Do bilevels make for effecient HSR?

I'm just curious as to whether or not bilevels would be efficient for use on HSR? I'm not familiar with any lines which use bilevels for HSR. I'm talking achieve 200+ MPH here, not 110 MPH diesel. I'll assume the lack of bilevels is either a) although demand is decent, it does not warrant bilevels or b) the increase in energy needed to maintain speeds with bilevels is not worth it.

The latest TGV's , in france , are bilevel , i believe .

JR East also has bilevels in operation, the E1 and E4 types. Bilevels (both in commuter and HSR applications) are best in situations requiring high passenger capacity but lower frequency of service (i.e. greater headways), as they require longer station dwelltimes than single level stock. Also, there are performance tradeoffs- they are typically heavier than single level stock, and thus tend to have lower acceleration. The bilevel structure restricts the space for underfloor electricals, which is important in the case of EMU types (less so in push-pull configurations such as with the TGV Sud). You have to consider the requirement of steps, which take up space and cause accessibility concerns for the disabled. These drawbacks are primarily why the latest HSR trainset designs are conventional single level types.

David Benton wrote:The latest TGV's , in France , are bilevel , i believe .

It's a useful way of carrying more people. However, it needs a ruthless attention to weight - making the components ever lighter. This is a rather alien concept in the US.

george matthews wrote:

David Benton wrote:The latest TGV's , in France , are bilevel , i believe .

It's a useful way of carrying more people. However, it needs a ruthless attention to weight - making the components ever lighter. This is a rather alien concept in the US.

Incorrect. Before the near extinction of intercity passenger rail, there were a number of very lightweight designs in North America - all of which met FRA standards, unlike their European counterparts. The real issue is that weight's really aren't all that critical in conventional passenger rail. We're not talking about aviation and that's an important distinction.

goodnightjohnwayne wrote:

george matthews wrote:

David Benton wrote:The latest TGV's , in France , are bilevel , i believe .

It's a useful way of carrying more people. However, it needs a ruthless attention to weight - making the components ever lighter. This is a rather alien concept in the US.

Incorrect. Before the near extinction of intercity passenger rail, there were a number of very lightweight designs in North America - all of which met FRA standards, unlike their European counterparts. The real issue is that weight's really aren't all that critical in conventional passenger rail. We're not talking about aviation and that's an important distinction.

For steel wheels on steel rails, the importance of weight depends mostly on how often the train stops. If a 79 mph train stops once every 80 miles or so (once an hour), or a 150 mph train stops every 150 miles or so, the train only has to accelerate back to speed once an hour, expending a force = mass x acceleration. If the train stops three or four times an hour, weight is much more important. And every time the train has to slow down for curves, diamonds, or move onto a siding, more force is expended to bring the train back up to speed.

goodnightjohnwayne wrote:

george matthews wrote:

David Benton wrote:The latest TGV's , in France , are bilevel , i believe .

It's a useful way of carrying more people. However, it needs a ruthless attention to weight - making the components ever lighter. This is a rather alien concept in the US.

Incorrect. Before the near extinction of intercity passenger rail, there were a number of very lightweight designs in North America - all of which met FRA standards, unlike their European counterparts. The real issue is that weight's really aren't all that critical in conventional passenger rail. We're not talking about aviation and that's an important distinction.

i think lightweight was a very relative term .It meant lighter than the 6 wheel bogied monsters . afaik , the only train from that era that was anywhere near light was the talgos .

BostonUrbEx wrote:I'm just curious as to whether or not bilevels would be efficient for use on HSR? I'm not familiar with any lines which use bilevels for HSR. I'm talking achieve 200+ MPH here, not 110 MPH diesel. I'll assume the lack of bilevels is either a) although demand is decent, it does not warrant bilevels or b) the increase in energy needed to maintain speeds with bilevels is not worth it

SNCF's TGV Duplex is one. They have a collision strength of 1.1 million pounds at the ends of their power cars, as a point of interest. Whole train has 545 seats. Empty weight of a whole train (two power cars plus eight passenger cars) is about 838,000 lbs or 935,000 lbs (depending on the source), necessary to meet axle load limits.



Another is the E4 series bullet train that runs on the Tōhoku Shinkansen (Japan Railways East); one eight-car train can hold up to 817 passengers, but since those trains are wider than US loading gauge (11' 1"; US passenger cars max out at 10' 6", and the Acela Express is 10' 4" wide), they'll remain on their home rails or any other custom-build railroad that can accommodate them. (They feature 3-2 seating, for the sake of information.)

I rode both decks of the TGV Duplex earlier this year. They were comfortable but had less room in the overhead luggage rack than the single-level TGV or Thalys trains, which I also rode on that trip. A lot of the reason is platform and paths-per-hour vs. demand: SNCF platforms generally accommodate two trainsets coupled nose-to-nose, which is a long walk out in a stub station (?all the Paris main stations?). Duplex gives you at least 60% more seats, which is required to meet demand.

It's been a while since I visited Japan, but my first reaction to 3-2 in the Japanese E-4 trains is that I should sample their seating before I plan a long trip during a high-traffic period (my shoulders were much wider than Japanese design standards, so I felt kind of like I was in one of the rearmost 3-passenger rows in a Southwest 737). Also, I have to give the nod to the French on exterior aesthetics.

The overhead luggage racks on the TGV Duplex cars could be described as "minimal" at best though the end luggage near the toilets/mobile phone bench seem a bit larger than the single level cars. Comical to see how jammed the LGV Rhône-Alpes trains get during ski season on a Saturday, gear piled up pretty much everywhere.