Not sure about this but it since it has to do with the weight, ruling grade and desired speed, I thought this comparison might help.
Cal Zephyr: 2-3 Genesis locs (8000-12,000 hp?) 10 cars @ 74 tons per Superliner = 740 tons. + engine weight (122 tons X 2-3 = 244 - 366 t) = 988 - 1106 tons. 4 sleepers X 35 passengers = 70; 5 coaches at 90 per car = 450; total = 520, top speed 110 mph?
ICE 3 on DB: 16 traction motors under the 8 car train, 12,000 hp, 409 tons carrying a maximum of 390 passengers at speeds up to 187 mph.
C&NW, CA&E, MILW, CGW and IC fan
Locomotive failure, schedule demands, and its Amtrak...
Sawtooth500I live in Chicago, and see many Amtrak long distance trains (California Zephyr, Southwest Chief, Empire Builder) running with 2 Genesis locos and ussually about 6-10 cars. Now let me get this straight - A Genesis has 4,000 HP, correct? Ok, so assuming that a freight train locomotive has 4000-4400 HP, the car/loco ratio for freight trains is a LOT higher than for Amtrak, not to mention I'm assuming freight cars are heavier...I know Amtrak trains go faster, but seriously, not that much faster than freights.So why the 2 locos?
The Empire Builder is pulled by two locomotives from Chicago to Spokane, where the train is split into Portland and Seattle sections. One locomotive is used to power the Portland section, whilst the other powers the Seattle section.
The Texas Eagle, which never has more than seven cars and usually runs with six, does nicely with one locomotive. I believe the same number of cars make up the City of New Orleans, which also gets just one locomotive.
Whether the trains gets one or two locomotives is probably a function of the number and weight of the cars, the grades that must be mastered, the speeds that must be maintained, as well as other operating conditions. Hopefully one of our engineers can enlighten us on why some of the long distance trains get two locomotives whilst others get just one.
Don't forget that as much as 700hp. is diverted to providing hotel power to the train. Then you have situations like on the climb out of the Colorado River basin to the top at Yampai Summit, over 100 miles of near steady 1.4% which all but the hottest freights climb at 25 - 30 mph. and Amtrak climbs at 70 mph. And then consider on a route like that if you lose a Diesel you have no AC in the summer and no heat in the winter if you have only one locomotive.
From what I have heard and read, the Head End Power(HEP) for Hotel power, is only adequate for a maximum of eight cars. A locomotive will be capable of handeling more than eight cars, but the HEP isn't. If there are (or possibly will?) more than eight cars, there will be 2 locomotives.
Doug
May your flanges always stay BETWEEN the rails
challenger3980 From what I have heard and read, the Head End Power(HEP) for Hotel power, is only adequate for a maximum of eight cars. A locomotive will be capable of handeling more than eight cars, but the HEP isn't. If there are (or possibly will?) more than eight cars, there will be 2 locomotives. Doug
I don't know whether or not that is true, but it fits with a recent experience. We rode the Blue Ridge Special from Spencer, NC to Asheville, NC about 3 weeks ago. It had 3 Amtrak engines pulling 25 cars.
Of course, it also had to pull those cars up a pretty steep grade through the Pisgah National Forrest.
Dave
Lackawanna Route of the Phoebe Snow
Keep in mind that speed restriction abound in the Northest Corridor. 90 mph over Metro North Railroad tracks, grade crossings between New London CT and Westerly RI, and all the 100 year old Draw Bridges.
In the Northeast Corridor, operating under electric power from Boston to Washington, the Acela is powered with two 6,000 hp power cars, one on each end, total 12,000 hp, runs at speeds up to 150 mph.
Regional service in The Corridor, also electric powered, is hauled at speeds up to 125 mph by AEM-7 (7,000 hp) or HHP-8 (8,000 hp). They can be double headed depending on train length.
Shorter trains running off The Corridor, such as the Springfield Shuttle or the Vermonter, are powered by one Genisis locomotive (Amtrak calls them AMD-103 as they are geared for 103 mph). The P40 is 4,000 hp and the P-42 is 4,200 hp. You are talking nearly new GE locomotives. After the early "bugs" were worked out, depenable operation is the norm.
Don U. TCA 73-5735
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Sawtooth500I know Amtrak trains go faster, but seriously, not that much faster than freights.
Sawtooth500Still, most of that stuff doesn't make sense to me....Cal Zephyr: 2-3 Genesis locs (8000-12,000 hp?) 10 cars @ 74 tons per Superliner = 740 tons. + engine weight (122 tons X 2-3 = 244 - 366 t) = 988 - 1106 tons. 4 sleepers X 35 passengers = 70; 5 coaches at 90 per car = 450; total = 520, top speed 110 mph?First off, to the best of my knowledge except on the Northeast Corridor, the max operating speed for most Amtrak as limited by tracks is 80 mph (or 79, if you insist). I do believe that certain trains, such as the Southwest Chief, do hit 90 at times because some of the track they run on is Class 5 track. I was talking with an Amtrak engineer once and I asked him the locomotive question, he didn't know the definite answer, but he did say that sometimes the Southwest Chief will operate on one engine, it just take a while to get to 90 on one engine, but you'll still get there. I don't believe the California Zephyr goes any faster than 80.Locomotive failure, schedule demands, and its Amtrak...Regarding locomotive failure, wouldn't it be cheaper just to have better maintenance than it would be two run another locomotive? Not to mention all the money you'd save for new routes if they didn't have to buy new locomotives... And regarding schedule demands, well if only 1 loco was scheduled and they had another free one, wouldn't this make the schedule more flexible? Scheduling 2 locos puts more strain on the schedule, not less....The Empire Builder is pulled by two locomotives from Chicago to Spokane, where the train is split into Portland and Seattle sections. One locomotive is used to power the Portland section, whilst the other powers the Seattle section. Now that kind of makes sense, if they are going to be spilling the train, but wouldn't it be cheaper just to store a locomotive in Spokane instead of running it every time to Chicago and back?Don't forget that as much as 700hp. is diverted to providing hotel power to the train. Then you have situations like on the climb out of the Colorado River basin to the top at Yampai Summit, over 100 miles of near steady 1.4% which all but the hottest freights climb at 25 - 30 mph. and Amtrak climbs at 70 mph. And then consider on a route like that if you lose a Diesel you have no AC in the summer and no heat in the winter if you have only one locomotive.Don't all passenger locomotives have head end units which provide the electric power for the train? And those units are separate from the prime mover, correct? I know that if you look through the back door of a genesis loco you see a second, smaller diesel in the back room. Also, regarding speeds through the mountains, if a helper loco is truly needed to maintain speed on a grade, wouldn't a helper district make much more sense than running the locomotive the whole distance to and from Chicago?FYI I'm not trying to offend anyone for the posts and thank you very much for giving feedback, I'm just playing devil's advocate here, and I'm trying to find the correct answer!
There are two primary methods for providing hotel power to a passenger train. the first is to draw it off of the locomotive's main alternator(which O.C does mean less power is available for the traction motors) and IINM this is the method most if not all of Amtrak's diesel fleet uses. The second method is to have an auxiliary diesel electric genset on the locomotive (or in some cases in a head end generator car). This is very common on commuter railroads. My understanding is that an HEP genset can save significant amounts of fuel in services where the train starts and stops frequently i.e commuter service..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Sawtooth500 That makes sense if you need two HEP units for 9 and more cars... but now the business man in me asks... wouldn't it not make more sense for Amtrak to simply upgrade the HEP unit to output more power? I'm sure that upgrading the HEP in the long run would cost a lot less than operating a second diesel on 2 thousand mile trips just for a second HEP...
That makes sense if you need two HEP units for 9 and more cars... but now the business man in me asks... wouldn't it not make more sense for Amtrak to simply upgrade the HEP unit to output more power? I'm sure that upgrading the HEP in the long run would cost a lot less than operating a second diesel on 2 thousand mile trips just for a second HEP...
No additional locomotives for HEP, only one locomotive can supply the HEP otherwise they would have to be synchronized (which is difficult on a locomotive with its variable power demands). But if the locomotive supplying HEP dies you have to have another that can be cut in.
Sawtooth500Still, most of that stuff doesn't make sense to me....Cal Zephyr: 2-3 Genesis locs (8000-12,000 hp?) 10 cars @ 74 tons per Superliner = 740 tons. + engine weight (122 tons X 2-3 = 244 - 366 t) = 988 - 1106 tons. 4 sleepers X 35 passengers = 70; 5 coaches at 90 per car = 450; total = 520, top speed 110 mph?First off, to the best of my knowledge except on the Northeast Corridor, the max operating speed for most Amtrak as limited by tracks is 80 mph (or 79, if you insist). I do believe that certain trains, such as the Southwest Chief, do hit 90 at times because some of the track they run on is Class 5 track. I was talking with an Amtrak engineer once and I asked him the locomotive question, he didn't know the definite answer, but he did say that sometimes the Southwest Chief will operate on one engine, it just take a while to get to 90 on one engine, but you'll still get there. I don't believe the California Zephyr goes any faster than 80. Amtrak has fuel saving instructions in place and locomotive assignments are a function of a combination of things: fuel consumption, power requirements, HEP eliability, grades and train weight. One item not mentioned is the fact that the P42's are much lighter than freight locomotives of the same horsepower rating and are therefore, a little more slippery with a poorer factor of adhesion. The fact that the locomotives are geared for passenger speed reduces the power output at the rail in terms of acceleration, i.e, these engines are built for speed, not lugging ability and as such are much more sensitive to train weight.Locomotive failure, schedule demands, and its Amtrak...Regarding locomotive failure, wouldn't it be cheaper just to have better maintenance than it would be two run another locomotive? Not to mention all the money you'd save for new routes if they didn't have to buy new locomotives... And regarding schedule demands, well if only 1 loco was scheduled and they had another free one, wouldn't this make the schedule more flexible? Scheduling 2 locos puts more strain on the schedule, not less....Locomotive maintenance is an issue on all railroads, and as it goes, Amtrak does a pretty respectable job of maintaining what can be considered an elderly fleet. The schedule is what it is, and the power assigned is based upon many factors, both permanent and temporary, schedule being just one part of the equation.The Empire Builder is pulled by two locomotives from Chicago to Spokane, where the train is split into Portland and Seattle sections. One locomotive is used to power the Portland section, whilst the other powers the Seattle section. Now that kind of makes sense, if they are going to be spilling the train, but wouldn't it be cheaper just to store a locomotive in Spokane instead of running it every time to Chicago and back?The Builder contends with one of the toughest grades in Montana and two units are needed to power the train on that grade and maintain that nasty old schedule. Remember, HEP reduces the second unit's traction output considerably, more than the 700 hp quoted elsewhere.Don't forget that as much as 700hp. is diverted to providing hotel power to the train. Then you have situations like on the climb out of the Colorado River basin to the top at Yampai Summit, over 100 miles of near steady 1.4% which all but the hottest freights climb at 25 - 30 mph. and Amtrak climbs at 70 mph. And then consider on a route like that if you lose a Diesel you have no AC in the summer and no heat in the winter if you have only one locomotive.Don't all passenger locomotives have head end units which provide the electric power for the train? And those units are separate from the prime mover, correct? I know that if you look through the back door of a genesis loco you see a second, smaller diesel in the back room. Also, regarding speeds through the mountains, if a helper loco is truly needed to maintain speed on a grade, wouldn't a helper district make much more sense than running the locomotive the whole distance to and from Chicago?Head end power as provided by an Amtrak P42 reduces the horsepower available for traction by considerably more than the 700 hp quoted above. What you see in the back is in fact the air compressor and its components and a small generator which develops HEP off the prime mover. There is no auxiliary diesl engine on a P42.FYI I'm not trying to offend anyone for the posts and thank you very much for giving feedback, I'm just playing devil's advocate here, and I'm trying to find the correct answer!
Amtrak has fuel saving instructions in place and locomotive assignments are a function of a combination of things: fuel consumption, power requirements, HEP eliability, grades and train weight. One item not mentioned is the fact that the P42's are much lighter than freight locomotives of the same horsepower rating and are therefore, a little more slippery with a poorer factor of adhesion. The fact that the locomotives are geared for passenger speed reduces the power output at the rail in terms of acceleration, i.e, these engines are built for speed, not lugging ability and as such are much more sensitive to train weight.
Hi,
Just a small correction, if I may... BUILDER runs with 2 units ex Chicago ( and certainly needs them....) with an average consist of 10-11 cars. The power does NOT split at Spokane.
The power might CHANGE...but the Seattle section, now averaging 6 cars, still has two units; and the Portland section has one...and quite often 2, for its own 4-5 cars average
IMO, as well, SouthWestChief wouldn't make it over Raton or Glorietta with only 2 units and its average 9 cars consist.....to say nothing of Cajon.
Of course, the Zephyr has a perfect mid-point stop....: Denver, where adding a third unit to a westbound consist exceeding 8 cars is a must...otherwise, the D&RG route and Donner pass will doom its timekeeping ( and might give you an experience in stalled trains....)
Just my opinion
Cheers
oltmanndHere's how it works. Start with the schedule, complete with stops. Figure out how much HP you need to get the train over the road on that schedule plus some padding for service reliability. You can do this by trial and error with actual operation or by simulation. For most Amtrak trains, you'll wind up in the 6-8 HP/ton range. Now, take a typical Amtrak train of 10 cars or so at 70 tons each plus a locomotive or two at 135 tons each. That's about 1000 tons. One P42 = 4.2 HP/ton (closer to 3.5 HP/ton with HEP accounted for). Not enough. Two P42s = 8.4 HP/ton (7.5 HP/ton with HEP). Bingo! Two P42s are needed. Could you run the train with one P42? Most likely, yes, you'd get there, but, you'd be late at destination more often (maybe even all the time). There is one added wrinkle. The TE at minimum continuous speed for a P42 is about 36,000#. The max ruling grade for one P42 with a 1000 ton train would be 1.8%. That would be OK from trains in the east that don't go over the Alleghenies. like the Florida trains, the Crescent and the City of New Orleans, but not for most of the western trains, so two are needed to keep from stalling. In fact, two P42s on the SW Chief would be cutting it kind of close for Raton, so three are a safe bet.
Only 36,000 lbs tractive effort without burning out the traction motors? Do you mean to tell me that a booster-equiped Northern is a match for a pair of Genesis locomotives?
I thought that with wheel slip control and improved electrical insulation materials that a B-B locomotive could do much better. Is this figure on account that the P42 is geared for a high top speed and it has DC traction motors? Would an AC-motored passenger locomotive result in "unit reduction" on Amtrak?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
CG-RiderIMO, as well, SouthWestChief wouldn't make it over Raton or Glorietta with only 2 units and its average 9 cars consist.....to say nothing of Cajon.
Looking at photos in New Mexico around Raton of the Chief from 2003 onwards, it looks like it ran in 2003 with a consist of 8 cars + a baggage car, but additionally had about 10 container cars or MHC's and 3-4 P 42's. More recently no freight/express, 8 Superliners + baggage and only 2 P 42's.
The "Empire Builder" has run with eleven cars for the past few years, 365. One is a baggage car, which doesn't require much HEP. Sometimes there will be PVs attached, too, especially in the summer. Sometimes there will be a car going to/from CHI, probably to Beech Grove. I have only been on it, west of Spokane once and am ashamed to say that I didn't notice how many units were on it, SPK-PDX or SEA-SPK. I do feel reassured with the "extra" power, for protection or a unit being disabled due to our numerous grade crossing incidents. My engineer neighbor said that he hit seventy antelope one day, but there was no damage to the locos. In the "old days", three run-through F40s were the rule, especially in the winter. Interesting thread, methinks....
Hays
Got thinking about it a bit more. In the "olden days", AT&SF ran with four Fs on their passenger trains. Ditto UP, unless E's were available. CPR always added a unit, or two, to the westbound Canadian at Calgary. GN ran with four Fs over Maria's Pass. Even NYC used three E7s on some trains on the "Water Level Route". Don't see many pictures of LD passenger trains with only one unit. Perhaps the CPR's "Alouette", with one E8, but they only had one! SAL and ACL regularly ran with three units. Please don't mention the RI. That was another type of animal...
Paul Milenkovic oltmanndHere's how it works. Start with the schedule, complete with stops. Figure out how much HP you need to get the train over the road on that schedule plus some padding for service reliability. You can do this by trial and error with actual operation or by simulation. For most Amtrak trains, you'll wind up in the 6-8 HP/ton range. Now, take a typical Amtrak train of 10 cars or so at 70 tons each plus a locomotive or two at 135 tons each. That's about 1000 tons. One P42 = 4.2 HP/ton (closer to 3.5 HP/ton with HEP accounted for). Not enough. Two P42s = 8.4 HP/ton (7.5 HP/ton with HEP). Bingo! Two P42s are needed. Could you run the train with one P42? Most likely, yes, you'd get there, but, you'd be late at destination more often (maybe even all the time). There is one added wrinkle. The TE at minimum continuous speed for a P42 is about 36,000#. The max ruling grade for one P42 with a 1000 ton train would be 1.8%. That would be OK from trains in the east that don't go over the Alleghenies. like the Florida trains, the Crescent and the City of New Orleans, but not for most of the western trains, so two are needed to keep from stalling. In fact, two P42s on the SW Chief would be cutting it kind of close for Raton, so three are a safe bet. Only 36,000 lbs tractive effort without burning out the traction motors? Do you mean to tell me that a booster-equiped Northern is a match for a pair of Genesis locomotives? I thought that with wheel slip control and improved electrical insulation materials that a B-B locomotive could do much better. Is this figure on account that the P42 is geared for a high top speed and it has DC traction motors? Would an AC-motored passenger locomotive result in "unit reduction" on Amtrak?
There is a trade off here. The locomotive's monococque body saves fuel since its construction makes for a much lighter locomotive, but........the loss of weight drops the factor of adhesion, hence the numbers supplied above.
And no, with maintenance, water and fuel stops and other variables such as required facilities and materials factored in, a booster equipped Northern still isn't a match for a pair of P42's in cost or efficiency, no matter what the tractive effort is.
Paul MilenkovicDo you mean to tell me that a booster-equiped Northern is a match for a pair of Genesis locomotives?
The P42 weighs... at least 270,000 lb? So we could hope adhesion would allow more than 36,000 lb continuous TE, despite the monocoque frame; the low rating is the disadvantage of gearing all the P42s for the same maximum speed (110mph?).
BNSFwatcherGot thinking about it a bit more. In the "olden days", AT&SF ran with four Fs on their passenger trains. Ditto UP, unless E's were available. CPR always added a unit, or two, to the westbound Canadian at Calgary. GN ran with four Fs over Maria's Pass. Even NYC used three E7s on some trains on the "Water Level Route". Don't see many pictures of LD passenger trains with only one unit. Perhaps the CPR's "Alouette", with one E8, but they only had one! SAL and ACL regularly ran with three units. Please don't mention the RI. That was another type of animal... Hays
Actually CPR had three E8s, but in the pictures I have seen of the Montreal-Boston train there was only a single E-unit, either a B&M E7 or a CPR E8, on the front. Of course the E-units had two diesel prime movers inside that carbody so the train was in some respects run with "two" engines. One of the trio was retired about 1969 following a head-on collision, the other two lasted into the VIA ownership.
In the early 1970s the Toronto-Sudbury section of "The Canadian" would often run with a single F-unit or FPA-2. The Montreal-Saint John "Atlantic Limited" also commonly used just a single unit, mostly an F-unit but for a time an E8 was the standard power.
John
Of course E7's had only 2000hp and E8's 2250, so not too surprisingly, some trains used 2 or more units.
timz Paul MilenkovicDo you mean to tell me that a booster-equiped Northern is a match for a pair of Genesis locomotives?The 4-8-4 would produce the same tractive effort at 5-10 mph that the two P42s produce at 30-35 mph. If that means it's matching them, then maybe so. The P42 weighs... at least 270,000 lb? So we could hope adhesion would allow more than 36,000 lb continuous TE, despite the monocoque frame; the low rating is the disadvantage of gearing all the P42s for the same maximum speed (110mph?).
Granted that does play to it, these things are sometimes as slippery as a Pennsy T-1.
Re: CPR E-8s -- I knew that! "It was just a typo!".
Wish I could figure out how to 'snip' and 'quote' to shorten the reply.
A bad week for the WB "Empire Builder": Fri, 20 Nov it hit a van parked, on the tracks, between Cut Bank and Browning, MT. Railroad-assisted suicide attempt? #7 was only seven minutes late into SEA. Next day they hit a trespasser in the same area. Dunno how it affected the sked. On Wed, 26 Nov they hit a boulder on the rails just west of Essex, MT. Derailed the lead wheelset. Lost about six hours while BNSF re-railed the loco. Good job, guys! That "second" unit gives some peace-of-mind, especially if it is facing the right direction.
If there is either the 9 or 10 car limitation on one HEP power source or not beirg able to parallel the outputs please explain AMTRAK's Auto Train consists.??
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