Steam smoke question

Discussion in 'Getting Started' started by TrainNut, May 7, 2006.

  1. TrainNut

    TrainNut Ditat Deus

    While watching some train videos, I've noticed before that the color of smoke from a steam engine can almost instantly change from black to white. I've always wondered if the blacker the smoke, the harder the engine is working? Today, I saw another video where a town asked that the trains not blow any black smoke within the city limits. Soooo, obviously this can be controlled. What does the engineer/fireman do that changes the color of the smoke?
  2. jim currie

    jim currie Active Member

    there are a lot of factors that affect smoke color like over fireing, shaking the grates,heavy handed enginer and quality of coal(oil).i understand that a lot of citys and towns had black smoke laws.
  3. Russ Bellinis

    Russ Bellinis Active Member

    I think with a steam engine, the combustion is a lot like a gas engine in that a richer fuel mixture burns black(incomplete combustion) while the ideal would be light or white (complete combustion). I think an engineer blowing out black smoke is wasting fuel, but I may be mistaken.
  4. doctorwayne

    doctorwayne Active Member

    Another cause of black smoke, at least for a short duration, would be when the flues became partially blocked by built-up deposits of soot. The fireman would hold a scoop of sand in the open firebox door and the draught would suck the sand through the flues, in effect sandblasting the deposits, which were the ejected out the stack.
    As noted, bad coal, poor firing practices, or a heavy-handed hogger could all be factors, along with the design of the boiler or lack of proper maintenance.

  5. brakie

    brakie Active Member

    Another thing a lot of that low grade coal had slate mixed in causing firing problems..
    Another thing is a lot of railroads had "no smoke" rules.At one time firemen was Leary of anybody standing track side with a camera..You see railroads had photographers that would take pictures of fireman violating the "no smoke" rules.
    My Grandfather Miller was busted for that rule infraction and when ask why he violated the no smoke rule my Grandfather looked the Division Superintendent in the eye and replied "Buy better coal and that kind of -censor-won't happen." or so the story goes..Knowing my ill tempered Grandpa I don't doubt that story at all. :eek: Grandpa was promoted to the right hand side about a year after this happen.
  6. N Gauger

    N Gauger 1:20.3 Train Addict

    I found this on the Gloucestershire Warwickshire Railway Web site :) :)

    Also there was a big thing in PA about a mythical lady known as Phoebe Snow who was in many ads for Lackawanna Road due to them burning anthracite which burned hotter, allowing for minimal debris out of the smokestack. Which caused mostly steam to be exhausted, Mostly White. :)

    Google "Phoebe Snow anthracite" without the quotes and you'll see the story :) really interesting :)
  7. 60103

    60103 Pooh Bah

    Black smoke is generally unburned coal. On Diesels it is unburned oil. The white "smoke" is largely steam that's been through the cylinders and is condensing in the cooler air. One of the principles of steam locomotives is that the force of the exhaust steam going up the stack pulled air through the fire and helped with combustion.
  8. isboris4449

    isboris4449 Member

    Coal burning and oil burning steam locomotives generate smoke for entirely different reasons. With a coal burner, some smoke is a constant. Whenever you add fuel to the fire, it takes a few seconds for it to ignite, which results in thicker smoke. A coal burner is also throwing cinders as it exhausts, which also darkens the smoke. When an oil burner smokes, it is usually the result of over firing. Sometimes this is for show, sometimes because there are factors effecting the firing, and sometimes its just poor firing.

    On an oil burner, the person firing it must stay right with the engineer's use of the throttle. More throttle, more fire, its that simple. If they are slow to respond to changes in the throttle, they will see the boiler pressure drop rapidly. When starting from a dead stop, as the throttle is opened, its best to open the firng valve a little too much, and let the increased use of the throttle clear up the stack. Otherwise you can be robbed of 10 or more pounds of pressure just like that. As you roll down the tracks, you must watch the engineer closely, increasing or decreasing the firing rate to match their use of the throttle. You want to maintain a very slight haze at the stack, while keeping the boiler pressure as consistently as you can to within 2 to 3 pounds of the pressure the safetys are set at without lifting them. But, as the "prime directive" is to make steam, if overfiring and smoke are neccessary to maintain pressure, you live with the smoke.

    Burning oil causes soot build-up on the walls of the tubes and flues, reducing the transfer of heat to the water and making it is neccessary to "sand" them. While the locomotive is being worked hard enough to create a very strong draught, a couple of scoops of sand are fed through the firebox door peep hole. The draught literally sucks the sand out of the scoop and down the flues, exhausting out the stack and cleaning the flues in the process. Needless to say, this can create some impressive smoke plumes.

    Besides mechanical and/or fuel issues, some locomotives have characteristics thet may result in the need for over-firng and black smoke. The 4449, normally a very easy locomotive to fire, has what we jokingly refer to as the "fireman's black hole". When the engineer is using between 45 and 60 pounds of cylinder pressure, it uses more steam than can the blower can create enough draught to replace, but at that pressure she doesn't have a strong enough exhaust draught to replace it either. This means you must over-fire, creating lots of smoke, and use every trick you know to fight the certainty of losing pressure. Doyle will use ever trick he knows to help you, but sometimes the only choice is to make a brake pipe reduction and literally drag the train a little to work the Daylight harder.

    Then there was the time at Roaring Camp and Big Trees in Felton, CA. The fuel supplier accidentally dumped more than 100 gallons of acetone into the ex-Westside Lumber Company Heisler number 3's fuel tank instead of oil. Even though we stirred the oil and acetone with air, for the next two days, even with the firing valve all but closed, we had a brilliant white flame and the safety's were lifting most of the time. An inspection of the firebox and boiler tubes revealed them to be absolutely clean and free of any soot what so ever, LOL.


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