View allAll Photos Tagged DistributedPowerUnit
Finally arriving in Neenah, WI after departing Green Bay, WI nearly 5 hours earlier U757's DPU (CN 2280) sits on the Neenah Yard Lead after having come around the Wye between the Fox River Sub, Manitowoc Sub, and the Neenah Sub.
WC 1552 (YNE258) was taking its sweet time to work the cut of 20 cars it just grabbed, or so it seemed to the conductor of U757.
The distributed power unit on an eastbound NS manifest freight passes a local sitting in a siding on a Sunday. The image was made from the former Pennsylvania Railroad station in Richmond, Indiana.
This is not a common shot at Santa Fe Junction. Canadian National ET44AC #3271 serves as rear DPU on a 2x1 Canadian National grain train (all CN power, 97 cars) in KCMO.
CSX eastbound manifest freight Q348 has a ES44AC-H No. 979 as a distributed power unit today as it rolls through Union City, Indiana. At Ansonia, Ohio, it will make a set off.
The distributed power unit of NS Train 197 is sandwiched between long strings of auto rack cars as the train passes Coounty Road E800N in Well County, Indiana, south of Ossian.
CN 2223 shoves hard on the north end of the southbound unit sulphur train. The DPU lights shine as bright as the unit was loud.
You have to be patient to capture a train in your camera's viewfinder, but it's pretty much a sure thing to happen at Harpers Ferry. I believe there were maybe 4 or 5 trains that went through here during my couple hours there that day. This train I just barely captured, as I was not close to the rails when I heard it coming. I got back to the station just in time to capture this Distributed Power Unit (DPU) that serves as extra mover power in the middle of a lengthy and/or heavy train.
BNSF SD70ACe #9377 & ES44ACH #3291 are the DPUs on the rear of a southbound BNSF coal (133 cars) at BN Junction in Kansas City, MO. This train is headed to James H Miller Power Plant, Palos, AL.
BNSF 5759 continues to push the coal loads past Parkman, WY. The train has just reduced from 2x3 configuration to 2x1 configuration without stopping. In just a couple miles this train will pass from Wyoming into Montana. July 28, 2013.
CP30th is the final stop for me catching this train. BNSF CW44AC #5607 and BNSF SD70ACe #9304 are the rear DPUs on this southbound BNSF coal train (134 cars) on the Ft Scott Sub in Kansas City, MO. This train is headed to Hugo Western Farmers Power Plant in Ft Towson, OK.
...and a GEVO shoving on the rear. Nothing like the purr of these babies. Red marker lamp shining as the train rolls south into the golden afternoon light.
This distributed power unit (DPU) brings up the rear of a westbound manifest freight at Lucin, Utah. In the United States the use of distributed power is on the increase, especially with Union Pacific Railroad. One advantage of having a pushing locomotive on the rear end is the reduction in the tendency of long trains in curves to "stringline."
Stringlining is the tendency of a pulled flexible thing (string, rope, hose, train) to want to form a straight line ("straight as a string"). Obstructions can prevent stringlining. Dragging a hose around the corner of a house or past a tree can force the hose to assume a less-than-straight line: the hose does not stringline. But without the obstructions, a dragged hose will be fairly straight (it stringlines).
A train is subject to the same physics, but instead of going around a house or tree, it travels through curves, which act as obstructions. While negotiating a curve, a freight car wants to move toward the inside of the curve. In fact, it is being pulled into the curve. Rails and wheels are designed to keep the cars on the rails in spite of this force, but the right combination of forces can overcome the best-designed track, resulting in a train's stringlining (forming a straight line in a curve).
The distribution of weight in a train plays a role, as does acceleration from a stop. Suppose a long train is stopped on curving track. There are three or four locomotives up front and none farther back. The first half of the train is empty freight cars. The rear half is loaded cars. When the stopped train starts up, two major forces are at work: the pulling force of the locomotives and the resisting (pulling) force of the loaded freight cars. Just as if a ground stake pops out of the ground, allowing a dragged hose to straighten out, the relatively weak holding force of the unloaded cars is not sufficient to keep them on the rails, and the train stringlines (derails). Starting a train slowly can counteract this problem. Assembling the train in a way that avoids the grouping of empty cars ahead of a grouping of loaded cars is a better solution but not always possible.
Another solution is to reduce the amount of pulling force from the rear of the train. That's what a DPU does. Thus the cars in the middle of the train are not pulled from both ends and they stay on the rails. (This description is simplified and incomplete, but it gets the idea across.)
The comments prompted me to add that DPUs are also used to reduce the strain on the drawbars and couplers of the locomotives and the cars near the front of the train.
The September 2010 issue of "Trains Magazine" had an informative article on the use of distributed power. The more I learn about railroads the more I realize I have much to learn.
Rather than counting cars I relied on the axle count by the MP181.1 & 194.6 detectors to determine the train size. Both said 830. 6 axles x 5 locos means 800 axles of jennies. 200 cars. I think this was the second U780 of similar size...maybe they'll start getting bigger. Rumor had it they would do up to 300 axles. These two units were shoving for all they were worth and sounded great.
A little of everything came with M342's 158 cars: potash, sulphur, lumber, long cuts of boxcars, gons...and a pair of mid-DPUs.
Rear DPUs on southbound BNSF coal (134 cars) on the Ft Scott Sub approaching W 67th St in Merriam, KS. This train is bound for Plum Point Energy Center in Osceola, AR. The DPUs are as follows:
#9025 - SD70ACe
@9375 - SD70ACe
#6029 - ES44AC
After M347 headed north and met a train at Dixie (siding) I decided to swing a bit further south to keep some kind of light available. Shortly thereafter M346 came by with lots of potash and a pair of DPUs working pretty hard.
The DPU on an eastbound ethanol load eases down to milepost 6 at the base of Stockton hill. The train will stop in a few hundred feet as the head end reaches the crew change point at MC junction.
Minnesota City, Minnesota
April 18th, 2021
BNSF ET44ACH #3638 and ES44ACH #3286 serve as rear DPUs on a James H Miller Power Plant (Palos, AL) bound coal train (135 cars) at BN Junction on the Ft Scott Sub in Kansas City, MO.
The is my first time catching one of the CSX heritage units. The disappointment is due to multiple factors. One is I had a shot eariler where I could have gotten this broadside, but, I screwed up and didn't go for it. Second, the camera didn't focus on the front of the train, so I missed getting the power up front. It wasn't anything significant, but considering it was CP & NS, would have been nice to get. Third, the Chesapeake & Ohio paint scheme is nice, but the front is typical YN3 CSX. The C&O on the rear is nice, but this could have been much better if the whole unit was that way. As for the train, this unit is the rear DPU on a 100 car southbound CPKC grain on the Pittsburg Sub at Duck Rd in Grandview, MO.
Norfolk Southern ES4AC #8042 is the DPU on the rear of a loaded grain hopper train (113 cars) at Santa Fe Junction in Kansas City, MO. This train is getting on the Emporia Sub and will head west.
Down near the Wyoming border you get a lot of that Montana big sky for the money. Another train of coal buckets make good use of the Little Bighorn Valley on their way west.
Benteen, MT, September 8, 2023.
The Black Hills Sub is a hopping piece of railroad this summer morning as an eastbound load is stopped at a crossover near Thornton, Wyoming and a DPU keeps a passing empty train up to speed. The DPU on the load can be seen near the signals in the distance, also the head end of the empties can be seen meeting the head end of another loaded train that's slowly moving into position behind the stopped load. July 28, 2013.
BNSF SD70ACe #8484 and Grinstein SD70MAC #9758 are the rear DPUs on a 2x2 all EMD power southbound coal train (135 cars) on the Ft Scott Sub at CP30th St in Kansas City, MO. This train had a SD70MACe leader with an SD70ACe up front. This train is bound for Hugo Western Farmers Power Plant in Ft Towson, OK.
H1 BNSF CW44-9 #968 as DPU on the rear of a CA bound stack (32 couplered cars) exiting the KCT-North-South Corridor for the BNSF Emporia Sub at Santa Fe Junction in Kansas City, MO.
BNSF ET44C4 #3780 and ES44DC #7356 serving as DPUs inside a 113 car BNSF grain train in the Gooseneck in KCMO.
On a snowy afternoon GEVO 2340 leads its train south through Oshkosh, WI. Nothing sounds quite like one of these motors working hard. This train also had a BCOL & second SD70M-2 as mid-train DPUs.
BNSF ES44AC 6380 & SD70ACe 9367 are DPUs on the end of a northbound unit coal train waiting to enter the Great Falls, Montana yard on 4/1/11.
Canon EOS 350D Digital Rebel XT
Canon EFS 18-55mm lens
M340 puts in an appearance and brought 4 locos with it. I had already seen 3 of the 4 locos, leaving me one shy of 1,000 CN "Family" locos today.
Tomorrow...that's gonna happen...I hope...
Canadian National SD70M-2 #8932 is the DPU on an all CN power 2x1 loaded grain (96 covered hoppers) entering the Emporia Sub at Santa Fe Junction in Kansas City, MO.
CN 2116 didn't have this red "box" before...what's it for? I presume it's tied to the split cooling or DPU hardware installed.
Would CN really try to emulate CP and stick only a GEVO on something like M346? Nah...IC 2698 was mid-train in DPU mode, slaving away.
BNSF 9080 crawls up the mainline at Parkman, Wyoming nearing the crest of Parkman Hill. July 28, 2013.
ES44ACH #3325 and ET44ACH #3651 are the DPUs on an eastbound coal (129 cars) on the St Joe Sub at Zeke Rd in Riverside, MO. This train is bound for James H Miller Power Plant in Palos, AL.
BNSF ET44ACH #3650 & SD70ACe #8793 serving as DPUs on the rear of a southbound coal (135 cars) coming off the KCT North-South Corridor onto the Ft Scott Sub in the West Bottoms of Kansas City, MO. This train is bound for James H Miller Power Plant in Palos, AL.
CP 9705, the trailing DPU on train 114-25, refuels before heading out over the Heron Bay Sub to White River.
September 29, 2011
The ends of the ore trains (empty on left and loads on right) stare at each other's red eye. If the meet was only an hour earlier...
A set of helpers cut off on the fly at Parkman, Wyoming having assisted a loaded coal train up the hill from Sheridan. July 28, 2013.