[PRR-talk] US&S "box" on axle of GG1.

[zootowerprr at webtv.net]

     I have a couple of questions about a modification to the GG1. There
was a "box" (US&S Automatic Train Control) attached to the second axle
on the lead truck of the GG1. I think that only one was attached to each
GG1 and it would be on the "F" end of the motor on the engineer's side.
My question is when did PRR begin installing these devices to the GG1?
And did all of the GG1's receive this modification?
     I never really notice these little boxes mounted to the lead trucks
until I came across some photos of close ups of the trucks. Then I
notice the "US&S" logo on the box. Also notice that the E44s also have
the same device on the "F" of the motor. Any info is appreciated. Thanks
in advance......

Dave Hopson