John's Jottings

125. Time, Speed, and Movement - Nov 2016

Posted on November 1, 2016 at 3:20 PM

Some of us had been on a club trip to a steam-worked heritage railway. At one of the stations there was a model railway, and we got round to comparing the way the two were run.


“It’s surprising how long it takes to fill up a real tender with real water,” Graham commented. “I reckon it was getting on for at least ten minutes, and that was after a journey of only a few miles. We don’t often allow anything like that amount of time with our models.”


“And what about the maximum speed of a light engine when shunting through platform roads?” Ken asked. “It tends to be at walking pace rather than Formula 1. Definitely not the speed of light!”


“On models, some steam locos never stop for coal, or to top up with water, or even to empty their ash-pans and smoke boxes,” Bill added. “They arrive with a train, run round and are away again before the guard has even time to carry the tail-lamp to the other end of the rake of carriages. There’s no time to couple up, connect brake and steam-heating pipes, establish the vacuum, test the pipe connections and so on, all practices that pre-date the modern railway’s preference for fixed rakes of coaches with driving cabs at each end.”


“At least with those electrically-heated 00 steam locos take some time to prepare and get into steam. In the larger scales, with more conventional firing by gas or meths it takes a bit longer, and it’s more like thirty minutes with coal-burners.”


“But you can go too far the other way,” Ken commented. “If trains aren’t moving, the public presume that something has broken down and nothing is going to happen. They drift away, no matter how exquisite the scenic modelling might be.”


“Isn’t that where showmanship comes in?” Felicity asked. “While one engine is stopped taking water, another is moving on a different task.”


“That brings electrical complexity,” Adrian pointed out. “All those section switches cluttering up the control panel, and having to remember where the rail breaks are. And that’s without having to co-ordinate several operators.”


“It doesn’t have to be complicated,” Fred said. “In the days before DCC, I once saw a model of a station where five locos were in action. But the operator only had one simple controller. He divided each loco’s moves into separate legs. When one stopped, ostensibly for its driver to reverse direction, the operator switched off that section and moved another loco on the next leg of its travels. Many in the audience were quite convinced they’d seen more than one loco moving at the same time, and in opposite directions! They were mystified as to how this could possibly be done with just a single hand-held unit. It was the slick use of section switches that created the illusion.”


“But the operator must have had a grasshopper mind,” Adrian commented, “forever switching his attention from one loco to another.”


“Perhaps he did,” Fred agreed. “But he must also have formulated an ever-evolving overall plan, so that he could see how each loco’s moves could be interwoven with others. Both aspects of mental agility are essential to handling moving traffic.”


“I wonder if air-traffic controllers make good operators of model railways?” our chairmen wondered. “And whether competent operators of model railways would make good air-traffic controllers?” But of course, none of us could answer either of his questions.


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