Q stock future running

[MatthewRead]

I was reading the latest issue of Express and it had an article about the Q stock's restoration will it be able to run before the surface network is entirely re-signaled in 2023?

 

[Journeyman]

I was reading the latest issue of Express and it had an article about the Q stock's restoration will it be able to run before the surface network is entirely re-signaled in 2023?

As discussed elsewhere, the section from Harrow to Amersham will remain available for conventionally-signalled trains, due to it having Chiltern traffic over it, so that's pretty much the only bit that it will be able to operate on.

 

[bluegoblin7]

I haven’t seen Rail Express but last I heard the Q stock was being restored to a condition to allow to be hauled on LU, not operate...?

 

[Met Driver]

As discussed elsewhere, the section from Harrow to Amersham will remain available for conventionally-signalled trains, due to it having Chiltern traffic over it, so that's pretty much the only bit that it will be able to operate on.

Albeit that will depend upon the train protection system installed for use by trains operating under lineside signalling. I'm not sure if this has been decided upon, but I would be surprised if TPWS grids were not being considered in lieu of trainstops, given that the primary (entire?) reason for providing lineside signalling will be to allow mainline stock to continue to operate as today.

 

[rebmcr]

Albeit that will depend upon the train protection system installed for use by trains operating under lineside signalling. I'm not sure if this has been decided upon, but I would be surprised if TPWS grids were not being considered in lieu of trainstops, given that the primary (entire?) reason for providing lineside signalling will be to allow mainline stock to continue to operate as today.

Isn't there something in the way of TWPS grids?

 

[bramling]

Isn't there something in the way of TWPS grids?

The -ve rail can be gapped fairly easily, albeit this isn’t a wonderful solution for various reasons.

Another wild-card possibility is this section never gets ATC!

 

[Met Driver]

The -ve rail can be gapped fairly easily...

As shown here at Wimbledon Park:

https://www.flickr.com/photos/citytransportinfo/22918838131/

 

[rebmcr]

As shown here at Wimbledon Park:

https://www.flickr.com/photos/citytransportinfo/22918838131/

Oh cool, is that a grid under a protective wooden ramp?

 

[Dstock7080]

Oh cool, is that a grid under a protective wooden ramp?

Has to be, or the negative shoe would tear up the grid.

 

[BS56]

If I recall correctly TPWS was designed to prevent head on collisions or being hit in the side and not for a rear end smash . But I could be wrong . Do not forget there are lots of four aspect signals on the metropolitan north of Harrow that means lots of gaps in the fourth rail .
As for the district to Wimbledon the line already has AWS so there is no need to fit TPWS on the automatic signals just a few at the junctions . So why put a grid in the north bound platform starting signal as it is automatic ? There are always gaps in the fourth rail for other reasons So is the gap shown in the photo really for a TPWS grid ?

 

[Met Driver]

If I recall correctly TPWS was designed to prevent head on collisions or being hit in the side and not for a rear end smash . But I could be wrong . Do not forget there are lots of four aspect signals on the metropolitan north of Harrow that means lots of gaps in the fourth rail .
As for the district to Wimbledon the line already has AWS so there is no need to fit TPWS on the automatic signals just a few at the junctions . So why put a grid in the north bound platform starting signal as it is automatic ? There are always gaps in the fourth rail for other reasons So is the gap shown in the photo really for a TPWS grid ?

I'm not sure what you're recalling, but essentially if a stop signal is equipped with a TPWS trainstop grid, then a TPWS-fitted train passing that signal at danger will receive an emergency brake application. Thus it would prevent (or mitigate against the effects of) whatever manner of collision that could arise as a result of said train passing said signal at danger, dependant upon the track layout and presence (or not) of bi-directional working in the section it protects. It is really no different in principle to the LU trainstop/tripcock setup, except the interface between the trackside and train-borne equipment is electronic(?) rather than mechanical. I am aware that not all automatic signals on Network Rail are TPWS equipped, but that is the difference between mainline and metro for you. By contrast, all LU legacy colour light signals have trainstops, whether they're automatic or semi-automatic (i.e. controlled).

The presence of four- (and indeed three-) aspect signals north of Harrow isn't really relevant; some of the signalling sections on the multi-aspect signalled sections of the Met are substantially longer than those on some of the parts of Network Rail infrastructure LU operate over, so you'd end up with proportionately less "gaps in the fourth rail" in some areas.

With respect to East Putney-Wimbledon, I would wager that all colour light signals on that section have TPWS; by Network Rail standards it's pretty high frequency, with all LU trains calling at all stations. So the probability of a rear-end collision would be high if a mainline train had a SPAD, the signal was not TPWS fitted, and the driver did not take action in time. For the avoidance of doubt, that is most definitely a TPWS trainstop grid in the photo.

 

[BS56]

Yes you are right that is a TPWS grid in the photo I just could not see it in the poor light in my study late at night but now in the daylight I can see the grid and the ramp over it and then a short gap beyond it. As I live just outside London I am familiar with LU and mainline signalling . But of course a lot has changed over the years it now looks like we have reached the stage in the city when even Automatic signals need TPWS in addition to AWS on some lines. When I said " Recall " I was thinking back to the early days of TPWS soon after Ladbrooke Grove and the like when a rear end smash was not the main priority for its invention but to prevent the above happening again. As for TPWS itself sometimes two grids are needed and with the AWS means three gaps in the centre rail will be needed but not much can be done about it.

 

[ijmad]

As discussed elsewhere, the section from Harrow to Amersham will remain available for conventionally-signalled trains, due to it having Chiltern traffic over it, so that's pretty much the only bit that it will be able to operate on.

What about Gunnersbury to Richmond, or the Wimbledon branch south of East Putney. Are they being resignalled? How will other rail trains operate there?

 

[Dstock7080]

What about Gunnersbury to Richmond, or the Wimbledon branch south of East Putney. Are they being resignalled? How will other rail trains operate there?

On the Richmond branch the existing signalling will remain and have the CBTC system overlaid, so LU trains will operate automatically. Trainstops are likely to remain for LO trains as there is no TPWS.
As LU own the infrastructure on the Wimbledon branch it will be resignalled, new posts with spacing optimised for CBTC operation, trainstops removed. LU trains will operate automatically.

The Wimbledon branch currently still has bulb signals and the older version of the position shunt signals (red & white at danger).

 

[BS56]

What signal box will control the line ? At present Wimbledon ASC controls the points and signals on the line and interfaces with Earl court at Putney Bridge. So after resignalling will there be some kind of dual control with Hammersmith looking after its own trains or will it mean Wimbledon ASC will over see the CBTC for LU trains ? l

 

[simple simon]

On the Richmond branch the existing signalling will remain and have the CBTC system overlaid, so LU trains will operate automatically. Trainstops are likely to remain for LO trains as there is no TPWS.
As LU own the infrastructure on the Wimbledon branch it will be resignalled, new posts with spacing optimised for CBTC operation, trainstops removed. LU trains will operate automatically.

The Wimbledon branch currently still has bulb signals and the older version of the position shunt signals (red & white at danger).

The quoted solution for the Wimbledon branch is new to me - I thought that it was going to be an overlay, similar to the Richmond route.

I assume that the signalling will therefore be similar to that on the two sections of the Met line also used by Chiltern / Piccadilly line trains?

As an aside, in many ways TPWS compatibility for mainline trains (on the Amersham route) would be optimal as then the line would return to its previous status of being suitable for a wide range of mainline trains - the only downside of this would be the effect on heritage train operations .. which in the future will include the Q stock.