The On-Line Magazine of Rideable Model Railroading
© August 14, 2011
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Running a Live Steam Locomotive
In the yard at Ridge.
Written by Tony Windsor
I have a 3-3/4" scale, 7-1/2" gauge British narrow gauge live steam locomotive. It is a tank engine, propane fired and weighs 350 pounds. It is 42Ē long, 16Ē wide, and 28Ē high. Operating pressure is 80 psi. Running this machine is akin to flying a Piper Cub, Cessna 152, a radial engine Stearman biplane, or a full-size steam locomotive.
Before lighting the fire, I have to check the locoís nuts & bolts, screws, and fittings for tightness. You donít want stuff falling off on the tracks: youíll never find them on 2 Ė 5 miles of trackage that most clubs harbor. Next step is to oil all the places ( 26 on my loco ) with bearing, sliding, pin, with tackiness additive oil. Next step is to oil the piston, slide valve, crosshead rods, steam, water, valve stems, (10 places), and the steam oil lubricator tank with special compounded steam cylinder oil. Next, check the propane (20 lb. ) bottle level and the regulator setting should be set at 8 Ė 10 psi pressure. Now fill the water tank on the engine and the tender and add 2 ounces of LSB8000 boiler water scale treatment to the water tank in the tender. Stir thoroughly.
Check the water level in the boiler. The gauge glass should read no more than half full ( water expands when heated ). Drain some water from the boiler if necessary.
Set the Johnson bar to neutral, and set the brake to on. Open the steam cylinder drains. Open the firebox door, insert the igniter and light it at the burner. Open the gas valve a little bit and observe the burner flame coloration. Shut the firebox door and place the electric exhaust fan on the chimney and plug in. Turn the gas up a little bit more. The blower steam valve and throttle should be closed. When the steam pressure gets up to 30 psi, crack the blower steam valve and remove the electric fan. Firing up takes about 15 Ė 20 minutes to raise the pressure to 80 psi, which is the operating pressure of this locomotive. The relief valves (2) are set for 90 and 95 psi because the boiler and tubes are copper. (steel boiler can operate at higher pressures).
On the steaming bay at Manatee Central
The whole operation takes me about 45 Ė 60 + minutes to steam up for the dayís running. This also takes into account yakking to other people at the steaming bays, all of whom are doing the same things. After a last check, Iím ready to move out. Releasing the brake, from the steaming bay I roll on to the hydraulic elevator transfer machine (or in some clubs to the turntable) to the freight yard or mainline and attach my freight cars to the tender and locomotive completing my train. Now Iím ready to start running under steam power. I set the Johnson bar to forward, open the throttle a bit (as the cylinder drains are still open) and purge the condensate out of the slide valves and cylinders. This is because they are cold and it takes hot (325 degree f.) steam to warm them up a for a few minutes. As I slowly move out I observe the condensate shooting out and finally just steam, travel a few more yards to make sure just steam and not condensate because if I donít, the condensate and oil will spit out of the chimney and shower me and the loco, and tender.
After about 50 feet or so, Iíll close the cylinder drains, advance the throttle a little bit more and get up to running speed which is about 4 Ė 6 miles per hour. During this period I observe the steam pressure, maintaining 80 psi by adjusting the gas burner control valve and keeping an eye on the water gauge level glass. If it starts to drop when Iím moving Iíll close the needle bypass valve at the engine water saddle tank crosshead pump and thusly divert the water to the boiler as needed. While doing this I have to open the gas valve at the same time to maintain 80 psi operating pressure or else failure to do so will result in the locomotive stalling on the tracks, holding up the locos behind me ! ! ! The reason this happens is because the water from the saddle tank is only about 112 deg. F. Big difference in temp of the boiler which is 325 deg. F. So, pumping water from the tank to the boiler results in a massive drop in temperature which has to be compensated by more gas to the burner. The other means I have available is to utilize the steam injector apparatus which draws water from the 6 gallon tank in the tender and injects it into the boiler. The beauty of the steam injector is that you can replenish the water in the boiler when stopped or when chugging along.
The Largo railroad club layout is fairly flat, not much change in elevation and very few grade rises and dips to contend with. At the Manatee Central railroad at Parrish the elevation is also fairly flat, but has many more rises and dips then the Largo railroad. The Ridge railroad club at Dundee Is a whole different ball game. Large changes in elevations with a long downgrade of 6% leaving Suicide Hill towards Coachwhip Cut. Lots of rises and dips throughout the layout. Big Boots and Western railroad club at Candler is a lot like Manatee Central railroad except a much bigger layout. The newest railroad just starting up is Central Pasco & Gulf railroad in Crews Lake Wilderness Park in Pasco county. Very similar to Big Boots.
Running a live steam locomotive at these clubs entails constantly watching the boiler water gauge level glass because of the rises and dips of the track as i chug along. I can only check the water level when the loco is on a level section of track. Also the throttle has to be constantly adjusted to compensate for the rises and dips along the trackage and try to maintain a constant speed. When going down Suicide Hill at Ridge railroad and rapidly picking up speed I flip the throttle to stop and pull the Johnson bar to reverse. This slows down the loco, and if Iím still gaining speed, Iíll open the throttle a bit more to further slow down to prevent a runaway locomotive. At the bottom of Suicide Hill I flip the throttle to stop and push the Johnson bar forward, advance the throttle a bit and chug through Coachwhip Cut and beyond.
So running a live steam locomotive entails watching boiler water level, operating the gas valve and throttle to maintain 80 psi running pressure, and keeping a constant speed. And oh yes ! ! Keep an eye on where Iím going ! ! ! When shutting down the locomotive at the steaming bay: first thing to do is connect the steam cleaning hose at the valve and steam clean the oil off the engine and tender. Then shut the steam blower valve and gas valve on the propane tank, then the gas valve on the engine. Open the cylinder drain valves, and blow down the boiler. (this valve is located at the bottom of the boiler at the firebox). After a cool-down period, close the blowdown valve and the water valve in the tender. Running a live steam locomotive is all about balance, just like flying real or model airplanes. Screw up and youíll crash ! ! !
Down the mainline at Manatee Central.
Written by Tony Windsor
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