London Bridge is falling down, my fair lady. Problem:______How will we build it up, build it up, build it up? How will we build it up, my fair lady? ______

Build it up with silver and Build it up with wood and gold, silver and gold, silver clay, wood and clay, wood Material:______and gold. and clay. Build it up with silver and Build it up with wood and Problem:______gold, my fair lady. clay, my fair lady. Gold and silver I have Wood and clay will wash none, I have none, I have away, wash away, wash ______none. away. Gold and silver I have Wood and clay will wash none, my fair lady. away, my fair lady. Material:______

Build it up with needles Build it up with stone so Problem:______and pins, needles and strong, stone so strong, pins, needles and pins. stone so strong. ______Build it up with needles Build it up with stone so and pins, my fair lady. strong, my fair lady. Pins and needles bend Stone so strong will last and break, bend and so long, last so long, last Material used to construct bridge: break, bend and break. so long. Pins and needles bend Stone so strong will last so and break, my fair lady. long, my fair lady. ______

39 Bridge Activities Straw Bridge Challenge

In groups of three or four construct a straw bridge that will be tested for strength using coins or weights placed on the midpoint of the bridge.

Guidelines Materials 1. The two ends of the span 4. The straws may be • 20 drinking straws must be made from two shortened, bent or cut. You • two stacks of wood or books • coins or weights stacks of wood or books do not have to use all of • masking tape and be placed 25cm apart. them. 2. The only materials that 5. When finished, place coins you may use for the bridge or weights on the bridge The engineers on itself are 20 drinking straws one at a time until the our team and one metre of masking beam collapses. • ______tape. 6. Complete a drawing of • ______3. No part of the bridge may your group design on the touch anything between back of this sheet. • ______the two ends of the span. 7. Complete the post • ______construction review below.

Post Construction Review

1. What type of bridge does your 5. What worked well with your design design look most like? and what didn’t?  Beam ______ Suspension ______ Cable-stayed  Arch 6. What do you think makes a bridge strong or weak? (Look carefully to 2. Total height of the bridge locate where the bridge gave way ______first.)

3. The length of the bridge ______

______

4. The weight it supported before it 7. How well did your group co-operate? collapsed was ______

______

40 Bridge Activities Lego Bridge Challenge

In groups of three or four design and construct a bridge that will successfully allow a golf ball to safely cross over it. Guidelines Materials • The bridge will need to cross • lego pieces a span of at least 30 cm. • golf ball • pier • The golf ball must roll from one side to the other unheeded. The ball cannot be The engineers on pushed across. our team • The bridge should be • ______mounted on piers set at least • ______five cm above the surface of the desks. • ______• The only materials that you • ______may use for the bridge are Lego pieces (or similar plastic bricks) provided.

Post Construction Review

3. The length of the bridge ______

______

4. The weight it supported before it 7. How well did your group co-operate? collapsed was ______

______

41 Bridge Activities Extra Classroom Ideas

1 Bridging Countries

Engineers are now capable of building bridges further and higher than ever before. Make a case for building a bridge between two extended land masses such as: •Mainland Australia and Tasmania •Australia and New Zealand •Africa and Europe •USA and Cuba •South Korea and Japan •Sicily and Italy Look at a world atlas to see where else you might one day want to construct a bridge. Examine the technical, political, social and economic challenges that such a project would face. Think about what the advantages and disadvantages of building such a bridge would be.

2 Living Bridges

A living bridge is a bridge lined with buildings, such as shops and houses. The Ponte Vecchio in Florence (Italy), the Rialto Bridge in Venice (Italy) and the Pulteney Bridge in Bath (UK) are famous examples of living bridges. Although not many were ever built, the ones that have survived are now popular tourist sites. Find out more about living bridges and then design your own. Write about What purpose your living bridge has. Who you would allow to live or trade on the bridge. You may also wish to make a scaled model of your design.

3 Compare Tunnels and Bridges Tunnels and bridges may serve a similar purpose, but they are different in their design. Bridges are structures that are built over or across physical obstacles, whereas tunnels are built under, or even through them. However, they both play an important role in moving people and goods around. Complete a Venn diagram to show the similarities and differences between tunnels and bridges.

42 Bridge Activities Extra Classroom Ideas

4 Wacky Invention

Invent your very own personal fold-away bridge that can fit on top of the roof of a car. • Explain what its benefits are and the purpose of the bridge. • Draw and label your design. Extra: make a scaled model of your design.

5 Who Helps Make Bridges?

A civil engineer helps design bridges. However, there are many more people involved in making the idea of a bridge a reality. • In groups, compile a list of all the different people and organisations that you think are needed to plan and build a bridge. • Select one job that you would like to do and explain why you would like to do it. • Create a table with the following headings on a separate piece of paper: People/Organisations, Job and Job I Would Like To Do and Why.

6 Sorting Out

In pairs: • Collect as many pictures of bridges as you can. • Group the bridges into different categories and paste them on seperate pieces of paper. (Justify your decisions by observing such things as size, style, purpose, construction materials, shape and location of the bridges.)

43 Bridge Activities Extra Classroom Ideas

7 Plan a trip

• Plan a trip around the world visiting famous bridges. Which bridges would you like to visit and why? • Make an itinerary of what you would like to see and do. Write down which is the best way to see each bridge.

1 8 Write About Bridges You have been asked to write a book about bridges. What are the top 5 topics that you would like to write about? Create:

A title for your book. Design a cover. Include a chapter list. Include a blurb.

9 One Minute Speech Deliver a one minute passionate speech to the class entitled, ‘Bridges are one of humankind’s greatest inventions.’

44 Bridge Activities Extra Classroom Ideas

10 What’s in a Name? The Sydney Harbour Bridge was once popularly known as the ‘coat hanger’. The Tacoma Narrows Bridge was nicknamed ‘Galloping Gertie’ before it collapsed and was renamed ‘Sturdy Gertie’ when rebuilt. • Collect some famous bridges and icons from around the world and have some fun re- naming them using nicknames. • Use pictures to explain your choice of names.

11 Buy a Bridge In 1968, the London Bridge was bought by American Robert P. McCulloch. He had the bridge disassembled and transported to Lake Havasu City in Arizona where it was used as an attraction at an English theme park. The Montrose Bridge in Scotland was another bridge that was dismantled and then put up for sale on ebay. • If you could buy any bridge in the world, which one would it be and why? • What would you do with the bridge after you had bought it?

12 Landmark Bridges Bridges frequently become attractive landmarks in towns or regions. • Which bridges do you think are most visually appealing? Why? • Use some well known bridges to illustrate your point. • Research and report your findings.

45 Answers Tell Me About Bridges 1, page 6 Claim to Fame 2, page 11 • The Longest Bridge: Lake Pontchartrain Comprehension Causeway in Louisiana is 38.4 kilometres long 1. In the early days of bridge building, engineers and is listed in the Guinness Book of World were still learning about which materials and Records as the longest bridge in the world. designs were the best. Engineers began to get better through a ‘trial and error’ process. • The Oldest Bridge: Answers will vary as it is 2. The Romans were able to move their armies impossible to know who first laid a tree trunk quickly around to the places that they were across a stream or river. However some of the needed most. This proved to be an enormous oldest bridges recorded are: tactical advantage over their enemies. • The Richmond Bridge in Tasmania built in 1823 and still in use today. Your Task • The Frankford Avenue Bridge built in 1697 is New York - Brooklyn Bridge the oldest bridge in the United States and is San Francisco - Golden Gate Bridge still in use today. Sydney - Sydney Harbour Bridge • The Tarr Steps in the Exmoor National Park, UK, London - Tower Bridge is a prehistoric clapper bridge and dates back Bath (UK) - Pulteney Bridge to around 1000 BC. Venice (Italy) - Ponte di Rialto or The Bridge of • The Widest Bridge: The Sydney Harbour Bridge Sighs is the world’s widest long-span bridge. Stronger Bridges, page 13 • The Highest Bridge: The highest deck-to- Your Task ground bridge in the world is the recently Stone, concrete, steel, rope, wood, plastic, ice. completed Siduhe Grand Bridge in China. It measures 649.83 metres above the ground. The Four Bridge Designs 2, page 15 • The Most Expensive Bridge: Part of The San 1. Answers will vary, but the beam bridge was Francisco Oakland Bay Bridge was destroyed probably the first, followed by the suspension, after the Loma Prieta earthquake in 1989. then the arch and finally the cable-stayed Repair work has commenced and is due to be bridge. completed in 2013. It will cost an estimated 2. Answers will vary, but a beam bridge is an US $6.3 billion to repair. This makes it the most obvious answer because it is cheap, quick and expensive bridge ever built. easy to build. • The Busiest Bridge: According to their own 3. Answers will vary, but suspension bridges have website, The George Washington Bridge is the proven that they can be built over the longest busiest bridge in the world, carrying nearly distances. 100 million vehicles each year. However, if we 4. An arch bridge is constructed in the form of an consider pedestrians, the Howrah Bridge in arch. India is even busier carrying 150,000 vehicles 5. Answers will vary, but the beam bridge is and 4,000,000 pedestrians a day. possibly the most popular bridge because it is • The Longest Main Span Bridge: The longest traditionally the cheapest and easiest to build. main span bridge (point to a connection to 6. Stone, concrete, steel, rope, wood, plastic, ice. another pier) is the Akashi Kaikyo Bridge in Japan, with a span of 1, 991 metres. Beam Bridge 1, page 16 Tell Me About Bridges 2, page 7 Your Task Comprehension When pressing down on the center of the bridge, 1. Bridges improve trade links by enabling a the two edges of the beam push together, while greater number of people to trade goods and the lower edges of the bridge become stretched. services in a more efficient manner. Adding too much weight will eventually cause the 2. Bridges are built to overcome obstacles that bridge to collapse because it is unable to resist the add travel time between two places. twisting and crimpling it’s causing. The length of a 3. Bridges help reduce the costs of living by beam bridge is thus, limited by the weight of the reducing the amount of fuel and time needed beam itself and the weight that it carries. to transport goods and services.

46 Make a List meet at the top. Carefully remove the temporary Advantages bracing. The structure will remain unstable until it • Cheap to build. is completed. • Simplest design. • Can be built in minimal time. The Arch Bridge 3, page 20 • Disadvantages 1. An arch bridge works by distributing the • Limited in length to less than 75 meters. weight from the deck outward along the curve • Don’t always easily allow traffic flow under the to the abutments at the bridge end. bridge. 2. Steel or reinforced pre-stressed concrete. 3. Answers will vary. It attracts many visitors Beam Bridge 2, page 17 because of its visual impact, age and the 1. A supporting lattice construction called a truss incredible building techniques used. can be added to the design. 4. Answers will vary. The bridge has lasted 2. Beam bridges work by shifting the weight from because: it was well designed and constructed, the vehicles traveling over them through to the it has been well looked after over the years and supporting piers and to the ground. it is being used for its original purpose. 3. Engineers use a technique called ‘continuous 5. Answers will vary. span’. This is more or less a series of beam bridges joined together. Research 4. Spans on beam bridges can be made longer Aqueducts are human-made open channels used using a cantilever. to carry water. A bridge can be constructed to help carry the water over barriers such as rivers and Where to Build Beam Bridges lakes. Sometimes the bridges are built to not only Beam bridges are usually built over shorter carry water, but people as well. The Romans were distances and over terrain that is easy to build most famous for building aqueducts, although over and provides easy access to cross. Students the earlier Egyptians also used them. Water is now should also consider what the bridge will carry, e.g. mostly carried in pipes buried under the ground. people, cars, bikes and so forth. However, aqueducts are still being built and many of the Ancient Roman aqueducts are still used Create a Venn Diagram today. Aqueducts are used to not just supply water Similarities for drinking, but also for irrigating crops and to • The weight is carried vertically to the piers and help control flooding. abutments and then to the ground. • They can look similar. Differences The Suspension Bridge 2, page 22 • Beams on a cantilever bridge are anchored at Comprehension each end, meeting in the middle. However, on a 1. Suspension bridges work by transferring beam bridge, a single piece of material reaches weight to the towers and then to the ground. from one side to the other. 2. Adding trusses will help stabilise the bridge. • Cantilevers have larger span sizes. 3. Suspension bridges are usually built over • Cantilevers can also be supported by trusses. longer distances, especially in places where building central supports is too difficult or The Arch Bridge 2, page 19 not practical – such as over rivers and deep Test It! crevices. If the test is carried out correctly, students should notice that: Make a List 1. The arch will bend and quickly collapse. Advantages 2. The arch is more resistant to increased weight • They are strong and flexible. and more difficult to collapse. • Suspension bridges can be built over greater 3. The books act as abutments that prevent the distances than other bridges. ends of the arch from spreading apart. • They can be built high over valleys and waterways, allowing ships to pass unheeded. Research Disadvantages How to build a stone arch bridge: begin by • They are susceptible to wind currents and may constructing a temporary scaffold that will be able have to be closed, in strong winds. to support the weight of the stones. Sit the stones • Suspension bridges are costly to build. on each other from both sides evenly until they

47 Research 5. A structurally deficient bridge is safer because 1. Wood, cast iron, wrought iron and structural it can still be used, but not as it was originally steel. designed. A structurally obsolete bridge must 2. Today trusses are made of structural steel as be torn down. this is the strongest material. Make a List The Cable-Stayed Bridge 2, page 25 Cracks, rust, general wear and tear, conditions of Your Task bolts and rivets. Students should feel the pressure shift from their arms (the bridge) to their heads (the towers). How Bridges are Made Safe, page 28 Task 2 Comprehension The triangle will offer the most resistance because 1. They both have decks suspended from towers, of its broad base and narrow top. Triangular shapes making them a suspension structure. are commonly used to help make bridges stronger. 2. The decks on a suspension bridge hang from the cables strung between the towers, but the Geronimo! 3, page 31 the decks on a cable-stayed bridge are hung 1. Earthquakes, cyclonic winds, monsoons, heat, from cables strung from the towers themselves. floods or freezing temperatures can damage 3. Well known cable-stayed bridges include: bridges. ANZAC Bridge, Stromsund Bridge, Viaduct de 2. They can be destroyed or attacked on purpose, Millau, Westgate Bridge, Rio-Antirio Bridge, they have not been looked after or properly Tatara Bridge and Sutong Bridge. maintained, they have been built or designed 4. The future of cable-stayed bridges looks very incorrectly, a terrible accident has occurred, promising. They are cost effective to build and like a car accident and has caused a structural have aesthetic appeal. weakness.

Make a List Bridges in Song, page 39 Advantages 1. The bridge represents a means of helping a • Can be built with only one tower. friend cross/overcome troubled times. The • They are well balanced. narrator compares helping his friend through • Aesthetically attractive bridges. rough times to the bridge helping someone to • Require less ground anchorage. cross the troubled waters that lay beneath it. • They are usually cheaper to build than suspension bridges over the same span length. Bridges in Tales and Rhymes, page 40 Disadvantages Three Billy Goats Gruff • Engineers need to take precautions to ensure 1. For the Billy Goats, the bridge represents a that the decks do not buckle. passage to a place where the pastures are • Generally suited more to shorter span distances green and they can happily chew the grass. than suspension bridges. It also represents an obstacle or hindrance because they have trouble crossing the bridge. 2. The bridge, for the Troll, represents power. He How Bridges are Made Safe 2, page 27 uses it to assert his dominance over the goats. 1. Redundancy can save lives because if one It also represents his downfall as he is thrown element of a bridge fails, it does not necessarily off the bridge. mean that the entire bridge will collapse. 2. Reduces the chance of errors in design and it’s London Bridge is Falling Down less likely that people will get hurt in building Material: silver and gold or using the bridge. Problem: too expensive 3. It takes time for weakness to show. It may be Material: needles and pins a waste of time to inspect a bridge more often Problem: not strong enough than is really needed. Material: wood and clay 4. Answer will vary. It can be considered a good Problem: won’t resist water idea because people’s lives and property are at Material used to construct bridge: stone immediate risk when a bridge is not properly cared for.