FAST AND HEAVY RAILWAY SERVICE. 263 
method of supporting it in the tunnel. Current is taken 
off by a snug-fitting brass shuttle carried on a toggle joint 
trolley frame, and leading to the motors by a flexible cable. 
Fig. 136 givesa clear idea of this trolley structure, which in 
practice does its work exceedingly well. Save for occa- 
sional trouble before the conductors were cleared of rust 
and dirt, at the very first, the arrangement has left little 
to be desired. The conductor in the tunnel is supported 
every fifteen feet, and outside the tunnel the spans are thirty 
to sixty feet. ’The trolley support has great lateral flexi- 
bility and the working conductor is normally alongside the 
locomotive rather than over it. 
  
  
  
  
  
  
  
S8ECTION THROUGH MAIN TUNNEL. 
FIG. 137. 
The power house is near the southern terminus of the 
electric system and current is taken from it to various 
points on the line over 1,000,000 ¢. m. feeder cables. The 
working conductor is carefully bonded at each joint by two 
No. oooo bond wires. 
Now as to operation. After continuous service for 
more than a year, the system has shown itself to be 
thoroughly efficient and reliable. Repairs have been light, 
the working conductors have been easily kept clean by 
running through a scraping shoe every two or three weeks, 
the leakage current in spite of the moisture of parts of the 
tunnel and very dirty insulators has been only about 
four amperes.