Searchlight type automatic block signals installed by Boston and Maine Railroad, on 17 mi of double track main line between Tower A in Boston Mass, and Silver Lake, Mass, to replace 2-arm lower quadrant semaphores; traffic conditions; 2-coil searchlight signal; wires on terminal board; new circuits developed; light-out relays; power distribution and battery supply; arresters and terminals; etc.
Boston and Maine replaces semaphores with light signals
Ry Signaling
Railway Signaling ; 35 , n 8
1942
5 pages
Article (Journal)
English
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