DPU Deployment

[Fly Device]

Listening to the numerous helper-related hang ups on the Whitethorne grade over the past few days, I'm wondering why DPU isn't already on just about every coal train out of WV / VA. Is it just a cost thing? Are they on the way?

During periods of high traffic, the amount of time and fuel they lose by stopping at Whitethorne, waiting on the pusher to get back, testing brakes, and accelerating into the grade makes me wonder how they can afford not to run them with DPUs. Add to that that lately they've had pusher units failing, lead units stalling out on the grade when they try to go it alone and a shortage of fly devices, requiring the pusher to go all the way over the mountain. They stack up at Whitethorne and have to drive in relief crews many times.

If my understanding is correct all these trains need help at least one additional place: on Clark's Gap on the PD side or the Elkhorn grade on the Pokey side. I wouldn't want any positions to get cut and I'm sure pusher duty is a nice assignment but I'm curious why the technology hasn't made inroads yet.

[steveiez]

Interesting you bring that up. I'm not familiar with your area but here in Pittsburgh the NS puts helpers on some trains only 60 miles away for a short push. Seems logical they would put them on at Conway or Pitt and push all the way to Altoona. East of there it is flat running.

[Conrail Tweety]

I agree it's a waste to stop a heavy train at the bottom of a hill. But it's still the most efficient process when you consider the cost of any alternatives.

The tonnage allowment from Williamson to Farm is nearly identical as the tonnage allowment from Bluefield to Roanoke, so those trains can efficiently run Williamson to Roanoke without adjusting tonnage. From Farm to Flat Top, twice as much power is needed so they run pushers eastbound from Farm.

It's about 700 miles from Bluefield to Lambert's Point and back, and it's nearly all downhill while loaded. It doesn't make sense to run DPU's when only a ten-mile section of that trip needs extra power. Where I see possible improvement would be for NS to keep a pair of ES44AC's stationed at Whitethorne, and purchase more on-the-fly EOT's to minimize the number of highway trips from the South Yard hauling them back for re-use.

It would be a total waste to send that much power all the way to the sea since it wouldn't be needed at all from Bluefield to Whitethorne, from North Fork to Lambert's Point, nor the entire return trip from Lambert's Point to Williamson. They already run 180 empty hoppers everywhere westbound behind just two motors.

If the DPU's were removed in Roanoke, and returned to Bluefield, it would at least equal the labor cost already being spent at Whitethorne.

I think the existing pusher arrangement should stay, and just use better equipment there.

Think about how many coal/grain trains are enroute from Bluefield at any given time. The current arrangment only adds TWO motors to the entire operation of moving heavy trains east of Bluefield.

Dennis

[Fly Device]

It's possible DPU would be advantageous if there were fewer coal and grain trains. With 6 to 12 of them on these grades per day, it would be a big capital investment to put the rear units on all of them (and cost some labor to shuffle them around) as you point out. On the other hand, if there were only two a day, the pusher man's time would not be fully utilized and you wouldn't need many DPU units to replace him.

Maybe that explains why the coal trains that run up the Pulaski/Christiansburg districts once in a blue moon tend to have DPUs.

Does anyone know if they're looking to expand DPU usage anywhere else in the system?

[Conrail Tweety]

The Pulaski District is a different beast. It's mostly single-track with two-way traffic. Most of the thru traffic is high priority intermodal. DPU makes sense on this line because it would cause major delays in both directions if a coal train should stall.

There are several hills, widely spaced along this line, where a motor failure could stall a coal train if not running a DPU. The rolling hills along this line make it more difficult to manage slack. A DPU allows better slack management, reducing the risk of breaking a coupler. And the extra power is always needed to get the coal up the hill beyond Walton.

Even though the Whitethorne District is single-track and one-way, the Christiansburg District parallels it. Faster, higher priority trains tend to move east from Narrows thru Christiansburg, so coal train delays at Whitethorne are not a big an issue in delaying overall operations.

The Pulaski District only allows 3500 trailing tons per Group5 motor eastbound from Bristol to Walton, as opposed to 7250 trailing tons per Group5 motor eastbound from Bluefield to both Whitethorne and Walton.

Dennis

[D300]

This one is very simple and the exact opposite of what you are thinking. You either dedicated a few extra units, say 2/4/6/8 to full time pusher or you have to give every train an extra unit, every day. In the long run you have to have more power to do the DPU thing.

What I can't quantify is the crew cost. I can not tell you how much 2 guys working 12 hours everyday for a year equals what percentage of a new unit's cost.

Everyone must keep in mind Southern was a big user of remotes and then that ended. Now everyone else is going to DPU, just high-tech remotes.

[wildweezel]

At best cost of 2 crew of engine service for a year $900,000 for 24/7/365 service...way less than one unit cost...cheaper to run em up and back down...why do you think they are building the SD40E's and SD60E's? Those units are not all going to stay between Conway and Enola.  Coming soon to a mountain near you south of the Mason Dixon...Reborn EMD power.

[Conrail Tweety]

This one is very simple and the exact opposite of what you are thinking. You either dedicated a few extra units, say 2/4/6/8 to full time pusher or you have to give every train an extra unit, every day. In the long run you have to have more power to do the DPU thing.

Not an extra unit per train, but three DC units per train, in order to make the climb to either Clarks Gap or Bluefield, bringing the total to five or six units per train. Two AC units added would be enough, but there are only 24 ES44AC's and 17 SD80MAC's in the entire NS fleet.

If the DPU's are to also replace the Whitethorne Pusher, then the nearest practical location to remove them would be Roanoke. If they are added dead-in-consist for the return trip with empty hoppers, that's a lot of weight to haul back up thru Princeton or Bluefield. For each extra unit of power added westbound, about ten empty hoppers would need to wait and ride a different train.

Keep in mind a pusher returning down the hill doesn't consume much more fuel than idling.

This still wouldn't eliminate the need for pushers for non-coal trains running from Farm to Bluefield. Just about everything gets pushed east into Flat Top or Bluefield.

What I can't quantify is the crew cost. I can not tell you how much 2 guys working 12 hours everyday for a year equals what percentage of a new unit's cost.

I think Whitethorne crews are just one man per shift. I've never seen more than one guy get on or off that train.

Dennis

[Fly Device]

I always found it amazing how efficiently the helpers worked on the pokey between Farm and Flat Top or Bluefield and how amazingly inefficient it is on the Whitethorne.

I was down there Monday and witnessed the efficiency firsthand. The pusher was up at North Fork (or maybe en route to Roanoke) having just pushed the 772 when the 814 tried to go up alone. 814 stalled on the hill and they had to send the 824's motors up to push him. Meanwhile a fourth train was already waiting beside 824.

[Conrail Tweety]

I always found it amazing how efficiently the helpers worked on the pokey between Farm and Flat Top or Bluefield and how amazingly inefficient it is on the Whitethorne.

The single-track main up the hill from Whitethorne is a huge bottleneck. Also, trains stacking up behind have to stop between Pembroke and Eggleston or earlier in order to not block grade crossings.

The double-track main plus a third passing track at Farm make for a much smoother operation.

Dennis