New build standards

[whole diary]

[grahame]

What are the new build standards for platform lengths?  3 car train at 23 metres / carriage calculates out at 78 metres, but what extra allowance is required for pulling up inaccuracies, or may be taken off to allow for doors not quite at end of carriages?  What about allowing for future carriage lengths of up to 26 metres?

[stuving]

What are the new build standards for platform lengths?  3 car train at 23 metres / carriage calculates out at 78 metres, but what extra allowance is required for pulling up inaccuracies, or may be taken off to allow for doors not quite at end of carriages?  What about allowing for future carriage lengths of up to 26 metres?

I think the answer is "yes, you are right". The official standard (GT/RT 7016) says:

5.1 General requirement for usable length of platforms

• 5.1.1 Except as identified in section 5.2, the usable length of platforms shall be long enough to accommodate the longest train formation regularly booked to stop at a platform, with allowances for inaccurate stopping and operational (including train control) requirements.
• 5.1.2 The usable length of terminal platforms shall include an allowance both for the train to stop before it reaches the buffer stops and for the length taken up by the buffer stop equipment.

There follow a number of let-outs and work-rounds for short paltforms.

But where (you reply) are the actual numbers involved specified? They are not in any standard, but to be determined on a case-by-case basis.

There is also a TSI (2008/57/EC), for high-speed lines, but in this case it is pretty much common sense.

4.2.10.1. Usable length of platforms
All TSI categories of line
(1) The platform length shall be sufficient to accommodate the longest interoperable train intended to stop at the platform in normal service. When determining the length of trains intended to stop at the platform, consideration shall be given to both the current service requirements and the reasonably foreseeable service requirements at least ten years following the bringing into service of the platform.
(2) It is permissible to build only the length of platform required for the current service requirement provided passive provision is made for the reasonably foreseeable future service requirements.
(3) The usable length of a platform shall be declared in the Register of Infrastructure.

[Chris from Nailsea]

But where (you reply) are the actual numbers involved specified? They are not in any standard, but to be determined on a case-by-case basis.

So, just how long is a piece of string, anyway ... 

[Visoflex]

So, just how long is a piece of string, anyway ... 

Twice half its length - obviously!

[stuving]

So, just how long is a piece of string, anyway ... 

Twice half its length - obviously!

But not twice the length of two pieces of string half as long, joined by a knot.

[Tim]

  What about allowing for future carriage lengths of up to 26 metres?

Is this a general trend or just the IEPs^▸ (Intercity Express Program / Project. This will offer more capacity on routes, save money, give a consistent and safe service and meet customer requirements. Intended to replace HSTs.)?

[broadgage]

I suspect that 26M vehicles may be a long term trend.
Considerable expense and trouble is involved in clearing a route for 26M vehicles.
Having spent all that money, it would seem reasonable that future builds of suburban trains or even new sleeper stock might well be 26M.

Within reason, longer rail vehicles are better, fewer bogies to maintain, fewer gangway connections to maintain, fewer air conditioning units to maintain. And less space in percentage of total train length is wasted in doorways, vestibules, and gangways between vehicles.

(I have previously expressed doubts about the IEPs^▸ (Intercity Express Program / Project. This will offer more capacity on routes, save money, give a consistent and safe service and meet customer requirements. Intended to replace HSTs.), but it is NOT the longer vehicles to which I object, longer is better within reason)

[grahame]

I am thinking that an 85 metre platform for services which may go up to 3 coaches is about right for the future.  That's 3 x 26 metres plus 7 metres "wobble" on stopping.