Virgin (XpressWest/DesertXpress) Las Vegas - Victorville - Los Angeles

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Chafford1
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Re: DesertXpress - 150mph self powered trains

Post by Chafford1 » Fri Dec 05, 2008 4:10 pm

lpetrich wrote: So the DesertXPress will likely require a similar maximum speed of 300 kmh / 186 mph, which is about right for off-the-shelf high-speed trains.
Yes, but their website states that ''DesertXpress will operate at a top speed of 150 mph" (240 km/h)

DutchRailnut
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Re: DesertXpress - 150mph self powered trains

Post by DutchRailnut » Fri Dec 05, 2008 10:51 pm

Currently the max speed under tier II is not to exceed 150 mph.
If Conductors are in charge, why are they promoted to be Engineer???

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lpetrich
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Re: DesertXpress - 150mph self powered trains

Post by lpetrich » Sat Dec 06, 2008 4:24 am

But an average speed of 142 mph is cutting it very close: 95% of top speed. It may be achievable if one can keep the line's curvature and grades down, but it may be difficult if the line is to follow I-15.


I measured the radii of curvature of some of the twistier parts of that freeway's route, and I found numbers like 0.6, 0.7, and 1 mi -- I'll take 0.6 mi or 1 km as the route's minimum radius of curvature. At 150 mph, that curvature will produce about 0.4 g of centrifugal acceleration. It is not as noticeable for highway traffic, which has 0.07 g's for 60 mph / 100 kmh, because the centrifugal acceleration goes as the square of the velocity:
a = v^2/r

where r is the radius of curvature. Using k = 1/r for the curvature, one gets a = k*v^2 The curvature for a curve given by (x(t),y(t)) is
k = (x'*y'' - x''*y')/(x'^2 + y'^2)^(3/2)
where x' = dx/dt, y' = dy/dt, x'' = d^2x/dt^2, and y'' = d^2y/dt^2

If I had the coordinates for positions along a route, like for Vic-LV I-15, I could easily calculate the curvature at each point, and find the most curved parts from that.


According to Design & Build a High Speed Railway: the French Experience, the maximum tilt height or cant used in French high-speed lines is 180 mm (200 mm for passengers only), and the maximum "cant deficiency" (extra amount needed to make the train's acceleration exactly perpendicular to the tracks) is 100 mm. For 300 kmh, that paper states a minimum radius of curvature of 3793 m / 2.4 mi, which is close to my calculations.

A cant deficiency of 100 mm yields a sideways acceleration of 0.07 g while one of 180 mm yields 0.125 g, with a total of nearly 0.2 g. So the existing I-15 route is too curved for full-speed DXP duty.

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Matt Johnson
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Re: DesertXpress - 150mph self powered trains

Post by Matt Johnson » Sat Dec 06, 2008 7:55 pm

DutchRailnut wrote:Currently the max speed under tier II is not to exceed 150 mph.
However, any trains that operate solely on dedicated rights of way, isolated from the national network, are exempt from FRA crashworthiness regs.

DutchRailnut
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Re: DesertXpress - 150mph self powered trains

Post by DutchRailnut » Sat Dec 06, 2008 9:24 pm

Ok name one such network ;-)
If Conductors are in charge, why are they promoted to be Engineer???

Retired Triebfahrzeugführer. I am not a moderator.

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Matt Johnson
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Re: DesertXpress - 150mph self powered trains

Post by Matt Johnson » Sat Dec 06, 2008 9:34 pm

Well, it's what this fictitious DesertXpress is proposing on its website.

DutchRailnut
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Re: DesertXpress - 150mph self powered trains

Post by DutchRailnut » Sat Dec 06, 2008 9:38 pm

Their gone pay for it with fictitious American Peso's too
If Conductors are in charge, why are they promoted to be Engineer???

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lpetrich
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Re: DesertXpress - 150mph self powered trains

Post by lpetrich » Sun Dec 07, 2008 11:41 am

The proposed California HSR system will be FRA-noncompliant, and the DesertXPress will have to be in order to get good performance.

Though no existing US intercity system is FRA-noncompliant, most urban heavy-rail (rapid-transit, metro) and light-rail systems are. There are a few that have some shared track with the intercity railroad network, but they enforce separation of operations (no mixed traffic).

PullmanCo
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Re: DesertXpress - 150mph self powered trains

Post by PullmanCo » Tue Dec 09, 2008 8:42 pm

The proposed California HSR system will be FRA-noncompliant
If I am not mistaken, it will have to meet at least Tier I in order to use existing tracks to enter the existing terminals at Los Angeles and San Francisco.

Chafford1
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Re: DesertXpress - 150mph self powered trains

Post by Chafford1 » Thu Jan 01, 2009 12:15 pm

DutchRailnut wrote:Their gone pay for it with fictitious American Peso's too
A modified DesertXpress project linking into the California HSR at Palmdale looks like a more viable prospect than the Maglev system. It will still need Federal funding, though.

goodnightjohnwayne
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Re: DesertXpress - 150mph self powered trains

Post by goodnightjohnwayne » Wed Jan 28, 2009 3:07 pm

Wouldn't it be advisable to reinstitute some sort of conventional train service between Los Angeles and Las Vegas over existing tracks before indulging in an improbably scheme? Honestly, why would anyone spend billion on a high speed rail line that terminated in the middle of nowhere? Look at dedicated high speed rail lines around the world, and they all connect two destinations. I can see getting onto a train at Union Station in LA and going to Vegas, but why would anyone want to drive all the way to Victorville in the middle of nowhere to get the train?

I would think that there would be potential for daily service, even over unimproved track. Just how many hours did it take Desert Wind, or subsequent charter trains, to make the trip? Honestly, isn't there enough of a market for a coach-only, daylight service conventional train?

lpetrich
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Re: DesertXpress - 150mph self powered trains

Post by lpetrich » Sat Jan 31, 2009 10:33 pm

ETA: I'd mentioned feeder buses in this earlier post. I had even tried to estimate their performance in this post.

The main problem with the feeder-bus approach is connecting to the train. Buses will likely get delayed in traffic, enough to cause some buses to miss their trains. And attempting to avoid such misses by making the buses arrive earlier will likely result in annoying wait times at Victorville.

Returning will be much easier, however. Passengers can go to the buses soon after their train arrives in Victorville, and the buses will be ready to go when all their passengers have boarded.

But the DesertXPress page on the route still mentions only driving to Victorville, with no mention of feeder buses.

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Re: DesertXpress - 150mph self powered trains

Post by thaitransit » Sun Feb 22, 2009 4:08 pm

If this HST line does not directly connect the innercity areas of LA and Las Vagas. It will be a failure. Any train service that relies solely on "Park and Ride" will never generate enough demand to offer a reasonable level of service and frequency to make the service attractive.

Really this line needs to start from a New LA central station that has direct bus and Metro connections to the main mass transport system in LA. Then end at a new underground station in the main casino district and again don't forget to add a connection to Las Vagas Metro and Bus systems.

The HST line could use elevated tracks within the urban area of LA and Las Vagas and tunnels in the inner city to access a good station location close to the business district of LA. As far as I know both cities have very low density areas only a few miles out from the inner city which should make building the elevated HST line easy.

There should also be a number of bus connected HST stations along the route as it passes the lower density urban area of LA to increase walk up and bus feeder passengers to the HST line. Good places for these are near universities, Major shopping centres, Other transport interchanges etc.

As per another poster it seems the line would need 200 Mph electric TGV or Shinkansen high speed trains for it to be time competive with both buses and aircraft over the whole line.
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David Benton
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Re: DesertXpress - 150mph self powered trains

Post by David Benton » Mon Feb 23, 2009 3:31 am

I'm not sure Los Vegas has a metro system , it didnt in the late 80's when i was there .
I'm sure the victorville part of the plans was to link to acalifionian hst there . Matybe the promoters fiqured by the time they got building , so would Califionia !
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Re: DesertXpress - 150mph self powered trains

Post by george matthews » Mon Feb 23, 2009 8:12 am

David Benton wrote:I'm not sure Los Vegas has a metro system , it didnt in the late 80's when i was there .
I'm sure the victorville part of the plans was to link to acalifionian hst there . Matybe the promoters fiqured by the time they got building , so would Califionia !
I think there is a monorail - a type of transit only used in play sites.

Personally I wouldn't recommend any investment in transport to las Vegas. I don't believe it has a long term future. For one thing alone, its supply of water is under threat from the dessication of the Colorado river. For another, I doubt if its parasitic economy has a long term future.

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