Musings of an Idiot

[JonRiley56]

I have seen folks turn their flywheel by hand in order to get their engine started, and have doen the same myself.

How in the world do you start a big engine, or a large side wheeler ?

jon

[Mike Rometer]

Shouldn't be necessary with a multi-cylinder engine, only singles, and only then when they stop on, or very near a dead centre.

[JonRiley56]

ahhhh.............that makes sense.............thanks mike !

[fredrosse]

On the big sidewheelers, virtually all of then single cylinder, they had a nice brass indicator to tell where the crank was positioned. The engineer had to stop the engine away from TDC or BDC. Woe to he who stopped the engine at TDC or BDC, that meant getting out jacks to force the engine off its center, a big deal, especially when you might need to maneuver.

On the Margaret S I tried working that way, but later added a 16 inch diameter aluminum handwheel to the paddle shaft so I could get the engine off center easily. Less crashing since then.

Picture is from the Ticonderoga in Vermont, a larger (1500 Horespower) sidewheeler.

[JonRiley56]

Is there a technique to keep a single from stopping at TDC ?

[fredrosse]

If the engine is going toward TDC while going forward, shift into reverse for a moment, that will stop rotation before reaching TDC. This of course took some practice, but these sidewheelers only ran at a full speed maximum of 20 RPM, and when approaching a stop they were only turning maybe 3 or 4 RPM, so there was much more time than you might think to do this shifting into reverse.

Smaller machines of course run faster, the Margaret S has a flank engine speed of maybe 60 RPM, and maybe 10 RPM when approaching the dock, much faster, but still allowing about 6 seconds per revolution. That is enough time to shift the reverse lever if the capitan is paying attention.

[Lopez Mike]

On my little single I've had no success in stopping it at any particular point. What works for me is to reverse it quickly when it is turning over at a slow but not dead slow rate. If it stalls then the next step is to rock the reversing lever back and forth quickly. If that doesn't work, then I aim a big kick at the flywheel.

By then, of course, I've hit the dock. I've found it prudent to approach fixed objects at a slow pace and not rely on the engine for stopping.

This is all a big vote for a multiple cylinder engine. But there are trade offs.

Mike

[quinten1231]

hi

I have actually seen a steam engine on "preston services" called a "Barring engine", the description stated that it was used to turn over lerge stationary engines. not sure if this was to remove it from tdc or bdc and whether it was used only for factory engines or marine as well.

maybe that answers your question.

here is a picture of it

[steamboatjack]

Folks,
Large marine engines were fitted with barring engines, usually referred to as “turning gear” on a ship. There primary function is to move the engine to a specific point for maintenance for example lifting out a piston, Turning gear is essential to avoid the engine moving and injuring anyone in the “works” It's also used to set the valve timing etc. and to turn the engine when warming through prior to starting to remove any water etc. Medium size engines use a hand ratchet worm wheel set up but large engine use a steam engine or nowadays a motor driven unit, either way the gear should had a fool proof way to disengage before attempting to start the engine, some spectacular damage has been caused when this has not secured.
Photo shows the turning gear of a very large engine used on a certain ship built in Belfast.
Regards
Jack.

[S. Weaver]

Nice shot, Uncle Jack.

Twenty-some years ago I was timing a large marine d--sel. [Bypassing the self-editing nature of the forum. Write D-I-E-S-E-L and see what happens to your post.] As I recall, the turning gear was some kind of manual bar and ratchet arrangement. The two hands assigned to me were less than pleased as I checked and re-checked my work; each "check" of course requiring to reverse a certain distance before TDC so that all lash and slop would be out of the movement while approaching the mark in the correct rotation.