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Advice on a superheater damper.
https://www.rypn.org/forums/viewtopic.php?f=1&t=37673
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Author:  Earl Knoob [ Sun Feb 08, 2015 12:26 pm ]
Post subject:  Advice on a superheater damper.

I have recently gotten involved with a locomotive which is still equipped with a superheater damper in the smokebox. It is set up to be closed when the throttle is closed and open when the throttle is opened. I know all the theory behind equipping a locomotive with one of these at the factory, but I also know that a vast majority of them were removed early in the locomotive's existence.

The device is a pain in the rear... It is constantly sticking (fortunately in the open position most of the time). By crawling inside the smokebox with a can of penetrating oil, you can free it up, but it usually gives up again in a short period of time. Obviously any kind of lubricant one applies burns off as soon as you put the engine to work.

I would think any type of movable device installed in the hellish atmosphere of a steam locomotive smokebox full of smoke, gas, cinders, not to mention temperatures in the 2000 degree range, would quickly fail.

Of the 20+ superheated steam locomotives I've seen or worked on, none of them have a damper, although early photos of most show them built with them.

I am inclined to block the thing open and ignore it until the day when the entire front end needs to be removed, then remove the damper in it's entirety.

What say the great gurus of steam?

Author:  filmteknik [ Sun Feb 08, 2015 12:36 pm ]
Post subject:  Re: Advice on a superheater damper.

Not a great guru of steam nor even a little one but...

As they were shown to be unnecessary what if you remove the actual damper assembly but keep the outside mechanism in place and functional for historical accuracy? If the shaft doesn't enter the smokebox it should stay free and moveable so those paying attention can see it move anytime the throttle is opened or closed. That would be kinda cool.

Author:  Frisco1522 [ Sun Feb 08, 2015 1:04 pm ]
Post subject:  Re: Advice on a superheater damper.

In order for the damper to open and close for "display" it would have to be working and Earl said that's the problem.
I've never seen one on engines after the early thirties and I suspect the reason is the same thing Earl is talking about.
I've seen remains of them in photos where the opening has been plated over. You could do that, or cut the insides of them out, leave the outside and weld it in position.
Don't need any more PIA stuff on a steam locomotive.

Author:  Dave [ Sun Feb 08, 2015 1:26 pm ]
Post subject:  Re: Advice on a superheater damper.

The damper was there to prevent the elements from being burned during dry periods, like drifting with the throttle closed.......combined with a dome rather than front end throttle. That's why they weren't used when front end throttles came about and the elements were constantly supplied with saturated steam. If you aren't working every day hauling heavy freights in China, in today's intermittent service in the tourist and museum venue, you probably aren't subject to as much potential trouble, so......

Block it open and take it out later. You're going to go through the elements in less than 1465 days anyhow.

dave

Author:  Earl Knoob [ Sun Feb 08, 2015 3:36 pm ]
Post subject:  Re: Advice on a superheater damper.

Dave wrote:
The damper was there to prevent the elements from being burned during dry periods, like drifting with the throttle closed.......combined with a dome rather than front end throttle. That's why they weren't used when front end throttles came about and the elements were constantly supplied with saturated steam. If you aren't working every day hauling heavy freights in China, in today's intermittent service in the tourist and museum venue, you probably aren't subject to as much potential trouble, so......

Block it open and take it out later. You're going to go through the elements in less than 1465 days anyhow.

dave



The engine does work for a living. The grade to Bald Knob is a force to reckoned with. We're not pulling tonnage trains, but the engines get a work out. The throttle is left cracked open when drifting to provide lubrication and to prevent carbonization in the cylinders. The only time the throttle is closed is when stopped. At the water hole, the blower is used to keep the boiler hot when syphoning water into the tender. This is the only time when a hot fire is maintained with the throttle closed, and it is no where near as hot as when out on the road.

Author:  Mike Tillger [ Sun Feb 08, 2015 3:43 pm ]
Post subject:  Re: Advice on a superheater damper.

I agree with Dave's post. You should not experience any issues.
Mike Tillger

Author:  Earl Knoob [ Sun Feb 08, 2015 4:06 pm ]
Post subject:  Re: Advice on a superheater damper.

On the former D&RGW narrow gauge, common practice is to drift down grade with the throttle closed, even after working hard up the hill from Chama (I know that is not good practice, but that's what's been done for 60+ years - that's not my point here). In the 20 years I was there, the only super heater issues we had were ends leaking from cinder erosion and leaking header joints.

Author:  Jdelhaye [ Mon Feb 09, 2015 1:38 am ]
Post subject:  Re: Advice on a superheater damper.

(disclaimer: I am in no way, shape or form a "steam guru")
The only 2 suggestions I can contribute would be:
1) larger clearances on the damper bearings, to avoid seizing.
2)a heavier counterweight on the external damper mechanism, to add more closing force.

Jeff
(Suggestions based on observations of J Neils Shay #5, at IRM)

Author:  Kelly Anderson [ Mon Feb 09, 2015 9:02 am ]
Post subject:  Re: Advice on a superheater damper.

.

Author:  10stewi [ Mon Feb 09, 2015 3:01 pm ]
Post subject:  Re: Advice on a superheater damper.

While it may not solve all problems, maybe try using graphite? When the oil in the mixture burns out, the graphite will still be left behind, acting as a natural lubricant. If it is decided to leave it in place, it might extend how long it is able to function for!

Author:  jasonsobczynski [ Mon Feb 09, 2015 11:39 pm ]
Post subject:  Re: Advice on a superheater damper.

Earl,

Try applying Kano Laboratories "Penephite" daily, likely best utilized at the end of the day so the graphite can work it's way through overnight. I'll bet you the cost of a can it'll help!

Cheers, Jason

Author:  tom moungovan [ Tue Feb 10, 2015 4:44 am ]
Post subject:  Re: Advice on a superheater damper.

Earl, FWIW, the Hillcrest 70 ton Climax 10 on Vancouver Island kept hers for her 40 year career there & it was operational all that time. I'd never seen one before and noticed right away the counterbalance pop up the first time that I opened the throttle.

Same with Rayonier's #2, a 75-3 class Willamette geared locomotive at Sekiu, WA. She kept hers from '29 through her last use in '61 or '62.

While they did offer some degree of protection for the units when no steam was passing through to cool them, they were indeed a maintenance issue and a trade off.

What engine is this for? 2 or 11? Either way, since they both were oil before, why don't you consider running a 3/4" line from the former atomizer source to right in front of the engineer with a valve and then out to the inlet side of the Superheater? You could have a drifting throttle that way and accomplish the same thing as the damper. West Side 12 had one before the Superheater was removed and I watched Soapy DeGiobbi use it after he shut off from the pull out of town to the Flume. Dandy little device

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