That video proves nothing. Not too mention, vehicles in motion crashing into stationary vehicles seem to always exhibit that "climbing" behavior. Note this "heavy" locomotive (heavier than an F40PH; look at the six axles, which indicates between 40 to 50 tons on the F40PH) slamming into stationary coal cars:
http://www.youtube.com/watch?v=mUF19acPBZA
Ham549 wrote:This video should leave no doubt in your minde that a F40PH is safer than a cab carhttp://youtube.com/watch?v=HZWpeU55J3EHell a F40PH is safer than a genes#it while cabbages take out loaded dumptrucks P42's derail when ramming tow trucks.
This video should leave no doubt in your minde that a F40PH is safer than a cab car
http://youtube.com/watch?v=HZWpeU55J3E
Hell a F40PH is safer than a genes#it while cabbages take out loaded dumptrucks P42's derail when ramming tow trucks.
All that proves is that the crash standards in the 1970s were higher than those in the 1960's. An F40PH won't meet current crash standards and neither will a Genesis. That is why the Wabtec MPExpress is the only commuter locomotive being built. Whether or not a locomotive derails when it hits a truck depends on whether the truck crushes and goes under the locomotive lifting it of the rails, a loaded dump truck with the high center of gravity will tend not to go under the locomotive as long as it doesn't break apart too quickly.
beaulieu wrote: HarveyK400 wrote: beaulieu,MY bad - I was assuming the Acela cars would be similar to 4 apparently lighter Bombardier LRC cars, which they resemble, with two 3000 hp HST gas-turbine locos, one loco being the rough equivalent of two cars. I used what I thought was a close example to represent the Acelas. If you have the information and the capability, I would be interested in seeing what you would come up with.The point is that a single 6,000 hp locomotive is capable of really good performance with a decent size train from an example without pushing around a heavy NPCC unit. A cab coach is much more efficient; and it can be built for safety. I really wonder if the Acela could be lighter and why it is as heavy as it is. I assumed the weight of 274 passengers which comes to another 24 tons.I'll repeat a source I found in Railway Gazette International for drag coefficients that I used with the traditional Davis formula: "Optimizing aerodynamics to raise IC performance," Jean-Luc Peters, Dec, 1982. Incidently, the default track resistance factor from the mid-1900s, 1.5 lbs/ton used by Davis, is too high for today's mainline track. Hay referenced a KCS study where 1.5 lbs/ton for 85# rail and 0.9 lbs/ton for 140# rail were found. I used 1.3 lbs/ton for a conservative approximation for 115# rail on the Chicago - Saint Louis corridor. I can't find the reference that deep, good quality ballast provides around 10 times the modulus of elasticity of the rail. Harvey I'm afraid its been too long since my math days without much use, for me to solve those equations. I just realized that you were using too low a weight and that it would skew the results. As far as why they are so heavy, I think it's a price we pay here in the US for fact that we challenge the train at grade crossings, and for the very heavy freight trains, with the result that passenger trains have to be much heavier and consume more energy, whether that energy is electricity or diesel. This wasn't much of a problem when energy was cheap, but we are paying the price now. I look at the Acela, and then at the TGV Duplex, and its pretty sad comparison. Using metric measureAcela weight 566 tonnesDuplex weight 380 tonnes Acela power 9.2 MWDuplex power 8.8 MW Acela capacity 304 passengersDuplex capacity 516 passengers Acela length (w/6 cars) 202 metresDuplex length (w/8 cars) 200 metres Acela weight per seat 1.9 tonnes per seatDuplex weight per seat 0.73 tonnes per seat Acela power to weight 16.3 kW per tonneDuplex power to weight 23 kW per tonne Acela power to seat 30.3 kW per seatDuplex power to seat 16.2 kW per seat PitifulJohn Beaulieu
HarveyK400 wrote: beaulieu,MY bad - I was assuming the Acela cars would be similar to 4 apparently lighter Bombardier LRC cars, which they resemble, with two 3000 hp HST gas-turbine locos, one loco being the rough equivalent of two cars. I used what I thought was a close example to represent the Acelas. If you have the information and the capability, I would be interested in seeing what you would come up with.The point is that a single 6,000 hp locomotive is capable of really good performance with a decent size train from an example without pushing around a heavy NPCC unit. A cab coach is much more efficient; and it can be built for safety. I really wonder if the Acela could be lighter and why it is as heavy as it is. I assumed the weight of 274 passengers which comes to another 24 tons.I'll repeat a source I found in Railway Gazette International for drag coefficients that I used with the traditional Davis formula: "Optimizing aerodynamics to raise IC performance," Jean-Luc Peters, Dec, 1982. Incidently, the default track resistance factor from the mid-1900s, 1.5 lbs/ton used by Davis, is too high for today's mainline track. Hay referenced a KCS study where 1.5 lbs/ton for 85# rail and 0.9 lbs/ton for 140# rail were found. I used 1.3 lbs/ton for a conservative approximation for 115# rail on the Chicago - Saint Louis corridor. I can't find the reference that deep, good quality ballast provides around 10 times the modulus of elasticity of the rail.
beaulieu,
MY bad - I was assuming the Acela cars would be similar to 4 apparently lighter Bombardier LRC cars, which they resemble, with two 3000 hp HST gas-turbine locos, one loco being the rough equivalent of two cars. I used what I thought was a close example to represent the Acelas. If you have the information and the capability, I would be interested in seeing what you would come up with.
The point is that a single 6,000 hp locomotive is capable of really good performance with a decent size train from an example without pushing around a heavy NPCC unit. A cab coach is much more efficient; and it can be built for safety. I really wonder if the Acela could be lighter and why it is as heavy as it is.
I assumed the weight of 274 passengers which comes to another 24 tons.
I'll repeat a source I found in Railway Gazette International for drag coefficients that I used with the traditional Davis formula: "Optimizing aerodynamics to raise IC performance," Jean-Luc Peters, Dec, 1982.
Incidently, the default track resistance factor from the mid-1900s, 1.5 lbs/ton used by Davis, is too high for today's mainline track. Hay referenced a KCS study where 1.5 lbs/ton for 85# rail and 0.9 lbs/ton for 140# rail were found. I used 1.3 lbs/ton for a conservative approximation for 115# rail on the Chicago - Saint Louis corridor. I can't find the reference that deep, good quality ballast provides around 10 times the modulus of elasticity of the rail.
Harvey I'm afraid its been too long since my math days without much use, for me to solve those equations. I just realized that you were using too low a weight and that it would skew the results. As far as why they are so heavy, I think it's a price we pay here in the US for fact that we challenge the train at grade crossings, and for the very heavy freight trains, with the result that passenger trains have to be much heavier and consume more energy, whether that energy is electricity or diesel. This wasn't much of a problem when energy was cheap, but we are paying the price now. I look at the Acela, and then at the TGV Duplex, and its pretty sad comparison.
Using metric measure
Acela weight 566 tonnes
Duplex weight 380 tonnes
Acela power 9.2 MW
Duplex power 8.8 MW
Acela capacity 304 passengers
Duplex capacity 516 passengers
Acela length (w/6 cars) 202 metres
Duplex length (w/8 cars) 200 metres
Acela weight per seat 1.9 tonnes per seat
Duplex weight per seat 0.73 tonnes per seat
Acela power to weight 16.3 kW per tonne
Duplex power to weight 23 kW per tonne
Acela power to seat 30.3 kW per seat
Duplex power to seat 16.2 kW per seat
Pitiful
John Beaulieu
A better comparison would be Acela Express to ICE 1 (a more even weight comparison); but even that is not parallel. Not to mention, the AE is not heavy when compared with other trains that have operated in the USA; the power cars are only 2,000 lbs heavier than the AEM-7, and the trailer cars are actually lighter than the PRR's MP54-E6. (Also, this is anecdotal, but some rails I've corresponded with insist that the power car HP of the AE is actually 8,000, same as the HHP-8.)
MBTA, average 6 to 8 cars now, about half Double Deckers. F40PH or GP40MC on the point.
The Ruling Grade north of New York is at Sharon Mass. as you climb from Boston Harbor, across the 170 year old Canton Viaduct, up Sharon Hill and then down to Providence on Narragansett Bay. No problem for an Acela at carded speed.
Don U. TCA 73-5735
The HP for the Acela trainsets came from working backwards from a mandated running time. If you keep bumping up the HP/ton, you keep shortening the running time. Not always so much because of trying to hold speed on grade or attaining a high maxiumum speed, but because recovery from reduced speed is faster.
The law of diminishing returns is in full working order with the Acela trains, though. They had to bump the HP/ton waaay up in order to shave those last few minutes to reach the mandated running time.
I think what Gunn was getting at was that a common sense approach would have allowed considerably lower HP/ton with only a small sacrifice in running time. Either longer or single ended train sets might have made more sense. It was a bad mistake for Congress to mandate a running time in the legislation.
The remarkable thing is, that for all their flaws, Acela does really well economically. Those 20 train sets are pulling in ~25% of Amtrak's revenue.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
I would have imagined passenger discomfort was more likely to register beyond the adhesion limit of the train. I'm a little surprised that Amtrak measured acceleration and surveyed passengers for this issue. More uncomfortable and likely to spill coffee are the sudden jerks starting and stopping.
Curve resistance is pretty insignificant for a small passenger train on the NEC. This is not Raton Pass and the Southwest with 10-15 express cars.
Now grades can be another matter. I was unaware of any substantial grades beside Hell Gate Bridge and the East and Hudson River Tunnels on the NEC. Even so, the power to accelerate rapidly to 150 mph isn't over-taxed in maintaining that speed on moderate grades. Acceleration on such a grade, however, would be drawn out.
My observation of the MBTA 20+ years ago was that trains were short, 4-6 light weight Bombardier cars. It's hard to think there would be any problem with grades.
The North Western had an 11-car train weighing around 960 tons with an E8 and passengers that could do not much better than 45 mph upgrade from a stop at Arlington Heights to Barrington.
HarveyK400 wrote:beaulieu,MY bad - I was assuming the Acela cars would be similar to 4 apparently lighter Bombardier LRC cars, which they resemble, with two 3000 hp HST gas-turbine locos, one loco being the rough equivalent of two cars. I used what I thought was a close example to represent the Acelas. If you have the information and the capability, I would be interested in seeing what you would come up with.The point is that a single 6,000 hp locomotive is capable of really good performance with a decent size train from an example without pushing around a heavy NPCC unit. A cab coach is much more efficient; and it can be built for safety. I really wonder if the Acela could be lighter and why it is as heavy as it is. I assumed the weight of 274 passengers which comes to another 24 tons.I'll repeat a source I found in Railway Gazette International for drag coefficients that I used with the traditional Davis formula: "Optimizing aerodynamics to raise IC performance," Jean-Luc Peters, Dec, 1982. Incidently, the default track resistance factor from the mid-1900s, 1.5 lbs/ton used by Davis, is too high for today's mainline track. Hay referenced a KCS study where 1.5 lbs/ton for 85# rail and 0.9 lbs/ton for 140# rail were found. I used 1.3 lbs/ton for a conservative approximation for 115# rail on the Chicago - Saint Louis corridor. I can't find the reference that deep, good quality ballast provides around 10 times the modulus of elasticity of the rail.
Acceleration rates are limited do to Passenger comfort. The HP is needed to Hold Speed on curves and hills. A locomotive hauled passenger train (MBTA) on The Corridor can lose 30mph on Sharon Hill between Boston and Providence.
Amtrak used the same model Acceleration Meters as we use in the Elevator Industry. While we can accelerate an elevator at 4fps/ps vertically, trains are set somewhere around 2 fps/ps so you "Don't Spill The Coffee".
Maybe we have a difference of opinion of what adequate performance is.
Admittedly, my first guess was a little off. I did some acceleration calculations a few years back; and one case in my notebook was for a 396-ton train, the rough equivalent of five cars with a 6100 hp locomotive. The sixth car may increase the distances and times by a quarter. A twelve-car Acela Express with two locomotive would do as well as the five-car train case.
Speed Distance Time
0-125 mph 4.2 miles 3.0 minutes
0-150 mph 9.0 miles 5.1 minutes
You do know you're moving!!!
HarveyK400 wrote:David Gunn's assessment of the Acela consist reinforces what I wrote, perhaps in the energy thread. It also suggests that a single Acela cab-power car, five business/first class and cab-business class end car would be a reasonable consist capable of quick acceleration to 125 mph and able to reach 150 mph (for bragging rights) in short stretches 8-20 miles long.
David Gunn's assessment of the Acela consist reinforces what I wrote, perhaps in the energy thread. It also suggests that a single Acela cab-power car, five business/first class and cab-business class end car would be a reasonable consist capable of quick acceleration to 125 mph and able to reach 150 mph (for bragging rights) in short stretches 8-20 miles long.
Harvey your suggestion of a trainset consisting of a powercar, 5 coaches, and cabcar, would essentially be a similar train to today with just one powercar. As the power cars are rated at only 4574 kW each (6115 hp) it wouldn't be anywhere near adequate. When David Gunn was talking about overpowered he was only talking about adding 1 or 2 cars, not halving the power to weight ratio.
You speak of sustained 150 mph Northeast Corridor operation with tilt technology and of a stretch through Princeton Junction, NJ where 135 is permitted. The segment through Princeton Junction and possibly another through Newark, DE may be the only ones with tangents and 0.5-deg curves where 175 mph with tilt suspension may be attained; but, from my experience, hardly sustained long enough to save more than a minute or two. Interestingly, the Princeton Jct. stretch is where the Turbo Train hit 170 mph on a test run.
Most of the former Pensyvania Railroad was built to a standard of 1-degree curves that result in 10.94 inches total underbalance at 125 mph. With 4 inches cant, the 6.94 inches deficiency is just within the Acela's design limit.
I see no reasonable way to build a new 217mph/350kph line through the Washington, DC - New York, NY - Providence, RI conurbation. Segments may be identified where less costly curve easement may be possible. 185 mph would require 0.457-degree, 12,600-foot radius curves with 10.94 inches underbalance. Given the additional distance needed to accelerate to 185 mph from 125 mph and presumably short segments, 175 mph may be a more readily attainable goal. Over 150 mph would require separate freight tracks as well; but relatively low freight limits and high cant already may have brought on separate tracks in certain areas.
I think the challenge and priority should be to provide capacity to meet future demand.
Ham549 wrote:The F40PH is very safe although same can't be said for the Genes#!+ (Genesis?)
remember this was caused by a SUV had a F40PH been leading that train the results would have probely been far less tragic.
DMUinCT wrote:To pull enough power from one pantograph riding one wire at 150mph, is it possible, don't know
passengerfan wrote:I understand why the Acela trains have a power unit at each end it just seems to me they could put more cars between the cab ends
DMUinCT wrote:True, South of Boston and southern Rhode Island is 150 mph track, but much of the line is 135 to 140 mph limit
On Metro-North, the Acela Express is held down to speeds of about 70 mph. In spite of the AE being two inches narrower than standard stock (Budd Cosmopolitans, the coming Kawasaki M8, Amfleets, et cetera are 10' 6" wide while AE is 10' 4" wide), Metro-North will not permit Amtrak to use the active-tilt system on their rails.
DMUinCT wrote:Acela, alone among bullet trains, have standard 8 wheel cars coupled together
HarveyK400 wrote:150 mph speed is unnecessary and not sustained for any significant distance; but Amtrack got a lot of marketing mileage out of only a few miles.For shorter base service trains, a cab control coach would be more sensible with all the horsepower in the locomotive. The same Acela nose and safety cab could be built on the end of a coach, much like the previously mentioned X2000. The X2000 runs at 125 mph with 4-5 cars, a cab coach, and an electric locomotive. A similar Acela train could have 352 seats
For shorter base service trains, a cab control coach would be more sensible with all the horsepower in the locomotive. The same Acela nose and safety cab could be built on the end of a coach, much like the previously mentioned X2000. The X2000 runs at 125 mph with 4-5 cars, a cab coach, and an electric locomotive. A similar Acela train could have 352 seats
Over the years I have sampled many trains and planes when they accelerate and can't help but recall returning one Sunday evening from Phoenix to San Diego my first time on Western Airlines (The only way to fly). I had taken the United 727 flight on many occasions so was rather surprised to see our flight was a 4 - engined Turbo Prop Electra. When we taxied out to the runway I had no idea what I was in for. The passenger seated across the aisle from me told his buddy he would put a twenty dollar bill on the back of the headrest ahead and when the plane accelerated down the runway he could not reach forward and pick up the twenty. The United 727 that I normally flew took off just ahead of us.
The Electra turned onto the runway and I have never been pinned into my seat like that plane did on its takeoff run. I know we did not fly as high as the 727 on that flight but we arrived just ahead of the 727. All in all it was one of the few planes that have ever almost taken my breath away. That acceleration I will never forget and by the way try as the guy across from me might he was unable to reach forward for the twenty.
Fastest acceleration I can remember on a train was a CN Turbo pulled by an FPA4 that made better time from Toronto to Montreal than when the Turbo had all of its turbines operating. This was a frequent occurrance in the winter on this run as the turbines did not like the fine snow along the route and one or more turbines failed. As long as they had one for hotel power they would assign an FPA4 or FP9A for power. The MLW smoked more than a GM would have but it could sure accelerate like a scared rabbit.
Al - in - Stockton
There are several high-speed EMUs in Western Europa, for example the ICE 3 in Germany (actually out of service because on one train, an axle broke, reasons not yet clear). The Italian Pendolinos and their British version are EMU's oder DMU's, too. Of course, there are o grade level crossings on proper HS-ROW.
France, Switzerland and Britain (and IIRC Germany too) run conventional push-pull-trains with a driving-trailer at one end and the engine at the other. Top-speed 100 mph. I rode some and did not feel scared.
Back to the original subject...
Just saw a (copyrighted, unfortunately) photo of a recently-built Japanese private railway EMU set. The 'interior' cars were of conventional appearance. The cabs looked as if they were inspired by Darth Vader's helmet! Obviously built of something approximating naval armor plate, the lower edge of the rather sharply angled pilot all but scraped the railheads. Just below cab window level, there was a 'fence' of protruding studs, obviously intended to keep anything impacted at a grade crossing from climbing into the driver's operating space. If that thing hit an SUV, it would punt it into the next county.
That particular EMU set would be an acute safety problem to anything or anyone that got in its way - but not to the driver or riders.
Chuck
This discussion of Acela service utilization/capacity more properly belongs in the current thread on energy consumption; but here we are.
The initial point was, I recall, that some of the hourly Acelas carried light loads while business was turned away or diverted to other trains. A more flexible schedule, ala Southwest, would be more efficient with. Recently advertised Southwest schedules for various destinations are not on an hourly, clocker, schedule.
You ask if this [Amtrak] needs more. Service would depend on the demand for travel and the train's capacity.
I had forgotten that the Acela is a premium First & Business service. It can't be very efficient; but passengers are paying for the priviledge. It's interesting to see what Acela might do in terms of numbers it it had coach seats.
The next question is what utilization is achieved on the Regionals?
Acela, First and Business Class only. In the Northeast Corridor, Amtrak does run a fixed consist Acela every hour (much like Southwest Airline).
They then run Locomotive hauled Amfleet Reserved Coach and Business Class trains every 2 hours.
Do they need more?
I agree with you to a point about adding cars to increase capacity. 150 mph speed is unnecessary and not sustained for any significant distance; but Amtrack got a lot of marketing mileage out of only a few miles.
For shorter base service trains, a cab control coach would be more sensible with all the horsepower in the locomotive. The same Acela nose and safety cab could be built on the end of a coach, much like the previously mentioned X2000. The X2000 runs at 125 mph with 4-5 cars, a cab coach, and an electric locomotive. A similar Acela train could have 352 seats.
The Southwest Airlines model is to vary frequency to match demand with fixed consists, in this instance a 737 aircraft.
Amtrak has the option for back-to-back Acela Locomotive+coach blocks without a cab coach with as many as 14 cars with reduced drag having roughly 680 coach and 140 business class seats for over 800 passengers and still accelerate quickly to 125-135 mph.
The next issue is whether pricing makes optimal use of capacity given the cost and revenue for the train.
Oh yes, The "TurboTrain", built by my former employer, United Technologies (AKA United Aircraft). Based on the Pullman-Standard "Train X", Pratt invented a "Pendular Suspension System" that was very successful. Patentes TALGO S.A. later adoped it as "TALGO Pendular".
UT's Pratt & Whitney division planned a 3 unit train with a power car on each end, wind tunnel tested. Each power unit would have 2, 3, or 4 P&W PT6 turbine engines, designed and in use in Turbo-Prop aircraft, direct geared to the two front axles. Each turbine weighted only 300 lbs yet put out 550 hp. Each Power Car could be rated at 1,100 1,650 or 2,200 hp. Turbines could be added or removed via side doors by field personel. Each power car had 28 seats below and 24 seats in the "Vista Dome" located over the jet engines. Design speed 160mph. Two trains could be coupled together with the "Clam Sheel" connection. One crew up front would then control all four Power Cars (one at each end and two in the middle)
U.S. DOT ordered 2 three car train sets with 3 turbines in each power unit. Top speed was geared down to 125mph do to New Haven Railroad track condition. Canada ordered 5 seven car "TurboTrains" to be built by the Montreal Locomotive Works. As I remember, Canada had problems, 5 intermediate cars, snow clogging the engine intakes. As for the Boston to New York run, Turbo equipment availability was 91.7% vs coventional equipment at 84.5% (but the Turbos were new, the New Haven was old). Amtrak later added more intermediate cars bought as surplus fron Canada.
Last I checked, the Japan Shinkansen used conventional 8-wheel coaches without articulation -- they may be semi-permanently coupled into pairs to share electrical equipment. I also thought the Metroliners had an A end with a cab and a B end without and that they were connected in pairs with back-to-back B ends.
The French TGV famously uses articulation -- Jacobs or Jakobs bogie it is called in the industry when the articulation shares a 4-wheel truck. That is in part a weight-saving measure as the wheels and trucks are a heavy item. In France, they have wheel shops that can take entire TGV trainsets and do the maintenance on them without taking them apart.
Southern Pacific back in the day had articulated "chair cars" and diners. Just because you articulate something doesn't mean the whole consist has to be one permanantly-coupled unit. You now have articulated spine cars and double-stack well cars in intermodal freight service, and the railroads had been experimenting as to how big a permanently-coupled chunk is desirable, a tradeoff between savings in having fewer switchable cars vs having a big string bad ordered all at once.
The TurboTrain was articulated and guided-axle and all of that, but the design had retractable clamshell doors to expose couplers and a passageway at the streamlined ends that allowed joining TurboTrain sets in multiple. They never had enough TurboTrains in service that this was done in practice, although I saw one picture from Canada where they retracted the clamshell doors to hook on an FP-9 locomotive when they had mechanical trouble with the turbine propulsion. The account was that the TurboTrain was so light that the FP-9 provided quicker acceleration from a standstill than those turbines, although the top end speed would be reduced form 150 MPH considerably owing to traction motor gearing. The TurboTrain could have been successful as locomotive-hauled equipment, just as the Amfleet coach is an unpowered Metroliner
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Passengerfan, you are right!
True, South of Boston and southern Rhode Island is 150 mph track, but much of the line is 135 to 140mph limit. Most trains run through Boston to Washington, station stops are short, even in New York, they can not take the time to add or remove cars and keep it a 6 + hour run.
Acela, alone amoung bullet trains, have standard 8 wheel cars coupled together. If needed cars CAN be added. If a problem developes with one car, it can be removed from service and even another car substituted.
A close look at a car, note the wheel encoders, air springs, the Rescue Windows, and yes, the Acela Cabs ARE fully armored.
ndbprr wrote:Any time the crew is inchs from the font of the vehicle there are going to be more injuries than if they are not if for no other reason then that is the crumple zone. The PRR streamlined the last of the P5a engines because of a crew being killed in a box cab. That is the reason for the cab location on a GG1. Now if a crew could be seriously hurt in a cab built with 1/4" or thicker plate and a cast steel underframe I think I would opt for another location if I had a choice. Wouldn't you?
How often and at what cost are the two issues you are ignoring.
Operating at 50 mph is safer than 60 mph, so why not always operate at 50 mph max?
Operating at 40 is safer than 50....I doubt there would ever be a fatality if trains operated at 5 mph max, so why not chose this as max speed?
At the same time the PRR converted the P5s into P5as, they continued to field a fleet of MP54s operating over most of the same territory (plus on the LIRR), allowed the PRSL to replace locomotive hauled trains with RDCs, and pursued new MU cars for NY, Phila and intercity sevice.
Also, "crumble zones" are almost completely irrelevant in North American frt locomotive design. Crumble zones are energy managment systems. There is too much energy in a frt train operating mainline speeds to manage using crumble zones. Unlike automobiles, deadly rates of deceleration rarley occur in derailments or collisions.
tomikawaTT wrote: gardendance wrote: beaulieu wrote: passengerfan wrote: I still do not see the need for Acela to have power on each end.Finally Acela needs both power cars to have enough horsepower to make the schedule. beaulieu: I'd tend to agree with you. TGV and Shinkansen have power cars at both ends, and I expect the general consensus is that they are the epitome of high speed rail.The Shinkansen trains have CABS at both ends - and powered axles under EVERY car. That's why they accelerate like scared rabbits.At a somewhat lower speed, JNR (pre-privatization) DMUs had powered axles under every car, both ends - with two notable exceptions, both on the highest-speed train sets. The KiHa82 class cab cars had one engine driving the train and the other (at the cab end) driving the HVAC package over the front truck. The SaShi80 class diners (specifically designed for and matched to the KiHa80 class trains) had no powered axles (presumably to keep the engine vibrations from disturbing the diners.)Interesting aside - when modeling an abbreviated KiHa80 class DMU train, the only places where a power truck won't intrude into passenger space visible through the windows are at the cab ends of the cab cars and the kitchen end of the diner - precisely the places where the prototype train DOESN'T have powered axles...Chuck
gardendance wrote: beaulieu wrote: passengerfan wrote: I still do not see the need for Acela to have power on each end.Finally Acela needs both power cars to have enough horsepower to make the schedule. beaulieu: I'd tend to agree with you. TGV and Shinkansen have power cars at both ends, and I expect the general consensus is that they are the epitome of high speed rail.
beaulieu wrote: passengerfan wrote: I still do not see the need for Acela to have power on each end.Finally Acela needs both power cars to have enough horsepower to make the schedule.
passengerfan wrote: I still do not see the need for Acela to have power on each end.
I still do not see the need for Acela to have power on each end.
Finally Acela needs both power cars to have enough horsepower to make the schedule.
beaulieu: I'd tend to agree with you. TGV and Shinkansen have power cars at both ends, and I expect the general consensus is that they are the epitome of high speed rail.
The Shinkansen trains have CABS at both ends - and powered axles under EVERY car. That's why they accelerate like scared rabbits.
At a somewhat lower speed, JNR (pre-privatization) DMUs had powered axles under every car, both ends - with two notable exceptions, both on the highest-speed train sets. The KiHa82 class cab cars had one engine driving the train and the other (at the cab end) driving the HVAC package over the front truck. The SaShi80 class diners (specifically designed for and matched to the KiHa80 class trains) had no powered axles (presumably to keep the engine vibrations from disturbing the diners.)
Interesting aside - when modeling an abbreviated KiHa80 class DMU train, the only places where a power truck won't intrude into passenger space visible through the windows are at the cab ends of the cab cars and the kitchen end of the diner - precisely the places where the prototype train DOESN'T have powered axles...
I understand why the Acela trains have a power unit at each end it just seems to me they could put more cars between the cab ends. They need more capacity on the Northeast corridor and twenty Acela trainsets are know where near enough as the gas price crisis deepens. Since the trains only achieve 150 mph for one short stretch of track north of New York maybe additional cars could be added to those trains operating south of New York. For all of the money spent on Acela I just feel we should get more bang for the buck.
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