Zoe

4 hours ago, The Stationmaster said:

What I can't establish is if the 1959 work at Action which involved closing Acton East and Middle 'boxes plus creating a new Acton Yard ' box was labelled as part of Hayes - Paddington.

It is listed as Paddington - Hayes stage 1C in the SRS archive catalogue although the notice itself is not a available for download.

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But by 1963 with some stage work and the commissioning of Sloiugh panel.  the 'Reading - Hayes Resignalling' title had gone from the notices.

Although the 1964 notice regarding the West Drayton area does refer to it as the final stage of the Reading - Hayes MAS scheme.

What I'm still not sure about though is if the plan in the 1950s could have been to install  MAS all the way through to Paddington but have this controlled from the existing boxes (considering power boxes were ruled out at this time except where they could be justified by exceptionally good financial return) and if this later changed when as you say there were changes to operational practice in the 1960s.

Would also be interesting to know what the original proposals (referred to in the document as involving several power boxes and considered too costly) would have been but I doubt that information survives anywhere today.

I recently found this https://www.jonroma.net/media/signaling/articles/irse/Some Signalling Developments on the Western Region. Tyler%2C J. F. H. IRSE Proceedings. 1954.pdf which gives some details of the1950s schemes, starting on page 106.

Considering the first part of the Paddington - Hayes scheme was introduced in 1953 but Paddington station was not resignalled until 1967 I have often wondered if the 1967 Old Oak Common panel was part of the original plan.  The above document says that initial proposals involving a number of power boxes were ruled out on cost grounds and so it was decided to retain the existing boxes for the MAS (except where exceptionally good financial return was  predicted).  Even the panel that was installed at West Ealing in 1955 could not be justified in its own right, but was used as a testing ground for a larger scheme elsewhere.

So it seems there was  a change of plan which explains why after the initial push eastwards from Southall to reach Acton Middle in 1955, progress was slow with the MAS not reaching Paddington itself until 1967.  I wonder if a panel taking over at least the Paddington Boxes and Westbourne bridge would have been justified had the plans not changed.

The box instructions for Barmouth South (again available from the SRS website at https://www.s-r-s.org.uk/html/gwu/S3224.htm) show:

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Regulation 4A

The Up Distant Signal for Barmouth North signal box being permanently fixed at Caution, this Regulation will not apply to the acceptance of Up trains."

This would seem logical for the situation where Truro East had a full clearing point available but did not have line clear through to the next box east.  Truro West's Distant would then effectively act as an additional fixed distant for East giving 922 yards to Truro East Up Main Home (This is however still less than the 1000 yards shown in the book for a falling gradient but the severe 15 mph PROS through the Up Platform may have been taken in account).  This would then avoid the seemingly unsatisfactory situation of a West having to maintain the Up Home at danger and the driver seeing it after having previously not been cautioned at Penwithers Junction.

The problem here though is if regulation 4A was used for the purposes of allowing East to accept a train without having the full clearing point available (which was suggested above would have been the case if modified clearing points were not used).  This I believe would require the train to be cautioned at Truro West and I can't see any way of doing this if the driver sees a cleared distant at Penwithers Junction (West having accepted under regulation 4).  Unless of course West did indeed maintain their Up Home at danger until the driver saw it after emerging from the tunnel but I feel very uncomfortable about that situation.

18 hours ago, Jeremy Cumberland said:

At Truro West, this almost certainly means that the driver sees the home signal at danger before it is cleared, and it probably appears to the driver much like a Rule 39 (a) caution, even though it isn't.

This doesn't seem ideal at all.  If after seeing Penwithers Junction Up Distant cleared, the driver assumes that they have the road into the platform at Truro then wouldn't the first  reaction after emerging from the tunnel be to slam on the emergency brake after seeing the Truro West Up Home at danger even if it does then get cleared?

16 hours ago, The Stationmaster said:

This might well come back to any modfied Clearing Points at Truro East and West and that PROSs through the station and when the two station 'boxes asked 'Is Line Clear?' forwards between each other' and the strong probability that 2-2-2 acceptances were also used

 

Let's assume for a moment that Truro West asked forwards on receiving the ILC? from Penwithers Jcn   If that was acknowledged and 'Line Clear' was pegged up by Truro East then West  could accept under full 'Line Clear' from Penwithers Jcn and the Penwithers Jcn Signalman could clear all his relevant Up direction signals including the distant.  If Truro East could not accept the train then West would implement Regulation 4A  (provided the line was clear to his Clearing Point) and the Penwithers Jcn Signalman would keep his Up Distant Signal at Caution  So there was clearly a situation in which Penwithers Jcn Signalman could clear his Up Main. Distant.

 

In the opposite direction things were different because Truro East had a full Clearing Point between his Down Main Home and his Inner  Home with the distant a very long way back from the Home.  So no restriction on acceptance from Probus (or Burngiullow when Probus was switched out or after it had been closed for good in 1965)  provided East's Clearing Point was not fouled.  But he could not clear all his Down Main stop signals and clear his Distant until the train had been accepted by Truro West under a full 'Line Clear.  So even if West accepted by 2-2-2 East could still accept under full Line Clear from Probus/Burngullow because his Distant had more than adequate braking distance to the Home Signal

 

In the Up direction if East accepted a train under Regulation 4A from West that still gives West a full Clearing Point so he could accept from Penwithers Jcn under a full 'Line Clear'.  It's interesting to note that according to George Pryer's diagram West did not have a two shot detonator placer on the Up Main Line but did have one on the Up Branch Line (the one between the two platforms which is nowadays the Up Main).  I suspect the reason for that was the very low PROS on the Up Main.

 

The big question which we don't know the answer to is what the Clearing Points were at both station 'boxes and if my assumption about possible Modified Clearing Points is correct or whether they had 4A acceptances between each other instead?  But even if West accepted 4A from East that would not affect East's acceptance from Probus and East would keep his Distant Signal at caution  As I said above an awful lot of this depends on what was in those Signal Box Instructions - West clearly had a potentially very short Clearing Point on the Down Main in any event.

 

Incidentally prior to the Knowle & Dorridge collision  (which involved the failure of a Signalman to properly apply Regulation 4A( application of the Regulation was effectively left entirely to the knowledge of the Signalman.  One of the consequnces of that collsion and the Inspecting Officer's Report was that its use was subsequently noted in the Signal Box Soecial Instructions at all places where it applied.  

 

Regulation 4A was amended in late 1965 and was removed completely from the Regulations booklet in the 1972 reissue.  However it did not disappear and was cinrinued in Signalbox Soecial Instrux ctions at those places were it still had any application.  This led to the strange situation of it no longer applying anywhere on the WR but still applying in at least one place which had been transferred frim the WR to the LMR.  Thus when i visited the 'boxes in the immediate Shrewsbury area c.30 years ago what had been GWR AB Regulation 4A was still in use and I even heard a 2-2-2 acceptance bell signal.  As little has changed at Shrewsbury since then it could wel be still in use there - 50 tears after it disappeared from the Absolute Block Regulations.

 

BTW. Oenwithers Jcn' Down was only 44o yds i. rear of the Home Signal so 4A presumably also applied there although the switchback gradient, albeit steep,. might have been considered to decide that it was not necessary.

Thanks for the explanation, I was a little uneasy about the fixed distant not always meaning to expect Truro West's  Up Home to always be at danger but driver knowledge must have covered that so if the driver saw Penwithers Junction Up Distant cleared then they would know they had the road into  the platform.

Regarding regulation 4A between the two  boxes,  the situation on  the down line is quite clear in the Truro East would have to maintain their distant at caution if West only accepted under 4A but what would regulation 4A achieve on the Up, considering that West's Distant was fixed at caution, it would stay that way even if East accepted under regulation  4.

Incidentally, after Probus closed  Grampound Road remained open through to 1972 (presumably just to break the very long section to Burngullow after all the sidings were taken out of use in the 1960s).

4 hours ago, Jeremy Cumberland said:

What happens in respect of Regulation 4A at Truro West when Penwithers Junction switches out?

 

I suppose Penwithers Junction keeps his up distant at caution when switching out, and that Truro West then sends full line clear to Baldhu (or wherever).

 

 

That was certainly the case at Taunton West Station, the box instructions (available from the SRS  website at https://www.s-r-s.org.uk/html/gwe/S732.htm) show that Taunton West Junction's Up distants were maintained at caution when that box was out of circuit with regulation 4A then not applying.

5 hours ago, The Stationmaster said:

 

Lots of fascinating stuff involved but at least the original question from Zoe was the simple bit as it was part of standard GWR practice for Distant Signals.

What I'm still not sure about though is why Penwithers Junction had a worked distant on the Up Main at all.  If all trains were accepted by Truro West under regulation 4A then it could never have been cleared. 

Looking at the diagram for Truro  East, it shows a worked distant on the Down Main which  could never have been be cleared if Truro West had to  accept under regulation 4A unless the 30 mph PSR through the platforms could have avoided this situation but it seems that the platforms were not long enough.

It would appear then that both Penwithers Junction and Truro East had worked distants which could never have been cleared.

You can find these in the relevant Service Timetables.  Michael Clemens has a full set of these for September 1949 at https://www.michaelclemensrailways.co.uk/?atk=592 although these are of course from just after the GWR became the WR.   You will find the information in the latter pages, after the end of the main timetables.

There are also some older timetables available on the same site at https://www.michaelclemensrailways.co.uk/?atk=625

I have just been looking at the George Pryer diagrams for the Truro area and have noticed that Truro West only had one distant arm for the up line (fixed at caution on  the same post as the Penwithers Junction Up section signal).  This however is shown to have been at a distance of 590 yards in rear of Truro West box, with the Up Main Home at 189 yards in rear leaving  only 401 yards from distant to home.  This would suggest that regulation 4A would have been required for every train but that would make it pointless for Penwithers Junction to have a worked  Up Main Distant at all if it could never be cleared.  There were also two other stop  signals in rear of the section signal which could have had distant arms below them to more braking distance but for some reason did not. 

There does not appear to have been a speed restriction at Penwithers Junction or a severe rising gradient towards Truro so would the driver have been expected to have known to expect Truro West box Up Home to be at danger even though the fixed distant would have been located after the point at which they would have needed to start braking?  There was I believe a speed limit through Truro station but the braking point for that would have been later.

On the subject of feathers, this video https://www.youtube.com/watch?v=NmPzB0qTy4M (filmed in 1962 just before the MAS reached Old Oak Common) shows feathers above Ladbroke Grove's  Down Main Home and Down Relief Home  signals  at 1:01.  I was informed elsewhere these were was added so that the original searchlight heads for the diverging routes could be removed and converted for use in the MAS.

Yes you are right it was done in stages the first in 1953 followed nearly two years later with a extension  in 1955 not sure why they chose searchlight signals for that stretch of line perhaps the signal engineer for that project may have had something to do with earlier ones at Paddington?

Searchlights were installed all the way to Southall by the GWR in the 1930s.  I believe these were converted for use in the 1950s MAS scheme.

Multiple aspect searchlight signals were used on the WR between Southall West Jcn and Ladbroke Grove both as part of the 1962 O.O. Common scheme and earlier resignalling between Acton and Southall, they lasted iuntil the 1967 (second) Old Oak Common panel box commissioning.

Looking at this video of Hanwell in the 1970s https://www.youtube.com/watch?v=vmiqdTadyRw  it seems that some MAS searchlights were still in use.  I believe the Hanwell signals would have been installed in 1953 as part of the first MAS installation from Hayes to Hanwell and in 1955 when the MAS was extended to Acton.

I have a train simulator route (the steam-era GWR line from Dorchester to Castle Cary) for which I have precise data on curvature, gradients and signal distances but no information on speed limits. So I'm wondering if I can use this data to deduce the latter. Can anyone assist please?

Speed restrictions were published in the service timetables, there is a full set of 1949 STTs available on Michael Clemens' site:  http://www.michaelclemensrailways.co.uk/?atk=592 Section 3 covers the route, you will find the speed restrictions for your section of line on page 158.  Note that only specific locations were subject to a speed restriction, elsewhere a 75 mph limit applied.

Not sure that this is correct.  AFAIK it was just a request from the TOC, nothing else.  

I've just gone back over some discussions a few years back elsewhere on the issue and on two separate occasions it was said that when the ORR were in the area following the crossing fatality the usage of platform 4 was picked up on and that it was then suggested that it didn't use that platform.  It seems that the issue was due to easy access to the doors on the unplatformed side of the train.  It may well be that the ORR informed the TOC of this observation and the TOC then requested the move to platform 1.

Hi,

 

Thanks guys, most helpful, the WTT (or at least the one we are using) doesn't show any of the shunt moves of the stock, so we didn't know what happened to it!

Simon

The WTT (available on the NR website) shows 5C99 departing Penzance at 0915 on Mondays and 0822 on Tuesdays to Saturdays.

Hi,

 

A question about operations for those in the know, when the Night Riveria comes into Penzance Platform 4, what happens to it? Does it sit there all day being service and a loco attaches onto the London end to take it away, or is there shunting that releases the loco from the stops?

 

Simon

I don't think it has used platform 4 for some time now even if the WTT still says it does.  I seem to remember the change to platform 1 was related to health and safety as a result of an investigation in the area a few years back following a crossing fatality.