Mechanicville Yard Hump Signal restoration

[Ham40PH]

I am rebuilding a signal from the Mechanicsville yard used in the hump. This signal has fore lights amber, green and then red and amber (although it could also be amber and red) I am wondering if anyone knows how this would be set up and what the various signals would mean.

[oibu]

I can't add too much relating to how the sigals are actually used and what the different colors convey, other than to say that there may be some additional funky colors involved beyond just standard signal colors. For example, IIRC on the ED hump signal I think PURPLE is one of the colors used. Hopefully others can add more, you may also want to try this question on the yahoo B&M group if you haven't already.

[690]

Sure that it's purple, and not a lunar signal?

[Zeke]

As a rule every hump yard had different special instructions guiding train crews engaged in humping cars as opposed to a flat switching type yard. Generally speaking Green or steady Amber meant Slow hump.....Flashing Yellow would indicate fast hump if a large cut of cars were staying coupled and then cut loose....Red signal would indicate stop humping ..... purple would indicate back up. The hump conductor usually would be in control of the hump signals, and as he read and progressed through the cut list supplied by the Yardmaster, work the signals accordingly.

[TomNelligan]

You should get a copy of a 1960s-era B&M employee timetable. They had a whole page of special instructions for Mechanicville yard, including the hump signal. Per the employee timetable effective January 4, 1964:

Green light indicates fast speed ahead.
Two yellow lights indicates medium speed ahead
One yellow light indicates slow speed ahead
Yellow above the red indicates back up
Red light indicates stop