DPU on intermodals.

I heard this from a person in my train and until know I just started seeing this. They have been using DPU on the rear of Intermodal trains here on the Chilli Sub. Has anyone else saw this and maybe give a reason as to why they are trying this out.

 

Jack,

Good question! I don't know about your specific region or instance, but BNSF has started running DPU's on a lot of different trains lately, including manifest freights, in Texas.

I've believe they've ran them on intermodals at Cajon and some other extreme grades for some time, and obviously on coal trains.

I'm guessing that they finally have enough trust in the technology involved that they will make this standard fare.

 

I find it weird whenever I hear that a railroad wasn't/isn't using DPU. I guess that's because I'm used to CP, which was an early user of remote-control helpers.

 

Triplex, just to clarify... I know that CP and others used remote "helpers" early on, but are we talking about the same thing here?

"Helpers" from my understanding are locomotives staged at strategic points to be added onto a train to help them up or down a hill. Once they have traversed that area, they are cut off. They have remote capabilities, but not the advanced electronics/features the current DPU systems have. BTW, I'm sure CP used DPU prior to others as well...not saying they weren't first here either.

"DPU" as I understand (and this is how BNSF does it, at least in Texas) is basically figuring up the motive power requirements for the long haul, and taking one or more of those locomotives (DPU-capable) and putting it on the other end. Benefits are train control, braking, etc. This is irrespective of any helper requirements along the way. BNSF adds helpers to DPU-configured trains on the ruling grade for the old FW&D line here in north Texas. I've also seen this at Crawford Hill in Nebraska.

 

Actually it hasn't just started. It's been around for a while on some symbols and there seems to be another push as it apears DP'd trains pick'em up quicker and handle better. A factor might also simply be that DP units are more common and they're trying to make better use of their capabilities...afterall, they paid for'em.

 

DPU are common on both BN's high line and CP main. CP uses DPU on every thing, grain, potash, stacks to get them over the line. Almost every grain on the BN has DPU's when they roll thru the funnel {Sandpoint} but I have also seen stack trains with a Dash 9 plugging away on the back. This is been going on for at least 3 years now.

 

CP pioneered the LOCOTROL system, the first DPU style operation. New units from both builders are available with the DPU equipment from the factory.

 

The only DPU we see here in the southeast is on run through powder river coal trains.

I find it strange that NS hasn't embraced DPU. Southern and then NS for years ran mid train remote controlled units on manifest and coal trains using radio control cars. Would have thought DPU would have been embraced as it eliminated the need for the special radio cars. Guess times and management of the trains changes.

 

DPU has it's advantages and disadvantages. The air brakes set and release/charge twice as fast, which is great on a long train. DPU takes up the draft when climbing hills. You get extra dynamic braking. But on the flip side, you get wierd slack action. If you get an alarm on the DPU, it's quite a walk to go fix it. If it shuts down going uphill, oh mymg: Been there done that:embarassed:

All in all, I like DPU trains. It's great on long heavy stack trains.

 

NS had many Locotrol units, as well as the radio cars. In the mid 80's division realignments and train assignments changed, and WV passed a law outlawing remote pushers in the early 90s, which forced NS to quit using them on certain Shenandoah line trains, as well as Appalachian District trains.

NS has tested DPU, and uses it on some PRB trains (run-through)... earlier this year, they also started a very limited DPU operation (can't remember the train or the exact line... but it is literally that specifc)

Operationally and cost-wise, DPU mkaes sense on long-distance moves that actually require the extra power/braking. Areas like Horseshoe, the Pokey, and the former VGN in VA are better served with short distance manned helpers.

 

Then that's like what Southern used to do, as others have noted.

 

I am a egnineer on the old FW&D railway from Wichita Falls Tx to Ft Worth. I am DP qualified and we run DP units on all the coal trains (which 90% on this sub), grains, and have recently started on the freight trains. Heading east out of Wichita Falls toward Ft Worth, we have a helper unit at Alvord which a seperate crew couples to the DP unit to help shove us up the hill at Decatur. That crew controls the throttle but they cut the air out of that unit so I can control the air from the head end. How they determine what needs to be shoved up the hill is by the HPT (horsepower per ton). This is the horsepower of the units divided by the tonnage of the train. For example, a coal train on this sub is 128 cars, about 18000 tons and 7017 feet with the 3 units. Each unit is 4400 hp each, so that is 13200 hp. 13200 divided by 18000 is .73 HPT. Anything that is below .90 HPT is required to be shoved up the hill. Hope this helps anyone.

 

What Mr. Biggs describes also happens on one of the BNSF run through powder river coal trains on NS. Braswell Mtn GA, the area between Rockmart GA and Dallas GA, is a NS helper district. I have to admit it looks pretty neat when a train passes with two BNSF units on the point and one BNSF and one NS unit on the tail. Before BNSF operated this train, it was UP and the operation was the same set up. But this train is old enough that I do remember it running with NS mid train radio control before DPU.

 

God, .73 HPT. You can't have any fun with that On the Mojave sub, the minimum HPT's are 2.7 eastbound and 2.4 westbound. I'm used to 2.5-3.0+ HPT:teeth: I wouldn't know what to do with one of your coal trains:embarassed: I did run one on the simulator. Subdivision specific run from Mojave eastward. I was in run 8 for 20 min, then dynamic 8 with air set for 10 min, then back to run 8 for the rest of the run.

 

BNSFBiggs,

Welcome to Trainboard and thanks for the info. If you ever see a foamer in a gray Tahoe it's probably me. :shade:

I would welcome any stories you can offer about the WF Sub/RR Sub.

 

It kind of sucks with that kind of HPT's. Whats funny is when the coal trains come into Amarillo, they have 2 units on the head end and 2 units on the rear end. Before it leaves there, they cut one motor off the rear to save on fuel..?? But then they have to pay an extra crew to push the train up the hill.?? Dont make sense to me but oh well. Also there is an incline between Amarillo and Wichita Falls we call Carey Hill and we usually get down to about 8 mph going up. That 4th unit would be very handy if they would just leave it on.

 

Thanks both yall for the welcome and will sure post any knowledge or experiences I have had. Yall feel free to ask me anything. Thanks
Casey Biggs

 

What's the grade at Decatur?

 

It is a 1.4% grade