Reading Station improvements

[whole diary]

[SandTEngineer]

On the western approach to P15 there is a large black board mounted on what seems to be a OLE^▸ (Overhead Line Equipment, more often "OHLE") mast.  What is it?

Its a screen to either prevent extraneous lighting from affecting signal sighting or to prevent cross-reading of an incorrect signal as there is a curve approaching the platform.

[ellendune]

On the western approach to P15 there is a large black board mounted on what seems to be a OLE^▸ (Overhead Line Equipment, more often "OHLE") mast.  What is it?

Its a screen to either prevent extraneous lighting from affecting signal sighting or to prevent cross-reading of an incorrect signal as there is a curve approaching the platform.

Thank you

[paul7575]

Webcam 1 tab 1 showing that final section of platform wall is up to the level where the 'oversail' blocks go on.  (The overhanging support for the coping slab.) 

Carrying on now to the stage where they can fit the platform edge copings all the way along would make it look like major progress...   

Paul

[stuving]

Webcam 1 tab 1 showing that final section of platform wall is up to the level where the 'oversail' blocks go on. 

If you look closely (by now) you can see a lot of these "oversail" things in place. You can also see them at the end, which still looks like there is a bit more to be added. It may be just the end wall, but why?

[ellendune]

Webcam 1 tab 1 showing that final section of platform wall is up to the level where the 'oversail' blocks go on. 

If you look closely (by now) you can see a lot of these "oversail" things in place. You can also see them at the end, which still looks like there is a bit more to be added. It may be just the end wall, but why?

It looks to me like the track on P10 will be realigned when that platform is rebuilt. In which case the end will be wider.

[stuving]

I expect it will, and needs to be as P10/11 really needs the greatest passenger capacity.

I think it's more a question of whether they want to build just the P11 half of the end wall or not. It may be that, as the kind of fence they are putting on platform ends can only be fitted at full width, they will fence it off initially anyway.

Come to that, with the starter signal on the gantry, what is the point of building this extra bit of platform now?

[paul7575]

It looks to me like the track on P10 will be realigned when that platform is rebuilt. In which case the end will be wider.

Definitely will, that's what all the drawings show - the up main basically 'parallels' the down main as a pair throughout the station area.  I'm fairly sure that's why certain crossovers between up main and down main east of the platform ends were not provided in the interim (current) layout, because the final position of the P10 track has not been achieved yet.

Paul

[paul7575]

I expect it will, and needs to be as P10/11 really needs the greatest passenger capacity.

I think it's more a question of whether they want to build just the P11 half of the end wall or not. It may be that, as the kind of fence they are putting on platform ends can only be fitted at full width, they will fence it off initially anyway.

Come to that, with the starter signal on the gantry, what is the point of building this extra bit of platform now?

I think when they did the other new islands, the foundation strip for the end wall was cast in one section across the end, you can see that the side foundation strip finishes under the blockwork.  The staggered blocks shown in your picture are probably to key in the end wall. 

The reason for the actual position of the platform end may not be directly relevant to the signals above - there could be a designed tolerance, eg to allow for the maximum length train expected plus a bit spare, 10 x 26m IEP^▸ (Intercity Express Program / Project.) maybe?  Or it is to do with down direction train positioning if they stop a little short of the down direction signal?  I don't know for certain - it's possible it is just a convenient position to square off the whole of both main islands that looks neat!

Paul

[stuving]

Well, a train absolutely must stop before the signal, mustn't it?
I only have Grimshaw's plans to work on which do not have any marked scales (how unprofessional!).

With a bit of calibration, I get the length of P12-15 to be 280 m. The end-of-platform stop board says "11 car" which, for 23 m each, is only 253 m. The boards are a few m from the ends, but it looks as if there is a significant margin in the length allowance too. I assume all platforms must take all trains, to support the "7-day railway" requirement.

P10/11 I measured off plan at 342 m, going past P12 by 50 m at the London end and 10 m at the other. As built it is much shorter at both ends.

The relevant standard (GI/GN7616) suggests a UK^▸ (United Kingdom)-specific minimum of 300 m, though the "Infrastructure Register" may say different (If it exists yet). This is a derogation from the general requirement for lines of category I, II and III to be 400 m long - which I think is to cope with a double-rake TGV^▸ (Train a Grande Vitesse), should one happen to turn up

Of course the ends of the platforms (outwith the canopies), the gantry, etc. might have been seen by NR^» (Network Rail - home page) as their business, that station architect don't need to trouble their fluffy little heads with.

[paul7575]

Well, a train absolutely must stop before the signal, mustn't it?

Yes, of course, but the point is that all platforms are bi-directional.  This is why I mentioned a hypothetical down train on what is normally an up platform, because it will be stopping at a signal at the other end.  So I further supposed that you could allow for a safety margin for the back of the train.

Does that make sense?

Paul 

[stuving]

Well, a train absolutely must stop before the signal, mustn't it?

Yes, of course, but the point is that all platforms are bi-directional.  This is why I mentioned a hypothetical down train on what is normally an up platform, because it will be stopping at a signal at the other end.  So I further supposed that you could allow for a safety margin for the back of the train.

Does that make sense?

Paul 

Well, no, not really. I would want a maximum-length train to stop in the same place in either direction. The signals and train detection would follow from that. I know that there can be peculiarities of the trackwork that sometimes prevent that, but surely there are none here? (except perhaps at the country end and temporarily.)

[paul7575]

Another perfectly feasible explanation that's just occured to me is that it provides for the safety refuge away from the trains?

But as I suggested I don't really know the designer's reasoning, all I originally intended to point out is that what we can now see is probably the final length of P11.

Paul

[aleph_0]

Another way of looking at it is the platform might as well be built the maximum length possible that doesn't prevent any reasonable future modifications of the trackwork? If it provides flexibility for the future at not much extra cost, then doing the job right once sounds like a good plan.

[Electric train]

Come to that, with the starter signal on the gantry, what is the point of building this extra bit of platform now?

In the photo attached to your previous post the lattice mast is an OLE^▸ (Overhead Line Equipment, more often "OHLE") TTC    (Overhead Line Equipment Twin Track Cantilever) 

[paul7575]

Come to that, with the starter signal on the gantry, what is the point of building this extra bit of platform now?

In the photo attached to your previous post the lattice mast is an OLE^▸ (Overhead Line Equipment, more often "OHLE") TTC    (Overhead Line Equipment Twin Track Cantilever) 

In context, I think stuving was referring to my earlier comment about the P11 starter which is already fitted and covered up on the main signal gantry.  In post #1792.

Hence all the discussion about why the platform needs to extend beyond the signal in the first place?