Endangered Species: EMU Trailers

In fact, EMU trailers may already have gone the way of the dodo bird. That is, cars that run with MUs but are not themselves powered. I was tryng to think this afternoon of a US electric rail or transit system that runs trailers and, there might be some, but I couldn't think of any.

You would think, given the cost of equipment, it might make sense to buy motor/trailer pairs but it just doesn't happen.

I believe for inspection purposes EMUs are considered the same as locomotives by the FRA. Another reason trailers might make sense -- not in married (semi-permanently coupled) pairs though -- but I guess not.

Years ago DL&W, IC and the New Haven operated MU trailers. Not positive about LIRR but they might've. On the transit side, up until the 1950s, about 30% of the old IRT subway fleet in NY City was made up of non-powered trailers.

Why has the American rail/transit industry turned its back on MU trailer cars?

You can add PRR and LIRR to the list of m.u. trailer operators. I can't give a reason why they've been abandoned for current use, but can speculate on a few issues.

The main problem is probably performance, especially acceleration from stops. Related to this, trains need to have a certain ratio of motor cars to trailers to achieve the required performance, and the shorter the train, the more problems in doing this. That would lead to a utilization problem: If trailers can only be used in, say, a ratio of three motors to a trailer, there may be too many instances where a trailer can't be effectively used and sits idle.

Hmmmmmmm.....You're right, there are no trailers in today's EMU concept. And I wonder if there were, couldn't such cars also, if properly designed and equipped, therefore, also be interchangable in push=pull technology (mind you I said properly designed meaning the electircal and control circuits had to be compatable, etc.)? Or the whole trainset could be hooked up to a diesel to be fowarded in places there was no third rail or catenary source? What an opportunity to enlarge a commuter fleet with interchangeabilty of service!!! It is July 5th, I think I had too many fireworks last night.

The South Shore LIne operates ten MU trailers purchased in 1992. They are blind trailers ( no cabs) and have pantographs for lights, heat, and air conditioning power. If I remeber correctly the reason for buying trailers was to save money over buying motor cars.

That's interesting about the South Shore trailers. Never heard of any equipped with pans for lights, a/c etc. Wonder why they did that? Are they set up in married pairs or assigned at random?

The only ones like that -- not the same but same idea -- I ever heard of were the old NH Mutts in PC commuter service. In the last years they were hauled by FL9s but with their pans up for lights and ventilation (no a/c).

Montreal's Deux-Montanges electric line (was CN - now AMT) has been using EMU trailers for more that 50 years and still does today. The 1954-1995 vintage ran in sets of three (Motor-Trailer-Trailer) with cabs at either end. The replacement EMU's received in 1994-95 are grouped in permanently coupled pairs and only have cabs in the motor car (except for 4 of 29 trailers). However, it looks like future equipment planned for this line will be electric or dual-mode locomotives hauling regular coaches. Similar equipment will also be used on the new Train de l'Est (a branch line to Repentigny/Mascouche) which will not be completely electrified.

A train car is considered a locomotive for inspection purposes when it has a cab. Hence the trailers at South Shore do not have cabs and are just plain passenger cars like a horizon or superliner. The pans are to power the heat/light, as there is no HEP trainline on the South Shore. This was similar to the Metroliner EMU being turned into a Capitolliner and pulled by E60 - they needed pans up for heat/light as well.

Tad are you sure about that, that control trailers -- trailers with cabs -- fall under locomotive inspection requirements? I wonder if cab cars on diesel trains also do? Wouldn't the inspection requirements have to be different since control trailers have no propulsion equipment to inspect? I would have thought it would be the other way around. That 'blind motors' (such as PATH operates, self-propelled cars without cabs) would fall under locomotive inspection requirements. Like one of the old EMD F7B booster units, they have no controls, yes, but they do move under their own power.

According to a gent I contacted who has done consulting work for CSS&SB, SouthShore's original order was for 28 motors and 8 trailers, but the price differential was so small that they bought all motors. Later, when funds were tighter, they bought an additional order which included the present 10 trailers.

So I guess that would be another reason trailer are no longer widely used. Their purchase price is not that much lower. Also, much flexibility in assignments is lost. Another reason, the consultant told me, for trailers not being too popular is todays' "blended braking" systems combining dynamic and air brakes. Without motors the trailer cars don't have dynamic braking and the wear rate on their wheels would be greater than on the motor cars thus requiring (possibly) more frequent inspections.

Finally, he noted some MU equipment use motors that are basically the same as subway car motors (saving a lot of design cost) and, because the rail cars are heavier, they don't have the power to haul trailers. He also mentioned that Silverliners were built for high performance, thus early on it was decided not to use motor/trailer sets.

Yes a Control trailer or Cab car is a locomotive for FRA purposes.
here is particular rule:


Subpart A_General



Sec. 229.14 Non-MU control cab locomotives.



On each non-MU control cab locomotive, only those components added

to the passenger car that enable it to serve as a lead locomotive,

control the locomotive actually providing tractive power, and otherwise

control the movement of the train, are subject to this part.

This part meaning CFR49-229 the locomotive inspection act.

DutchRailnut[i] wrote:"On each non-MU control cab locomotive, only those components added to the passenger car that enable it to serve as a lead locomotive, control the locomotive actually providing tractive power, and otherwise control the movement of the train, are subject to this part."[/i] CFR49-229 the locomotive inspection act.

Thanks Mr. Dutch, that's very interesting to learn. So the inspection is primarily of control equipment. Brake stand, throttle, cables, cab signals and the like I suppose?

Now I understand why a railroad like Metro-North would remove cab equipment from older MUs and call them 'motor trailers.' They'd no longer fall under the locomotive inspection requirements.

NJT has "EMU Trailers" all the time

They are called "broken arrows"

Im only 1/2 kidding hahhaha

The Reading had trailers with cabs as well as the PRR. Any cab car must be inspected as if it were powered per the FRA. Versatility seems to be the reason they were abandoned by most operators. De-motored MUs seem like an inexpensive way to increase the lifespan of older cars. Adding one car to a four car train would help during rush hour.

Jtgshu wrote:NJT has "EMU Trailers" all the time

They are called "broken arrows"

Im only 1/2 kidding hahhaha

SEPTA's Broad St subway had a similar situation in the late 1970's-early 1980's as the old equipment started dying before they got new cars. I remember somebody mentioning that at the absolute low point they had less than 30 motors, all the rest were trailers. I commented that I didn't know any of the subway cars were trailers, he told me that they hadn't been intended as trailers, the motors were broken, so they were just dead weight. Probably they were dead resistance as well, since they probably were still gear or electrically connected to the wheels, and so even if they weighed nothing would still slow the train down.

Only MU's with "trailers" that i know of us the colorado railcar stuff, but those are diesel.

- A

Tommy Meehan wrote:According to a gent I contacted who has done consulting work for CSS&SB, SouthShore's original order was for 28 motors and 8 trailers, but the price differential was so small that they bought all motors. Later, when funds were tighter, they bought an additional order which included the present 10 trailers.

So I guess that would be another reason trailer are no longer widely used. Their purchase price is not that much lower.

The South Shore ended up with 44 1982 cars - all dual cab motors ... eight purchased by the RTA out of Illinois. The 1992 order was 10 cabless trailers (with a single pantagraph for power) and seven regular cars (3 for wreck replacement). The 2001 order for 10 single cab cars could be considered a compromise. Motorized with a cab only on one end, two pantagraphs and placed into service at the end of the train. Nothing is married, but some cars seem to find themselves together often.

NICTD saved money in 2008-09 by adding cars to a Metra Electric gallery car order. Instead of the manufacturer tooling up to build more single level cars they simply made more of what they just made for Metra ... Metra has received 26 cars, NICTD received 14. The money savings meant NICTD could get more new cars. They are single pantagraph single cab units that run in unmarried pairs in trains up to six cars long.

I suppose they could figure out a way to pass power between MUs so the trailers don't need to have pantagraphs but the power is just a few feet above the roof. Unless the pantagraph is damaged direct power is easily available.

I don't see NICTD ordering any more single level cars, so in a sense I agree that you're unlikely to see any new trailers on the line. Another downside to the trailer cars is that when ordered NICTD was fighting overcrowding, so they decided to remove the center door and restrooms from the cars and provide more seating room. The single cab single level cars also have no restroom. But NICTD puts enough of the full service cars in each train to provide facilities for their passengers. If they did order more the next order would not have to be the same as they made in 1992 ... but gallery cars seem to be the less expensive way to go, and provide a nice ride.