I know no matter what you're burning, a close to clear stack is an indication of good combustion, draft and fuel economy. I find it tough to think of a time I've seen the Cass engines with a clear stack. I'm guessing it has something to do with spark arresting stacks. Or maybe it's done on purpose. I'm curious if there IS a reason for the rolling black clouds up to Bald Knob.

Coal dust blowing up the stack. No choice.

Unburnt oil up the stack - change the fuel and/or air mixture.

I've been to Cass more times than I can remember, throughout my whole life. I think the "standard" at Cass is:

1) Make Steam! 2) Don't allow any cool air in to stress the firebox 3) The railfans like smoke 4) Don't burn TOO much coal, because it's expensive.

In that priority.

Yes, I've seen clears stacks, but not for long......

Mark,
Based on my own experiences as an exceeding rusty (hand fired, coal only) steam locomotive fireman, I would agree that you have the priorities correct, except that 3 & 4 are possibly reversed. I still remember the butt-chewing I got over 30 years ago for using too much coal on a photo runby by a legendary Master Mechanic-Steam on a former class 1 railroad Steam Program.

Greetings:
Coal with a volatile content less than 16% +/- produces little if any smoke (think anthracite or Pocahontas) while coal with a higher volatile content will produce smoke unless it is pulverized (or nearly so) and blown into the fire almost like oil firing and/or mixed with air or steam (think Wardale's "Irene" and "Red Devil" which were equipped with Gas Producer System fireboxes).
J.David

Am I correct also that these engines do not have arches?

I am not a steam mechanic, but I work seasonally at Cass now, and have observed the same phenomenon enough to be curious.

Mark Jordan Wrote



While it's true that the engineers at Cass are known to create theatrical effects for railfans, it is also true that the stacks are rarely clear, even when business is slow and the only passengers are tourists who are unlikely to care if their picture makes the cover of Trains. I've been around to watch often enough, and ridden the cab enough times, to believe that it's got less to do with firing practice than something else. With more conventional locomotives, it does, I know, but I've seen firemen doing what they were supposed to, and the smoke was still heavy. The problem is just too consistent from fireman to fireman, and from day to day, for it to always be their fault.

Also, I don't think it's the coal. Last year's supplier was a Pocahontas-seam mine, and though the smoke was a lot cleaner-smelling and less sooty than the noxious, yellow clouds that a previous year's high-sulfur stuff produced, it wasn't diminished enough in density or quantity to suggest that low-volatile is the only thing affecting the smoke level.

AlderGulch12 wrote:

softwerkslex wrote:


I haven't looked into every firebox, but I believe you are right about the arches. This may have something to do with it. So might those stacks, because the Western Maryland 6 is the only one with a straight stack, and it is consistently cleaner than the others.

Even if it is neither of those things, though, and even if firing has something to do with it, I believe it is at least partly a mechanical question. Perhaps I'll see if I can get a more knowledgeable answer the next time I am there.

I'm not a fireman either, but I would suspect the answer is firing rate. Even good coal smokes when green coal is added to the firebox until the volatiles "coke off", and with the operation at Cass, the fireman is ALWAYS adding coal on the run up the hill. Thus, the engine always smokes.

I'm familiar with KL&L 5 at IRM, a seventy ton engine, IIRC, about the size of No. 4 or 5 at Cass. KL&L 5 rarely smoked, but then again, running through the cornfields of northern Illinois, the fireman was rarely adding coal. The joke used to be that for our operation, the engine was fired with a teaspoon.

Actually, Dennis, I'd buy your answer before my own - I think it's the most plausible.

The 4-mile (give or take) climb from Cass to Whittaker takes about 45 minutes--all but a few hundred yards of which is uphill, averaging 3-4%, and as high as 9% in one spot. Keeping the pressure guage where it's supposed to be on the smaller engines seems to require pretty constant shoveling, between the engine's consumption of steam and the regular need to add water (injector's probably running somewhere between 1/4 and 1/2 the time).

The shop gives a figure of 1.5 tons of coal consumed per round trip (half of which is downhill). Someone, I don't recall who, claimed that it worked out to about a shovelful every 30-60 seconds on the uphill trip. In actual practice, by my observation, a fireman will probably add 3-6 shovelfuls every 3 minutes or so, so I guess it's not too far off.

With some of the firemen, the safety valve will often lift as soon as the locomotive levels out in the switchbacks, but this is probably more a question of stopping too late with the shovel than of consistently over-firing all the way up the hill, since the safety valve usually stays quiet during the climb with all but the greenest of firemen.

I'll still see if I can pick a knowledgeable brain when I go down there this weekend.

I first started going to Cass in the early 70s and while it has now been over twenty years since they converted the oil burning shays 2 & 3 to burn coal; I seem to remember that the oil burners put about as much black smoke up into the air as did the coal burning shays 4 & 5 and Heisler 6. So I'd have to agree with David Vago that it is not the type of coal that causes the smoke.

A little over thirty years ago I was given the rare chance to fire at Cass. At that time the coal was of questionable quality and much to fine. From this experience I can tell you that firing at Cass is about making steam. I had no time to worry about pleasing railfans on the train and knew that the passengers reasonably expected to make the trip to Whittaker and back on schedule. To make steam on steep grades with hand fired saturated engines equipped with simple boilers working that hard you are going to make smoke. While the quality of the coal will increase or reduce the amount of smoke to some degree you are still going to make lots of smoke.

While sitting at the Cass depot waiting for departure time the engine is sitting on a spot fire. Knowing what kind of railroad is ahead the engine will still usually pop frequently because you just can not afford to depart with nothing behind the doors. Upon departure the railroad is only flat until you start up the grade going by the shop. That means you have to start building your fire for the steep grades almost immediately. The fire must be gotten hot and thicker in order to maintain steam on the mountain. In addition to building the fire you are also on a grade that is slowly increasing and you are now making steam against the injector more frequently. When you cross the second highway crossing the grade starts getting much steeper and your fire had better be ready. All of this is going to produce smoke.

When against the mountain I spent my time between firing, breaking up clinkers with the hook, and watching the smoke to know when to lay the next fire. With the coal being used at that time, when the smoke went from black to a dark brown it was time to add more coal. I remember no time when I was able to let the stack go clear. When approaching Whittaker I had to make a judgement on when to quit firing to allow the engine to get into the station but limit the poping after stopping. When the train stopped more black smoke would appear. There is virtually no way to change from a hard exhaust to a quick stop with a coal fired engine without making smoke.

Most of the boilers at Cass over the years have been saturated with no circulators of any kind in the firebox. They were simple machines that are easy to maintain. The pacific coast shay had superheateres. Perhaps the 11 that is there today does as well. I am not sure. In order to get maximum work out of these boilers it is necessary to fire them hard. That makes smoke, especially with coal.

Only 1 of the 2 original oil burners, 2 and 3, is still at Cass. The other is in Oregon and has been operating for years as the Mt. Emily shay it really is. The oil burners did make smoke but not as much as the coal burners except when the flues were being sanded as I recall. WM 6 may have the most advanced boiler ever applied to a shay. WM was a big believer in Nicholson Thermic syphons and 6 has at least 1 in her firebox including a brick arch. Add superheaters to the boiler of the 6 and it should use considerably less coal proportionally than the older saturated engines. It also is so much bigger than the other engines that 6 is seldom worked as near to capacity. As a result I have noticed the 6 does not usually make as much smoke as the other engines.

The only way I can see for Cass to greatly reduce smole form the engines would be to convert the fleet to oil. In West Virginia that would be very close to treason. My experience at Cass was the first time I had fired a locomotive over the road that was working hard. I will always be grateful to the guys who offered the opportunity to me. The learning curve is sharp and the experience invaluable. Thanks again to a great steam railroad.

John Bohon

I'm thinking a well retrofit GPCS and feedwater heater would significantly reduce coal consumption and, if combined with an exhaust that didn't haul the fines from the firebox and toss them out of the stack even before they are burned, might also cut some of the visible particulates as well. Of course, they wouldn't be 1920 era Shays any longer. I've kept fairly clear stacks on similar sized oil burning Shays hauling maximum tonnage on steep grades in Colorado with well designed and maintained combustion systems so why the oil burners at Cass have problems I couldn't say. It generally comes down to the location and proportion of various components in the system as an interrrelated whole and needs to be considered as such. Reliable quality fuel is also extremely important......

dave

AlderGulch12,
I think everyone has given pretty good aspects for the reason for smoke and that your own observations are true. If you assessed the locomotive symptoms as you would a human body, you might see the smoke as a fever - a sign that there is a problem with the combustion systems or that the steam consumption of the engines is pushing the firing rate of the combustion systems outside of their practical operating range. The cause could be design as much as condition or operating practices – but it is not an “act of god” that they must smoke.

As hostler and occasional fireman on the East Broad Top, I have some input on this subject. Over the past decade we have used some sort of coal from western PA that smoked like the devil. One shovel would produce billowing clouds of smoke from the stack. It seemed to burn cool and was sometimes hard to ignite when firing from a cold start. It was also coated with oil, or some other petroleum product to reduce dust.

The coal we use now is "smokeless" Broad Top coal, the same coal the EBT was built to transport. It is semi-bituminous and has a very low sulfur content. Rarely does it smoke and 99% of the time the stack is clean. It burns very clean and doesn't clinker at all. Though, it does produce a decent amount of cinders that litter the train behind.

So, if I had to take a guess, I'd say it mostly depends on your coal, and less to do with how you fire. Granted, everyone fires in different ways and some may fire in a way that will cause a smoky stack, but for the most part this plays a small roll in how clean a stack is.

I could be wrong, but this is just my observations from the EBT.

.