With great delight, I have just read Alan Bates'
Western Rivers Steamboat Cyclopoedium and
Western Rivers Engineroom Cyclopoedium. I was surprised to learn that the historic American sidewheelers (such as the classic Mississippi sidewheelers) all had independently driven wheels by a horizontal, single cylinder steam engine each.
For single cylinder engines, starting from a dead center position usually is an issue. I have heard of walking beam steamers for example, that is such a case some crew members had to enter the paddlebox an pry the wheel a few degrees forward. Once started, the huge momentum of inertia of the wheel would take it past the following dead cenetr position.
Curiously, A. Bates doesn't mention this problem at all. Neither he mentions any theoretically possible auxiliary device to pry or turn the wheel to a starting position. Instead, he praises the easy operation and great manoueverability of such boats. So I have to assume that stopping dead center wasn't a big problem in daily life, even in manouvers with multiple stopping and backing bells. How so?
Here are at random some crude assumptions of mine how this problem might have been overcome:
- By delicately controlling the throttle, the engineer could stop the engine at quarter position.
- Or once stopped in an arbitrary position, the weight of the massive pitman would turn the engine back to quarter position.
- Or unless finished with engine, the engineer wouldn't stop the engine totally, but continue to let it turn very slowly even under a stopping bell.
- Or as long as the boat was moving, the wheel would be turned by the water resistance and continue to turn even an engine with closed throttle.
- Or when docked in a swift river, the wheels would be turned by the water current.
- Or it was sufficient to get one engine started; the second one would soon be turned off center by the water resistance of the moving boat.
So which assumption is correct? Maybe a little bit of everything? Maybe none of these?
And what if several influences (e.g. 1, 2 and/or 5) cancelled each other under specific conditions, so that the engine stopped at dead center anyhow?
Can anyone give some enlightenment please?
Thanks, Moritz