Steam & Excursion > What am I - no, really - I have no idea?!

Looking through some old(er) images and came across a
pic taken from an overpass featuring SOU #630.

Already posted last year here:
http://www.trainorders.com/discussion/attachments/fullsize/874000/SOU_630_Kings_Mountain_Cut_V_LR_0001.jpg

Wondering - what might that round piece be on the pilot?

/Mitch

Stack cover.

It's a stack cover. When we took the one off 1522, we stowed it on the tender. One time we forgot and it turned into a flying saucer in Kansas. We managed to find it. Someone had left it on top of the sand dome and when we were running along at track speed it got airborne.
I blew it off at Union Station when we had the boiler charged with air and was blowing it out for the winter. Made a helluva noise.

Are stack covers commonly used on coal-burners? I've got very little experience with coal, and I know the overnight procedures can be a lot different than with oil.

Posted from iPhone

flash34 Wrote:
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> Are stack covers commonly used on coal-burners?
> I've got very little experience with coal, and I
> know the overnight procedures can be a lot
> different than with oil.
>

Definitely Yes.

What are stack covers and why are they used?

It would seem, a stack cover would be used to,
what else - cover the stack of a steam locomotive.
Why? And when was this done?

And, is there a reason the stack cover was sitting
on the pilot during the run? Where were stack
covers often placed - somewhere on each engine
or instead, at the yard or roundhouse?

/Mitch

On an oil-burner it is literally used to keep the heat in when a locomotive is shut down overnight. It helps slow down the cooling off process MATERIALLY. On a coal-burner it apparently serves more or less the same purpose. When running they are typically stored on the pilot, running board, or back on the tender, depending on the speed you'll be running, etc. In a long term storage situation they keep rainwater from getting down into the smoke box to minimize rusting of the front end components and the bottom of the smokebox.

Posted from iPhone

Thanks flash, everyone!

Safe to assume the stack cover is typically stored in the tender as
I do not recall ever seeing one before which photographing steam
trains on excursion.

/Mitch

Long way to carry it back in forth from tender to stack.

Some railroads' locomotive storage procedure instructions called
for removing one of the cylinder head covers on a locomotive and
using that to cover the stack, with a wooden plug driven the stud
hole to keep water from getting in that way.

Mgoldman Wrote:
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> What are stack covers and why are they used?
>
> It would seem, a stack cover would be used to,
> what else - cover the stack of a steam
> locomotive.
> Why? And when was this done?

On a coal burner the fire is not put out at night, but rather is banked. First, turn on the blower just enough to draw the smoke and dust out through the flues to the stack, so you can see what you're doing and don't have to breathe all that stuff.

With the rake and hoe, see Picture 1, reach in through the fire door and push all the burning material from the back half of the grate onto the front half. Then dump the remaining ash from the back into the ash pan. This is a very dirty, dusty procedure. Next, rake all that burning material, and any other burning stuff you can find on the front grate back into a pile against the back sheet of the boiler below and on each side of the fire door. Dump the remaining ash from the front of the grate. Hand shovel a layer of fresh coal (called "green" coal) about 2" deep over the entire grate, then about 20 to 40 scoops onto each pile of burning stuff at the back. This will look like the drawing, in Picture 2 below. You get to learn exactly where its best to pile that. Some engines like it right back against the back head, while others will clinker if you don't put it a couple feet farther forward. Have your boiler water right up to the top of the glass, shut off all appliances, close the fire door and cap the stack. The cap will have a small hole, maybe 3" diameter, with a damper. Usually only an opening of about 3 or 4 square inches area should be open. It can be left this way for up to a day without any attention, depending upon the size of the bank you've built.

When you return to the engine to start her up, you've likely lost about 100-150 psi, again depending upon how good of a bank you'd built, and when you look into the door this is what you'd see, Picture 3. The dark area right in front of the door is the stokers pot, so there's never any burning there. Opening the door let in enough oxygen that I immediately got a flare of flame to the left of the door. Some glowing embers are seen near the left front corner. But, there's more glowing stuff under that coating of ash.

Check the water glasses to be sure they are working properly and that you have sufficient water. If not, fix that situation before anything else. NOTHING is more important.

So, remove the stack cover, turn on the blower - just enough to keep the smoke and ash out of the cab. Sort out the burning stuff from the front and pull it to the back, then dump front grate. Sort through the stuff at the back, dropping as much ash as you can, break up any clinkers you can - remove any you can't break up. Sprinkle green coal, and slowly spread the fire as you add more coal a tiny bit at a time.

-John



Edited 1 time(s). Last edit at 12/19/14 12:53 by LarryDoyle.

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Here's what a stack cover looks like up close and personal. Weighs about 20 pounds.

-John

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John,
Interesting summary on banking a fire overnight. I know in the days of steam, railroads had people who's job was to keep the water level up and a fire going overnight on locomotives at engine terminals. Of course part of this would be to have the locomotive ready to go when called. How prevalent was/is the practice of leaving a locomotive unattended in the manner you describe?

This leads up to a question I have had for a long time. I know a little about steam locomotives and the need to keep water over the crown sheet. I have heard stories of the water getting low and someone turns on the injector, resulting in the cold water hitting the crown sheet and causing a boiler explosion. I was once told that the best thing to do is run if I found no water in the sight glasses or test cocks. My question is that if you felt like it was necessary to do risk doing something in such a situation because of a lot of people in the immediate area, is there anything that you could do to lower boiler pressure and not cause an explosion. Like opening the boiler blow down, or would that make things worse?

Charlie

1019X Wrote:
-------------------------------------------------------
> John,
> Interesting summary on banking a fire overnight. I
> know in the days of steam, railroads had people
> who's job was to keep the water level up and a
> fire going overnight on locomotives at engine
> terminals. Of course part of this would be to have
> the locomotive ready to go when called. How
> prevalent was/is the practice of leaving a
> locomotive unattended in the manner you describe?
>
There's a lot of subjectivity to these answers. The important thing today is to do what is best for the engine, and even that's subjective. For my part, I'd say that if the engine is going to be used within the next, say, four hours - keep her hot. If, for say ten or 12 hours I'd bank it, unless you've got someone to stand by and babysit. Even with a watchman, though, you might want to let her pressure drop 50 to 100 pounds.

> This leads up to a question I have had for a long
> time. I know a little about steam locomotives and
> the need to keep water over the crown sheet. I
> have heard stories of the water getting low and
> someone turns on the injector, resulting in the
> cold water hitting the crown sheet and causing a
> boiler explosion. I was once told that the best
> thing to do is run if I found no water in the
> sight glasses or test cocks. My question is that
> if you felt like it was necessary to do risk doing
> something in such a situation because of a lot of
> people in the immediate area, is there anything
> that you could do to lower boiler pressure and not
> cause an explosion. Like opening the boiler blow
> down, or would that make things worse?
>
> Charlie

This gets subjective, too. Some say adding water to an overheated crown sheet will not harm it. I've been taught otherwise. The immediate thing to do is reduce the heat in the firebox. I would not put water into the firebox to try to cool it or put out the fire. Instead, shut off the blower and the engine, so as to not use steam which would encourage the draft. Stiffle the fire, by shoveling as much coal in there as fast as possible, with no draft and keeping the door closed as much as possible. Overfireing will cause the fire to consume the available oxygen, and the temperature will very quickly drop from about 2500 degress to below 1750 degrees - the temperature required to support complete combustion. 1750 degrees is reasonably safe, and soon the temperature will drop down to about 900 degrees.

Here's a link to a demonstration of how to check the proper operation of the waterglass.
http://www.trainorders.com/discussion/read.php?10,3186924,3186928#msg-3186928

-John



Edited 2 time(s). Last edit at 12/22/14 06:26 by LarryDoyle.

There is certainly documentary evidence that putting cold water into a boiler in a hurry with low water can blow the boiler, even if the engine is fairly cold.

There is I think an ICC report, though it might be earlier than that, of a young boy who was hired to watch the engines sit overnight and make sure they did not run low on water with the fire banked. One night he fell asleep, and when he woke up the water was nowhere to be seen. At that point he panicked and turned on fresh water into the boiler as fast as it would go. Shortly he found himself in the next township.

Its *probably* the case that adding water *slowly* to a boiler with a bare crown sheet would have a chance of recovering the situation. But what is "slowly" and what is "fast"? Since the answer is "if it is slow enough it doesn't blow up and if it is too fast it blows up", I don't think I want to make the experiment at less than 100 yards and behind some sandbags. Larry's suggestion of getting the temperature down on the crown sheet seems like the safest idea.