I recall visiting the East Somerset Railway some twenty or more years ago, with a family I know.
"Black Prince" (8F??) was standing cold, and with no apparent prohibition to visitors climbing on board – which we did. If anyone saw us they did not challenge us.
"How do you drive it, then?" my friend asked.
"Well, first by changing places. You're on the fireman's seat" , I replied.
Obviously we did not disturb any of the controls, but I pondered the "ergonomics" , a word probably unknown in Riddles' day and earlier.
From the driver's perch, two things were immediately obvious to me. The restricted view ahead, but the driving controls being all within my reach, with the ejector and brake-application handles about level with my ear. Even when standing though, I realised I could not have operated the manifold valves mainly the province of the fireman. Too high up for we of economy size, at least without being griddled by the back-head and closed fire-doors.
I did wonder how short men ever managed as Cleaners (a head for heights useful), never mind as Firemen, especially in decades past when people generally were shorter.
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{For a few years I sometimes drove a Ruston-built, narrow-gauge, 4-wheeled diesel locomotive, but had to stand for much of the trip. If I sat on the side-facing tractor-seat bolted to the gearbox top, my eye-line was only just above the edge of the windscreen, and my own track horizon created by the bodywork was a good fifty yards ahead of the locomotive! }