Double Tandem Compound Horizontal Mill engine.

[Dan Rowe]

Hi Jo,
Like Dave my focus has been on marine engines and I have never seen a clad fly wheel. It must have been a safety issue so maybe it was not something used everywhere as safety standards can vary by location. Nice job it looks good.

Dan

[Jo]

Hi Dan,

The reason for cladding a flywheel was to stop it producing a draft.  Something you would not want in a cotton mill as it would whip up the cotton waste which would then get caught in the spinning making an uneven thread or clump together as a fire hazard.

I now need to think of some sort of centre and outer edge to the cladding to attach it to the flywheel, the problem being that I was hoping of adding some bolting plates to the inside of the flywheel to represent how the felloes were bolted together but that would get in the way of mounting the cladding .

Jo

[Dan Rowe]

Jo,
Thanks for explaining the reason for fly wheel cladding. Yes factory size dust bunnies... I can see how that would be a problem.

Dan

[smfr]

This build looks great, Jo, and very instructive. That cylinder has a crazy number of studs!

Simon

[NickG]

Yep ... that's a big ring of studs! Engine is looking superb 

[Jo]

I'm feeling guilty on the studs, these are cut down 2" long 8BA csk screws. Today I would look to make them out of stainless with shoulders in the middle however there are 220 of them so I opted for cut down screws, naughty but far less boring. I still have 32 to make for the valve chests and another 20 for the steam pipes .

This evening was successful and the second cladding plate is done and they are both sporting a nice stain. But enough for tonight, I seem to have some spare birthday cake which will go down nicely with a glass of wine .

Jo

[b.lindsey]

The cladding looks great Jo.  Like others I was wondering what it would look like and what its purpose was and now I know the answer to both, so thanks for that!!

Bill

[Maryak]

The reason for cladding a flywheel was to stop it producing a draft.  Something you would not want in a cotton mill as it would whip up the cotton waste which would then get caught in the spinning making an uneven thread or clump together as a fire hazard.

Interesting................I always thought that the flywheels were clad to reduce wind resistance and thus increase HP. In the cotton mills where my parents both worked the engine house was separate from the spinning and weaving rooms and the spinning and weaving machinery was driven by an open system of shafts and flat belts. The belts were levered on and off the appropriate pulleys to stop and start each machine. This was a very hazardous place to work as if the machine didn't get you the belt would. Believe me there was heaps of windage from the various pulleys, (some up to 3' dia), and belts flanging around without any form of guard.

In fact that's how my parents met, Mum made a slip up and before they cold get the loom stopped, she was stripped to her underwear and somewhat untidily packaged in amongst the warps. Dad was sent to extricate her from this situation. All I can say is he must have liked what he saw because they were happily married for over 50 years.

Mum's second mistake was..........................

Best Regards
Bob

[Jo]

I agree with a smaller high speed engine windage losses of flywheels can be significant  but with these slow running 2000+ HP engines with flywheels of 40+ tons ?

I found this photo of the ropes on the flywheel to give the marine engine lovers amongst us an idea of what these big engines were used for:



Jo

[swilliams]

Amazing the things you find out around this place. I had no idea there was such a thing as flywheel cladding.

BTW - looks great Jo

Steve

[Maryak]

I agree with a smaller high speed engine windage losses of flywheels can be significant  but with these slow running 2000+ HP engines with flywheels of 40+ tons ?

Jo

What do you think the rim speed would be and/or the peripheral spoke speed? At 70 rpm, I estimate it around 65 mph, or Storm force on the beaufort scale. IMHO that's a reasonable amount of energy loss.

http://www.ribblevalleyrail.co.uk/Gallery16%20Ellenroad%20Steam%20Museum.htm

As you say it would sure shift a lot of lint about the place especially if it was in the same room as the gin/loom etc. and uncladded.

Best Regards
Bob

Best Regards
Bob

[steamer]

OH I've seen plenty of rope drives Jo,   but with the primary industry not being cotton mills, I've not seen the cladded flywheels...makes perfect sense though...

Dave

[derekwarner]

Thanks for sharing......some very interesting commments

The Steam pressure gauge is then checked to ensure sufficient steam for the running period envisaged.

First, the drain cocks are opened to prevent condensed water in the cylinders from forming a "hydraulic lock" and damaging the ends of the cylinders, (which I have observed causing much damage on mainline locomotives).

The inlet valve on the right hand high pressure cylinder is opened with a spanner from the outside, at the same time as the main steam valve is opened.

The engine then slowly begins to turn and the mechanical system for the valve gear takes over, admitting steam to the cylinders in the correct synchronisation.

Derek

[steamer]

Don't forget a couple of hours with the drain cocks open and a small amount of steam feed to the cylinders to warm up....while this is happening the engineer will bar the engine over (see the baring slots in the middle of the flywheel)  to get steam to both sides of the cylinder and crack open a bypass to the LP's to get some warming steam on them too.   JUST  A BIT  we don't want any rotation under power here ....too much condensation when it cool.  Once the HP cylinder is way too hot to touch ( I hope they're jacketed or it will take a while) I would start with the HP cylinder ONLY and start opening the throttle gently as she's still far too cold to start.   Once through two cycles or so...I would start to close down the HP cocks slowly and listen for any signs of water....and let her turn slow.   After a bit...not sure how long but long enough for the LP's warm up and stop spitting condensate out the open draincocks I would start to close the LP cocks down.    I am sure there was some whistle blow before anything moved to let everyone in the plant know the line would be starting..... ......talk about scary!

Dave

[Maryak]

Dave,

These big engines were usually barred over by a small barring engine so the slots are most probably gear teeth. I mean you'd need a hell of a long bar to shift 40-80 tons of flywheel and 50-100 tons of engine. I  don't think there was any bypass to the LP, the barring engine would ensure that the steam used to warm through went to all parts of the engine as it slowly went through several complete cycles before it was disengaged and the engine deemed ready for running. With a condensing engine this is usually when the inlet to the LP reaches 160⁰ F or you can just touch it but not linger the finger. This is equivalent to the boiling temperature at 20"hg. You don't want it too hot or you will run the risk of cooking the condenser, again because the air and circulating pumps were usually driven by the engine itself.

Best Regards
Bob