Bigt wrote:Maybe posting in wrong place, but, here goes. Was in Massena yesterday and saw a northbound
leaving the yard. Two units #s 907 & 911 (?). From my vantage point, I was looking at the fireman's
side of both cabs. The second unit had a small (about the size of the old tractor trailer type cab
clearance lights) amber light on the side of the cab - below the window, and, directly in front
of the unit number. This light was lit. The lead unit had the same light, but, was not lit.
My question is: what is this light, and, what does it signify?
When those lights are lit it means the LSL is cut in. The LSL enforces the speed in conjunction with the cab signal indication. For example: you are running on a clear cab signal doing 50MPH. The cab signal then drops to approach. You have 20 seconds to get to 30MPH or it will give you a penalty brake application. It will enforce a speed even in non cab signal territory if it is cut in, 20MPH due to the cab signal always displaying restricting in non cab signal territory.
This only applies when the locomotive is setup for lead, if the locomotive is set up in trail it has no effect if cut in but the lights will still be on.
The only place I know for sure that uses the LSL are the Amtrak lines from Hoffmans to Poughkeepsie. I think the NEC does too and I'm not sure about Metro-North
The B&A, even though it is cab signal territory does not use the LSL.