WCML signalling

[Railsigns]

The first flashing yellows I recall seeing, around about 1984, where [were] on the Down line on the approach to Weaver Junction.

Provided on 11 January 1981.

 

[QueensCurve]

Provided on 11 January 1981.

Thank you. I had no idea they had been there that long.

== Doublepost prevention - post automatically merged: 23 Jul 2023 ==

WCML electrification was really done on the cheap. Boxes at Euston, Watford ? and Rugby and Nuneaton then mechanical interlocking Atherstone, Polesworth, Tamworth TV, Litchfield TV (Was there a box between for a level crossing or was it a gate box?), then a power installation at Rugeley, then mechanical through Stafford and Crewe except for a small panel at Norton Bridge. not sure about between Crewe and Weaver Jct, then into the 70's power boxes at Warrington, Preston and Carlisle.
And lets not forget Stockport!
They will have to replace Warrington, Preston and Carlisle soon. They are 50 years old now.

Don't forget Motherwell which retained its original flat rooves.

== Doublepost prevention - post automatically merged: 23 Jul 2023 ==

The bi-di between Rugby and Lichfield is worth further scrutiny. To my knowledge, it’s the only bi-directional 4-track in the country. Elsewhere it’s assumed that during engineering work, all traffic can be accommodated by two of the 4 tracks in the normal direction.

Can anyone advise how often the bidi facility gets used?

The 4 tracks there are paired by direction, rather than use. The Fast lines are bidirectional so that trains can be run on one pair of tracks while work procedes on the other two.

 

[MadMac]

The first flashing yellows in the country were at Didcot in March 1979. I don't where they were first provided on the WCML, but Law Junction got them in April 1980.

Trawling the memory banks here, Uddingston?

 

[Railsigns]

Trawling the memory banks here, Uddingston?

The flashing yellows at Uddingston came into use one week after Law Junction's, according to the weekly notices.

A quick trawl through some LMR notices for 1979/1980 hasn't revealed anything earlier, so Law Junction may have been the first flashing yellows on the WCML.

 

[jfollows]

My memory, which has often been faulty I admit, is that the rules allowing implementation of flashing yellow signals preceding junctions were more restrictive when introduced than they are now. In particular, the speed of the diverging route had to be within a certain percentage or amount of the speed of the normal route. So Uddingston (65mph versus 90mph today) and Law Junction (50mph versus 90mph today) were allowed, but I recall that Cheadle Hulme (45mph versus 100mph then) wasn't. For sure Didcot would have been fine of course. And Hanslope in due course. As experience was gained the restrictions on their use were relaxed, I'm not sure there's any speed-related restriction now other than that the flashing yellow can only be used for the fastest diverging route if there's more than one. Cheadle Hulme now has flashing yellows.
Others will correct or amplify this I'm sure!

 

[Railsigns]

I'm not sure there's any speed-related restriction now other than that the flashing yellow can only be used for the fastest diverging route if there's more than one.
Others will correct or amplify this I'm sure!

The present speed-related criteria for the provision of flashing yellow aspects are:

For an approach speed of 80-125 mph, the divergence speed must be 40 mph or greater.

For an approach speed of 40-80 mph, the divergence speed must be between 25 mph and 40 mph.

Flashing yellows are not permitted where the approach speed is below 40 mph.

 

[LNW-GW Joint]

Could do with some on the Down Fast approaching Warrington BQ P4 (90-50mph).
Every train (mostly from from Chester), heading for the Slow/P4, gets checked to walking pace on the approach to red, reducing fast line capacity.
There are two turnouts, the second to 10mph, but seemingly from post #65/66 flashing yellows on the earlier 50mph turnout would be allowed.

 

[zwk500]

There are two turnouts, the second to 10mph, but seemingly from post #65/66 flashing yellows on the earlier 50mph turnout would be allowed.

If there is no differentiation in the routing indication, presumably it would not be allowed to reduce the risk of confusion?

 

[td97]

Crewe won't be ETCS as it stands, only Warrington, Preston and Carlisle.

The thinking is that Crewe will be eventually, in combination with ATO. But it will be resignalled with lineside signals for HS2, so this would be a long, long way off
*Automatic Train Operation

 

[a good off]

Having a flashing aspect from the DM into P1 at Rugby would improve things no end. I’d also make the DF bi-di at Rugby too as it would be of great use when the Up side of the station is under possession and we’ve got freights stood waiting relief in the station. I’d also make the UM at Northampton bi-di too so there’s a through route for Down trains when all platforms are occupied with abandoned units.

 

[jfollows]

Could do with some on the Down Fast approaching Warrington BQ P4 (90-50mph).
Every train (mostly from from Chester), heading for the Slow/P4, gets checked to walking pace on the approach to red, reducing fast line capacity.
There are two turnouts, the second to 10mph, but seemingly from post #65/66 flashing yellows on the earlier 50mph turnout would be allowed.

My notes, could be wrong, is that WN217 has position 1 & 2 junction indicators only, implying down passenger loop & down slow both via the 50mph turnout only, with subsidiary signal plus theatre indicator which might allow a route over the 15mph turnout (as was, you & sectional appendix say now 10mph). If so, there can be no confusion.

 

[Boodiggy]

Having a flashing aspect from the DM into P1 at Rugby would improve things no end. I’d also make the DF bi-di at Rugby too as it would be of great use when the Up side of the station is under possession and we’ve got freights stood waiting relief in the station. I’d also make the UM at Northampton bi-di too so there’s a through route for Down trains when all platforms are occupied with abandoned units.

This is in progress. Route in to P1 will have the speed lowered to 50mph from 60mph as a mitigation due to P2 route being 40mph from the DF it reduces the risk of anything happening should a train traverse the route to quickly.

 

[Oxfordblues]

When is the 126-year-old LNWR Basford Hall Junction signalbox due to close?

 

[jfollows]

When is the 126-year-old LNWR Basford Hall Junction signalbox due to close?

Soon (https://www.railforums.co.uk/threads/crewe-resignalling-crewe-south-basford-hall.234061/)

Crewe Basford Hall and Independent Lines resignalling - Rail Engineer

Listen to this article If you have ever stood on Crewe station, you may have noticed that hardly any freight trains pass through it. This is because they are diverted via a separate four-track railway in a deep cutting to the west. Known as the Crewe Independent Lines, it is tunnelled beneath...

www.railengineer.co.uk

 

[The Planner]

Soon (https://www.railforums.co.uk/threads/crewe-resignalling-crewe-south-basford-hall.234061/)

Crewe Basford Hall and Independent Lines resignalling - Rail Engineer

Listen to this article If you have ever stood on Crewe station, you may have noticed that hardly any freight trains pass through it. This is because they are diverted via a separate four-track railway in a deep cutting to the west. Known as the Crewe Independent Lines, it is tunnelled beneath...

www.railengineer.co.uk

Next year at the earliest.

 

[Elecman]

When is the 126-year-old LNWR Basford Hall Junction signalbox due to close?

December 2024 was this year but now delayed

 

[MarkWi72]

Is it true to say headspan catenary is less reliable?

 

[LNW-GW Joint]

The Rail Engineer article is over 2 years old (April 2021), so some details are likely to have changed (not to mention the 2-year pause on HS2 reaching Crewe).

 

[The Planner]

December 2024 was this year but now delayed

2025 more likely.

 

[plugwash]

Is it true to say headspan catenary is less reliable?

My understanding is that compared to cantilivers or portals headspan wires have two major downsides.

1. They are more vulnerable to wind.
2. If something goes wrong with a pantograph then it is likely to screw up the catenery on all the lines.

 

[Nym]

The other consideration to make is that the majority of headspans are spaced further apart where cantilivers and portals were generally closer together, so adding the nature of headspans to the generally less optimal nature of the rest of the install.

 

[Bald Rick]

My understanding is that compared to cantilivers or portals headspan wires have two major downsides.

1. They are more vulnerable to wind.
2. If something goes wrong with a pantograph then it is likely to screw up the catenery on all the lines.

3. If an upgrade is required to the OLE system, it is much more disruptive than if gantries are provided (see MML)