Signal box prefix codes

A (hopefully) comprehensive listing

'Boxes beginning N

Last update 14 April 2025

Additional information is always gratefully received, whether entirely new records (particularly historical records) or information to fill in gaps or correct errors, via the contact link under the Miscellaneous entry in the navigation bar above. Thank you.

Please select a starting letter from the links below:

Code Signal Box Note ELRMileage Opened Closed Control to
N Naburn Code probably used from 1951 TCW2≈184m 20ch 2 April 1967 York [PSB] (Y)
R Distant signals
U Up line automatic signals
Nafferton HBS21m 43ch ? 26 November 1989 Driffield (D)
Nailsea & Backwell Named Nailsea East to 1905 MLN1126m 37ch 1876 4 December 1971 Bristol (B)
Nailsea East See Nailsea & Backwell
NA Nairn ANI3128m 72ch 10 April 2000 7 October 2017 Inverness (HN)
Nairn East ANI3128m 63ch 1891 10 April 2000 Nairn (NA)
Nairn West ANI3129m 04ch 1891 10 April 2000 Nairn (NA)
NH Nantwich SYC4m 19ch 1948 or 1954 12 October 2013 South Wales Control Centre (SC)
NR Narborough WNS11m 65ch 1875 28 July 2006 Croft (CT)
NH
NN Navigation Road CDM17m 06ch 1882 7 July 1991✖full replacement signalling into use 22 July 1991 Deansgate Junction (DJ)
NJ Neasden Junction Closed, reopened 1 September 1991 CAW7m 03ch 1899
NS Neasden South Junction MCJ1200m 63ch 1906 22 September 1990 Marylebone [new] (ME)
D Distant signals
NB Neath & Brecon Junction VON41m 21ch 1892 Wales Rail Operating Centre (PT) (planned)
N&B Code reported in 1982 notice, probably in error
NE Neath General East Downgraded to ground frame 1 October 1973 SWM2207m 60ch 5 July 1926 5 May 1977 Port Talbot (PT)
N Neepsend MAC340m 11ch 1888? June 1978✖burnt down
NH Neilston Named Neilston High 2 June 1924 to 6 May 1974 Code used from 1961 NNH108m 45ch 1 April 1903 31 October 1982 Cathcart (C)
Neilston High See Neilston
NJ Netherfield Junction NOG1125m 17ch 30 October 1960 29 July 2013 East Midlands Control Centre (GN, NN)
Neville Hill Depot Merger of east and west consoles 4 February 2001 HUL418m 40ch 1968✖or 27 January 1969?
NHE Neville Hill East Closure date uncertain HUL418m 28ch 6 October 1968 Leeds (L)
NHW Neville Hill West Closure date uncertain HUL418m 74ch 6 October 1968 Leeds (L)
N Code also reported: possibly later code
N Newark Named Newark South to 11 July 1977 Code used from renaming ECM1120m 02ch 12 April 1931 3 February 1980 Doncaster (D)
NS Code when named Newark South
NC Newark Castle NOB116m 79ch 15 September 1912 5 November 2016 East Midlands Control Centre (NN)
X Newark Crossing Earlier code ECM1120m 57ch NOB117m 68ch 5 February 1870 17 May 1981 Doncaster (D)
NC Later code
D Down direction automatic signals
RD Distant to down direction automatic signals
RU Distant to up direction automatic signals
U Up direction automatic signals
NN Newark North ECM1120m 26ch 14 August 1875 27 February 1977 Newark (N)
Newark South See Newark
NB New Barnet Named New Barnet North to 31 May 1970 Code used from renaming ECM19m 19ch 4 April 1895 4 September 1976 Kings Cross (K)
BN Code used to 30 May 1970
DF Down fast line automatic signals
DS Down slow line automatic signals
UF Up fast line automatic signals
US Up slow line automatic signals
New Barnet North See New Barnet
BS New Barnet South ECM19m 01ch 1906 30 May 1970 New Barnet (NB)?
EBO New Beckenham LCH 10 September 1904 27 September 1975 London Bridge (L)
New Brighton BEN7m 06ch 1888 18 September 1994 Merseyrail (ML)
NM Newbury Middle Unclear if code carried BHL52m 78ch 1910 4 March 1978 Reading (R)
N Newcastle ECM680m 16ch ECM70m 00ch 12 April 1959 19 April 1991 Tyneside (T)
B Manors-South Gosforth route signals. Code probably used from February 1964 until taken over by Metro
DN Down north line automatic signals. Code used from February 1964
DT Down Tynemouth line automatic signals. Code believed used from February 1964
R Banner repeater signals. Code used from February 1964
U Up line automatic signals. Code used on line NEN from 6 February 1966
UN Up north line automatic signals. Code used from February 1964
UT Up Tynemouth line automatic signals. Code used from February 1964
N1 Newcastle No 1 Code used from March 1956 12 April 1959 Newcastle (N)
K New Cross Named New Cross A to 30 June 1929 XTD≈4m 60ch 13 December 1903 1 December 1929 North Kent East Junction (K)
New Cross A See New Cross
MC New Cross Gate LBW2m 59ch 8 October 1950 20 July 1975 London Bridge (L)
CA Automatic signals
NC New Cumnock New Cumnock interlocking. Code used from 2002 GSW54m 66ch 1909
NG Greenburn Junction interlocking. Code used from 25 April 2004
A New England Shunting Cabin A Code not confirmed. Gradual cutting back of control from 16 April 1989 PHS? 1902 23 September 1989✖delayed from 16 April 1989 To hand controlled points
New Fishbourne Crossing TBH230m 08ch ? Chichester (CC)
NH Newhaven Harbour STS56m 58ch 1886 1 December 2019✖delayed from 15 April 2015 and again from 11 March 2019 Three Bridges Rail Operating Centre (TLW)
CCO Newhaven Town STS56m 20ch 1879 1 December 2019✖delayed from 15 April 2015 and again from 11 March 2019 Three Bridges Rail Operating Centre (TLW)
NH New Hythe Original code PWS237m 79ch 14 May 1939 5 November 2005 Aylesford (AF)
NW Later code
N Newington [Hull] Hessle Road Junction (HR)
Newland See Newland East
NE Newland East Level Crossing Named Stocks Lane to 1929, then Newland to 1943 WAH126m 23ch April 1900
N Newlands OVE3m 50ch December 1921 12 April 1975 Port Talbot (PT)
WM New Malden BML19m 72ch 1880 8 July 1990 Wimbledon (W)
Newmill See Carmont
NM New Mills Central TTA1173m 11ch 1924
NS New Mills South Junction NMC1172m 17ch 1903
NMS At least two signals
N Newport SWM2158m 36ch 9 December 1962 4 January 2010 in part; 29 October 2012 remainder South Wales Control Centre (NT)
A Magor East and Undy area shunt signals
B Ebbw Junction area signals
DH Down Hereford line automatic signals
DM Down main line automatic signals
DR Down relief line automatic signals
DT Unknown precisely to what signals this code refers
E Newport East area shunt signals
G Gaer Junction area shunt signals
J Severn Tunnel Junction area shunt signals
L Maindee North Junction area shunt signals
NO Code reported in November 1975 notice, probably in error
RS Banner repeater to Llanwern Tippler Siding shunt signals
S Llanwern Tippler Siding shunt signals
U East Usk area shunt signals
UH Up Hereford line automatic signals
UM Up main line automatic signals
UR Up relief line automatic signals
W Newport West area signals
D Newport Down direction automatic signals. Demolished in shunting accident BGK39m 71ch 1884 October 1972 Newport [new] (D)
D Newport [new] Down direction automatic signals BGK39m 71ch 11 November 1972 11 December 1983 Cambridge (CA)
E Newport East SWM2158m 32ch 29 May 1927 9 December 1962 Newport (N)
N Newport East DSN213m 69ch 11 August 1962 Tees (TY)
D Down direction automatic signals
U Up direction automatic signals
W Newport West SWM2158m 61ch 24 June 1928 9 December 1962 Newport (N)
N Newsham South EJM12m 44ch ? 5 August 2024 delayed from 30 May 2024 Tyneside Rail Operating Centre (BA)
N Newton Code used from 1960 WCM295m 53ch 5 September 1960 28 August 1973 Motherwell (M)
NAE Newton Abbot East Unclear whether code carried MLN1213m 79ch 25 April 1926 4 May 1987 Exeter (E)
Newton Abbot West MLN1214m 32ch 3 April 1927 4 May 1987 Exeter (E)
NH Newton Hall ECM568m 00ch December 1964 Durham North (DN)
D Down line automatic signals
U Up line automatic signals
NH Newtonhill Code used from 2002 ECN5230m 59ch 1876 27 April 2019✖last train; official closure 29 April 2019, delayed from 18 March 2019 Aberdeen (A)
N Newton Junction HAJ7m 22ch December 1984 Guide Bridge (GB)
NR Banner repeater signals
NN Niddrie North Named Brunstand Park Junction to 28 November 1926 NDE14m 16ch 9 August 1915 6 May 1973 Portobello (P)
NW Niddrie West SUB26m 34ch 17 June 1900 27 June 1976 Portobello (EP)
N Noblethorpe Gate box: line controlled by Doncaster (D) ECM2161m 34ch ?
NY Norbury Hollow Crossing Some signals have HG (Hazel Grove), most not plated BEJ3m 60ch January 1974
D Normanby Park Scunthorpe (S)?
NN Normanton Station North 'Normanton' 'box closed 19 December 1973: unclear whether Station North or Station South (or neither) TJC3185m 24ch Castleford (CD)
NS Normanton Station South 'Normanton' 'box closed 19 December 1973: unclear whether Station North or Station South (or neither) TJC3184m 79ch Castleford (CD)
NA North Acton ANL4m 15ch 25 August 1940 2 December 1966 Old Oak Common (OO)
N Northallerton Codes used from opening. Slow lines have suffix S ECM530m 09ch 3 September 1939✖built 1937 14 April 1990 York [IECC] (Y)
D Down line automatic signals. Code used until 1974
DF Down fast line automatic signals. Code used from 1974
DS Down slow line automatic signals. Code used from 1974
U Up line automatic signals
UB Up branch line distant signals
UF Up fast line automatic signals
US Up slow line automatic signals
E Northallerton East LEN20m 36ch LEN342m 79ch LLP242m 79ch 6 March 1960 Low Gates (LG)
WDQ Northam Junction BML278m 15ch 8 July 1923 11 October 1981 Eastleigh [new] (E)
NT Northam Junction Traincare Depot Stop boards BML1 10 May 2004
BS Northampton Bridge Street Downgraded to ground frame 10 August 1969. Out of use for some time before official closure, reported as 15 April 2006, but BS signals replaced by RY stop boards in 2012 resignalling BPH4m 57ch March 1907 5 June 2012 Rugby Signalling Control Centre (RY)
DS Northampton Down Sidings HNR≈66m 52ch Northampton No 4 (NH4)
NG Northampton Gateway Strategic Rail Freight Interchange HNR 19 April 2025
NH1 Northampton No 1 HNR65m 53ch NMH0m 56ch July 1881 28 July 1991 Rugby (RY)
NH2 Northampton No 2 HNR66m 05ch or 65m 79ch? January 1882 3 December 1982 Northampton No 3 [new] (NH3)
NH3 Northampton No 3 HNR66m 18ch 1 November 1981 Northampton No 3 [new] (NH3)
NH3 Northampton No 3 [new] HNR66m 18ch 1 November 1981 28 July 1991 Rugby (RY)
NH4 Northampton No 4 HNR66m 59ch ≈June 1885 28 July 1991 Rugby (RY)
WH4 Shown in 1981 weekly notice in error
BH4 Shown in 1981 weekly notice in error
DW North Camp GTW251m 12ch by 1902 7 May 1980 Ash Crossing (FW)
NN Northenden Junction EJN3m 72ch WJP133m 49ch 1881
NJ
NF Northfleet HDR21m 68ch 1891? 14 March 1971 Dartford (D)
Northfleet APCM Control Room See Northfleet Blue Circle
N Northfleet Blue Circle Opened as Northfleet APCM Control Room NFT 14 December 1970 19 March 1993✖last train line closed
A Line A draw ahead signals
B Line B draw ahead signals
C Line C draw ahead signals
K North Kent East Junction XTD4m 34ch 1 December 1929 15 April 1976 London Bridge (L)
A Automatic signals
Northolt Junction East ANL10m 06ch NAJ10m 09ch 1905 29 May 1990 Marylebone [new] (ME)
N North Ormesby MBW10m 38ch 23 December 1990✖believed delayed from 28 October 1990 Middlesbrough (M)
NY Code used from 26 January 1986 when downgraded to gate box
N Northorpe MAC382m 14ch 1886
NP North Pole WLL5m 32ch 1922 4 October 1992 Old Oak Common [new panel] (OO)
NP North Pole IEP Depot WLL9 2014
ND North Pole International Depot WLL9≈5m 50ch 14 February 1994 Depot closed
NRE North Road East MLN1245m 66ch 25 June 1939 26 November 1960 Plymouth (P)
NS North Seaton Downgraded to gate box 2 January 1971: line controlled by Marcheys House (MH) BWC1m 75ch ≈1872 9 Apsil 2024 Marcheys House (MH)
WBR North Sheen Crossing Downgraded to gate box 10 November 1974 RDG19m 12ch 1 January 1895 31 October 1976 Barnes (WBO)
NS North Shore [Stockton-On-Tees] Code used from 1973 LEN360m 47ch 7 December 1986 Bowesfield (B)
R Banner repeater signals
Z North Sidings [Worcester] Code most likely to be merely a note on a signalling plan OWW120m 17ch ?
North Somerset Junction MLN1117m 46ch 22 March 1886 18 July 1970✖delayed from 10 May 1970 Bristol (B)
NP Northumberland Park Downgraded to gate box 10 March 1969 BGK6m 77ch 1 April 1913 24 April 1988 Brimsdown (BD)
NW North Walsham WHC115m 76ch 1896 26 June 2000 Trowse Swing Bridge [new] (TB)
NW North Wembley CWJ8m 60ch 10 December 1988 Willesden Suburban (WS)
NN Norton CHW113m 17ch 3 September 1972 20 September 2021 Frodsham Junction (FJ)
NB Norton Bridge LEC4138m 72ch 8 October 1961 24 June 2004✖last train; official closure 26 June 2004, delayed from 4 May 2004 Stoke on Trent Signalling Centre (NS, SC)
NC Norton Crossing Downgraded to gate box 2 September 1972: line controlled by Warrington (WN) CGJ2≈177m 40ch Warrington (WN)
N Norton (Doncaster) Gate box: line controlled by Doncaster (D) KWS65m 11ch 26 October 1980
NJ Norton Junction Planned closure 10 February 1990 was cancelled OWW117m 26ch May 1908
N Earlier code
NE Norton on Tees East Code reported but not seen on site LEN362m 20ch 1870 6 February 2021✖last train; official closure 10 February 2021 York Rail Operating Centre (NS)
E Code shown on signalling plan
NS Norton on Tees South LEN361m 70ch 1870 6 February 2021✖last train; official closure 10 February 2021 York Rail Operating Centre (NF, NS)
S Code shown on signalling plan
N Norton on Tees Station LEN362m 64ch 1897 6 February 2021✖last train; official closure 10 February 2021 York Rail Operating Centre (NS)
NT Code shown on signalling plan
NW Norton on Tees West STF0m 31ch ≈1921 30 January 2021✖last train; official closure 10 February 2021 York Rail Operating Centre (NF)
W Code shown on signalling plan
NO Norwich [temporary] LTN2≈123m 68ch 2 February 1986 8 June 1986 Norwich Station (NO)
CP Norwich Crown Point Depot Control Cabin NCW0m 25ch 3 October 1982
NO Norwich Station LTN2123m 66ch 8 June 1986 15 March 1987 Colchester [new] (CO)
NJ Norwich Thorpe Junction LTN2123m 62ch July 1886✖inspected 27 April 1886 13 July 1986 Norwich Station (NO)
NP Norwich Thorpe Passenger Yard Code used by 5 October 1985 LTN2≈123m 68ch 1886 1 February 1986 Norwich Station (NO)
PY Code uncertain
NX Norwood Crossing Ground Frame NX signals still thought to be present 2016 PSE147m 71ch ? ? Shirebrook Junction (SJ)
JC Norwood Junction LBW8m 66ch 21 March 1954 28 April 1984 Three Bridges [new] (T)
CA Automatic signals
N Norwood Junction Demolished 26 May 1974 NEC1≈1m 75ch Tyne Yard (TY)
ND Unclear if code used
JC Norwood Junction North LBW8m 35ch 27 January 1904 21 March 1954 Norwood Junction (JC)
CA Automatic signals
N Nostell DOL1170m 35ch 12 May 1929 28 November 1970 South Kirkby Junction (SK)
GY Nottingham Goods Yard NOB1127m 56ch 23 September 1899 6 April 1986 Trent (TT)
GE Nottingham Goods Yard East Shunt Frame TSN2 Trent (TT)
GN Nottingham Goods Yard North Shunt Frame MJT1 Trent (TT)
GW Nottingham Goods Yard West Shunt Frame TSN2 Trent (TT)
NW Nottingham Station West TSN2≈123m 52ch 19 December 1969 Trent (TT)
NN Nuneaton Code used from opening LEC296m 65ch WNS0m 08ch 6 October 1963 8 September 2008 Rugby Signalling Control Centre (CN, NL, NW, RN)
R Banner repeaters
NDS Nuneaton Down Sidings Downgraded to shunt frame 6 October 1963 LEC2≈97m 20ch 12 March 1978 Nuneaton (NN)
MJ Nuneaton Midland Junction NMA11m 31ch WNS0m 58ch 1867? 1 March 1992 Nuneaton (NN)
NUS Nuneaton Up Sidings Downgraded to shunt frame 6 October 1963 LEC2≈97m 10ch August 1976 Nuneaton (NN)
R Nunhead CAT6m 10ch NTL6m 10ch 11 October 1925 17 January 1982 Victoria Signalling Centre (VS)
A Automatic signals
NM Nunnery Main Line Junction NUJ1≈158m 77ch TJC1≈158m 77ch 20 January 1973 Sheffield (S)
RNM Banner repeater signals
U Up direction automatic signals
N Nunthorpe Code not carried MBW14m 30ch 1903
B Battersby point indicators (code is carried)