Why isn't the 2009 stock walk through like the S stock?
 

On Fri, 06 Jan 2012 15:57:45 +0000, Roland Perry wrote:

Paris Metro MF2000

Are they articulated?

As far as I can tell, having looked at the posted images and played with
contrast, they're not articulated in the sense of adjacent cars sharing
the same bogey, no.

Rgds

Denis McMahon

Why isn't the 2009 stock walk through like the S stock?
 

wrote in message

On 06/01/2012 12:48, Recliner wrote:
wrote in message

Was there a particularly good reason not to do it? I can't think of
any disadvantages.

It was discussed at length here, last year I think. Basically, there
isn't room in non-articulated small Tube stock. Future Tube stock
may be articulated, and would then have open gangways.


I always thought that was the initial plan, and was slightly surprised
when I found out they were not walk through.

Yup, it is a disappointment. Had it not been for the PPP scheme, there's
a reasonable chance that the 2009 stock would have been based on the
space train ideas, with articulation, wider carriages, open gangways and
maybe even some form of air cooling.

Why isn't the 2009 stock walk through like the S stock?
 

In message , at 19:45:42 on Sat, 7
Jan 2012, Eric remarked:
Or, better still, this pictu

http://www.metro-pole.net/actu/IMG/j...4287_p1200.jpg

That's a much better picture.
--
Roland Perry

Why isn't the 2009 stock walk through like the S stock?
 

"Roland Perry" wrote in message

In message , at 19:45:42 on Sat,
7 Jan 2012, Eric remarked:
Or, better still, this pictu

http://www.metro-pole.net/actu/IMG/j...4287_p1200.jpg

That's a much better picture.

If those are indeed two separate twin-axle bogies, they're very close to
the ends of the carriages, which means there won't be much relative
movement between them (compared to normal carriages with much more
overhang). This makes it much easier to fit open gangways.

Why isn't the 2009 stock walk through like the S stock?
 

On Mon, 9 Jan 2012 11:53:53 -0000
"Recliner" wrote:
"Roland Perry" wrote in message

In message , at 19:45:42 on Sat,
7 Jan 2012, Eric remarked:
Or, better still, this pictu

http://www.metro-pole.net/actu/IMG/j...4287_p1200.jpg

That's a much better picture.

If those are indeed two separate twin-axle bogies, they're very close to
the ends of the carriages, which means there won't be much relative
movement between them (compared to normal carriages with much more
overhang). This makes it much easier to fit open gangways.

First it was because tube trains are too narrow, then it was because they're
not articulated, now you're grasping at this straw. Just admit you were wrong.

B2003

Why isn't the 2009 stock walk through like the S stock?
 

wrote in message

On Mon, 9 Jan 2012 11:53:53 -0000
"Recliner" wrote:
"Roland Perry" wrote in message

In message , at 19:45:42 on
Sat, 7 Jan 2012, Eric remarked:
Or, better still, this pictu

http://www.metro-pole.net/actu/IMG/j...4287_p1200.jpg

That's a much better picture.

If those are indeed two separate twin-axle bogies, they're very
close to the ends of the carriages, which means there won't be much
relative movement between them (compared to normal carriages with
much more overhang). This makes it much easier to fit open gangways.

First it was because tube trains are too narrow, then it was because
they're not articulated, now you're grasping at this straw. Just
admit you were wrong.

If the bogies are very near the car ends, then the effect is close to
articulation. But with the circular profile of Tube tunnels, I'm certain
that reasonable sized open gangways are not feasible without true
articulation. If you look at the relative movement of Tube car ends, you
can see just how difficult it would be -- look at how much smaller the
gangway is compared to the outer body in S stock and 378s in order to
accommodate all the movement.

So, sorry Boltar, you won't be seeing open gangways in LU Tube stock in
the absence of articulation.

Why isn't the 2009 stock walk through like the S stock?
 

"Recliner" wrote in
:

If the bogies are very near the car ends, then the effect is close to
articulation. But with the circular profile of Tube tunnels, I'm certain
that reasonable sized open gangways are not feasible without true
articulation. If you look at the relative movement of Tube car ends, you
can see just how difficult it would be -- look at how much smaller the
gangway is compared to the outer body in S stock and 378s in order to
accommodate all the movement.

If cars have shared bogies, or bogies very near the ends, the centre throw
will be greater than with the current placement of the bogies. Given the
tight fit of tube trains in their tunnels I would imagine that that would
give a clearance problem on curves - unless you go for substantially
shorter (and more) cars, like the Space Train.

On the Waterloo and City they solved a similar problem by grinding part of
the flanges off the tunnel lining segments, but as I recall the Victoria
Line has concrete linings without flanges.

I had a look this morning at the width/height issue, and 3 average height
people can stand side-by-side in the vestibule area facing along the car.
So I think a wide gangway would probably allow two people to pass, provided
the gangway was about as high as the internal car body.

Peter CS

Why isn't the 2009 stock walk through like the S stock?
 

On Mon, 9 Jan 2012 13:20:08 -0000
"Recliner" wrote:
So, sorry Boltar, you won't be seeing open gangways in LU Tube stock in
the absence of articulation.

... in your opinion. I think you're wrong.

B2003

Why isn't the 2009 stock walk through like the S stock?
 

On Mon, 9 Jan 2012 13:35:17 +0000 (UTC)
Peter Campbell Smith wrote:
I had a look this morning at the width/height issue, and 3 average height
people can stand side-by-side in the vestibule area facing along the car.
So I think a wide gangway would probably allow two people to pass, provided
the gangway was about as high as the internal car body.

Yup. Give it 18 inches either side to allow for movement and you're sorted.

B2003

Why isn't the 2009 stock walk through like the S stock?
 

"Peter Campbell Smith" wrote in message

"Recliner" wrote in
:

If the bogies are very near the car ends, then the effect is close to
articulation. But with the circular profile of Tube tunnels, I'm
certain that reasonable sized open gangways are not feasible without
true articulation. If you look at the relative movement of Tube car
ends, you can see just how difficult it would be -- look at how much
smaller the gangway is compared to the outer body in S stock and
378s in order to accommodate all the movement.

If cars have shared bogies, or bogies very near the ends, the centre
throw will be greater than with the current placement of the bogies.
Given the tight fit of tube trains in their tunnels I would imagine
that that would give a clearance problem on curves - unless you go
for substantially shorter (and more) cars, like the Space Train.

On the Waterloo and City they solved a similar problem by grinding
part of the flanges off the tunnel lining segments, but as I recall
the Victoria Line has concrete linings without flanges.

I had a look this morning at the width/height issue, and 3 average
height people can stand side-by-side in the vestibule area facing
along the car. So I think a wide gangway would probably allow two
people to pass, provided the gangway was about as high as the
internal car body.

The carriages in an articulated train will certainly have to be shorter,
roughly the spacing of the bogies in a conventional carriage (just as
Eurostar carriages are). That would be needed both for clearance reasons
as you say, and also to keep the axle loading down. In fact, it may be
made particularly short to allow for wider carriages, unless the linked
carriages are mounted on extended pivots, rather than the shared bogie.

With non-articulated stock with conventionally spaced bogies, there's a
lot of relative movement at the car ends on entry to curves, which the
gangway bellows have to absorb. This makes them thicker, and reduces the
gangway width. The same is true in vertical direction. So if you were to
try and install open gangways on a train like the 2009 stock, the
gangways would be very very cramped (narrow and low).