Hello there, as part of the work I'm doing to develop a concept for a layout I'm getting ready to do (currently in the planning stages), I'm trying to get some info that I've been having some difficulty in finding as I've been sifting through various sites and forums.
As Accucraft nolonger makes an electric K-28 model, I am considering the alternative of possibly trying a live steamer version (probably starting with something smaller to learn on first). The questions I have are primarily to see if it would be feasible for the restrictions I've been given for what can and cannot be on the layout.
The primary questions I have is "how hot do the engines tend to run at for 1:20.3?" and "how much oil and the like I could expect to have come off a loco of that scale running under steam."
Part of my questioning on this, particularly the engine temp, is the knowledge of how smaller models may be able to run at a cooler temp. For example, a rare case of an HO scale live steamer I saw once ran at a temp cool enough to be able to touch it without burning your hand upon contact with the boiler partly due to the water not being required to actually reach the boiling point to generate the needed steam to power the loco.
My ancient chemistry class had a lesson or two on water turning from a solid to a liquid to a gas as temperature was increased at a given pressure. It is possible to reduce the pressure to lower the boiling or vaporization point to something cool enough to touch however to do that you would need something less than atmospheric pressure. Perhaps the HO scale live steamer had a condenser to lower the exhaust pressure? If so what cooled the condenser? If not a condenser then perhaps something other than water was being "boiled"?
I worked in the nuclear industry for a number of years. Our nucs used pressurised water systems. The primary coolant, kept at a high pressure so it never became steam, circulated through the reactor vessel to get hot and then through a boiler to transfer the heat to the secondary coolant at a much lower pressure so it became steam. This secondary steam went through various turbines to provide mechanical power and then exhausted into condensers which were cooled by the environment. The condensed water was fed back into the boiler to go through the cycle again.
Unlike the closed nuclear world our steam locos use water to make steam which is exhausted to the atmosphere so by definition they must produce pressure higher than atmopheric to get any action out of the pistons.
Bottom line - Water boils at 100 C or 212 F at 14.7 psi and that's hot relatively speaking. Please correct me if I'm wrong.
Rex
The Home of Articulated Ugliness
Rex and Ralph are correct, any live steam locomotive, regardless of size, will be somewhat above 212 degrees F (100 degrees C). Lagging on the boiler will reduce the temp of the boiler jacket somewhat, but it will still be hot enough to burn with long enough contact. However, if the locomotive is a saddletank style locomotive, you would be able to touch the tanks alongside the boiler without getting burned. Another type of "steamer" is the dry ice loco. Dry ice is placed inside a sealed tank, as it absorbs heat and evaporates it produces pressure that can drive the engine just as steam does. The problem with this type of loco is not a burn from heat, but frostbite from the extreme cold of the dry ice.
Are you thinking about a layout inside the house? An outside track usually doesn't have any issues with the heat or oil drippings from a steamer. No doubt about it, a steamer can be messier than an electric loco. However, with careful oiling of the moving parts, it can still be fairly clean. I subscribe to the theory that oil is cheaper than engines, so I tend to be somewhat liberal with my lubrication. Needless to say, my steamer will mark its territory if it sits in one spot for any length of time! Nevertheless, I have seen G scale steamers running inside at a couple of different train shows, but never on a scenicked layout, just a display track. I think you could safely run them on an indoor layout if you have adequate ventilation to get rid of the exhaust gasses, but an outdoor layout won't be a problem.
- James
Another consideration is that few of the presently available Live Steam Locomotives have insulated wheels... i.e.: if you plan to supply track power for other trains or lighted passenger cars, or to supply power to track-side features, the Live Steamer will short out the rails!
Yes, a Live Steam Locomotive can be "messy", mainly because we tend to over-oil the running gear. The original "toy" Live Steamers were usually built by a machinist and he was protective of his "baby", knowing how much work he put into making the parts and what it will take to re-make the parts when they wear out. Electric toy trains also need lubrication, but most of the parts are not "close fitting" and thus do not wear as rapidly or as badly. A Live Steam Locomotive can cost from 2 to 10 times the equivalent electric powered model, so you tend to want it to last.
The other cause of the "messies" is because of the method of supplying lubrication to the pistons and cylinder walls... you put steam oil in a container (Roscoe or Dead-leg lubricator) and the steam picks up some oil and carries it to the cylinders. The exact amount necessary is not well understood nor easily controlled... many Live Steamers do not even have a simple method (valve) to do that control. Even for those that do have a valve it is a trial and retrial method of adjustment... run the engine and see how much oil is left after a standard length run. If there is a lot of oil left then you didn't use enough. If there is none left, then you probably have lots of oil spots all over the engine - and track-side, too - so you need to reduce the flow somehow, either by closing the valve (if there is one) or modify the size of the hole where the steam and oil interchange (fill it with solder and re-drill the hole to a smaller size).
Gas fired Live Steam is much safer for use "indoors". Alcohol and coal firing can be quite dangerous if the engine derails and turns over (not that gas is all that much safer!). Gas can be shut off (if you can reach the valve) and all you have to do then is put out whatever caught fire due to the flame. Coal needs to be cooled considerable to get it to stop burning and this can be difficult. Alcohol becomes a liquid fire, running downhill where ever it splashes... Not nice in running around the Christmas tree!
On insulated boiler can be touched without much harm to the fingers, but few Live Steamers have that much insulation. There ain't no such thing as "cool" steam. Even steam blowing out the stack after being used in the cylinders can be well above 212 deg (f) and can scald easily. Hot oil droplets in the exhaust is worse since it does not evaporate like water, but remains on the skin to transfer more heat.
Semper Vaporo
Pkgs.
Get the Garden Railways newsletter delivered to your inbox twice a month