We had a design, build and test module. We were given a sheet of aluminium around 50cm wide and you had to make a one-metre bridge out of it. We were shown videos of the four basic types of bridge we might construct – and we then had to do the calculations for breaking strain etc. and design our own structure, with a proper engineering drawing, all the associated maths – and then we had to build it, take it to the lab and watch it being destroyed.
At the beginning of the 20 minutes or so that we had to do the basic maths, I sat and thought about how I would build my bridge. After a minute or two I noticed that all of the other undergraduates were scribbling furiously, doing breaking strain and moment of inertia calculations. They were simply working towards one of the four bridge designs we’d just been shown. I realised that I was the only person in the room who’d spent two of my twenty valuable minutes considering whether there was a better or different way to build a bridge.
I did actually design a different structure. I cut the aluminium sheet in half and then folded it into two Y-shaped beams, with one that could slide inside the other and then be riveted all along the bottom. So it was very quick and easy to make, had double thickness in the central section and it couldn’t buckle. Out of the 70 undergraduate designs, mine was the third strongest. The two that were stronger were simple truss designs that by sheer chance braced the structure in the ideal place to resist the loading in the test jig. But when I went and looked at the marks for this, I was below halfway on the marking. So I went to the Professor and said, “Look, I don’t understand. I made the third strongest bridge and it was the only one that was a novel design that we weren’t shown.” To which he replied, “Oh, there are no marks for strength.” At which point my world collapsed and I asked myself, “What am I doing here?”
RG – So marks were awarded for following the plan?
RB – Exactly. All the marks were for doing as you are told and being lucky. That really stung. And since then there’s something that I’ve noticed about engineers. Because there’s so much pressure to get through the workload and get it done, there’s no time or tolerance for lateral thinking. They don’t want to waste time on airy-fairy ideas or thinking that you might be able to do this better. Get on with it, get it done, within the time constraints and within the budget. Keep the customer happy and move on to the next project.
In a thermodynamics lecture, the professor wrote a huge and hugely complex equation with multiple factors, right across the board. Then, looking at it, he said, “In the region we’re interested in, you can see that this factor is going to be about ten times this one, so let’s just rub that second one out.” I was completely shocked. That isn’t maths, it’s magic! But that’s how you build a jumbo jet. If you don’t simplify things the problem is so massive and complex that you never solve it. Which in the world of commercial engineering, that’s the way it has to be.
