Stanley Hooker

“A number of Ford engineers arrived at Derby, and spent some months examining and familiarizing themselves with the drawings and manufacturing methods. One day their Chief Engineer appeared in Lovesey’s office, which I was then sharing, and said, ‘You know, we can’t make the Merlin to these drawings’. I replied loftily, ‘I suppose that is because the drawing tolerances are too difficult for you, and you can’t achieve the accuracy’. ‘On the contrary’, he replied, ‘the tolerances are far too wide for us. We make motor cars far more accurately than this. Every part on our car engines has to be interchangeable with the same part on any other engine, and hence all parts have to be made with extreme accuracy, far closer than you use. That is the only way we can achieve mass production’.”
― Stanley Hooker, Not Much of an Engineer: An Autobiography