. Electric railway journal . pper. It is this largedifference in cost which has been the main reason forusing steel conductors on the branch lines of some ofthe big power distribution systems. This difference incost is greatest when the price of copper is highest. Steel cables have the added advantage of being me-chanically stronger and less liable to be burned througharcs. Their useful life is much shorter than that ofcopper cables and their scrap value practically price of copper cable per pound may be assumed asbeing ten times that of galvanized steel cable. Thisratio is the usu
. Electric railway journal . pper. It is this largedifference in cost which has been the main reason forusing steel conductors on the branch lines of some ofthe big power distribution systems. This difference incost is greatest when the price of copper is highest. Steel cables have the added advantage of being me-chanically stronger and less liable to be burned througharcs. Their useful life is much shorter than that ofcopper cables and their scrap value practically price of copper cable per pound may be assumed asbeing ten times that of galvanized steel cable. Thisratio is the usual one, being approximately true fortimes of low price of metals as well as for high times,and the use of steel will always increase the reliabilityof the transmission system. Installing Pit Lighting Conduit At the Hooker Street shops of the Springfield (Mass.)Street Railway, now under construction, conduit for pitlighting service is installed in horizontal runs as shownin the accompanying illustration, alternate recesses in. HORIZONTAL RUN, SHOWING CONDUIT AND JUNCTION BOXINSTALLED FOR PIT LIGHTING the pit walls being equipped with single and doubleoutlets. The pit walls are about 8V2 in. thick and arereinforced with %-in. rods which are tied to the con-duit pipes by iron wire at alternate vertical supports-Junction boxes located at the ends of the conduit runsare mounted at the top of wooden form boxes as shown,the concrete being poured around the rods and boxesso as to cover the junctions. The form boxes are re-moved after the setting of the concrete takes place,leaving the pit outlet recesses open and ready for pull-ing the wire. Pit recesses equipped with single out-lets are 12 in. x 7% in. x 10 in. x 5 in. in size, andthese outlets are provided for drop light service by theuse of flexible cords. The recesses containing two out-lets each are designed to accommodate pit lamps ofthe fixed type, and are about double the length of thesingle recesses. <
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