Model bridges

Construct the lightest strongest bridge using icy-pole sticks and or skewers.

The bridge must span a distance of 50 cm and be 4 cm wide. The height of the bridge is left up to you. The strength of each bridge will be tested by placing weights in the middle of the bridge. The maximum weight that the bridge is capable of supporting, before it collapses, is divided by its total mass. This figure is used to calculate the winner. The highest score wins.
Score = total mass (grams) / mass of bridge (grams)
Below are some models that have been submitted in the past.

Click on each picture to see a larger image.
What type of bridge is Tass' bridge?
Marcus constructed this light weight bridge.
What type of bridge did Marcus construct?

If a 1 kg mass was placed in the middle of these bridges indicate the parts of the bridge under tension and those under compression. Don't forget tension means stretching while compression means pushing together or squashing. Use red for tension and blue for comparison.

What type of bridge did Matthew construct?

When a load is placed on this bridge what parts of it undergo compression?

Identify the type of bridge shown on the right.
What type of bridge is Anthony's?
Advanced models
Building a city