I’m Lorna Slater. I am an electro-mechanical engineer and I design the control systems for automated machines. I’ve worked on a lot of very different projects – at the moment I am the lead Controls & Instrumentation Engineer at Aquamarine Power Ltd who are designing and building devices that capture energy in nearshore waves and convert it into clean sustainable electricity. Here I am “on location” in Orkney going to test one of our machines:

In Orkey to test wave power machines

The different parts of my job

Until I read James A. Michener’s ‘Space’ I always thought I wanted to be a scientist, an astrophysicist mostly. Michener describes scientists as the people who come up with the ideas, while the engineers were the people who make the ideas reality. After reading that book, I knew that I wanted to be an engineer. Well, an astronaut, really, but lots of astronauts start out as engineers.

To me, a machine has a frame, some sensors, some actuators (the bits that move) and a computer that links the two together and lets the operator see what is going on. My job is to build the machine; what it does is the scientist’s problem.

When, as a STEM ambassador I talk to teenagers about what I do, they tend to say things like “That sounds really hard, I could never do that.” I try to reassure them that no one would be expected to assemble a machine from scratch on their first day: I have 2 degrees and 16 years of experience to learn all this stuff. There’s a secret to it anyway (shhh, don’t tell any one): all the components come with manuals, a significant portion of what I do is reading the manuals and plugging things into each other by following the instructions…the rest of what I do is project management, documenting my work and attending meetings.

Oh, and programming. Programming is fast becoming a basic skill that everybody needs, like reading, writing, typing and arithmetic. Pretty much any scientific or engineering role these days is going to require some level of computer programming, even if it is just writing Excel macros or using MathCAD. I feel strongly that everyone in STEM fields should learn at least basic skills in programming.

How engineers and scientists see the world

In the jobs that I’ve had since leaving university I’ve worked very closely with scientists. There is a very real difference in how scientists and engineers see the world and the kinds of problems that they solve. In most research and development endeavours scientists and engineers work together. Generally we get along very well, but you occasionally get amusing examples of the immovable rock of reality getting in the way the unstoppable force of scientific vision.

My first job out of university was writing software to control robotic optical telescopes. At this company the engineers designed the telescopes, and the astrophysicists did the maths and the astronomy to develop the software that knew where to point them. There was an ongoing battle between the physicists and the control engineers about how good the alignments of the telescopes had to be. The physicists couldn’t understand why we couldn’t make it ‘perfect’ and we couldn’t understand why they couldn’t give us a ‘working tolerance’. In fact nothing can be perfectly aligned and systems need to be designed to deal with the imperfections of reality, but I’ve wasted many happy lunch hours arguing the point with my physicist colleagues, usually in fits of giggles at their insistence that perfection must be possible if only we engineers were doing our jobs properly.

Lorna Slater in the lab at memsstar ltdThen for 10 years, I designed machines that make Micro-Electronic Mechanical Systems (MEMS) devices. The scientists in this industry are physicists and chemists doing research into the chemical reactions that take place on the surface of silicon, germanium and glass wafers. They would figure out what chemicals, temperatures, flows and pressures were needed to get the reactions that they wanted, and I built the machines to deliver these things to the reaction chamber exactly as demanded (give or take). Here is a photo of me in “the clean room” – the lab at memsstar Ltd:

The sticking point between the engineering and the science in this case was the number of decimal places displayed on the screen. Just because my instruments will report data to 6 decimal places, doesn’t mean that anything past the first couple means anything. I always felt it poor practice to display meaningless digits, but my colleagues like to see them. In the end we compromised, I rounded away the offending nonsense and displayed them lots of nice tidy zeros. Everybody was happy.

I recently started working for Aquamarine Power Ltd designing the control and instrumentation systems for their current and next generation wave energy. The scientists here are largely mathematicians who do the hydrodynamic modelling of the Oyster 800. My instrumentation collects the data that they need to see how well the models compare to reality. They love pointing out to me the many ways in which reality is seriously deficient!

One of the major problems that I’ve been solving on the Oyster 800 is cable protection. In the past the cables weren’t armoured or well protected and the waves just tore them apart. Replacing them with armoured ones and adding new features and conduit to secure them to has been the largest part of the work that my team have undertaken this summer. Armoured cables are a lot stiffer and have larger bend radii than unarmoured – here is a photo of me and a mechanical engineer trying to figure out the cable routings given the bend radius of the cable – as you can see it is a rather different working environment to my previous job!

lorna slate aquamarine workshop

“Machine is working”

Science allows unfettered creativity, but engineering is often constrained by logistics such as using parts that you can buy at the local store. I love solving those sorts of problems and building actual machines that I can see and touch. It is a great feeling the first time you get a newly designed machine working and it does what it is meant to be doing. I even do a little dance when this happens (much to the mortification of my more reserved British colleagues), I call it the ‘machine is working’ dance.