# Intersections: Mathematics and the mechanical engineer

- Cambridge Mathematics
- Mathematical Salad
- Intersections: Mathematics and the mechanical engineer

## Intersections: Mathematics and the mechanical engineer

John is a retired Mechanical Engineer whose career spans different branches of engineering, including diesel engine design work, clutches, industrial gearboxes and electric motors.

**How would you characterise your current work?**

I worked in mechanical and electrical engineering since leaving school at sixteen. I joined a diesel engine manufacturer as an apprentice for four years. I then became a design draughtsman, followed by a design and applications torsional vibration engineer. I then had various career pathways, mainly in sales and technical application roles, which are related to power transmission equipment involving clutches, industrial gearboxes and electric motors.

**How do you feel about maths? **

I have always been enthusiastic and engaged in maths. Mathematics has always been an integral part of my career, whether designing various products, applying engineering, or technical selling. Using and applying mathematics is crucial in designing and selecting equipment to find solutions to engineering problems. I have a GCE O Level in Maths and an HNC in Mechanical Engineering, which involves in-depth maths, calculus and understanding formulae.

**What is it about your work that is mathematical?**

Throughout my career I was involved in many aspects that required mathematics, such as engineering drawings, measuring, using engineering formulae covering a multitude of engineering topics, weighing, evaluating centres of gravity of diesel engines and generator sets. Additionally, I was involved in evaluating engine performance and had to understand engine performance data and water, oil, fuel, and air flow rates and temperatures. When working in sales, I had to calculate profit and discounts for customers.

**How do you use maths, calculation or numeracy in your work? What tools do you use to help you?**

All of the detail from my answer to question 3 can also be used here. With regards to the tools, I used rulers, calculators, computers and computer programs involving Fortran language for scientific applications. An example of the latter would be when employed by Mirrlees Blackstone as a Torsional Vibration Design Engineer. The job primarily involved the design suitability of marrying up different types of diesel engines to driven machines, electrical generators, compressors and marine propulsion propellers and analysing machine inertias, ensuring the avoidance of critical speeds and harmful vibrations within the machinery system. Optimised designs were assisted by using a specialised mathematical Fortran computer program, which evaluated stress and vibration values caused by the reciprocating nature of a diesel engine. Basically, the computer program quickly number-crunched inertia and stiffness values to evaluate the natural frequency (a Holzer tabulation) of the machine. Applying the diesel engine speed, power and number of engine cylinders into the program then mathematically evaluated stresses and vibrations within the system.

**Do you think maths is creative? If so, how?**

Without maths one cannot design products correctly. You need to know which are the appropriate formulae to apply. You also need maths to measure and build structures to create an end product.

**Do you use or rely on any maths that you learnt in school?**

Yes. I tend to rely on addition, subtraction, multiplication and so on for everyday mathematical issues mainly involving finance.

**How would you change the school curriculum, if you had the chance? Why?**

First and foremost, I would teach pupils everyday practical examples to give them confidence and ability to do whatever life throws at them. I think it is important to teach young people things like how to calculate how much income tax you pay in your job or how to evaluate domestic energy (electric, gas) consumptions and costs to check your bills. One should also be taught how to measure walls and floors to determine how many rolls of wallpaper and square metres of carpet are needed for DIY purposes or how to evaluate the everyday costs of running a home, a car and shopping. It would also be useful to know how to understand bank charges, how they are worked out and how to evaluate the cost of initially buying a home or a car.

**Join the conversation:** You can tweet us @CambridgeMaths or comment below.