Rules for switching out signalboxes or workstations.

[Ken H]

Following on from https://www.railforums.co.uk/thread...e-to-staff-illness-16-04.230507/#post-5619177 about a line closed because no signaller avaliable

What are the rules re switching out a signal box. Are there some that must be manned? Is there a maximum distance between block posts?

Can power boxes have work stations switched out so all signals work automatically and no turnouts allowed?

 

[lineclear]

Following on from https://www.railforums.co.uk/thread...e-to-staff-illness-16-04.230507/#post-5619177 about a line closed because no signaller avaliable

What are the rules re switching out a signal box. Are there some that must be manned? Is there a maximum distance between block posts?

Can power boxes have work stations switched out so all signals work automatically and no turnouts allowed?

In Absolute Block, a signaller is in control of their own station limits, and jointly responsible with the adjacent signaller for the Absolute Block section between them. When a box (let's call it B) with a block switch switches out, its block switch connects the block instruments of the boxes either side (A&C) together, creating a longer block section between A and C. Those two signal boxes are now jointly responsible for the Absolute Block section between them. The presence of a train in the section is shown on their block instruments.

Not many surviving boxes have a block switch now. The presence of a level crossing generally precludes it. In the case of Blea Moor, the single line over the viaduct precludes it.

In the past, many boxes in a row could switch out. For example, at night, the boxes between Kirkstall and Kildwick used to switch out.

In Track Circuit Block, the principle is different. Each signaller is solely responsible for their own area. If an intermediate box is closed, nobody is responsible for that box's area. The presence of any trains in it would not be visible to the signallers either side.

 

[jfollows]

I remember that Adswood Road signal box (between Edgeley Junctions and Cheadle Hulme) used to be switched out at weekends, which then meant that the slow and goods lines couldn't be used south of Edgeley Junction No. 1, so caused a slight operational inconvenience. In due course (1 November 1981) it was abolished and its points and signals transferred to Cheadle Hulme (which was always open, so the slow and goods lines could be used all the time), which lasted until it was replaced with a temporary panel on 27 August 2000, which was in turn replaced by the current Manchester South signal box on 29 March 2003.

 

[30907]

Not many surviving boxes have a block switch now. The presence of a level crossing generally precludes it. In the case of Blea Moor, the single line over the viaduct precludes it.

Garsdale is, presumably, still among them? I remember it being normally switched out, maybe as late as early 1990s.

PS Settle Jn to Carnforth is pretty long as block sections go.

 

[D6130]

Garsdale is, presumably, still among them? I remember it being normally switched out, maybe as late as early 1990s.

During most of the 1990s - prior to the return of significant freight traffic to the S & C - Garsdale and Appleby boxes were switched out most of the time.

 

[Tomnick]

Following on from https://www.railforums.co.uk/thread...e-to-staff-illness-16-04.230507/#post-5619177 about a line closed because no signaller avaliable

What are the rules re switching out a signal box. Are there some that must be manned? Is there a maximum distance between block posts?

Can power boxes have work stations switched out so all signals work automatically and no turnouts allowed?

If an AB box switches out, as explained above, it simply extends the block section to run between the adjacent boxes on either side of it. If there any user worked crossings supervised by that box, then the crossing phones will be transferred to one of those boxes too. The signals at the box that switches out are cleared and left cleared, thus there are few circumstances in which a train will encounter and need to pass a signal at danger on its own authority (and the rules cover that eventuality). As others have said, relatively few boxes are able to switch out nowadays because most have level crossings or something else to supervise, or are at the fringe between AB and TCB. I had one (Melton) that could/can switch out, and indeed was booked to switch out on Sundays when traffic levels were generally lower, and sometimes switched out at other times for exactly the reason under discussion, when it or another box couldn't be covered.

I don't know if Earles Sidings still has a functioning block switch, but the boxes on either side (Edale and Grindleford) are occasionally switched out due to short-staffing. I was briefly held at Chinley earlier this month because there was no early turn at Edale so I had to wait for the previous train to clear Earles. If Earles can switch out, though, that'd potentially make a Totley - Chinley section in extremis!

I know of at least one TCB box that could switch out (West Burton), with its signals then left to work automatically. Presumably there was some provision, perhaps in the box instructions, for one or both of the adjacent boxes to talk past signals at danger if necessary - I don't know.

You really can't apply these principles to a full workstation, though. The area is too large, with too much other stuff like user worked crossings to manage, to allow responsibility for evek straight running to be transferred to another, itself already busy, workstation.

 

[Supercoss]

Power boxes (PSBs) junction areas can be placed in " automatic" so straight line running, aside of terminal areas/end of line, trains effectivley run themselves so multiple panels/workstations can be " spervised" by fewer staff
Its surprising how far you can get without making junction moves.

 

[Gloster]

I don’t know about a maximum distance, although I believe that there can be problems with ‘current drop’ (I think that was the term) over long distances, although this might have been due to the number of block switches that the circuits had to go through. The longest on normal AB that I can think of was Hungerford-Heywood Road Junction, which was just under 33 miles and was worked on Sundays in the 1970s: a slow engineering train could be in section for an hour. Wilton Junction-Yeovil Junction was longer at just over 36 miles, but this was included in the design when the line was resignalled in 1967.

 

[TheBigD]

PS Settle Jn to Carnforth is pretty long as block sections go.

Longest block section in the country I believe.

 

[Llanigraham]

On the Marches line between Abergavenny and Sutton Bridge Junct the only Box that can be switched out is Dorrington, so the section then goes from Sutton Bridge to Marshbrook.

 

[High Dyke]

Melton Mowbray can still, and does switch out. Barkston East used to switch out overnight, which made the section Allington - Ancaster, though it was done away with when the box permanently closed.

 

[MadMac]

I don’t know about a maximum distance, although I believe that there can be problems with ‘current drop’ (I think that was the term) over long distances, although this might have been due to the number of block switches that the circuits had to go through. The longest on normal AB that I can think of was Hungerford-Heywood Road Junction, which was just under 33 miles and was worked on Sundays in the 1970s: a slow engineering train could be in section for an hour. Wilton Junction-Yeovil Junction was longer at just over 36 miles, but this was included in the design when the line was resignalled in 1967.

Some boxes in Ayrshire had a "Sunday Battery" to boost the voltage on the block circuits. It would be switched in as needed due to few boxes being open on Sundays.

 

[john prytherch]

I think Pontrilas can switch out.

 

[TheBigD]

Melton Mowbray can still, and does switch out. Barkston East used to switch out overnight, which made the section Allington - Ancaster, though it was done away with when the box permanently closed.

Melton Mowbray shuts and switches out from around 2200 Saturday through to around 0530 Monday.

When there are MML diversions the box is manned and open.

 

[Gloster]

A number of things can make switching out impossible. Level crossings, unless the crossing is either closed for a period or has a crossing-keeper for times when the box is closed, neither of which exist any longer (I think). Automatic or user-worked crossings, unless the ‘In order’ indicators or telephones are switchable through to an open box. Junctions, single to double or multiple to double track connections that may be needed. It is possible for boxes at junctions to set the road for one route and switch out, leaving the other line as dead road; a similar situation can occur when goods lines merge with passenger ones (the situation at Templecombe where the line went from one to two tracks was a real oddity). There were a few other, but much of this is now historical due to the spread of TCB and the reduction in boxes.

 

[GB]

Automatic Route Setting and the ability to have some routes remain set in are there as aides to the signaller, not replacement. It would be far to risky to let a panel or workstation work on its own without supervision as there would be no one there in an emergency and most locations deal with at least one level crossing and a number of user worked crossings.