Building Bridges

I moved to university on the 19th of September and for our welcome week we got into groups to take part in a bridge project. The specification was that we had to make a bridge that would span a 3m gap and could only have 30cm either end resting on the table. We also had very limited materials, including cardboard, foam board, paperclips, elastic bands, tubes and fishing wire, the amounts are shown in the image. As well as being a fun team building activity that gave us the opportunity to get to know one another, it was a competition, there were prizes for the most aesthetically appealing, the one that took the most weight and then the best overall.

We decided that we were going to do a triangular prism shape out of the cardboard making three seperate prisms, as the cardboard wasn't long enough to reach all the way across the gap. We also had to work out a way of keeping the triangular shape together when we had no tape! So we had to be creative and bend out the paperclips and use them as if we were sewing the pieces together.

From this we then used the tubes and cut a hole for the prism to rest in. However we could see that the middle of the bridge was already dropping and we hadn't even applied any weight! At this point we then sat down and had to think what we could do with the little amount of remaining materials that we had.

A decision was made that we needed to do some suspension, like you see on some bridges. So we cut strips of cardboard and made triangular shapes at either end and supported these with a smaller triangle made from foam board. Then using the fishing wire we created suspension, by tying the wire around the paperclips and then up and down the triangle pulling up the middle section as much as we could.

It was then time to test how much weight could be applied to the bridge before it collapsed! First we had to get the bridge itself outside which caused a bit of an issue because of all the doors and the side of the bridge. When I saw the other teams bridges I knew that we wouldn't win! As a group we had to estimate how much weight we thought the bridge could withstand, we weren't too optimistic about it and so went with 1.5kg.

The weights were applied on top of each other in the centre of the bridge, and to my surprise more and more weights were being applied. It definitelly was doing better than I had expected, taking 1.7kg. Although our bridge wasn't pretty enough or strong enough to win, we did manage to have the closest weight to our estimate and unlike most of the other bridges ours didn't actually break! As a plus we got a box of Heroes anyway!

Overall it was a good activity which I enjoyed and was definitely challenging. If I was to do a similar challenge I would know where to start and the idea of a triangular prism was a good start but making it stronger by using two smaller ones strapped together would have been a lot stronger. We could have still used the wire for suspension and maybe we could have won for the most weight!