The Arrow IIIs are limited to 80 anyway, so the fast acceleration will only balance it out, with little to no clear advantage.
However, if NJT were to buy Arrow IVs (with the rate they're purchasing MLs, this is looking more and more unlikely...) capable of 125 (or even 100), then there would be a major advantage there.
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Except for expresses and semi-expresses, running at track speed won't accomplish that much for a suburban local with stops about one to three miles apart, even with high-performance MU cars. They will still be appreciably slower than a through train making few to no stops.
They are not intended to haul 100-car freight trains. I am sure they will accelerate rapidly with the normal up-to-twelve commuter-car consists. Why not have them run at track speed when they can? Amtrack's goal is to have the NEC as close to a one-speed high-speed railroad as possible, to help keep everything on time. Between Rahway and Sunnyside Yard or Penn Station they will share tracks also used by Acela. They will, of course, use diesel west of Newark to High Bridge or possibly Trenton in the future, and south of Long Branch.
[quote user="aegrotatio"]
I rather think speed increases fluidity. No longer needing to schedule around 60 and 90 mph rattletraps would be a big gain in efficiency. Indeed, the MARC electrics down here in DC top out at 125 MPH and even reach that speed for considerable legs.
In a perfect world -- perfect fluidity would be for all trains to go the same speed with the same stops. Edit: This is on a 2 track RR. The slowest train on any route will cause the most problem with fluidity. There is always the possibility that the slowest train will delays faster trains.
aegrotatio I rather think speed increases fluidity. No longer needing to schedule around 60 and 90 mph rattletraps would be a big gain in efficiency. Indeed, the MARC electrics down here in DC top out at 125 MPH and even reach that speed for considerable legs. Fred F. quotes a MARC HHP-8 engineer as saying 121 MPH is more comfortable for the riders even if they lose about 2 minutes on that leg).
I rather think speed increases fluidity. No longer needing to schedule around 60 and 90 mph rattletraps would be a big gain in efficiency. Indeed, the MARC electrics down here in DC top out at 125 MPH and even reach that speed for considerable legs. Fred F. quotes a MARC HHP-8 engineer as saying 121 MPH is more comfortable for the riders even if they lose about 2 minutes on that leg).
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
NJT tends to put A LOT of extra padding in. Sometimes it's used, but it's often way more than needed.
For example, many WB NJCL trains have about twenty minutes scheduled between Point Pleasant Beach and Bay Head, when the stations are only about a mile apart. When I have to get picked up from Bay Head, I always tell my ride to get there much earlier than the scheduled time.
Typical NJT 3900s 58 miles in 69 minutes, 50 mph (really great for a commuter train)
Typical Amtrak Keystones 58 miles in 52 minutes, 67 mph
Both schedules include 3-5 min padding, I'd assume. (Keystone schedule are about that much faster SB)
35 miles at 125 mph vs 100 saves 4 minutes, assuming the whole distance is run at the greater speed. Whether that's worth it or not is a job for RTC!
With the exceptions being 3900 series super-expresses
blue streak 1 beaulieu: . Don't forget that these locomotives will employ Quill-Drive with truck mounted motors, so less force will be transmitted to the track. Beaulieu: That is a very important point that our posters need to remember. I had missed that feature myself. The reason for certifying the 125 MPH speed IMHO is for future use when more of the NEC is upgraded for higher speeds. It is very important for future fluidity that all trains be at least 125 capable on the north end as MARC electric is on the now on the south end. Upgrading the NJ transit passenger cars? That may be problematic unless new equipment is ordered. The SEPTA SL Vs are 125 specified but not yet qualified.
beaulieu: . Don't forget that these locomotives will employ Quill-Drive with truck mounted motors, so less force will be transmitted to the track.
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Don't forget that these locomotives will employ Quill-Drive with truck mounted motors, so less force will be transmitted to the track.
Beaulieu: That is a very important point that our posters need to remember. I had missed that feature myself. The reason for certifying the 125 MPH speed IMHO is for future use when more of the NEC is upgraded for higher speeds. It is very important for future fluidity that all trains be at least 125 capable on the north end as MARC electric is on the now on the south end. Upgrading the NJ transit passenger cars? That may be problematic unless new equipment is ordered. The SEPTA SL Vs are 125 specified but not yet qualified.
beaulieu . Don't forget that these locomotives will employ Quill-Drive with truck mounted motors, so less force will be transmitted to the track.
oltmannd Amtrak didn't let the GP40PH-2s over 90 mph. They weighed about the same. I would suspect Amtrak has not approved these beasts for 125 mph... It should be a moot point. These locomotives are for taking "Erie" commuter trains into Penn Station. There are only a few miles where they'd be allowed anything over 90 mph anyway. However, if they want to use these on the ACES train, then it would matter.
Amtrak didn't let the GP40PH-2s over 90 mph. They weighed about the same. I would suspect Amtrak has not approved these beasts for 125 mph...
It should be a moot point. These locomotives are for taking "Erie" commuter trains into Penn Station. There are only a few miles where they'd be allowed anything over 90 mph anyway. However, if they want to use these on the ACES train, then it would matter.
The 3512 is not exactly a Lightweight motor either. It weighs in at around 18K Dry. They use 2 of these Beasts to move the Big Dump Trucks used at the Stip Mines and at the Oil Sands.
Correct. Having three separate engines in the carbody (plus transformer and all other electrical equipment) would be absolutely rediculous.
The PL42s have a 4200 hp prime mover, and when HEP is being drawn, it's somewhere a little under 4000 hp. It has no problem moving six cars (a PL42 with six MLs is about the same as a GP or F40 with six Comets).
No Aux HEP motor due to weight and space confinements.
HEP drawn from main engines like the trans con Amtrak engines.
Max. Diesel power: At alternator: 4,200 hp (3,100 kW) intermittent, 3,600 hp (2,700 kW) continuous At wheels with no HEP load: 3,889 hp (2,900 kW) intermittent, 3,350 hp (2,500 kW) continuous **At wheels with consist: 3,084 hp (2,300 kW) while providing HEP for 10 MLV consist** **At wheels with consist: 2,950 hp (2,200 kW) while providing HEP for 12 MLV consist**
The engines seem to me really heavy. If they do not haul 125mph-trains, why gear them for that speed? With a lower top-speed, there would be better acceleration.
The wikipedia article doesn't mention an auxillary-diesel for HEP.
ns3010 The ex-CNJ geeps (4100-4112 ONLY) are limited to 70 on Amtrak. All other diesels (PL42s, all other Geeps, and P40s) are limited to 100. It is unknown if the DPs will be good for 100 or 125. Until the Multilevel IIs arrive in 2013 (that's simply my estimate, no date actually annonunced), there are no cars good over 100, and we don't even know if the MLIIs will be for 100 or 125. And it has been explicitly stated that they will not be used on ACES due to contract reasons and the lack of cab cars owned by ACES.
The ex-CNJ geeps (4100-4112 ONLY) are limited to 70 on Amtrak.
All other diesels (PL42s, all other Geeps, and P40s) are limited to 100.
It is unknown if the DPs will be good for 100 or 125. Until the Multilevel IIs arrive in 2013 (that's simply my estimate, no date actually annonunced), there are no cars good over 100, and we don't even know if the MLIIs will be for 100 or 125.
And it has been explicitly stated that they will not be used on ACES due to contract reasons and the lack of cab cars owned by ACES.
OK. Thanks. That makes me feel better....
oltmanndAmtrak didn't let the GP40PH-2s over 90 mph.
crewshuttle Careful design of the internal layout and has helped to keep weight of the four-axle loco to 130 tonnes. Maximum speed will be 200 km/h when running under 25 kV 50 Hz or 12 kV 25 Hz catenary, or 160 km/h on diesel.
Careful design of the internal layout and has helped to keep weight of the four-axle loco to 130 tonnes. Maximum speed will be 200 km/h when running under 25 kV 50 Hz or 12 kV 25 Hz catenary, or 160 km/h on diesel.
32.5 tonne axle loads at 125 mph - ouch !
Tony
crewshuttle had a look at wiki http://en.wikipedia.org/wiki/ALP-45DP and came up with this document listed in the footnotes: http://www.nxtbook.com/nxtbooks/sb/ra0808/#/20 [Copied to activate the LINKS] Weight was an issue with the engine block, so 2 light weight blocks are less than 1 heavy block.
had a look at wiki http://en.wikipedia.org/wiki/ALP-45DP
and came up with this document listed in the footnotes:
http://www.nxtbook.com/nxtbooks/sb/ra0808/#/20
[Copied to activate the LINKS]
Weight was an issue with the engine block, so 2 light weight blocks are less than 1 heavy block.
Also found this article: http://www.railwaygazette.com/nc/news/single-view/view/alp-45dp-electro-diesel-locomotive-debut.html
With an overall length of 21·8 m, the dual-mode loco is around 2 m longer than the electric version. Careful design of the internal layout and has helped to keep weight of the four-axle loco to 130 tonnes. Maximum speed will be 200 km/h when running under 25 kV 50 Hz or 12 kV 25 Hz catenary, or 160 km/h on diesel.
The ALP-45DP has a 4 000 kW rating in electric mode, and 3 134 kW on diesel. It has a pair of Caterpillar 3512C engines rated at 2 100 hp arranged symmetrically around the transformer and converter pack to balance the weight. The engines are certified to meet EPA Tier 3 emissions standards. A Trans-Tech pantograph is mounted above the rear bogie.
had a look at wiki(http://en.wikipedia.org/wiki/ALP-45DP) and came up with this document listed in the footnotes: http://www.nxtbook.com/nxtbooks/sb/ra0808/#/20
weight was an issue with the engine block, so 2 light weight blocks are less than 1 heavy block.
Semi-educated guess - maybe a variation of genset concept? Only run 1 engine when that's all the horsepower needed for the train size and route.
Also even though twice as likely(?) to have a prime mover failure but will still be able to limp in at a slower speed to a repair or replacement location.
I assume also that you only need to have one going when you're sitting somewhere like in a station to provide head end power and to keep things warm when the locomotive is idle. Saves wear and tear on the mechanical components, reduces air and noise pollution, and reduces fuel consumption.
Of course if it has a dedicated engine to provide HEP and the main engines can be shut down in cold weather like some CAT engines can (I personally don't know), you can ignore my post.
Thank you, that is surprising.
Frank
"If you need a helping hand, you'll find one at the end of your arm."
two high speed diesels are much smaller than one medium speed EMD engine of same combined HP.
the weight is much less too, even with twice cooling and generators..
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