63 



in prices of the two metals, copper and aluminium (see page 59) 

 explains why. Several United States transmission companies even 

 went so far as to replace already existing aluminium lines with copper 

 for economic reasons. The following are notable examples: 



Rochester (N.Y.) Railway and Light Co. " Arrangements have 

 been made by the Rochester (N.Y.) Railway and Light Company to 

 substitute No. stranded copper wire for the 428,000-circ. mil. 

 stranded aluminium conductors of a duplicate three-phase trans- 

 mission line between Mortimer, N.Y., and the city of Rochester." 

 The aluminium transmission line was built in 1907 and designed to 

 transmit 18,000 h.p. This capacity has been reduced by the change 

 in conductors to about 12,000 h.p., which is considered sufificient for 

 future service. With the price of aluminium at 56 cents per pound 

 and copper at 20 cents per pound — the basis on which the substitution 

 was made — a net amount of $8,400 has been realized from 63,000 

 pounds of aluminium through the change.* 



Northern California Power Co. — " On account of the present 

 abnormally high price of aluminium, and also because it has deemed 

 it advisable to increase the capacity of certain of its transmission 

 lines, the Northern California Power Company, Consolidated, of San 

 Francisco, has taken dowTi some of its aluminium wire and substituted 

 therefor copper ware. The proceeds from the aluminium wire taken 

 down have been sufficient to cover the cost of copper wire of greater 

 capacity together with the labour and other costs involved. The 

 company has made this change from aluminium to copper wire on its 

 high-tension lines between Hamilton City and Nord, a distance of 

 about 9 miles, and between Hamilton City and Chico, a distance of 

 about 13 miles. It is at present engaged in making a similar change 

 from Hamilton City toward Butte City, a distance of about 20 miles, 

 and, as soon as this is finished, it will change the line from Orland 

 northerly, a distance of about 30 miles. "f 



Montana Power Co. — " Recently advantage has been taken of 

 the high price of aluminium by the Montana Power Company in the 

 reconstruction of transmission lines from its power stations on the 

 Madison river to Butte. Originally three 50,000-volt lines were 

 constructed between these points, two of them using aluminium 

 conductors on wood poles and one No. copper on steel towers. 

 The steel tower copper line has been re-insulated for 100,000 volts 

 and the aluminium lines abandoned. General Manager F. ^L Kerr 

 of the Montana Power Company gives the cost of re-insulating the 



♦ Electrical World, Dec. 25, 1915. 

 i Electrical World, Feb. 19, 1916. 



