Passenger Trains > Cabbage and control car questions

On a cabbage, there are operator controls.  My question is... are all the passenger cars MU'd like freight engines?  Or is there a radio link like DP?   Are control cars (operator controls in passenger car)  MU'd also?   Was curious how these works with passenger cars in between engines.   Thanks.  

MU

I don't believe Amtrak locomotives are set up for radio-controlled distributed power operations like freight trains. So the long cable between ends of the train it is. As far as how long a train can be run in that mode I would have to defer to those with more knowledge on the subject.

Could Amtrak then have two powered units, one at each end of the train?

For instance, could the Ski Train run with it's current two units, but one at each end? They could then dispence with the cabbage and save weight.

Yes. It is common to see engines on both ends of corridor trains in Michigan, Wisconsin and Illinois.

You won't see such an operations running out of RTD-Denver owned Denver Union Station. Having a locomotive on the downhill end would cause fueling and exhaust problems because of the station layout.

One interesting consideration is line drop of voltage as it travels from the locomotive. The 72 volt source of control DC power originates in the controlling lead locomotive, and then  travels down thru the MU jumper cables and the MU conductors in the cars to the cab car at the opposite end.  When I worked for MARC, we measured it one time, when we were running a special train to western Maryland for some special occasion or another.  We were unpleasantly surprised at the line drop, by the time the electricity left the controlling locomotive, went back thru the train to the cab control car, and was used make up the throttle signal, and then traveled back to the locomotive(s) powering the train.  We arbitrarily limited the length of our push-pull special trains, after that.  Either that or ran the locomotives around the train. I remember the line drop was 50%. I don't remember how many cars we were running, that weekend.

G.F.Payne
Baltimore, MD

Thanks for the info!

406 is not a regular cabbage, it has head end power generator thus the #406 not 90406.

There was eight cars on the train.