logoSignal box prefix codes

A (hopefully) comprehensive listing

Irish signal boxes

Last update 4 August 2018

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:

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This listing includes both Northern Ireland Railways/Translink and Iarnród Éireann/Córas Iompair Éireann signals.  Instances where a prefix is known but its controlling signal box is not are shown at the end of the table.

Code Signal Box Note
AD Adelaide  
AN Antrim  
AE Athlone  
AE R Distant signals
XG Level crossing signals
BY Ballybrophy  
NBX Ballycoskerry Crossing Automatic signals 'numbered' NBX DS and NBX US
BA Bangor  
CL Belfast Central  
BH Birdhill  
BWX Bishopswood Crossing Automatic signal 'numbered' BWX UD
BG Bleach Green  
BN Booterstown  
BR Bray  
C Castlebar  
R Distant signals
CS Carrickfergus?  
- Carrick-on-Suir Semaphore signals; no prefix
CK Castlerock  
RC Charleville Prefix derived from Irish name 'Rathluirc'
RC R Distant signals
CY Cherryville Junction  
CY R Distant signals
CR Church Road Downgraded to shunt frame 7 July 1991
CA Clara  
CA R Distant signals
XA Ashfield Crossing
CL Clonmel Semaphore signals; prefix not carried
CL Clonsilla Also manages Dublin West (DW) and Maynooth (MN) signals
CN Clonydonnin  
CN R Distant signals
CE Coleraine  
CY Connolly New panel installed 22 May 1983.  Also manages Geashill (CY-GH) and Portlaoise (CY-PE) signals
C Connolly Central  
EW Connolly East Wall  
S Connolly Station  
CW Connolly West  
WR Connolly West Road  
WR R Distant signals
CK Cork  
CK R Distant signals
CE Cork East (uncertain; near Midleton)  
DK Dalkey  
DA Drogheda  
DN Dromkeen  
DN R Distant signals
DC Dublin Central  
DS Dublin Docklands  
DN Dublin North  
DL Dun Laoghaire  
DD Dundalk  
FL Fingal  
XF Foynes Level crossing signals
GL Galway  
GL R Distant signals
XG Level crossing signals
HN Heuston Named Dublin Kingsbridge to 9 April 1966
HN BR Banner repeater signals
HN R Distant signals
HK Heuston-Kildare main line  
HJ Howth Junction Named Junction to 30 June 1912
KN Killagan?  
KR Killester  
KJ Killonan Junction  
KJ R Distant signals
L Lagan or Larne  
PL Laois Train Care Depot  
LY Liffey Junction  
LJ Limerick Junction  
LJ R Distant signals
LJ S Limerick Junction (South)  
LK Limerick Station  
LK R Distant signals
LKCK Limerick Yard  
LF Lisduff  
LF R Distant signals
LNX Lisnolan level crossing Automatic signal 'numbered' LNX DS
LY Londonderry  
MH Malahide  
ND Malahide (North Dublin)  
MW Mallow Unclear whether this was previously North or South signal box
MW R Distant signals
MJ Manulla Junction  
R Distant signals
ML Code in use 2015
ML Mayo Line (Athlone to Westport and Ballina)  
ML R Distant signals
XM Level crossing signals
R Moathill Crossing Distant signals
MR Moira  
NN Navan  
PD Portadown  
PN Portarlington  
PN R Distant signals
PH Portrush  
RP Rathpeacon  
RP R Distant signals
- Roscrea Semaphore signals; no prefix
RL Rosslare Line (Greystones to Rosslare)  
RS Rosslare Strand  
RS R Distant signals
SL Sligo Line (Maynooth to Sligo)  
TK Templepatrick?  
TNX Thomastown Level Crossing Automatic signals 'numbered' TNX DD and TNX UD
TS Thurles ECP  
TS R Distant signals
TY Tipperary  
TL Tralee Line (Mallow/Killonan Junction to Tralee)  
TL Tullamore  
TL R Distant signals
XA Level crossing signals
WL Waterford Line (Cherryville Junction to Waterford West)  
WL R Distant signals
XW Level crossing signals
WT Waterford West  
WT R Distant signals
WD Whitehead  
YR York Road  
BN Unknown NIR signals   
BY Unknown NIR signals   
CLN Unknown NIR signals   
CLRR Unknown NIR signals   
CLS Unknown NIR signals   
CLX Unknown level crossing near Ballybrophy  Automatic signal 'numbered' CLX DD
DA Unknown NIR signals   
FL Unknown near Howth Junction/Malahide   
FP Unknown near Glasnevin Junction/Heuston   
FP Unknown near Waterford   
GVS Unknown NIR signals   


  1. CIÉ operational documents sometimes show distant signals with only the prefix R.  It is understood that this may be a convenient shorthand; the current standard is for the signal plate to carry the full code (e.g. Athlone signals carry AE R).  However, for signal boxes closed before current standards came into force, this may not be the case.
  2. CIÉ shunt signals carry the suffix (S) if they are attached to a main signal (e.g. Galway signal GL378 carries shunt signal GL378(S)).


Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Non-National Rail | Ireland | Western region MAS dates | Mechanical signalling bell codes