Walk-through cars

[Deleted]

I'm just curious, but why has it taken so long, until the S stock, for walk through trains to finally come to London? The technology was there (see en.wikipedia.org/wiki/Bluebird_Compartment_Car_%28New_York_City_Subway_car%29 and it could have been applied quite easily. The excuse that Metro-Cammel did not produce such vehicles must be false, as Hong Kong's original MTR cars were walk through.

[100andthirty]

I have seen the NY cars in their museum. They are articulated (one bogie shared between two cars), but the gangway is very narrow.

MTR cars were produced at about the same time as D stock. MTR was a new network and their curves are very easy and thus their gangway could be quite compact. The tighter the curves a train has to negotiate, the longer, and more flexible a gangway has to be - look at a London bendy-bus. producing a gangway on a tube train is not impossible but would be a challenge bigger than has been faced by anyone before. LU hasn't bought any of the sub-surface trains since D stock, so S stock is the first low risk opportunity.

Gangway suppliers now have much more experience than they did in 1978 and so the time might, perhaps, be right to look at tube stock

[tubeprune]

100andthirty said:

Gangway suppliers now have much more experience than they did in 1978 and so the time might, perhaps, be right to look at tube stock

I agree but who would pay for the development costs? Could they be recovered from the improved JTC score? Do I have to do some calcs.

[Deleted]

A narrow gangway is still a gangway and still allows for end-to-end access.

[Deleted]

Having done some snooping around, it seems, according to this-http://www.nycsubway.org/cars/bmt-c.html, that externally mounted sliding doors are also nothing new. (The BMT was just great)

[prjb]

We considered a gangway for the 09ts but it got rejected very early on. The shape of the train (dictated by the tunnel) and the structural requirements of the car body meant that we would have ended up with a gangway about the same width as the current connecting doors. This made it not worth the time, money, and effort.

[Deleted]

In the plans, did the gangway remove the car-end windows?

[prjb]

I don't believe it did , but don't qoute me as it was a long time ago(before I joined the project).

[Deleted]

Well if it didn't then how wide can a gangway be?

[Chris M]

If the car end-windows are retained, then I cannot see how a gangway can be significantly wider than the current inter-car doors.

[Deleted]

Exactly. The two don't mix.

[prjb]

It didn't include the end car windows, but even so the gangway was not much wider than the connecting doors apparently.

[sm]

Could you not shorten the carriages and hence increase the gap between carriages, allowing for a larger arc when going around tighter bends?

Having shorter carriages would be off put by the added space of having a walk-through design.

[Deleted]

sm said:

Could you not shorten the carriages and hence increase the gap between carriages, allowing for a larger arc when going around tighter bends?

Having shorter carriages would be off put by the added space of having a walk-through design.

Shorter and wider articulating, and walkthrough cars were planned in the now abandoned Space Train concept for just that reason. The Space Train cars would have been approx 11m long, as opposed to the conventional 16-17m cars.

[Deleted]

if they can't do it on the Victoria line, I doubt it could be done anywhere else. The Victoria was built with curves no less than 400m radius, where other lines have some really tight sections.

[Deleted]

rob said:

if they can't do it on the Victoria line, I doubt it could be done anywhere else. The Victoria was built with curves no less than 400m radius, where other lines have some really tight sections.

The Paris Metro has walkthough cars on lines with 20m radius curves, so curve radius isn't the issue! However a compact S curve such as Bank X-over on the W&C Line may cause problems for non-articulated walkthrough cars, as the car ends misalign.

[sm]

I can't find much about them on google, so why were the space trains scrapped?

Seems like a pretty good idea?

[Deleted]

sm said:

I can't find much about them on google, so why were the space trains scrapped?

Seems like a pretty good idea?

The Space Train would have had high development costs, and with the onset of PPP, more off the shelf conventional designs were chosen. There is a recent Space Train thread here:-
districtdave.proboards39.com/index.cgi?board=victoria&action=display&thread=1184678526

[Deleted]

Hm. It seems that the Space Train had a very slanted front. I personally feel that this is not a good idea. The current flat noses are sufficient.

[100andthirty]

The Space Train was LU's version of a car manufacturer's concept car. All the ideas rolled up into one. Some were good, some were interesting ideas at the time that have since spawned other ideas.

In parallel with space train other ideas were being developed including the train of cars with a single axle each. This axle was mounted under the centre of each car like a caravan. Stability was provided by a mechanical or hydraulic linkage between cars. Another concept that served to remind everyone that in general bogies are good things!

None of these were or are destined to go into production.

Oh, btw, sloping fronts look good on models and artists impressions, but usually designers get a reality check when a 132m long train is required to fit in a 133m long siding!

[Deleted]

Agreed. Also, I feel that for cars measuring 10m or less should only have one bogie.

[Deleted]

100andthirty said:

In parallel with space train other ideas were being developed including the train of cars with a single axle each. This axle was mounted under the centre of each car like a caravan. Stability was provided by a mechanical or hydraulic linkage between cars. Another concept that served to remind everyone that in general bogies are good things!

Copenhagen's S-trains have single axle bogies, however they are placed between articulating cars, as opposed to being in the middle of cars.

[prjb]

100andthirty said:

Oh, btw, sloping fronts look good on models and artists impressions, but usually designers get a reality check when a 132m long train is required to fit in a 133m long siding!

How true that is, we are having headaches with the length of 'S'.

[Deleted]

How about chopping of round ends? Stick to the pretty flat noses of 'D'!

[Deleted]

axewielder said:

How about chopping of round ends? Stick to the pretty flat noses of 'D'!

But round is the new flat!

[Deleted]

Hence, flat is the new round? Hm

[Chris M]

axewielder said:

Hence, flat is the new round? Hm

I hope the designers do not apply this principle to the wheels...

[Deleted]

awkward42 said:

axewielder said:

Hence, flat is the new round? Hm

I hope the designers do not apply this principle to the wheels...

I should hope not.

[metman]

Also, I heard the space train was designed for over head line operation! Crazy!

[Deleted]

Overhead bar. Not a bad idea