And to add to this discussion - we saw 5 just the other day. But as they passed by, only 2 were actually doing the work. The rest were just along for the ride. There was a mix of very new and some old (9’s and 70’s)
Mookie
Look into my web site then the California March 2006 gallery & you will see a UPRR train with at least 14 engines in the consist. I have seen BNSF trains on the FT. Madison webcam with more then 10 engines from time to time as well.[:D]
Boy are you lucky to live only 75 monutes from train heaven. The 14 loco or more lashup I saw was in the Cajon pass on the upper most (UPRR only) track. [:D]
I have been under the impression that railroads restrict the number of units on the headend due to excessive horsepower snapping a coupler knucker if the brakes were not totally released through out the train, along with the excessive weight of mulitpe units in excess of six exceeding bridge live load restricions.
As far as the independent brakes goes, they apply braking forces on the head end only that in itself should not snap a train, wheres as the automatic brake applied at speed in full emergency has the capability of laying a train out all over the ground.
Remember what I said about buff force that exceeds 250,000 lbs. I wouldn’t try it !
I’ve moved dead engines ( not with the dead engine feature cut in ) in consists of 24 locomotives with little problem. I don’t think I would want to try it with a freight train though.
I have read before that 9 units is the practicle limit of the MU equiptment, is that true?
In all the years I have been railfanning Cajon I have never seen more then 9 on line, although I have seen 9 with 2 helpers on the point for a total of 11 but that was rare. As the 4000+ HP units started to dominate the consists shrank. These days it’s rare to see more then 4 units on the BNSF, not counting helpers. I was up ther from Friday till sunday and did see a UP train on the cutoff with 7 units (includeing 2 SP) but it was dark and I didn’t get pictures. It was as short train and I doubt more then a couple were on line. I recently got a Cabride on a UP on this line and the engineer actually took one of the 4 units off line because we had too much power (it’s easier to leave it in run 8 then fiddle with the throttle to keep speed under the limit, we still maintained within 2 mph of the limit).
I wish use of the slang word “lashup” would die out. The proper term is “consist” whether you’re a pro or a railfan.
Bear
Why are locomotives running when in a consist but not contributing to pulling the train?
We simply gathered up engines between Christmas and New years , cold weather means they stay running, albeit not all on line .
Canadian National in the old days placed a limit on engines of 24 motorized axles or 4 three axles units 6 four axle units under power any more would be dead or idling and along for the ride. The reason given was the draw bars and couplers could and would kick out sideways under heavy braking and pulling load derailing the engines. My guess that different locomotives GM, EMD, would load up or brake differently causing excessive forces.
The main reason I can think of for there not being 10 or more engines coupled is the newer power does not require them to do a job.
I don’t know much about current locomotives, but back in the day, the engine speed was controlled by a governor. The governor had four solenoids that were energized in various combinations by the amount of voltage applied to that circuit. Starting with 74 volts maximum, as you began to string together more and more units with MU jumpers of various condition between them, you started to get voltage drop. After 8 or 9 units there was a good chance that you wouldn’t get enough voltage to the trailing units to get the engine up to the desired speed.
As for anyone who objects to the term “lash-up”, they need a little more misery in their lives to give themselves something real to be concerned about. Yeah, I’ve never heard the term used on the four railroads I spent 36 years working for, but the book of rules always defined it as a “locomotive”, regardless of how many units it was made up of, yet whenever you reported a train move or dispatched power from the pad, most people called it a “consist”. No matter which term you use, I think we all know what you’re talking about.
Most railroads lash up with “genuine Saskatchewan seal skin bindings” as pioneered by CN & CP.
Larry
I remember 10 SP SD45’s pulling a train over the Sierra Nevada mountains, but they were distributed 4-5 up front, 2-3 2/3 the way back in the train and the rest pushing. I would imagine that 36000 HP pulling a 100-125 car train would rip it apart.
I started reading this thread slowly, one post at a time. With each passing post, I wondered how many more would go by before someone would bust on Deadeye for repeatedly using the term “lash up” instead of “consist”. It’s really no surprise that Old Timer would show up to throw a bucket of cold water on the new guy.
It would have been nice to read this thread without the smart-a** remarks. People who have knowledge could have supplied some education to those of us with less without the putdowns. But I guess that’s OK, because I’ll probably not read any more forums if I have to put up with such jerkiness.
VERY INTERESTING INPUTS AND OUTPUTS. I SEE BY THE ABOVE YOU KNOW I AM READING THIS ARTICLE. IT WAS MOST ENLIGHTNING. I SAW SOME COAL DRAGS BY THE BNSF WHEN ON VACATION “OUT WEST” IN 1897 THE ONE I REMEMBER HAD 3 BIG UNITS DRAGING ABOUT 200 OF THE NEW ALUMINUM HOPPERS. MOST IMPRESSIVE.
REDCABOOSE11
CPR is prohibits running more than 8 units in a consist, regardless of whether they are on-line, isolated, or dead. Apparently this is because the AEI readers on the CPR system are calibrated to recognized no more than 8 locomotives to a train and exceeding that limit causes the system to crash. As to why the limit was set at eight, I have heard varyious reasons of which the most likely seems to be that the combined weight of locomotive consists exceeding eight units was believed to a contributing factor in multiple incidents including several rolled rails and and least one serious derailment.
There are limits for a consist’s number of driving axles and dynamic braking force as well, but with today’s high horsepower units they are usually reached long before the 8-unit maximum.
Would the current lack of lashups also be due in part to how long and how slow an AC powered unit can go vs a DC traction motored unit? Someone one correct me but wouldn’t 4 or so AC4400s be able to take a train that required 10 SD40s before not just based on horsepower but also because they can handle prolonged slower speeds.
Here’s the thing about it, guys:
If you want to ask a question of railroaders, ask it in terms railroaders use. If you have a question about terminology, ask somebody. We’ll give you a straight answer.
If you want to appear “hip” to other railfans, use terms that railfans use.
Deadeye, I see you have 40 years in the law enforcement business. Congratulations. I’ve got you beat by three years in the railroad business.
Old Timer
CGW once ran 12 F units in a consist to pull 276 cars. Train handling skillls had to be very good to start a train w/o breaking a coupler.