Cambridge Signal Box - Fringe Boxes

[bjt10]

Hello,

I have heard the terminology 'fringe boxes' when it comes down to signal boxes quite a few times now. Can anyone tell me what a 'fringe box' is please?

Also does anyone know what 'fringe' boxes Cambridge is linked with please?

Many thanks in advance.

 

[transportphoto]

A fringe box is the next controlling signaller.

For example, Cambridge fringes with Manea (towards Peterborough) and Colchester (at Hethersett).

 

[mr_moo]

A 'fringe' box is the one that a signal box (or centre etc) joins to, so trains will be passed to/from a 'fringe' as they enter or exit the area controlled by the box. Signallers will often (but not always) have visibility of trians further away, whilst under the control of fringe boxes, so they can see what's coming and plan for it, on modern computer based systems anyway.

 

[Gloster]

I am hoping that I am not too out of date on this. My understanding was that a fringe box is only one that is the next box to a large (or largish) panel box and works Track Circuit Block (or similar) to it: it is at the fringe/edge/end of the panel’s track circuits and responsibility. Signal boxes that work Absolute, Tokenless, Electric Token and other Block systems to each other do not fringe to each other.

 

[ac6000cw]

A fringe box is the next controlling signaller.

For example, Cambridge fringes with Manea (towards Peterborough) and Colchester (at Hethersett).

...and AFAIK also fringes with York ROC (just north of Royston on the line to Kings Cross), Littleport (towards Kings Lynn), Liverpool Street IECC (north of Stansted on the line to Liverpool Street), Dullingham (towards Newmarket) and Chippenham Junction (from the Soham line).

But the ongoing Cambridge area re-signalling project will abolish Dullingham, Chippenham Junction and Bury St. Edmunds signalboxes and transfer control to Cambridge, so it will then gain another fringe (in addition to Hethersett) with Colchester PSB somewhere east of Bury (and obviously lose the Dullingham and Chippenham Junction fringes). See https://www.networkrail.co.uk/runni...y-in-anglia/cambridge-resignalling/#our-plans

(Correction - changed Romford ROC to Liverpool Street IECC)

 

[Annetts key]

My understanding of the term:

Where a power signal box / signalling panel / control centre / signalling centre has a boundary with a smaller existing signal box. As the power signal box / signalling panel / control centre / signalling centre will most likely be using track circuit block (or the same but with axle counters), so will part of the area controlled by the smaller existing signal box.

The remaining area controlled by the smaller existing signal box could be Absolute, Electric Token, TCB or other conventional signalling.

Hence to the power signal box / signalling panel / control centre / signalling centre, the smaller existing signal box is a fringe box, as it’s the boundary or fringe between the area controlled by the (newer) signalling controlled by the power signal box / signalling panel / control centre / signalling centre.

As more power signal boxes / signalling panels / control centres / signalling centres etc have taken over, now rather than the fringe being a conventional signal box, the fringe is the adjacent panel/desk of the next power signal box / signalling panel / control centre / signalling centre.

For conventional mechanical signal boxes that are a fringe box, they often will have a fringe train describer (TD) system. This communicates with the main TD system in the power signal box / signalling panel / control centre / signalling centre. This does not apply when two power signal boxes / signalling panels / control centres / signalling centres fringe one another. Instead, the main TD systems communicate directly with one another.

 

[Class 170101]

...and AFAIK also fringes with York ROC (south of Meldreth on the line to Kings Cross), Littleport (towards Kings Lynn), Romford ROC (north of Stansted on the line to Liverpool Street), Dullingham (towards Newmarket) and Chippenham Junction (from the Soham line).

Romford ROC doesn't fringe with Cambridge PSB its still Liverpool Street IECC. Romford has no signalling staff there only controls of various TOCs.

 

[LAX54]

...and AFAIK also fringes with York ROC (south of Meldreth on the line to Kings Cross), Littleport (towards Kings Lynn), Romford ROC (north of Stansted on the line to Liverpool Street), Dullingham (towards Newmarket) and Chippenham Junction (from the Soham line).

But the ongoing Cambridge area re-signalling project will abolish Dullingham, Chippenham Junction and Bury St. Edmunds signalboxes and transfer control to Cambridge, so it will then gain another fringe (in addition to Hethersett) with Colchester PSB somewhere east of Bury (and obviously lose the Dullingham and Chippenham Junction fringes). See https://www.networkrail.co.uk/runni...y-in-anglia/cambridge-resignalling/#our-plans

Romford ROC does not have any Signalling staff in the building, and is unlikely too either, no room, Cambridge / Liverpool St / Colchester etc are for all intents mini-ROC'S (pebbles)

 

[ac6000cw]

Romford ROC doesn't fringe with Cambridge PSB its still Liverpool Street IECC. Romford has no signalling staff there only controls of various TOCs.

Romford ROC does not have any Signalling staff in the building, and is unlikely too either, no room, Cambridge / Liverpool St / Colchester etc are for all intents mini-ROC'S (pebbles)

Thanks for the corrections - I wasn't sure myself.

Where will the new boundary/fringe (after the re-signalling project is complete) with Colchester PSB be on the line towards Ipswich?

 

[LAX54]

Thanks for the corrections - I wasn't sure myself.

Where will the new boundary/fringe (after the re-signalling project is complete) with Colchester PSB be on the line towards Ipswich?

Notg 100% sure as I am not at Colchester anymore, but I think it's just Ipswich side of Bury St Eds, will be axle counters too

 

[ac6000cw]

Notg 100% sure as I am not at Colchester anymore, but I think it's just Ipswich side of Bury St Eds, will be axle counters too

Thanks - so probably where the current Bury/Colchester boundary is (which is logical).

I was only wondering about it because this NR graphic suggests that Cambridge control will extend to the east of Elmswell (but says Thurston in the text at the bottom!):

 

[Steve Harris]

...and AFAIK also fringes with York ROC (south of Meldreth on the line to Kings Cross), Littleport (towards Kings Lynn), Liverpool Street IECC (north of Stansted on the line to Liverpool Street), Dullingham (towards Newmarket) and Chippenham Junction (from the Soham line).

But the ongoing Cambridge area re-signalling project will abolish Dullingham, Chippenham Junction and Bury St. Edmunds signalboxes and transfer control to Cambridge, so it will then gain another fringe (in addition to Hethersett) with Colchester PSB somewhere east of Bury (and obviously lose the Dullingham and Chippenham Junction fringes). See https://www.networkrail.co.uk/runni...y-in-anglia/cambridge-resignalling/#our-plans

(Correction - changed Romford ROC to Liverpool Street IECC)

I think you will find the boundary is closer to Royston than Meldreth. In fact, it's very close to the A505 (Royston bypass), slightly to the north of Royston.

 

[ac6000cw]

I think you will find the boundary is closer to Royston than Meldreth. In fact, it's very close to the A505 (Royston bypass), slightly to the north of Royston.

Thanks - original post changed to 'just north of Royston'

 

[LAX54]

Thanks - so probably where the current Bury/Colchester boundary is (which is logical).

I was only wondering about it because this NR graphic suggests that Cambridge control will extend to the east of Elmswell (but says Thurston in the text at the bottom!):

View attachment 144022

It can't really be Elmswell, that would cause a nightmare of a situation for Stowmarket Gate Box, talking to both Cambridge & Colchester. (although they could do it that way !)
Colchester's first signal (679 Auto) is at Thurston, so that would be logical

 

[ac6000cw]

It can't really be Elmswell, that would cause a nightmare of a situation for Stowmarket Gate Box, talking to both Cambridge & Colchester. (although they could do it that way !)
Colchester's first signal (679 Auto) is at Thurston, so that would be logical

I also think the boundary is going to be between Bury and Thurston (and the info on the NR web page is a bit confused/confusing). The current situation in that area is in the diagram below (a snapshot from OpenTrainTimes) - I assume signals 679 & 680 are Colchester PSB, 17 & 50 are Bury St. Edmunds box?

 

[LAX54]

I also think the boundary is going to be between Bury and Thurston (and the info on the NR web page is a bit confused/confusing). The current situation in that area is in the diagram below (a snapshot from OpenTrainTimes) - I assume signals 679 & 680 are Colchester PSB, 17 & 50 are Bury St. Edmunds box?

View attachment 144109

yes CO680/ CO679 are Colchester (both Auto signals currently) the other two are BY17 and BY50 (Bury)

 

[ex-probationer]

yes CO680/ CO679 are Colchester (both Auto signals currently) the other two are BY17 and BY50 (Bury)

I seem to remember the boundary was close to Cattishall crossing, approx half-way between Thurston and Bury, when I was leading an Ipswich based S&T Fault team in the mid 1980's.