MU's As "Engines"???

This probably has been brought up in the past...but I've always wondered if an MU car (such as a Silverliner IV/V, or even an RDC) can play the role of a locomotive and be used with push-pull coaches (such as the "Bombers")...
Has it ever been attempted before (maybe not by SEPTA, but other agencies who use both MU's and locomotive-hauled coaches)??? Would it at all be possible to rig a Silverliner where it would be capable of pulling/pushing a 2 or 3 car consist of Bombers in revenue service???

I'm pretty sure they don't have HEP passthrough, and even if they did, they don't use jumper cables, they use connectors mounted below the coupler. They also don't have much spare horsepower to pull additional cars, and they use a different type of coupler. So no, they wouldn't be able to do so without modification. They can, however, pull specially designed trailers that have a pantograph or 3rd rail shoes to power lighting etc.

MUs are not designed to pull anything except each other. They are not powerful enough to pull dead weight. Sometimes we use MUs in the yard as "horses" to pull dead cars around. In a pinch to get dead cars off the mainline, we can couple up live cars to get the train moving. They do not have high voltage running between the cars for lights, HVAC or other functions. Those are all self contained on each car. The only exception are the married pair cars which have a high voltage jumper wire on top of the cars. Only one car has a pantograph.

Using a "compromise MU" cable, a home-brew 9pin MU from an RDC controlled an AAR 27 pin locomotive. Not all 8 notches were available though & no brake line PSI "status info" was sent through the 9pin connection like it is on typical EMU couplers.

Theoretically a SL IV to AAR-27 or an SL V to AAR-27 compromise MU system built into the compromise coupler is possible, if you throw enough money at it. But for technical reasons below, it just isn't probable for everyday use, or even rescue scenarios.

The Budd Company's official stance on using RDCs to pull coaches was 'NO'. They warned this would void any warranty and repairs would be made at the owners expense. That being said it did happen and apparently with no ill effects. Budd's goal was to sell RDC9 cars.
I believe the GE 1259 traction motor used on SL-IV cars is rated at 160hp, x4 yields 640hp per car and 1280hp for a married pair. with a higher axle ratio it should be more than enough to pull one coach. I recommended doing just that with the Budd Pioneer cars, splitting married pairs and splicing a P-III car in the middle. Or making them an additional push-pull set, but to no avail.

MU's can and have pushed or pulled "dead" cars when necessary to complete a run. I'm not sure if this is still a permitted practice but they even have the capability of being operated by another car in the consist if the lead car dies, obviously with a qualified crew member on the head end who is in radio contact with the engineer.

nomis wrote:Using a "compromise MU" cable, a home-brew 9pin MU from an RDC controlled an AAR 27 pin locomotive. Not all 8 notches were available though & no brake line PSI "status info" was sent through the 9pin connection like it is on typical EMU couplers.

Theoretically a SL IV to AAR-27 or an SL V to AAR-27 compromise MU system built into the compromise coupler is possible, if you throw enough money at it. But for technical reasons below, it just isn't probable for everyday use, or even rescue scenarios.

This is exactly what is done on the Cape May Seashore Lines when they run the RDC's push/pull with a diesel on the other end.

Were there not trailers that had no powered axles but took juice off the motor units for lighting etc? I think they had to work in sets, like 2 motors and 1-3 trailers or something.

The rdc-9? no it had an engine

TrainPhotos wrote:Were there not trailers that had no powered axles but took juice off the motor units for lighting etc? I think they had to work in sets, like 2 motors and 1-3 trailers or something.

I know the PRR's MP-54E3 were designed (and upgrade to 740 HP) to operate with one unpowered trailer per powered car.

TrainPhotos wrote:Were there not trailers that had no powered axles but took juice off the motor units for lighting etc? I think they had to work in sets, like 2 motors and 1-3 trailers or something.

There are unmotorized trailer cars on Metro-North that run with the M-8s. They're just going into service now. They do draw power for HVAC and lighting, etc., but are not powered and don't have cabs.

chrisf wrote:

TrainPhotos wrote:Were there not trailers that had no powered axles but took juice off the motor units for lighting etc? I think they had to work in sets, like 2 motors and 1-3 trailers or something.

There are unmotorized trailer cars on Metro-North that run with the M-8s. They're just going into service now. They do draw power for HVAC and lighting, etc., but are not powered and don't have cabs.

They draw power from their own third rail shoes and pantographs.

jackintosh11 wrote:

chrisf wrote:

TrainPhotos wrote:Were there not trailers that had no powered axles but took juice off the motor units for lighting etc? I think they had to work in sets, like 2 motors and 1-3 trailers or something.

There are unmotorized trailer cars on Metro-North that run with the M-8s. They're just going into service now. They do draw power for HVAC and lighting, etc., but are not powered and don't have cabs.

They draw power from their own third rail shoes and pantographs.

Yes, I should have clarified that. They do draw power as above for lighting and HVAC but do not have motors and can't move on their own.

Yes, the RDC9 had one motor but no controls. It was intended to be coupled in the middle of the train as a 'powered' trailer. I don't think many were built.

According to Wikipedia, the Boston and Maine was the only customer at 30 units, in conjunction to 57 RDC1's, 15 RDC2's and 7 RDC3's.