rcs@linus.UUCP (Richard C. Smith) (08/09/85)
The sand towers had nothing to do with the fires in locomotives. Rather, they were used to add a little friction to the drive wheels when needed. These towers are one (or possibly more) of the domes that rest on top of the boiler. Sand is placed in them. A pipe runs from the tower to the drive wheels, just above the rails. When the wheels slipped, the engineer would give a metal rod a pull-push, and a quantity of sand would slide down the pipe to the wheel. I wasn't aware that these were still in use in todays engines, but, I can't think of any other reason of carrying a sand tower on an engine. Rick Smith
Dan_Bower%RPI-MTS.Mailnet@MIT-MULTICS.ARPA (08/13/85)
A few points: I'd always heard them called "sand domes" when referring to the supply of sand on a steam locomotive. The sand dome was always placed atop the boiler so the heat would keep the sand dry. (Wet sand will not flow, just like wet sugar.) On diesel locomotives (and electrics, and streetcars...) I've always heard the sand supply called a "sand box". Most diesels have two or four sandboxes (one for each truck or one for each side of each truck) so as to minimize the length of pipes needed to carry the sand. The shorter they are, the steeper they could be, minimizing the chance of clogging. Also, for many years now, locomotives have had pneumatic sanders. With these, air pressure actually blows the sand between the wheel and rail. Railroads found out long ago that a hefty crosswind would blow the sand off the rail before the wheel would run over it. PS. I have heard the term "sand tower" used to refer to an overhead supply of sand at a locomotive servicing track. Typically sand towers are found near fuel racks (for diesels) or coal tipples (for steam). Some railroads also had combination coal and sand tipples.
drockwel@CSNET-SH.ARPA (Dennis Rockwell) (08/13/85)
[ ... ] I wasn't aware that these were still in use in todays engines, but, I can't think of any other reason of carrying a sand tower on an engine. Rick Smith As far as I know, they are still in use, but they are no longer so readily visible at the top of the locomotive. After all, there is still the need for additional traction (steel-steel is not the best match for adhesion). As backup evidence, I have a short article (anecdote, really) which mentions that the GG1 (the greatest locomotive ever) had sand available to the engineer and it was used routinely in accelerating away from stops; also, on a recent (business) trip to Stockholm, I spent an entire afternoon at the central RR station and the RC1 thru RC5 locomotives all had sand pipes leading to the wheels. The RC class locomotive is the basis for the AEM7 (?) currently in use by AMTRAK in the Northeast Corridor. Dennis
Swenson.PA@Xerox.ARPA (08/13/85)
Sand is indeed needed. I was on a trip on the California Western last summer (or perhaps the summer before)-one of the first steam trips in several years. The steam engine ran from Fort Bragg to the midpoint and swapped cars with a diesel from Willets. We went on to Willets behind the diesel. The sanders on the diesel were empty or clogged. The engine was unable to pull the train around an uphill curve. Finally after many failures, the train crew went along the tracks and picked up pinches of sand along the track & put this sand on the rails. After perhaps a half hour of this, the train was able to proceed.