Train 4007 on 5/6/08

Hello. I'm a new member to this forum, even though I have been frequenting it out of plain curiousity for the past month or so.

Anyway, I have a question. This morning, I took train 4007 on the West Trenton line into work. I noticed while waiting on the platform that it was running a bit late. What was really peculiar was that it was apparent after boarding that the lead car was not receiving enough power to generate propulsion, light, or ventilation. The emergency lights were on though.

I sat there thinking and wondering how in the world a car that appeared dead and not receiving any power from the overhead could lead an entire train and still have power for the headlights, emergency lights and horn.

I'm a little dumbfounded by this. Could someone please explain it to me?

Oh, and btw, the car was S-IV #278. Thank you.

Welcome aboard, and good question.

The trains have multiple power systems, one of which is a battery backup system for the emergency lighting, and the other being the main power for propulsion, lights, and HVAC. I presume that backup system is also powering the cab signals and other safety-sensitive equipment (our manuals are at the office so I can't give you the exact specifics, but that is the case in the Silverliner V specs).

The control circuits and stuff like the communications line run through the entire train. There are no wires between the cars like you would see on an Amtrak train: Silverliner couplers contain pins that make those contacts between cars.

One of you operating guys please fill in details or correct any of this that happens to be wrong.

Matt Mitchell
Delaware Valley Association of Rail Passengers
www.dvarp.org

Everything Matt said was true. I think the problem with the particular MU you mentioned is that the motor alternator (MA) had shut down, requiring someone to open up one of the electrical boxes on the exterior of the train to reset. Otherwise, there may have been an overload on one of the other breakers, mainly a transformer overload or overheating.

Thank you very much, Matt. If it was indeed a battery that was providing power to the emergency and safety systems, it must be a pretty powerful battery. I don't get to see Amtrak trains often, nor do I ride them (I've only ridden the Acela once on the company's dollar). Besides, I would assume that Amtrak and its equipment is a different beast that wouldn't be comparable to SEPTA anyway.

I don't know exactly what the problem was, but apparently the backup procedures worked and got us downtown safely. That's all that matters in the end, right?

I had made a reply, but it didn't post.

Around this time last year, I was on 4007 heading into school one morning. The lead car had a problem with its pan at Woodbourne, but it was the lead car on my train. On the car, the external lights were out, and all the internal lights were too, except for the emergency lights (every other few lights were on). I also believe the horn worked.

Well remember that SEPTA's passenger train fleet consists mostly of MU's. Even though one unit may not provide traction power, the others will, in effect towing around a dead horse, a dead unit. Amtrak's passenger trains are primarily loco-hauled coaches, so that the locomotive provides the electricity to the coaches via the HEP cables. No HEP, no lights.

Battery power is trainlined on all MU's thru the coupler. That means that all the cars in the consist share battery power which is able to keep the controls operational from a lead dead car. This includes headlight, train control, ATC and radio.

I had a similar problem on the R5 coming from Glenside last Sunday. We hit the phase break after Temple and the first 2 of 3 cars lost power. Listening to conversation/radio chatter, something happened to the pan. The crew got off the train to look it over/check electrical stuff, got back on, and dispatch told them to proceeded to Suburban, and everyone switched to a waiting train set there.

Fairly common occurrence? First time it happened to me.