PRR
Spent many a Saturday morning on the Honeywell Street bridge over Sunnyside Yard with my father.
Honeywell crossed the yard right by the motor pit, where GG1s received sand and water and fuel oil between runs.
There was a small engine house where the Sunnyside wire train power was kept. Originally it was a DD1, which now resides at the RR Museum of Pennsylvania. That was replaced by the last former NYC T-3a motor. The wire train used 3rd rail electric locomotives so sections of the catenary in the tunnels and in Penn Station could be de-energized at off hours for maintenance.
