Human engineering guide to equipment design
I picked up this book last week from a second hand shop for a pound. It’s a compilation of research into the design of machines, systems and environments to maximise the efficiency of those using them. It was sponsored by the US Army-Navy-Air Force Steering Committee and published in 1963, the height of the Cold War.
Despite being a very dry and functional book, it manages to capture the tension of the time simply by being so exhaustively comprehensive. Nothing is left to chance. From the more obvious stuff such as the logical grouping of controls in instrument panels and the dimensions of walkways it also covers the minutiae like the optimum resistance of levers and the best actuation force and throw angle of switches. It’s beautifully typeset with clear diagrams and graphs and lots of lovely tables of data. I sometimes worry how excited this kind of thing makes me.
Much of the book details various human parameters, such as height, weight and limb length based on the ‘average male Air Force personnel’. All this data is circa 1955 when, if you are to go by the illustrations, the average Air Force personnel wore slacks and had a short back and sides. However I was very pleased to see I would have been in the 95th percentile regarding height, a veritable man-mountain. But while there’s lots of data that is now obsolete, there’s just as much that is still valid. The chapter on ‘Human Dynamics’ treats the human as another component in the machine with their own unique system response, while the chapter on ‘Selection of Signals’ addresses those tricky situations when you have to choose between a buzzer, a bell or a klaxon. Rather more applicable to today is the section ‘Intelligibility in Speech Communication’ that details methods to maintain speech quality in noisy channels with limited bandwidth. These problems are still with us today, we just have more sophisticated tools to apply to them.
The book is full of simple illustrations from the text – snapshots of ‘the right way’ to do something. They all make perfect sense when you have them pointed out to you and these techniques will be entirely transparent to those using the devices. But omit them, and you can bet they’ll be the first thing an operator notices.
There are so many great articles in this book, and I’m sure I’ll post some more in the future, but currently this image sums it up for me:
Here’s to comfort and efficiency!