How do two signal boxes at the same location work together?

[petejones]

How do two signal boxes at the same location work together?

 

Thanks

Pete

[Gareth 73]

Your question is a little vague but I'm guessing you mean the likes of either end of a station then it's usual absolute block regs and bell signal communication.

I am not aware (so there probably is somewhere) where track circuits block regs are used for 2 boxes close together like a station because if they had gone to trouble of putting tcb in they would of abolished at least 1 box to save money.

[Dunsignalling]

3 hours ago, petejones said:

How do two signal boxes at the same location work together?

 

Thanks

Pete

If you mean two situated at either end of a long station, much the same as any other pair of adjacent boxes, just closer together than usual.

 

Maximum length of pull on mechanical points is (normally) 300 yards, above that, slack accumulates in the joints etc., and operation, especially of Facing Point Locks becomes unreliable. Having worked some that were right on the limit, I can also testify that it's ruddy hard work, especially on hot days.    

 

Therefore, any station that is to be worked from a box sited centrally can't have its outermost points more than 600 yards from one another. Above that, you need either powered points or separate boxes to work each end.  

 

As for which box works which signals, it's logical, each box works the home signal(s) for trains arriving at its end and the starter(s) for those leaving from its end. Distants would be slotted to the other box to prevent them being cleared without the starter being off. Normal bells, block instruments etc in between as any other section.

 

John  

[Compound2632]

An example: Hawes Junction on the Settle-Carlisle line. This originally had a South Junction box, controlling the connection from the Hawes branch to the up line, together with the connection from the up side sidings to the down line, and a North Junction box, controlling the connection from the branch to the down line, together with the connections to the sidings at that end of the station. These two boxes were replaced by the extant single box on the down platform, which was brought into use on 10 July 1910. This was just under six months before the Hawes Junction accident - though I've never seen a suggestion that the change in signalling arrangements was a contributory factor. It would have been further for the fireman of the light engines to walk to carry out rule 55. A 1956 signalling diagram shows that the furthest points from the box, controlling the connection from the down siding to the down line at the northernmost point of the layout, were worked from a ground frame released from the box. What's not evident is whether this frame had to be introduced when the North Junction box was abolished.

 

Ref. V.R. Anderson and G.K. Fox, Stations & Structures of the Settle & Carlisle Railway (OPC, 1986).

 

 

[beast66606]

1 hour ago, Gareth 73 said:

Your question is a little vague but I'm guessing you mean the likes of either end of a station then it's usual absolute block regs and bell signal communication.

I am not aware (so there probably is somewhere) where track circuits block regs are used for 2 boxes close together like a station because if they had gone to trouble of putting tcb in they would of abolished at least 1 box to save money.

 

Allteron and Speke Junction, Ditton No.1 and Ditton No.2 to name two quick examples.

[iands]

2 hours ago, beast66606 said:

 

Allteron and Speke Junction, Ditton No.1 and Ditton No.2 to name two quick examples.

And prior to the resignalling in the early 80s, Doncaster North and Doncaster South. 

[petejones]

Thanks for the replies and information so far.

 

Yes I did mean at the opposite ends of a station. At the one example I have in mind (Glyndyfrdwy on the Llangollen Railway), the station is on a curve so there is no line of sight between the two boxes.

[Compound2632]

Then there were places such as Rugby where the boxes were packed in head-to-toe. Even a relatively out of the way place could be like that - somewhere on here there's a description of Oswestry, with five boxes in a row, sufficiently close together that the distant for the box in advance was slotted by all four of the preceding boxes; presumably each box's starter doubled up as the home for the box in advance? 

[Reorte]

Stockport must be a good current example, the two Stockport boxes and the two Edgely Junction ones.

[beast66606]

20 minutes ago, Compound2632 said:

Then there were places such as Rugby where the boxes were packed in head-to-toe. Even a relatively out of the way place could be like that - somewhere on here there's a description of Oswestry, with five boxes in a row, sufficiently close together that the distant for the box in advance was slotted by all four of the preceding boxes; presumably each box's starter doubled up as the home for the box in advance? 

 

Oswestry ? - I think you mean Wrexham

[Compound2632]

1 minute ago, beast66606 said:

 

Oswestry ? - I think you mean Wrexham

 

Thanks. I knew it was somewhere in that neck of the woods.

[Gareth 73]

1 hour ago, petejones said:

Thanks for the replies and information so far.

 

Yes I did mean at the opposite ends of a station. At the one example I have in mind (Glyndyfrdwy on the Llangollen Railway), the station is on a curve so there is no line of sight between the two boxes.

The 2 boxes at glyn arnt connected in anyway only the box by the level crossing controls the railway. The one carrog end came from barmouth and is a museum piece not connected to any signalling ( well it was as there is no reason to have 2 working boxes there).

Bewdley for example on the Severn valley has a  box at either end of the station worked by absolute block between them.

And as for tcb boxes together I had a major brain failure as where I work is exactly that oh well it was early in the morning 

[DY444]

5 hours ago, Gareth 73 said:

Your question is a little vague but I'm guessing you mean the likes of either end of a station then it's usual absolute block regs and bell signal communication.

I am not aware (so there probably is somewhere) where track circuits block regs are used for 2 boxes close together like a station because if they had gone to trouble of putting tcb in they would of abolished at least 1 box to save money.

 

They've gone now but the two boxes at each end of Stafford station (No4 and No5) retained after electrification used TCB.  By contrast the Stockport boxes use AB.

[Compound2632]

Communication between adjacent boxes wasn't always perfect - Tamworth, 1870...

[DCB]

Communication between boxes at Elgin was by the signalman using a pushbike to move from box to box well into the 1980s.  Great rationalisation, 2 boxes, 1 bloke 1 bike.  

[Compound2632]

Presumably one box was not a block post but released from the other - a glorified ground frame - otherwise he'd have got very fit dashing to and fro to answer his own bell signals!

[peanuts]

3 hours ago, Reorte said:

Stockport must be a good current example, the two Stockport boxes and the two Edgely Junction ones.

and dont forget my old stamping ground Heaton Norris .when i started as a trb in 1981 you alos had Cheadle Hulme and Adswood road  boxes making it seven boxes in around  three miles 

[62613]

6 hours ago, peanuts said:

and dont forget my old stamping ground Heaton Norris .when i started as a trb in 1981 you alos had Cheadle Hulme and Adswood road  boxes making it seven boxes in around  three miles 

 

March was another similar one; it's been said that going from Ely to Peterborough, you fairly boxed the compass, with South, North, East and West Junctions within barely three-quarters of a mile, two level crossings, and Whitemoor Junction off to one side of the triangle formed by it and East and West. South and North are still open, because of the level crossings, there is less than 500 yards between them.

[Edwin_m]

One reason to put a box at each end of the station rather than in the middle was so the signalmen could observe tail lights on arriving trains.  Otherwise they would have had to rely on hand signals from guards or wait until the train departed before they could give out of section.  For this reason the two boxes are normally at "NW" and "SE" corners (for a north soute line, rotated appropriately) as at Stockport. 

 

Many large stations had a box each end and one or more in the middle to control mid-platform crossovers.  Sometimes these boxes only had authority over some of the parallel tracks - both main Nottingham stations had two middle boxes (which can still be seen at Midland, though now used for other purposes).

[caradoc]

20 hours ago, Compound2632 said:

Presumably one box was not a block post but released from the other - a glorified ground frame - otherwise he'd have got very fit dashing to and fro to answer his own bell signals!

 

 

IIRC The practice was to have the signalling instruments in a central location, eg the station  buildings, and the 'boxes' at both ends worked the points and signals.

 

[96701]

Shrewsbury Crewe Junction and Severn Bridge Junction boxes are at either end of the station.

[Compound2632]

15 minutes ago, 96701 said:

Shrewsbury Crewe Junction and Severn Bridge Junction boxes are at either end of the station.

 

I don't imagine that's a case where the block instruments are in the stationmaster's office!

[96701]

1 hour ago, Compound2632 said:

 

I don't imagine that's a case where the block instruments are in the stationmaster's office!

Nope, definitely in the boxes. 

 

[The Stationmaster]

On 03/08/2019 at 10:41, beast66606 said:

 

Oswestry ? - I think you mean Wrexham

Were the Distants slotted there or not?  

 

There were places on the GWR where the Distants were not slotted - Reading Main Line East and Reading Main Line West being a prime example where the distance between the two 'boxes was only 770 yards and Regulation 4A working applied using the ex GWR bell signal 'Line Clear to Clearing Point Only'.    Interestingly that also applied at Shrewsbury - and still applied when I visited the Shrewsbury 'boxes in the early 1990s although the Regulation itself had long been discontinued as a Regulation but was included in the Signal Box Special Instructions instead.

[johnofwessex]

Given that the vast majority of movements would be in accordance with the WTT, I assume that the Signalmen would have known exactly what to do without having to talk to each other