I’ll toss in here–I think a lot of ‘memories’ we have of steam have to do with photography during the steam era when it was considered a great photo to have the loco steaming like crazy–“Cleaning the Flues” as it was often called, when a lot of steamers ran with otherwise fairly clean stacks.
I’ve got some video of Rio Grande L-131’s 2-8-8-2’s charging up Tennessee Pass with a freight train (one pulling, one mid-train and one pushing ahead of the caboose) and for the most part they’re running fairly clean for coal-burners–the photographer is not trackside but filming them from a distance-- but occasionally there are these huge plumes of black smoke erupting from the stacks, and though it looks magnificent, I read in a book about Rio Grande steam that these particular Alco 2-8-8-2’s were prone to ‘blowing off’ when least expected–almost as if they were self-programmed to clean their flues without any help from the engineers. Most of the action photos I have of Rio Grande steam (standard gauge) shows the locos running with a fairly clean stack. And again, I’ve got video of Missabe 2-8-8-4’s running at speed with ore trains, and there’s not that much coming out of the stacks.
All that magnificent smoke seems to be something that possibly the engineers and the photographers might have arranged prior to either filming or photos. For the most part, all the steam locomotives that I grew up with, ran with fairly clean stacks. Or if they did spew it out (I remember SP MT 4-8-2’s being particularly good at this) it was while starting a heavy train. As the train gained momentum, the stack got cleaner and cleaner, until at full speed, it was hard to see anything but a little vapor.
But watching a steam locomotive sending huge plumes up the stack seems to remain an indelible and romantic image, if not exactly accurate. What it does, I think, is excite
Crandell, you’re not wrong, cold weather is the best time to chase leaks and weeps!
From your description, it’s an anti-vacuum valve, or snifter valve as they are commonly known as. They’re designed to prevent a vacuum forming in the cylinders when the loco is drifting. A typical design has the valve open to atmosphere by gravity when there is no steam in the valve chest. Opening the regulator/throttle closes the valve under steam pressure, and you get that characteristic little squirt as the valve seats. I couldn’t find a clear photo of 2816 on the web that shows the snifter valve, but I’d be about 99.999% certain that’s what it is.
Again, you’re not wrong. Drain cocks can be manually operated by a reach rod, or air or steam operated, but whichever method is employed there is always the potential for them to blow through if they don’t seat properly. I was out yesterday “having a play” on an steam trip, and the bloody drain cocks gave us nothing but trouble all day. Here’s a couple of photos my wife took as we ran through Waterfall and Mortdale, you can see them quite clearly blowing. On this engine they’re manually operate
Chuck, that sounds like our old party trick we’d play whenever we had an engine on display, or at a function. We’d make sure we had less than half a glass of water, then shut down everything, close the ashpan dampers and firehole door, let the fire go flat, and keep the engine very quiet. When it was time for the off, we’d make a great big show of putting a fire on, and quickly opening up all the accessories, so that the engine would seem to roar into life. It was a great fun to see the looks on people’s faces!
{EDIT} I’ve got some video of us doing this stunt at Maitland - if I can figure how to post it to Utube I will put it up!
Howmus, that’s a great photo, as it confirms the point Chuck and I were making. Those M-1s are near the end of their working lives, and they quite obviously haven’t had the maintainence kept up to them. They’re leaking from the cylinder drain cocks, snifter valves and whistle valves. Well maintained engines wouldn’t leak like this…
Thanks, Mark. I was just a toddler when steam was replaced on the NYC and PRR where I grew up so any memories of steam when it was in revenue service are dim at best. Most of what I have photoshoped into my photos have come from what I have seen in old photos and from museum pieces. I will have to rethink how I add that to my photos.
One question. It would be normal for steam to be seen coming from the generator and the air pump, right? Where and when on a generic loco would steam normally be seen?
Hi folks - I bumped into this thread, and lo and behold, there I was! (thanks Crandell)
The OP was asking about our preferences for enhanced phtos that show smoke, steam, etc. I have to agree with everyone that said “if done well, it’s great, and if done poorly, it looks bad”. There are lots of different ways to achieve this effect, and at least half of the time, maybe more, I DON’T cut and paste actual smoke, but rather, render it (paint it) digitally.
Regarding the pic that Crandell posted, the steam effect is based on prototype photos. I emulated the real thing based on what the old photos showed me because unlike many of you, I’m not all that familiar with the fine details af how particular valves work - I simply look at history and try to copy it faithfully. The pic I was referencing had steam pretty much like the steam in Crandell’s photo.
In some ways, this is an old can of worms - where does modeling stop and digital wizardry begin? Of course, everyone has their preference. For me personally, I model because I want to reproduce the world in miniature. When I take images of my layout, I feel the need to crop in the photo what my imagination crops for me automatically. For example, I want to take wide angle pics of my miniature world without the distractions of the real world, like train room doors and windows, layout fscia, etc. Taken a step further, why not add smoke, smoke etc? After all, it’s what we WISH we had on our layout. Provided one is honest and forthcoming about the digital enhancements used, and also provided these enhancements don’t alter / enhance the modeling itself, I see digital photo work as just one more element of this great and diverse hobby to enjoy. Cheers.
Tom, what you’re describing is a couple of separate things that aren’t related. The big plumes of smoke that erupt intermittently happen when the fireman puts on a fresh fire - as the volatiles in the coal and the smalls get burnt away they make smoke, but once the coal is burning fully bright, the exhaust will go back to being fairly clean. Aiming for the sweet spot in the fire is always a little more difficult on a stoker-fired engine, but an experienced fireman should be able to do it.
Flue cleaning is more associated with oil burners, although it wasn’t unheard of for coal-fired locos to equipped with soot-blowers if they were burning soft, sooty coal. But in most cases, the action of the cinders passing through the tubes and flues on their way up to the smokebox was enough to prevent soot depostion form becoming a problem.
“Blowing off” refers to the safeties valves opening, rather than making smoke. I would hazard a guess and say that the DRGW engines had the usual problem of a long-boilered loco operating on steep grades, where the boiler water surges back and forth, causing the safeties to lift unexpectedly.
Again, a photo that confirms our point. The big cloud of steam blowing from the turret is coming from the blowdown separator, most likely discharge from the foam meter - that’s normal. There’s a wisp from the turbo-generator - that’s normal. The steam blowing from under the cab is from the feedwater heater cold water pump exhaust - that’s normal too. But the steam blowing from the second engine’s cylinders is a leaky drain c.o.c.k. That’s not normal when running, and indicates a part that needs attention.
{EDIT}Two other thoughts also occur to me. One, this particular engine is again near the end of its working life, and the maintenance wasn’t all that it could be. Two, it’s being overfired to buggery for the benefit of the camera, as Tom mentioned earlier. You’d NEVER catch me making that much smoke!
Mate, I envy you those dim memories. I would have loved to have seen Central or Pennsy engines in service!
Funny thing is, I thought your photo looked the most convincing of the lot. To me it looked just like a slightly run-down engine should look, with a little wisp of steam here and there in the right places. That’s assuming you want that look, of course!
Now that’s a hard question to answer simply! As you say, the generator and pump both have a visible exhaust when running, but there are a number of other accessories that also exhaust steam, depending on the engine, and what it’s doing at the time.
There’s pump drains, lubricator heater drains, blower drains, feedwater heater pump drains and exhausts, booster engine exhausts, steam heat fittings, injector overflows, blowdown mufflers and separators, foam meter discharges, stoker motor exhausts, coal pusher exhausts, tank heaters, burner heaters, there’s quite a list. If you post a few photos, I could suggest where you’d most likely find steam escaping.
Mark, I always manage to learn something from you…thanks for rewarding me once again. [:)]
I would expect to see some steam coming from the low tube orifice under the fireman that would be the injector overflow, if I recall, but only if and when the injector were used…to top up, to check it, or because it was all that got water into the engine…no feedwater heater. Is that correct?
And, to be honest, I have never felt completely comfortable the way a thread five or eight months back concluded, about that short plume for’ard or aft of the stack. Is that feewater heater pump? Surely not the turbo-generator because that almost always had its own local short pipe exhaust. Where would the air pumps exhaust…which is what I felt the consensus was on that thread.
Yes, they are the largest built in the Western world. But not the heaviest, and not the most powerful. The heaviest were the H-8 Allegheny engines from the C&O (my avatar photo and the subject of my images on this weekend’s photo fun thread), and the most powerful was the Y6b from the Norfolk & Western on simple steam at start up…in tractive effort, that is. After several miles per hour, it would revert to double expansion in the Mallet mode and be surpased in horsepower by the Yellowstone, the Allegheny, and probably several other engines.
I’ve no doubt you copied the picture you were referencing accurately, and I have to say I’m well impressed by your skills with Photoshop. It’s a great example of your work. And I agree with your views about digital rendering of model images, it’s a fascinating aspect of the hobby - but I suspect I’m just a bit harder to please than most!
Crandell, it’s my pleasure - thanks for the compliment!
You’re correct, the 36 doesn’t have a feedwater heater, they weren’t something my railway ever used, except for one experimental installation that wasn’t a great success. The 36 just has a pair of live-steam injectors. When you’re starting them, you get a squirt of water and steam when they pick up, otherwise the only time you’d get steam from the overflow is if the steam ranges were blowing through. That’s something you don’t want, apart from wasting steam the injector bodies will eventually get so hot that they won’t work properly - big drama!
I remember that thread, it was a little inconclusive wasn’t it, but the answer would depend on what loco you were looking at. On the 36 the air pump exhaust is indeed just behind the stack.
I think smoke enhances a model picture as to look more realistic. Also its fun to play with Photoshop. And still trying to get a picture on thi page that doesn’t work like it use to.
Thank you Mark! That is exactly what I was hoping to achieve. It is a hard working yard goat that gets some hard work and little TLC like most of the road engines would have in 1925. (I was trying to find an excuse to do some weathering on the loco…)
Very kind of you to offer. I will round up some shots of my fleet and through you a PM. Even though I love steam locos and know basically how they worked, specifics of how each part functioned are often beyond my knowledge.
