Im not sure if this has come up but which Signal Boxs have the shortist / longist area of covered by them and which Power Box's has the shortist / longist area covered by them.
By this I mean track miles
From memory, simplified control areas of major Power signals boxes are:
Plymouth: Liskeard (ex) - Totnes (ex and branches)
Exeter: Totnes - Altheney/Bridgewater area
Westbury: Berks and Hants and connections, Westbury-Altheney
Reading: Didcot East - Ruscombe and Berks and Hants to Westbury (ex)
Slough PSB: Ruscombe - West Drayton
Slough IECC: West Drayton - Paddington and Heathrow branch
Swindon B IECC: Didcot area, Uffington-Didcot East and Radley
Oxford: Radley-Heyford, Bicester line, Cotswold line to Ascot-u-Wychwood
Swindon: Uffington - Chippenham and near Chipping Sodbury
Bristol: Bridgewater-Charfield/Box-Severn Tunnel and connections
Newport/Port Talbot/Cardiff, undergoing resignalling - S Wales main line
Gloucester: Charfield-Bromsgrove and connections
Three bridges: East Croydon-Brighton and connections
Victoria (situated at Clapham): South London area/Victoria station/Sevenoaks (ex)
London Bridge: Charring cross/Canon street/London Bridge, SE London area
Wimbledon: Waterloo to near Surbiton and Windsor lines
Ashford IECC: HS1, parts of SE London and parts of Kent
Woking: Working area, Surbiton-Fleet
Basingstoke: Basingstoke area, Fleet-West of Worting Junction
Salisbury: Salisbury area, Tisbury Loop
Eastleigh: Worting Junction (ex) - Totton and connections
Brockenhurst: Brockenhurst area
Bournemouth: West of Brockenhurst - Parkstone
Dorchester: Dorchester and Weymouth, small SSI panel in former signalbox
Portsmouth (situated at Havant), Portsmouth area
Guildford: Guildford area
Feltham: Kew-near Wokingham
Wembley Main line: Euston-Bushey
Willesden suburban: DC lines WCML London area
Rugby SCC: Kings Langley- south of Colwich (Armitage) and west of Trent Valley junction (small areas of 1960s signalling still exist at Watford and Bletchley controlled by the respective PSBs)
Stoke SCC: Stoke area, North Staffs to Congleton, Norton Bridge area
Manchester South: Edgeley-near Crewe and Style line
Manchester Picadilly: Heaton Norris Junction-north of Bolton, including Picadilly
Huddersfield: Huddersfield area
Manchester Victoria: Parts of North Manchester including Victoria
West Mids Signalling centre: Coventry area, Saltley - Warwick and Birmingham Moor street and Snow hill. Due to control whole of West Midlands area
East Mids Signalling centre: Lines north of Nottingham: Due to control whole of East Midlands area
Sheffield: Conisborough-Chesterfield and connections
Derby: Ambergate - South of Burton-on-Trent and Spondon
Trent: Nottingham area, Toton, connections to Loughborough (ex)
Leicester: Loughborough (inc) - Sharnbrook summit north of Bedford
West Hampstead: St Pancras - Sharnbrook summit and connections
Marylebone IECC: Marylebone-Aynho (south of Banbury) and Aylesbury, excluding met lines
Leamington: North of Banbury-Warwick
Crewe: Crewe station area
Chester: Chester area
Warrington: North of Weaver Junction - South of Preston
Preston: Leyland area to Carnforth (inc)
Carlisle: Carnforth-Scots border
Sandhills IECC: Liverpool suburban area
Birmingham NS: Birmingham International - Soho, and loop, including New Street.
Aston: Small PSB for north part of cross city line
Saltley: Water Orton to near Burton (being progressively replaced) and to Reddich
Wolverhampton: Soho-Penkridge
Walsall: Walsall area
Kings Cross: Kings Cross-Sandy (ex) including Hertford Loop
Peterborough: Sandy (inc) - Stoke tunnel
Doncaster: Stoke tunnel - Aldwick/Shaftholme and connections
York IECC: Shaftholme - Danby Wiske ECML, Leeds area, Bradford area, North of Skipton
Tyneside IECC: Danby Wiske - South of Morpeth ECML and Sunderland
Morpeth: Morpeth area
Alnwick: Alnwick area
Tweedmouth: Berwick area - Scots border
Cambridge: North of Stansted airport connections - North of Ely and connections
Liverpool Street IECC: GEML - South of Manningtree, Southend area, Cambridge line to Bishop stortford
Colchester: Manningtree - Norwich and connections and Clacton area
Scunthorpe: Scunthorpe area
Lincoln: Lincoln area
Upminster IECC: London, Tilbury and Southend
Edinburgh: Scots border- Cupar and Falkirk (ex)
Dundee: Dundee station area
Aberdeen: Aberdeen station area
Inverness: Inverness station/Culloden, RETB post of Far north
Yorker IECC: North Glasgow Suburban
West of Scotland SC: Parts of Glasgow, including Central and Queen street, to be progressively extended
Motherwell: North of Motherwell - Scots Border
Aviemore: Highland main line Kingussie-Moy
There are a lot of smaller panels not mentioned, and RETB block posts at Banavie (West Highland line), Saxmundham, and Cambrian lines.
LUL signalling is:
Central: White city
Jubilee: Neasden
District/Picadilly/parts of Circle: Earls court
Victoria/Northern lines: Cobourg Street (Euston)
Bakerloo line: Baker Steet
