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Fancy designing a bridge?


Whilst there are over 30 million cars in the UK nobody would get very far without the 80,000 plus bridges that  carry all the cars,  large lorries and tractors safely everyday. At school or home it is not uncommon to build model bridges from drinking straws, lego, spaghetti or rolled up paper and card and test them to distruction with increasing loads.  Alternatively, a really good piece of software can be downloaded for free and allow young and old to design and test bridges as outlined below.



The West Point Bridge Designer 2012 will introduce you to engineering through an authentic, hands-on design experience. This software provides you with the tools to model, test, and perfect steel and concrete highway bridges, based on realistic specifications and performance criteria. This software allows you to design and test any bridge that you wish to design which may succeed or fail depending on your design.



Steps to triumph!

Triangles or squares?

Triangles are the building blocks of many structures mainly because of their ability to bear large loads without breaking. They are considered the strongest shape because a triangular structure can only collapse due to the material breaking down due to stress. It is easier to understand why triangles are so strong when compared to a square or rectangular structure.



Once you have designed a bridge and selected test mode you might see your structure starting to sag a bit, as it begins to carry its own weight. All that steel and concrete is heavy. Then along comes a truck-a 360 kilo-newton vehicle representing the largest loading that this bridge is expected to experience in its lifetime. The truck moves out onto the bridge and...the structure collapses into the river. Ouch!

Our design has failed the load test--but don't worry. Engineering design is an iterative process. Some trial-and-error is always necessary to achieve a successful product. If at first you don't succeed, then go "back to the drawing board" and try again.



Another good learning tool with the software is that it calculates the cost of your bridge as you go along. You can quickly change the type of bridge, add support piers or increase the size of components to refine your design and reduce costs. The average value of the 80,754 bridges in the UK is estimated at £215,000 or around £2000 per square metre. 

Super safe bridge costing $1.6m

Basic but safe with abit of sag costing $330,000... 

After an hour or so you should be able to create a variety of bridge designs and explore the art of design.


If you require some further inspiration - Dan Cruickshank's book titled "Bridges" gives you a detailed history of bridges around the world from the Roman Empire's Pont du Gard to the Millau Viaduct and other modern mega bridges of tomorrow.



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