SW1500 question...

I saw a video of an SW1500 pulling some passenger cars for a railroad musuem excursion. Now the cars were just regular coaches, no cab car. But my question is would an sw1500 be compadable with a cab car? If a cab car was at the end of that train with sw1500 powering it, could you use the cab car to come back, or are they not compadable.

If the passenger cars were wired for MU, and it was the same type of MU used by the SW1500, then I can't think of any reason why it wouldn't work.

A basic cab car should work, as the diesel, (whatever model, SW1500 or whatever) doesn't know what its connected to, and uses the 27 pin jumpers (the big black cables inbetween 2 locos and push pull passenger cars). the 27 pin jumper relays information from one diesel to another in a consist or in the case of a push pull passenger train, from the cab car to the locomotive. They act the same way. It sends info like throttle position, direction, alarm signals, etc.

A more modern passenger car might not work, because of the amount of computers needed and sometimes if it doesn't get all the info it wants, it might not work. Most push pull trains also use an additional 27 pin jumper cable (usually orange or blue plugs on the end of the cable) that sends other communication information inbetween the passenger cars and locomotive. Like end/center door closed information, EP brakes, communication buzzer, etc. Stuff that in theory isn't necessary to make teh train move, but again, with more modern equipment it might not work because it doesn't have that info.

I BELIEVE the LIRR used their MP15's (a swticher like the SW1500s, but designed for road use as well with different trucks and a few other things) in push pull service in the not to distant past.

Very interesting thank you! I just thought since SW1500 lacks hep generator to power lights and such in a passenger car, whether or not it would work with a cab car.

airman00 wrote:Very interesting thank you! I just thought since SW1500 lacks hep generator to power lights and such in a passenger car, whether or not it would work with a cab car.

There could be an HEP car, which is usually a converted boxcar or a baggage car that has an HEP generator on board and produces electricity for the cars to use. One of the vids you watched had that on the end of it.

Also, the cars could have their own on board generator as well, diesel or axle driven.

IIRC, the LIRR MP15ACs could supply HEP?

Maybe not.

For example, the Rock Island 27 pin jumper was wired different for Push/Pull service and the HEP units had a second MU receptacle on the lower rear end. The standard MU receptacle was located over the rear eng room door. When the cab cars were not available the unit replacing them was not plugged in to MU receptacle on coaches.

Other roads may well have done too. IIRC the open/close door commands to name one thing were carried through an MU wire.

speaking of switch engines, what is the maximum number of cars a single sw can pull by itself alone. Be it a sw1001, 1200, 1500, etc. I've seen some vidoe's where an SW seems to pulling a fair amount of cars by itself. Also how would that compare say with the max number a cars a single alco s-2 switcher could pull.

Triplex wrote:IIRC, the LIRR MP15ACs could supply HEP?

Yes. And they often did. Back when they used the GP38-2s for main power, a HEP FP7A (no prime mover) or a MP15 unit was used to supply HEP power to the cars. Today, one DE30, or DM30 can do that job by itself.
In the past though, Yes, LIRR did use MP15s in push-pull commuter service.

airman00 wrote:speaking of switch engines, what is the maximum number of cars a single sw can pull by itself alone. Be it a sw1001, 1200, 1500, etc. I've seen some vidoe's where an SW seems to pulling a fair amount of cars by itself. Also how would that compare say with the max number a cars a single alco s-2 switcher could pull.

I've seen switchers haul some balsy loads before! Switchers can usuallypull similar amounts of cars as larger engines, they just can't do it as fast or as far. Just Sunday our local terminal Railroad the Tazewell and Peoria picked up an empty coal train, 113 cars from the Iowa Interstate, who used 2 GP38-2's to pull the train through the Illinois river valley at 25mph or so. The train was handed of to the Tazewell who used a lone SW1500 to move the 113 cars about 6 miles to the other side of the river, the journey is relatively flat, being slightly downhill at first, then a slight climb before the bridge. It put in lotsa work to get the train started, then barely was moving up the grade, they almost stalled at one point, but just made it, so cool, and loud!




But on the topic, Metra has done this when engines have broken down. I've seen an SW1500 get pulled off a work train to push an MPI Express engine and 6 cars. Once the engine broke down, and a WSOR freight was coming in, and the Metra unit broke down, they MU'd it up behind, and pushed the passenger train.

To answer Airman00's question about what an S-2 will pull: plenty! Almost thirty years ago, I was a partner in one of the earliest contract switching operation. Our customer, a long-gone chemical plant, wanted their storage yard re-arranged, putting all of the old friction bearing and out-of-test-date tank cars at the far ends of the storage tracks. The cars were an assortment of MTs and loads, 55 and 90 ton, friction and roller bearings.

We took turns running the engine, over one Saturday and Sunday, and I distinctly remember asking the guys in the ground how many cars I had on the nose of the RS-1 we had at the time. It was upwards of sixty! True, we weren't going very fast, due to track conditions and handling hazmats, but the old girl didnt really breathe hard, either. Just slow and steady-

I know Airman asked about the S-2, but an RS-1 has the same mechanicals and electricals, just on a stretched frame to accomodate a boiler and the road trucks, so the comparison is valid (OK, so the RS-1 is typically five tons heavier-)

Something to remember here is a very basic rule of thumb, perhaps over-simplified: Weight produces tractive effort, needed to get a train moving, while horsepower provides the acceleration, once the train is moving. The Tazewell example is impressive, but within reason, any other switcher could have moved that train, if the unit was of equal weight, and the motors could have been kept out of the red. The RS-1 I used to run could have pulled that train, but granted the SW-1500 would have accelerated it faster.

Wow, thanks! That Tazewell sw1500 is quite an engine!! It's cool to know switchers can get the job done whereever needed!

Guarenteed that any S2 in good shape could've gotten those 113 cars rolling. And THAT, would be one hell of a show. Listening to that old 539 chug, and belch black smoke like a business man chomping on a cigar.
No matter what, it really is the weight factor, like mentioned before. weight = tractive effort.

Sean

Yeah that engine was putting on quite a show. I wish I had a shot of it first starting, it did a nice alco impersonation. Usually when this happens, the railroad will send a lone SD unit or both of their SW1500's working together, but the switcher was just in the area that day, so it was put on the job.

A little switching railroad in Chicago, who's SW1200 is picture as my avatar, occationally gets some big loads and it really puts on a show. I've seen it really smoke and move 20 or so loaded scrap gondolas which are like 70 tons each empty, but close to 200 loaded (I think). The last time it was during winter, and they had 35 cars to move up the hill to the BNSF. They built the train up with the switcher, but knew that with the snowy rails, there was no way that the lone SW1200 would move all those cars up that grade. So we drove the crew up to the BNSF to borrow the yard power. (They planned this all the night before and let me know early) But the 2 geeps that were there the night before was now just a single GP50. They charged the hill with the lone geep, and half way up it stalled. But slipping and smoking, the Switcher banked the geep and the two slowly moved their train up the grade.

Like everyone said weight is key!

If that switcher in the avitar is a Belt Railway of Chicago unit, one minor correction is in order; they are a very LARGE switching and transfer railroad.

One thing about the BRC is that they liked heavy power. In the '60s they wanted some heavier road switchers for transfer runs. EMD would not ballast a unit like a GP-30 or GP-35 to what BRC spec'd-out, something like 280,000 pounds, so BRC went to Alco for the six C-424s, built at the weight they wanted.