Reading Station improvements

[whole diary]

[paul7575]

Just a point about that "5/10" stop board. I assume it's there not just for future SETs^▸ (Super Express Train (now IET)), but for a 5+5 Voyager - which should be possible, though I've only once seen even a 4+4 at Reading. Now obviously you don't want a 5-car train stopping down there, unless it's taking up just the A end. So if it's not, I think it has to be allocated and directed into the B platform and use the Rear Clear signs as a stop board. If that's forgotten and it's sent to a full platform, it's a longer walk (as it was when P8 was not divided).

10 car will also work for a pair of 180s if they ever need to run a pair.    The Friday afternoon XC^▸ (Cross Country Trains (franchise)) double Voyager to Bournemouth (1246 is it?) that ran into P8 yesterday was a 9 car - wonder which marker they use?

Sometime after the flyover opened I saw a XC 221 heading for Bournemouth run right through P8, possibly heading for the temporary 5 car stop board which was just past the London end platform buildings while the platform section by WH Smiths was out of use, but presumably as the temp marker had gone he therefore had to run up to the A end 5 car marker.   This left all the waiting passengers behind the train at the B end, and very soon after the auto announcements and displays reported a sudden 'platform alteration'.

Paul

 

[W5tRailfinder]

Interesting that the down train in P9 must be on a red as the points in advance of the starter signal are reversed, as are the points from the Festival line further in advance at High Level Junction.  Yet we see from the video that the route on the DM from P9 was clear to at least Tilehurst.

So I wonder why the down train was on a red?  I can^t believe it was waiting time, down HST^▸ (High Speed Train)^s are never early at Reading!

XC^▸ (Cross Country Trains (franchise)) from P3 to go first when up FGW^▸ (First Great Western) inbound from UW clears junction.

[paul7575]

Interesting that the down train in P9 must be on a red as the points in advance of the starter signal are reversed, as are the points from the Festival line further in advance at High Level Junction.  Yet we see from the video that the route on the DM from P9 was clear to at least Tilehurst.

So I wonder why the down train was on a red?  I can^t believe it was waiting time, down HST^▸ (High Speed Train)^s are never early at Reading!

XC^▸ (Cross Country Trains (franchise)) from P3 to go first when up FGW^▸ (First Great Western) inbound from UW clears junction.

I'm not convinced the points outside the station really are 'reverse', I've looked at it a few times and can't be sure.  But surely that train that you mention coming into P8 would mean that the crossover leading from P8 to the down main would be held in the normal position.  The points at either end of such a crossover will always act together, surely?

Paul

[Gordon the Blue Engine]

Yes, W5tRailfinder, you^re probably right.  Detective work reveals that:
1   the cab ride train arrives in P10 at 1055 hrs, and Daily Motion says that video was taken a few days after the viaduct opened
2   the only northbound XC^▸ (Cross Country Trains (franchise)) that could be waiting to leave from P3 is a late-running 1E36 1040 departure to Newcastle
3   Recent Train Times shows that 1E36 runs pretty reliably, but on Thursday 8 Jan 1E36 was late and left at 1056, which ties in with it waiting for that HST^▸ (High Speed Train) from UW to clear and then to precede the HST in P9.  So I think II^s video was taken on that day.

Paul, on my monitor with the video in HD it^s clear the points are reversed.  I would think that the signalling and overlaps etc allows for a down train to leave P8 while a down train runs into P9 and vv, else you would lose a lot of flexibility.  So the points can be either position as a down train runs into P8 or P9 with a red at the end of the platform, and there^s no reason why they should co-act with any other points.


Edit: "down" inserted in second para for clarity

[stuving]

But surely that train that you mention coming into P9 would mean that the crossover leading from P9 to the down main would be held in the normal position.  The points at either end of such a crossover will always act together, surely?

But P9 is the Down Main, and P8 the DM Loop. You can pair off the points and call them crossovers, but it's a bit arbitrary to do so. When you do that, going "straight on" from P8 gets you to the Up Westbury into P3, and while that's going to be a common enough routeing it probably isn't "straight on".

[SandTEngineer]

I can confirm that the signalling interlocking allows simultaneous movements to be made in the Down direction into/out of both P8 and P9 as well as in the Up direction into both P10 and P11, the overlaps of the platform exit signals being clear of the (merging) trailing points in both cases.

[paul7575]

But P9 is the Down Main, and P8 the DM Loop. You can pair off the points and call them crossovers, but it's a bit arbitrary to do so. When you do that, going "straight on" from P8 gets you to the Up Westbury into P3, and while that's going to be a common enough routeing it probably isn't "straight on".

I've altered my earlier post because I should have referred to P8 on both occasions.  The points allowing the move from P8 to the down main nearest the station must operate together surely?  How are they numbered?

Paul

[SandTEngineer]

OK.  This is going to get a bit technical

Here is a simplified extract of the Reading station west end signalling plan (as it stood in November 2010).  Points are shown numbered in the 8xxx series.

A solid line through the points indicates the NORMAL position of the points with the broken line being the REVERSE position of the points (The NORMAL position is usually allocated by the designer to be the highest speed or straightest route or safest route (e.g. to direct a train away from a potential collision with another train; trap points in sidings being an example).  This is decided at time of initial production of the signalling plan, but can be altered later during any risk assessment of the layout.

If a point end has an A or B suffix then both ends (A and B) are operated together otherwise each point end is independent.  However, the interlocking can demand certain points not in the direct line of a signalled route to be set to protect that route and divert a train away from conflict.  This is called Flank Protection.

Note that after use points do not automatically return to the NORMAL position (with some exceptions in special cases) and will therefore remain in the position last set after the route has be traversed by a train.

Hope that makes sense but if not then please ask away

[eightf48544]

From above:

"Note that after use points do not automatically return to the NORMAL position (with some exceptions in special cases) and will therefore remain in the position last set after the route has be traversed by a train."

And herein lies the danger that in not returning Normal then there may not be Flank Protection, from a SPAD^▸ (Signal Passed At Danger) on another route.

Ladboke Grove and Colwich being examples where Flank Protection could have been provided.

 

[Oxonhutch]

I think S&TE covered that in his previous paragraph ...

If a point end has an A or B suffix then both ends (A and B) are operated together otherwise each point end is independent.  However, the interlocking can demand certain points not in the direct line of a signalled route to be set to protect that route and divert a train away from conflict.  This is called Flank Protection.

I have looked at the report for Colwich and can see that Points 21A reversed could have provided the necesary protection were they not designed to be co-acting with 21B - a relic of the original LNWR^▸ (London North Western Railway) mechanical installation I would think.

Ladbroke Grove was subtly different in that the lie of the points taken by the Thames Trains local, having SPADed the infamous SN109 was designed into the system.  Shortly after that incident, it became apparent from people involved in the original design that it was implemented with full ATP^▸ (Automatic Train Protection) as part of the overall signal control on this part of the GWML^▸ (Great Western Main Line).  Full ATP was subsequently removed from the programme but the point's normal lie was not changed.  'ATP-lite' or TPWS^▸ (Train Protection and Warning System) was one of the outcomes of this disaster IIRC^▸ (if I recall/remember/read correctly).

[stuving]

Here is a simplified extract of the Reading station west end signalling plan (as it stood in November 2010).  Points are shown numbered in the 8xxx series.

Thanks - that establishes what the plan is (or was).

Evidently the feeder line (RUFM) is the normal route into P11, and 5445A/B are a crossover from the Up Main. However, the merged festival Line and Up Westbury is not the normal route into (or should that be out of?) P8.

I suspect that's less arbitrary than it looks. Two main line split/join here, so the UM and RUFM are both Up Mains that merge east of the platforms, and the label "Up Main Loop" on p11 gets ignored.

On the other side, the old Up Westbury is no longer an Up Main, at least it won't be when the work is finished. Up trains use it to access P1-P3, P7 & P8 only to terminate or reverse. It also gives Down access from P8. The festival line is also to be used both ways, though it is more essential for Up movements into P3, 7, 8. Of these, P8 also functions, as labelled, as Down Main Loop - most reversals should be in P3 and P7. So the normal route from P8 is back onto the Down Main, and no other dominant usage overrules that.

So while the alternative of pairing 5451 and 5439, proposed by Paul7755, has its merits, I imagine it lost out 30:70 in the vote.

[paul7575]

The main reason I was wondering about the state of play shown in the video though, is why the points 8451 are already set reverse towards the passing train coming into P8.   To make a useful route through those points you need 8439 normal as well - so is the video showing a partial stage in an eventual route being set, in other words 8439 will move to normal as soon as the up train has entered the platform and is beyond points 8439.

Hypothetical example here, the next train to approach could be a XC^▸ (Cross Country Trains (franchise)) train into P8 that is coming along the down main in the up direction having crossed over at the high level junction.

My intuition would have been that the signaller demands the route on his VDU and the points required all move at once, so maybe  SandTEngineer can confirms it doesn't actually work like that...

Paul

[paul7575]

On the other side, the old Up Westbury is no longer an Up Main, at least it won't be when the work is finished. Up trains use it to access P1-P3, P7 & P8 only to terminate or reverse...

That leads to an obvious question, for the final layout, would it not make sense to swap the line names, i.e. the direct route from Reading West towards P11 should become the Up Westbury, with the existing line being renamed the Feeder Main.

I imagine it becomes too expensive as it's a cost with not much benefit except to clarify how it all works normally...

Paul

[IndustryInsider]

Just seen confirmation that Reading's Depot Connection 'A' will be brought into use a little later than the rest of the Easter upgrades, in May.

[Gordon the Blue Engine]

Interesting that the down train in P9 must be on a red as the points in advance of the starter signal are reversed, as are the points from the Festival line further in advance at High Level Junction.  Yet we see from the video that the route on the DM from P9 was clear to at least Tilehurst.

So I wonder why the down train was on a red?  I can^t believe it was waiting time, down HST^▸ (High Speed Train)^s are never early at Reading!

XC^▸ (Cross Country Trains (franchise)) from P3 to go first when up FGW^▸ (First Great Western) inbound from UW clears junction.

Without wishing to flog this little issue to death, the down HST in 9 could of course have a route set as far as High level Junction, so the platform starter would show yellow.

Edit...

I^ve just realised the above could be read in different ways.  What I meant to say is that although a route was not set up for the HST at P9 (as evidenced by the reversed points in advance of the platform starter signal), it would have been possible for the signaller to set up a route as far as High Level Junction.  If he/she had done this the P9 starter would be showing a yellow.