Stack

A special section just for steam engines and boilers, as without these you may as well fit a sail.
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Jack Innes
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Stack

Post by Jack Innes »

My boiler case is essentially finished & now I have 2 questions on the Stack:

1/ Many steamboats seem to have a band toward the top of the stack, very often painted a deep red. Is this of some significance or does it just plain look good?

2/ Most whistle valves seem to be at the base of the whistle but some are at the boiler end of the line to the whistle. Is there a way of placing the valve at the boiler end without creating a situation of hot, condensed water being sprayed by the whistle?

Thank you,
Jack
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barts
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Re: Stack

Post by barts »

Many steamboats seem to have a band toward the top of the stack, very often painted a deep red. Is this of some significance or does it just plain look good?
Purely decorative; sometimes a place to put names or company insignia on commercial steamers.
Most whistle valves seem to be at the base of the whistle but some are at the boiler end of the line to the whistle. Is there a way of placing the valve at the boiler end without creating a situation of hot, condensed water being sprayed by the whistle?
  • * Use a leaky valve (or a small bypass needle valve) to heat the tube and whistle.
  • * Run the line inside the stack to keep it warm
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Bart Smaalders http://smaalders.net/barts Lopez Island, WA
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Lopez Mike
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Re: Stack

Post by Lopez Mike »

What?? No gurgling and spitting and scalding everyone? Not traditional!

Actually, I've never been on a boat with the valve anywhere but at the whistle. Does it work at all with a long pipe between the valve and the whistle?

I keep intending to insulate the whistle pipe and have a small bleed valve returning to the hot well to keep everything nice and toasty. Some day.

I may try just insulating the pipe to see if that is enough to keep it hot.
If you think you are too small to make a difference, try sleeping with a mosquito.
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DetroiTug
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Re: Stack

Post by DetroiTug »

The tug has the whistle valve at the boiler and the whistle up high and it works ok. The water in the whistle is a common problem it seems. A friend of mine has been grappling with it for a few years, trying different whistles, separators, return lines, insulation, etc. His boiler is a Stanley FT type and not very tall. I've mentioned to him that the boiler may just not be able to handle large whistles. Preaching to the choir here: When a high draw is put on a boiler like when a whistle valve is opened, if the boiler is small there is a sudden drop in pressure which triggers and instant higher rate of boil, thereby raising the water level and the water exits the whistle port known as carry over. The only remedy is a smaller whistle - OR possibly a large whistle designed for lower pressure (smaller passages between the languid plate and the outside shell). Then meter the amount of steam going to it with small piping or a metering valve.

I picked up a whistle out of New England a few years ago and the seller insisted that it is a whistle from a small steamboat from the late 1800's. It's five inches tall, triple chime, 1.25" diamater with a 1/4" NPT fitting.

-Ron
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fredrosse
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Re: Stack

Post by fredrosse »

I have a big (real locomotive) whistle, with 3/4 inch connection. If I open the whistle valve (also 3/4 inch), severe priming generally resulted.

I also had a problem of the whistle valve leaking slightly, so when the boiler cools down a good vacuum is NOT formed in the boiler. That is bad because air is sucked into the boiler, while I want the boiler to fill up with deaerated water, completely liquid full, from a feedwater tank. To remedy this I installed a new ball valve between the boiler and whistle valve, so now I have good sealing (the ball valve does not leak), and I can set the ball valve in a throttled position such that when I blow the whistle to boiler does not have so high a steam flow, and priming is avoided.

The water spewing out of the whistle on first blowing is still a problem, but big sound is not. I think the only solution would be to put the whistle pipe, plus the whistle, inside the stack. I have just over 400F stack temperature. Many boats run with far higher stack temperature, and very high temperature could damage the whistle possibly.
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Lopez Mike
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Re: Stack

Post by Lopez Mike »

I have a VFT with perhaps 6-8" of steam space between the water level and the various valves including the whistle. I'm not sure what it would take to get any priming.

When I blow down hot, the water in the glass (I know. Not necessarily indicative of the boiler water surface) shows no disturbance other than falling rapidly as the boiler empties.

I have a movie of a boiler surface at high output and it is remarkable how violent it is complete with little tornados feeding up into the steam pipe.
If you think you are too small to make a difference, try sleeping with a mosquito.
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