for Randy Stahl:
There was a ruling some time back prohibiting locomotive lashups from exceeding ten units in one single segment. Prior to that time, railroads were routinely running lashups to answer horsepower needs, regardless of the number. Do you know of the event that changed that freedom and imposed the limitation of nine units maximum in a single lashup?
Before the advent of very high horsepower locomotives,a large consist of engines would be appropriate as the maximum drawbar forces would not come close to the maximums. A wheel slip on a low horsepower locomotive of a dozen or so low horsepower locomotives should not destroy the train. A slip on a high HP locomotive will tear a train to bits. The possiblity of stringlining a train and drawbar forces exceeding 150k in draft is the primary reason for DP. Even in the days of many MU’d locomotives this number could not be exceeded. With 1500 hp locomotives it would take many locomotives to approach this limit.
On dynamic brakes there are serious limitations on the number of breaking axles, read, reverse stringlining. Not to exceed 200k in draft .
Randy
For Randy:
Define “High Horsepower”… EMD’s GP-60’s and GE’s Dash-8-40B’s, were advertising 4000 horsepower. Were these engines types, the fore runner of the exceeded draft problem? So, you are saying that number of engines lashed together is limited by their combined horspower, rather than simply the number of engines physically connected to each other? Taking it one step further, I gather that a railroad may, even today, if they have enough low horsepower units available, can still put together a 12-13 engine lashup at the head of a train and there would not be any rule infractions with that many power units mu’d together?
So, if I am a short line railroad, I can’t lash up 12 RS-1s? I realize that isn’t going to happen. I am just curious of the restriction. I have never heard this before.
Gabe
I’ve never heard of a restriction such as this laid down by the Feds, but each railroad has had instructions regarding the number of units, number of units online, number of dynamic braking axles, and so forth, as necessary, for a long time. This is nothing new.
Modern steel knuckles and drawbars are rated for a maximum . The restriction is simply steel limitations . Guess which metal is tougher, the knuckle or the drawbar ?
Simpy put , the class “D” steel knuckes are rated for 150,000 lbs.
As far as 12 RS-1s , I wonder of the MU system would work without tripping the control breaker in the lead unit ( overload )
For Gabe, Randy and all others:
I raised the question about long lash-ups, because I live 75 mins from Cajon Pass, (in Southern California). While there one day, I was photographing trains. A stranger standing several yards away commented to his friend that “You’ll never see anymore 10 locomotive lash ups here again”. I didn’t hear what came before that remark, or after it, but I was stunned to learn of that situation. Prior to that fateful day, you could go there and see Santa fe Yellow Bonnet engines in strings of 10, fairly routinely. As I thought about it, I couldn’t remember seeing any 10 unit lash ups for a very long time. In recent times, the most you’ll see now are 8-9 units together and there may be a dash 9 as the lead unit. I have been laboring under the impression that something had happened in the railroad world to limit the number of locomotives that could be physically connected together. Having not seen a 10 unit lash up in a very long time, I had to assume the stranger was alluding to an event that occurred causing a ruling or practice that outlawed the 10 unit locomotive practices. There may be nothing whatsoever to limit long lashups, but we don’t see them any more and there was never an explanation to account for the absense of that condition. Randy Stahl, has commented that it’s all about horsepower and that is the determining factor. I’ll have to accept that as gospel because I certainly am in no position to know differently. Thanks for your responses
Does this new restriction only apply to 4,000hp+ locomotives?
the rule governing number of locomotives mu’d together has to do with setting and releasing brakes. The more locomtives in the consist the longer it takes to set and release brakes, and can have bad consequences as far as wheels sliding, flat spots, and over heated wheels.
I think it was in Trains, but it may have been in a “lesser” magazine. But, anyway, I remember seeing an article about big six axle GEs, I think U30bs, but this isn’t my area of specialty. In any event they were monsterous locomotives before the Dash era.
Anyway, the article had pictures of 9 such units regularly hooked up together. That had to be one heck of a lot more horsepower than 10 Geeps or RS units.
Gabe
To Youngengineer:
Does your company allow 10 engine lashups, with all of them on-line, on the headend…have you ever seen a lashup of ten high horsepower engines, all on-line, on the headend? What would be the determining factor for a brake release problem on new, high horspower locomotives. Do they have brake release problems?
Deadeyebobinsocal -
How does your company la***hem up? Do you use string? Duct tape? Baling wire?
Most railroads couple up units together to make consists. I’ve been around, and I’ve never seen a railroad “lash up” units together. I’ve heard about it a lot, though.
Old Timer
Old Timer
I have heard the Class 1 railroads have started to use raw hide, but each railroad uses the skin of a different animal.
When I worked for the SP (1964-75) there was a restriction of 10 units max in multiple. This was pretty much the stnd power consist for Valley trains by Burbank jct. I don’t think there was a particular incident but that the limitation was due to the limits of the MU system (although time for a full consist brake set-up could have something to do with it.)
re; the above. This was when the stnd Valley unit was SD-9s.
Old Timer. I’m with you. In working for 3 RRs I’ve never heard the term “lash-up” except from railfans. It’s always power consist, units, or (most often) engine.
OLD TIMER
Well Bub, it probably doesn’t matter one tiny iota, whether they’re glued, blued screwed or tattooed together, you knew exactly what was being put on the table. Since I never worked for any railroad, it’s possible that I wouldn’t know bowline on a bite vs a turkey knot, or anything else in perfect diction or terminology. You can call them anything that blows your skirt up, I could care less. I was asking a question to seek an answer. your contribution didn’t raise any flags of respect on this end. It’s also very possible that I’m older than you are. Thanks for your fine help, if you have any questions about the police business, I have about forty years of that to draw on.
As the youngster said it has more to do with braking effort than anything. RRs would already have a limit to the equivalent number of powered axles on line in power and even less powered axles in dynamic brake. Those units might be idling, but only so many are online.
As for the brakes, the more units in the consist the longer it takes to apply the independent brake if they are all MU’ed. The time seems to increase expotentially as each unit is added. This is also true for releasing the brake. It takes forever to get the brakes to release. This is not good when trying to switch cars, doubling over tracks and such. Anything over three units with the independent brakes cut in is a pain in the butt to move around.
The really big deal about having all of the brakes cut in is all of the braking force that they attain. There is enough there to buckle a train.
BIGJIM
Thanks BIGJIM, for getting me dialed in on an answer to a question that’s been nagging at me for a long time. I’ve never been inside an actual locomotive in person. so it’s difficult to visualize how the functional problems are established. I didn’t have a clue as to how the brake system works in a “consist” configuration, (as you’re sitting in the seat trying to make it release). I think I have a much greater understanding of why I don’t see any 10 unit locomotive consists any longer. Your thorough explanation is most appreciated and I thank you. Take care.
It is not unusual to see large “consists” (lash-ups for the railfans) of Hi HP late model power in KC but these are power moves at the head of manifest or intermodal freights. While all are usually running (heat from above radiators) they are probably not on line. No smoke from all the manifolds when they start rolling.
jeaton and Old Timer, This makes you wonder if the BNSF has unearthed a couple of old cars that had been hiden away in a building somewhere with a supply of old Frisco coonskins?[}:)][}:)][(-D][(-D][(-D]