STEAM HEATING FROM THE LOCOMOTIVE.
The committee on car heating at the last convention of the Master Car Builders’ Association reported the results of thirty-three practical tests of eighteen different systems of heating, all of them using steam from the locomotive. The reports did not cover any scientific tests of the amount of steam used and for the most part covered only short tests. The main results have been thus summarized by The Engineering News :
Twelve systems use steam with direct radiation, four of them using also indirect radiation ; three systems use steam to heat water in connection with the Baker heater ; two use direct radiation from water, which means much the same thing. Five systems have the main pipes inside the car, all the others under the floor. One system (Wisconsin Central) disposes of the water of condensation by a condenser under the car; two (the Pennsylvania R. R. and Automatic Car Coupler and Heating Company) by returning it to the locomotive, and all the rest by traps. The temperature is controlled by a regulating valve which requires constant attention in two, more or less attention in six, very little attention in eight, automatic in one (C. M. and St. P.) “one adjustment per trip ” in one. Not much reliance can be placed on these reports; for instance, two systems which have been tested on different roads are reported by one to need “constant” attention, and by another to need “ very little.” The fact as to all of them probably is that they need about as frequent attention as ordinary heaters, while automatic thermostyle regulating valves can be attached to any of them if desired. None of the heaters employ any other resort for occasional heating without the locomotive except the Gold, which has a drum filled with brine. As a rule the pressure is low, not exceeding ten pounds. It appears to take from thirty to sixty minutes to heat a car to seventy degrees when outside temperature is twenty degrees, but the reports on this head are very unreliable. The ordinary brass and iron expansion steam trap is the one almost universally used ; only one uses a float trap (N. W. Car Heating and Lighting Companj-). Steam must be wasted through the rear coupling, according to the reports in seven, need not be in eight, responses are divided in two (as there probably would have been for others, had there been more tests of them), and there is no response for one. The flexible connection between cars is rubber hose in thirteen, two of which use corrugated rubber; metallic couplers are used in five. The metallic connections seem to be a rather weak point. The pith of the whole elaborate abstract and report, apart from the easily ascertained mechanical details of each, some of the statements as to which should be received with reserve, is contained in the following condensed abstract of “general results:”