# English locomotive cylinder drains?



## Two Blocked (Feb 22, 2008)

What is the reason that larger 1:1 English locomotives exhaust their cylinder drains forward. Why the exposed "trombone" piping?


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## Charles (Jan 2, 2008)

Kevin
Might be due to inside cylinders...


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## Taperpin (Jan 6, 2008)

Possibly to avoid nuisance when starting of with UK high platforms, side discharge would cause vision problems for the driver looking forward.both Outside and inside cylinder locos had the drains point forward. 
Same thing here in Oz.. 

Gordon.


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## David Leech (Dec 9, 2008)

Maybe tradition! 
That's the way it was always done! 
and you get to use lots of copper pipe. 
All the best, 
David Leech, Delta, Canada


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## Two Blocked (Feb 22, 2008)

I think that Jerry Hyde, Accucraft Gauge 1 Project Manager, got it mostly right by speculating that in the age of steam locomotion, when locomotives were plentiful, scant attention was paid by work-a-day fares to the train's "front end", but rather more attention to their accommodations/ compartments and possessions. It would then make blowing cylinder drains via trombone like piping in a forward direction the way to go for passenger comfort since in the olden-days folks would tend to avoid the front end of locomotive, in steam, at grade level.


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## iceclimber (Aug 8, 2010)

So it seems like you already had your answer.


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## David Leech (Dec 9, 2008)

Posted By Two Blocked on 22 Jan 2012 08:38 PM 
I think that Jerry Hyde, Accucraft Gauge 1 Project Manager, got it mostly right by speculating that in the age of steam locomotion, when locomotives were plentiful, scant attention was paid by work-a-day fares to the train's "front end", but rather more attention to their accommodations/ compartments and possessions. It would then make blowing cylinder drains via trombone like piping in a forward direction the way to go for passenger comfort since in the olden-days folks would tend to avoid the front end of locomotive, in steam, at grade level. 

Sorry Two, but not sure what that all means.
I would point out that a lot of the time British tank engines are running backwards, and certainly tender engines would sometimes run tender first, which would mean that the drain steam is pointing directly at the first carriage!
All the best,
David Leech, Delta, Canada


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## Dave Meashey (Jan 2, 2008)

Guys; 

I believe TAC Foley once wrote that it was to prevent debris beside the tracks from blowing onto folks standing on the platform. If the water and steam shot forward/backward, the debris was sent in that direction INSTEAD of up towards the platform. 

Just my $0.02, 
David Meashey


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## David Leech (Dec 9, 2008)

Posted By Dave Meashey on 23 Jan 2012 09:01 AM 
Guys; 

I believe TAC Foley once wrote that it was to prevent debris beside the tracks from blowing onto folks standing on the platform. If the water and steam shot forward/backward, the debris was sent in that direction INSTEAD of up towards the platform. 

Just my $0.02, 
David Meashey 
David,
I'm really not sure that that makes sense really.
First of all, the cylinder drain cocks would only be used after a locomotive has been standing for a while. 
A normal two minute stop at a station would not I think require their use.
Secondly, since the locomotive would normally stop passed the end of the platform, where the ramp is, there should not be a problem with passengers standing there.
Maybe some train spotting kids!
If there was a short train where the locomotive was stopped beside the platform, I would think that it would be unlikely that sidewards steam would result in ballast coming up to platform level, but maybe.
More likely, if this is the case, it would be damage to the brickwork of the platform sides that would be of concern. 
But, maybe TAC was correct, but I will still stick with 'tradition' until I see proof!!!
Keep looking.
All the best,
David Leech, Delta, Canada


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## Dave Meashey (Jan 2, 2008)

David;
I was not referring to ballast. At least the 1:1 locomotives I ran never disturbed the ballast, and they had undirected cylinder cocks. What I think TAC meant were things like platform litter (candy wrappers, cigarette packs and butts, and other litter) that had fallen off the platforms and were now lying by the track. That stuff would be light enough to be lifted by the steam and water escaping from the cylinder cocks.

Not trying to argue. His premise just made sense to me - providing the locomotive were starting from beside the platform. As you wrote, a two-minute stop would not be long enough, but I suppose there were longer pauses.

Yours,
David Meashey


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## Phippsburg Eric (Jan 10, 2008)

Not being a steam engineer myself for real, I have noticed that full scale engineers tend to open the cylinder cocks fairly often even while running. I would bet they would be opened when starting from a brief station stop.. why they shoot the steam forward??? Just to look cool!?!?!


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## Dave Meashey (Jan 2, 2008)

Eric; 

I was initially taught how to run and care for a steam locomotive by a steam traction man. He preferred that I opened the cylinder cocks each time I started, then close them as soon as I noted only steam coming from the cylinders. Traction people had to maintain their own engines, so they tended to be more cautious than, say, a mainline engineer might be. It got me in the habit of opening the cylinder cocks frequently, but not those times when I had just stopped so someone could change the direction of a turnout or other stop and go operations. 

I also understand where David Leech's opinion may be coming from. TAC's explanation just made sense to me. 

Now, I remember seeing photos and films of steam locomotives running in cold, snowy conditions with a small amount of steam constantly leaking from the cylinder cocks. Somebody told me that a small grove may have been cut into the cylinder cock valves to keep them from freezing shut in the sever winter weather. Don't want to change the thread entirely, but does anyone know whether this idea is accurate? We have lost a lot of information about regular steam practices, so I'd be eagar to have an answer to that observation. 

Best, 
David Meashey


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## Phippsburg Eric (Jan 10, 2008)

I would not think that the cylinder cocks would not freeze during operation. the cylinders would be warm enough to melt any ice even if cool enough to condense steam. I would guess some care may be needed when starting an engine from cold iron in sub zero weather. Though I guess they were usually fired in the engine house which would not be as cold as outside even early Monday morning. Fires were kept going low overnight during the week. 

I suspect that any engine in service for any length of time might have worn the cocks enough that a whiff of steam would show in cold air even when closed. 

The Engineers on the WW&F open the drain cocks from time to time along the line, certainly to show off for photographers but other times too. #10 is a very small engine, and might be different than a big boy.


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## Dave Meashey (Jan 2, 2008)

Eric; 

I do know that opening the cylinder cocks will generally encourage slow-to-move critters to vacate the middle of the tracks.







The train (almost) always wins, but who wants to clean up that mess.









Best, 
David Meashey


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## Pete Thornton (Jan 2, 2008)

While you guys are speculating on the forward direction of english drain cocks, could someone point me to an explanation or a diagram of how they work? I understand they are for draining/blowing condensed water out of the cylinders - but if all they do is provide an open path out of the cylinder, why doesn't incoming steam just rush out the drain and not do any work on the piston? Vice versa, how can the piston (and engine) move if the drain is open? 

What am I missing here?


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## Phippsburg Eric (Jan 10, 2008)

Here is a shot of the cylinder cocks of WW&F #10 which is a Vulcan former plantation engine, a tiny US two foot gauge engine. You can see its cylinder cocks hanging down from the cylinders. they are quite small and let only a small amount of steam out compared to the amount that comes from the boiler. the engine still chuffs from the stack when the cocks are open so not all the steam leaks out. The chuff does get a bit louder when the cocks are closed though.

By the way, the goats run for cover when #10 comes around the bend but a Moose would be a problem! He would stare right into the headlight! Jason better whistle for brakes!!!


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## Dave Meashey (Jan 2, 2008)

Pete;

This is the best I could come up with from a Bing search:

CYLINDER COCKS 

The use of steam in locomotives causes much condensation which appears as water in pipes, valves and cylinders. Water can reduce the efficiency of the steam and could damage cylinders where steam is admitted on top of water which has collected in them. To eliminate the water, cylinders are fitted with small exhaust ports called cylinder cocks so that the water can be expelled under steam pressure.


The cylinder cocks should normally be left open when a locomotive is standing. They should remain open as the locomotive is started so that, when steam is admitted into the cylinders the water is blown out. Once the locomotive is moving and the cylinders are warmed up, the cocks can be closed and full pressure is available. There are normally three cocks per cylinder linked together. They are controlled from the cab and can be steam operated or mechanically operated by a lever.

No diagrams, but perhaps someone else will find a good diagram.

The best way I can explain why all the steam does not escape is like this: These valves are relatively small compared to the size of the cylinders, so the volume of steam and water that escapes is also relatively small. Water cannot compress, so even the very small amount of water that may have condensed in the cylinder while the locomotive was sitting could cause a great deal of harm. That water is already settled to the bottom of the cylinder, so once the valve is opened it starts to drain, then gets ejected by the steam entering the cylinder. The ejected steam is a relative small volume compared to the rest of the steam in the cylinder, but as it exits via the cylinder cock, suddenly there is nothing left to keep it under pressure. As the steam expands and cools rapidly, it produces those prodigious "clouds" seen when a locomotive first starts up.

Hope this helps,
David Meashey


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## Chris Scott (Jan 2, 2008)

Posted By Two Blocked on 21 Jan 2012 05:54 PM 
What is the reason that larger 1:1 English locomotives exhaust their cylinder drains forward. Why the exposed "trombone" piping? 

The reason? They just do things diffently[_sic_] acoss the pond. The same reason they drive on the left side of the road.


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## Pete Thornton (Jan 2, 2008)

they are quite small and let only a small amount of steam out 
Ah, so that's what I was missing. It's all relative. Guess I need to get a loco with working drain cocks so I can experience the thrill.


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