What does this mean when a fireman on a steam locomotive does this?
I'll take a guess (not having seen this passage or quote)...it means the fireman used his own injector to fill the boiler with needed water. The injector uses steam across a venturi to draw water 'up' or 'down', depending on the design of the injector, and the water flow moving with the steam cools it quickly, creating a vacuum in a recess that acts like a ram, forcing water at high enough pressure down the feed pipe that it presses past a check-valve at the front of the boiler, running into the vessel.
So, the fireman, whose job is to keep up steam, must spend some of it to keep water in the boiler for the production of that same byproduct.
-Crandell
Crandall's guess sounds completely logical, but I wonder if the term might not have a negative connotation - ie, losing a certain amount of steam pressure due to injecting cooler water into the boiler. Of course, it's a necessary evil.
After some experience with an injector on a steam locomotive (despite some excellent guidance, I couldn't get it to lift), I did some reading, though, and found that due to the way an injector works, it does warm the water a bit. Also, the water is usually injected at the "far" end of the boiler, away from the firebox.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
I thought it was the result of fresh comparatively cold water into the boiler - regardless of how it got there, injector or pump, etc. - which needs to be heated before it turns to steam, and which cools off the existing boiling water and steam somewhat, thereby slowing down the steam production for a few minutes until it all gets hot again. The alternative - not adding the water - maintains a high steam generation rate, but is not sustainable because before too long the boiler will run low on water and cause bad things to happen to the crownsheet.
Kind of like a teapot on your kitchen stove, when it's boiling but low on water. Add more water, and the boiling/ steam stops for a while, then restarts. Don't add water, and it'll boil dry, which will then cause its own kind of havoc, depending on the details. An unpleasant tradeoff either way, but when you think about it for a moment, there's not really much of a choice, is there ?
- Paul North.
This is something I found in a story in the Spring 2004 Classic Trains on page 41. The fireman ran his stoker and overloaded the firebox with coal and couldn't get steam and then talked about trading steam for water.
We all know a crew {fireman}, had to make sure his boiler had proper water level as the train moved over the district....And from what I understand this was not automatically accomplished.
Knowing that controls on such machines were not as sophisticated as controls in our modern era, and this required function of keeping the water level where it needs to be.....makes me wonder why, perhaps there wasn't more explosions back then....
Crews certainly were human....and sometimes the conditions must have been somewhat less than good....in many ways.
Quentin
What it means is the fire is sub standard and the loco is in danger of going cold. The fireman ran the stoker too fast and covered the grate with too much coal which in turn smothers the fire. Trading water for steam is common practice if the loco has a poor fire. The engineer will have less water over the crown sheet just to keep the loco moving. With little water over the crown it takes less heat to make steam. If they were out on the main and the fire went cold it would tie up the main line until either a helper or a new fire was built. Either way the fireman would have been fired (no pun intended). And the engineer would have up to a week sitting at home thinking about what went wrong. When he returned he more than likely would have lost his position in the call list or be relegated to some less desirable route. An experienced fireman would run the stoker slow and throw a couple scoops in with the shovel as needed. Stokers were not perfect and needed constant adjusting.
Running high speed needs a different fire than a slow drag freighter. Usually a named trains fireman would bank coal heavy in the sides and front and rear of the grate and stoke the center thin. A thinner fire was less likely to smoke out the passengers. A drag freighter would keep the most heat near the front and both sides by keeping the fire thinnest there. That way the water legs and combustion chamber were used to make steam too. When I say thinner it means about an inch or so. Not much difference in thickness but is thick enough to control the draft with out holes in the fire. Too thick of a fire wastes coal and smokes up the firebox.
Hope this answers your question.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Good grief guys,
I have no idea what this means, but my grandfather who died in a boiler explosion in Traverse City,MI in 1902 may be able to explain it if he were still alive.
I'm sure it dates back a long way, but I'm 70, and the expression is way beyond me.
Norm
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