Ex-Conrail Units

I notice in many pictures lately and several trains I have seen, that ex-Conrail units are placed in the lead. Is this just coincidence (which I can totally believe), or are they better units to operate from? And if so, why?

Thanks

Depends on where you are, my friend. Perhaps on former PRR territory with cab signals? I don't think NS equips all of their fleet with such equipment, thus requiring a Conrail unit to lead (and trail in the consist, I believe).

LCJ wrote:Depends on where you are, my friend. Perhaps on former PRR territory with cab signals? I don't think NS equips all of their fleet with such equipment, thus requiring a Conrail unit to lead (and trail in the consist, I believe).

What are cab signals and how do they work? I railfan the "middle division" between Enola and Altoona sometimes, and have been told they use cab signals, hence why foreign power is never in the lead. I've always wondered how the cab signal system works.

Scott

Seek and ye shall find, guy. The former PRR "Middle Divsion" does indeed have coded cab signals. Coded signal info is passed through the rails themselves, and is picked up by inductive receivers on the locomotives.

http://en.wikipedia.org/wiki/Cab_signalling

The cab signals need to be working also, because if they aren't, it really slows things down.

Thanks LCJ, I am in Northern NJ, and many of the photos I was talking about are from the same area. I guess this is mostly former Conrail territory?

Yes indeed, although that part of Conrail had no cab signals. Cab signals are on the Amtrak Northeast Corridor and the Keystone Corridor to Harrisburg, and the current NS main track from Harrisburg to Pittsburgh. Also the NS Enola branch/Royalton branch/Port Road branch (not sure what NS calls them now).

LCJ, also the Morrisville Line from CP-King to morrisville yard is also cab-signal energized. The neat thing there, along with the conemaugh line from Pittsburgh to Conpit, is that it is Cabs with no waysides except at interlockings.

The wiki entries on cab signals include very good description of the PRR system thats still in used.