TELPHEEAGE. 



283 



Theoretical liorsepoircr lu'ceitsiirit To propel 1,000 jwumU at various Kpee(h and up various 



(jrnde.i.at satne xpeeda. 



Although the amount of power may be easily figured out, it is some- 

 what in the nature of a surprise when we consider that to carry half a 

 ton on a level track at a speed of 6 miles per hour, nnich less than a 

 horsepower is requin^d. including all losses. This is a revelation to 

 most manufacturers. The aljsence of gearing, the motors being 

 attached directly to the driving wheels, gives th(> highest efficiency 

 pos.sible, as well as freedom from noise. 



The actual power consumed, according to the table given above, at 

 6 miles per hour for 1,(HH) pounds on a level is only 0.16 horsepower. 

 It is therefore seen that ample allowance is made for losses and extra 

 weights not provided for in the load, such as down-comes, buckets, or 

 carriers. The po^ver required increases greatly with the grades, and 

 when this reaches certain limits it is deemed advisa))le to use gears in 

 order to reduce weight of motoi's. 



Maintenance. — Although telpherage has not as yet been in operation 

 for a sufficient number of years to determine exactly what the main- 

 tenance will be, 3^et, at the same time, in lines that have been operated 

 for a j^ear and a half the maintenance has been exceedingly small. As 

 stated above, the driving wheels being of steel, none of them has thus 

 far shown any signs of wear, and trailer wheels are of the same material 

 and type which have l)een used on mechanical cable lines foi- ten yc^ars 

 and are still in good serviceable condition. The motors, on account 

 of their elevated position, have shown a better mainteniince than sta- 

 tionary motors of the same type. This may possibly be from the 

 extra care taken in their construction. In regard to the track, this 

 has also shown most excellent results, also due to the fact that it is 

 above grit and dirt and crossing teams and, when well painted, has 

 shown little signs of wear or depreciation. Wherever a change is 

 made from cable to solid rail or where cable passes o\er hangers or 



