How come it seems CP Rail uses only 2 or even 1 AC unit on reallly long trains? It seems that on other railroads that more units would be used for the same length of train?
Those AC’s are luggers, if it can pull it and thats all that is available, that’s what goes out. One unit is avoided when possible because in the event of a breakdown your SOL.
Adrianspeeder
I live about 25 minutes from the CP’s line through central MN and you see one unit on trains all the time! I’ve even seen a single SD60 SOO unit a couple times as the lone unit. But you are correct, most of the time it is an AC4400CW. It does seem strange since if you did have a unit die, you’d be stuck as just noted in the last post, but they do it all the time. I’d even venture between 25 and 30 percent of the trains I see on that line have just one unit. They must really have faith in their diesel maintence folks.
They dont pair units for the pleasure of having them if you break down the reason for big units is that on big unit will replace 2 smaller ones . 1 sd70 will out preform 2 sd40 hence saving fuel.( in thery) track speed is not a issue when setting up power for trains pulling power is.
Now in there thery of 1 unit replaces 2 if you work the guts out of one unit it cant be saving fuel or maintainace. in fact you are wearing it out faster. In my thery if 2 can work easier than 1 using less to do the work then you are saving . in other words if you never come out of notch 8 your not saving fuel. your drinking it by the gallon.
All railroads have a section of track on each division that has a ruling grade. That translates to how much tonnage a given engine can pull on that division. It stands to reason that a railroad with no grades could pull more cars per train than one that needs to pull them uphill. To take this to the ludicrous if you have 600 cars to go from A to B and it was all downhill once you got them rolling all you need is braking to get them there. It could be and probably is that the stretch you are seeing single engines being utilized doesn’t overload the engines. Beside it is good business practice. Minimize costs by not wearing out additional engines, track, waste fuel, etc. In the end it is a business not a hobby.
CP scheduals many of their trains to use only one AC unit. And if there is no AC unit available they will sometimes use some other single garbage unit. Even where there are some grades like between Milton and Guelph jct, up the Niagaga escartment that is. They will use one unit all the way from Chicago to Montreal and back, and sometimes 10,000 tons. These trains move along ok when going down a grade and keep the speed up on the flat, but once they loose their speed, boy do they go slow for a long way.
CP has a tradition of sweating the assets, they’ve done it for decades. Rob Ritchie himself said that they were going to work these, units, and so now they send them out with as much tonnage as the yardmaster dares to hang on the drawbar. Most AC units I’ve ever seen on a train is 4…
Power and speed costs money. If Ritchie has gone as far as making a comment on the subject, I’ll bet lunch he had his folks run the numbers.
I’ve seen 3 AC’s as the most on CP Rail trains. I’ve seen 2 AC4400’s on a 156 Car Coal Train on CPR.
Aside from unit trains … CP trains are too friggin short. 2 Geep 9’s could pull almost every CP freight train I have seen. I have rarely seen one over 100 cars. Stupid single tracking is what it is. Gimmie a 160 car CN train any day … that is the norm for them
Many of CP’s lines are relatively level, like the former Milwaukee across Wisconsin, But, the old D&H has only light trains with a single unit, since it is anything but level! Running out of Buffalo, they will put a single SD40-2 on as many as 100 empty autoracks, while the AC44s/ES45ACs and SD90MACs (both the full 6000hp version and the never to be upgraded ones, which I call SD75 MACs since that is what they are, for all intents)will move up to 7500 tons. I don’t know how they do on the old TH&B’s grades on the Niagara Escarpment into Hamilton. NS allows this rating for CPs AC motored units, but doesn’t have the same faith in its SD80s, which if the rumor mill is to be believed will be returned to their lessor later this year ,as Conrail had leased them for ten years. We’ll see.
Assigning power to trains is a simple matter of tonnage and speed. The ruling grade on the terrirory defines how much tonnage can be handled on the territory per unit of power. To haul that tonnage a more than the minimum continuous speed for the locomotives requires more power. Today’s locomotives are sold on the basis of a high MTBF number (Mean Time Between Failure), as well as the 2 for 1 replacement factor when compared to SD40’s; therefore, unless you have a priority train involved, the minimum amount of power will be used to move the tonnage.
The biggest drawback with today’s high capacity locomotives is the fact that forward is only in one direction. The wide body cabs and the normal lack of ditch lights on the trailing end of the locomotive limit the use of the engines in turn around service where there are no locomotive turing facilities. This is the same problem that existed in steam days, howerver, in steam days there were many more turning facilities on the railroads than exist today.
It is an attitude. CP tells NS that they are good for more tonnage then NS’s AC units. NS doesn’t want to shorten the life of it’s own AC units. I guess CP"s attitude is burn them out and then buy new ones again. The real funny theing is some of CP’s hottest trains use SD40’s like the Expressway or even GP9"s for the frame train. These are the hottest trains in Southern Ontario !
The other drawback to the big CPR AC units is that they are so big and heavy and derail rather easily in yard trackage and “turn around points”. Three or four GP 9s are more light footed and can go fast and pull too, AND can be split up.
neat. thanks for all the good info and insight.
As stated the rulling grade is the biggest factor + fuel conservation.
Most trains are restriced to 45mph for fuel conservation purposes, unless they are 100 series hot trains. I work out of Vancouver BC most hot trains for example the eastbound 102 will have 2 units on the head end and a robot on the rear. More than ample for a 6000ft. mix of stacks and autoracks, it must maintain track speed. Now instead we take the eastbound 268 which is a junk train it has all sorts of different types of cars, not a hot train, 2 units on the head end to climb over the mountains, 1 is cut off in calgary.
Now here are some facts:
-AC4400cw can run constantly at notch 8, AC traction motors are built for it
-AC4400cw will crawl up hills doing 4MPH, crews do it all the time
-SD40-2s use DC traction motors
-SD40-2s can run full load for only a short period of time before traction motors overheat
-GP38s see above, less pulling power than the SD40
-GP9s see above, less pulling power than the GP38
Comments from a know it all Foamer[V]
Are you a railroader / running trade employee? How many years of service do you have in? [B)]After you put some time in as an RTE your comments may have some fact
2 Gp9s could pull 100 loaded cars up a grade for a few minutes, right up until the traction motors overheated. Yes, I have overheated a few GP9 traction motors pulling 40+loaded cars up a grade with a single unit.
Stupid single track?? Do you know about the west cap project? time to do some more reading[:I]
Its quite obvious you haven’t talked with any CN conductors. Guess what happens when you break a knuckle on a 10000 foot/ 160car train? The conductor gets to go for a walk in the nice balast to find it, in rain/ snow/ dark/ wildlife/ cliffside[:0]. CN doesn’t use remote locomotives, the forces on the drawbars and knuckles from slack from 160 cars are very high, hope ya got a smooth engineer. CN and CP have a track sharing agreement from Vancouver to Kamloops. Trains run East on the CP Cascade/Thompson subs and west on the CN Ashcroft/Yale subs. CN breaks knuckles CP Cascade sub often, CP crews don’t. On the Cascade sub CP has no problem making track speed, CN has problems making track speed even with 5+ SD40-2 (CN power shortage) pulling a 10000 foot trains.
The long of the short
CN
needs to shorten trains
use remote locomotives
get more new power
Dave CPR Conductor Vancouver BC
CP in general, has seems to be able to maintain their locomotives well. I don’t recall to many problems with their locomotives except for some of their SD90s but that is a different story.
The AC4400CWs usually I find, are on shorter trains but sometimes long trains with a majority of empties, making the haul not so bad; rather like seeing a very long switching train moving at that kind of speed. The only time where multiple GEs are used are usually for the intermodals and that’s because of the fact that they have a schedule to maintain and need the speed.
The Expressway often uses 3 SD40s either just SD40-2s or the SD40Fs. Same reasoning though.
As far as the coal trains and other unit trains; I often see pictures of them including other ore trains with a unit at the front and one at the back. Grain trains use multiple GEs or even more EMDs too my knowledge.
is there any CP lines in IL
Two points:
I retired before the SD70’s came online, but I find it hard to believe 1unit replaces 2 40-2’s. Maybe 1.5, but not 2. I am not disagreeing with you, being as I have no experience with the 70’s, but I would like to hear more details. The reason I am surprised, is that with 2 40’s, you have twice the number of wheels looking for traction, and is not the 70 rated at only 4400hp, compared to the 3000hp of each 40-2?
And unless the new units differ greatly, a diesel engine is most efficient at full rpm.
And regarding the ‘wear-out’ factor; when Metra got the first F40’s we all thought they would fly apart after a few years, being as they are in run8 at least 6 hours per day, sometimes more. And here we are, 25 years later, and they are still going strong! Granted, they are not under very load much during that time, only when leaving stations. But each unit goes thru a power/dynamic cycle many times per day; indeed, many units make middle trips between rush-hour assignaments, and those units might make 100 power/brake cycles per day! We never thought they would last nearly this long.