Mathematician or Magician: what kind of an engineer are you?

If you have read my book, then you will know that first principles are at the core of good engineering practice. They provide you with excellent constraints when making decisions. This in turn means you can focus your energies on other well less defined decisions.
 
An illustrative example that given by Gordon Murray when he was explaining his thinking process, involved the specification of a steering shaft in F1.
 
It was quite common for engineers to simply specify a nominal diameter – 25mm (around 1”) for example. That was because that was what everyone had done, it seemed to work, and it was thus easier to do that on all other cars.
 
However, that meant you could either be carrying excess weight. Or, it might even mean that you were close to failure and steering could be lost part way through a race. Neither option is ideal. So by taking a relatively small amount of time to calculate the diameter that would be able to transmit forces required, one could, in such an instance, know that they have an optimised and safe design.
 
That’s the power of being a mathematician as an engineer. You optimise.
 
But, there is also something more; something nearly magical. You gain great insights when you use first principles. Insights that can almost make you look like a magician.
 
Back to steering columns.
 
When Gordon Murray started to analyse the steering column, he realised that there were two types of loads: bending and torsion. Bending was mostly from the driver leaning on the steering wheel. Torsion was from the column’s main purpose: steering.
 
From this insight, which was provided by the use of theory and mathematics, it was possible to re-frame the problem. There was to be a structure designed to support radial loads, and the shaft was to be optimised for transmitting torque. This allowed for further optimisation of the overall design.
 
And it all started with the decision to use first principles and mathematics.
 
So by being a mathematician as an engineer, you can also be a bit of magician.
 
But it can also stop you from being a fool.
 
I also mentioned in my book when I was designing a dynamometer for model solar boats. They were small vehicles designed by students. So, it seemed to me, it should not be too much of a challenge to have a design where the water flowed under a stationary boat. That would allow for the boats to stay tethered in one place under a lamp (emulating the sun). Then, students could experiment with different configurations for different solar conditions. It all seemed like an easy way to offer great outcomes.
 
But then I decided to apply some first principles.
 
This was to choose the right pump. And, as it turned out, I needed a pump that could move 1 tonne of water every second!
 
I felt embarrassed.
 
But the senior technician, who was to organise the implementation of the dynamometer I designed, was grateful that I at least did the calculations – later, but before we actually started any construction. It seems many other engineers he had dealt with were neither mathematicians nor magicians.
 
And you now know what that leaves!
 
So, make the choice now to use first principles to guide your engineering decision making. Do some mathematics. And then make the most of those extra magical insights you will gain.