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Interlocking machine room

From Wikipedia, the free encyclopedia

An Interlocking machine room (IMR) is a component of the London Underground signalling system. Interlocking is an arrangement of signal apparatus that prevents conflicting movements through an arrangement of tracks such as junctions or crossings. On the London Underground signals and points are operated and controlled by an array of electrical, pneumatic and mechanical components.[1] IMRs are unmanned and generally located adjacent to points or at platform ends, and provide a secure and weatherproof enclosure for pneumatically controlled mechanically and electrically interlocked levers mounted horizontally in an upright lever-frame or with a converted manual lever frame.[2][3]

Liverpool Street Interlocking Machine Room

The table below is an alphabetical listing of the extant Interlocking Machine Rooms on the London Underground network in August 2024.[4]

London Underground operational Interlocking machine rooms
IMR Code IMR name / location LU Line Location Multiple codes controlled
BB Queen's Park Depot Bakerloo
BD Paddington Bakerloo in middle of platform
BM Baker Street Bakerloo
BP Piccadilly Circus Bakerloo
BR BS Waterloo Bakerloo
JB Harrow-on-the-Hill North Subsidiary Metropolitan
JB Harrow-on-the-Hill South Subsidiary Metropolitan
JF Northwood Metropolitan
JJ Watford South Junction Metropolitan
L King's Cross Piccadilly
MM Neasden Depot Metropolitan Jubilee
JB Harrow-on-the-Hill Metropolitan within manned cabin JB subsidiaries and JF
JP Watford Metropolitan
JP Rickmansworth Metropolitan within manned cabin JP, JJ
JT Chalfont & Latimer Metropolitan
JW Amersham Metropolitan within manned cabin JW, JT
MD Finchley Road Metropolitan was MD JB
MG JG Wembley Park Metropolitan
MP Rayners Lane Metropolitan Piccadilly With manned Cabin MU, MW
MU Ruislip Siding Metropolitan Piccadilly
MW Uxbridge Sidings Metropolitan Piccadilly
PB Green Park Piccadilly at end of platform
PD Holborn Piccadilly
PG Wood Green Piccadilly at end of platform
PJ Arnos Grove Piccadilly
PK Oakwood Piccadilly inside former cabin
PM Cockfosters Piccadilly inside former cabin
WD Hammersmith District Piccadilly
WF Parsons Green East District
WF Parsons Green West District
WG Putney Bridge District
WK Waterloo Waterloo and City inside former cabin
WK Turnham Green District Piccadilly
WL Acton Town (East) District
WL Acton Town (West) District
WM Ealing Common District
WM Hanger Lane junction District
WP Ealing Broadway District inside former cabin
WR Northfields Depot Piccadilly
WS Boston Manor Piccadilly
WT Hounslow Central Piccadilly
WV South Harrow Piccadilly
WW Hatton Cross Piccadilly at end of platform
WY Heathrow Terminals 2 and 3 Piccadilly at end of platform
WZ Heathrow Terminal 5 Piccadilly

As London Underground train control is modernised[5] and updated some Interlocking Machine Rooms are made redundant. The table below is an alphabetical listing of the IMRs on the London Underground network that were operational in 1994[6] but had been decommissioned by August 2024.[7][8][9][4]

London Underground decommissioned Interlocking machine rooms
IMR Code IMR name / location LU Line Location Multiple codes controlled Decommissioned
AC Colindale Northern at end of platform 2008-19
AE Edgware Northern inside former cabin 2008-19
B Kennington Northern 2008-19
B Shoreditch East London 2002-08
C Charing Cross Northern inside former cabin 2008-19
CG White City Central within manned cabin EAB, NOA 1994-2002
E Camden Town (Platform 1) Northern 2008-19
E Camden Town (Platform 4) Northern 2008-19
EAB Ealing Broadway Central 1994-2002
ET Canal Junction (south of Surrey Quays) East London within manned cabin 1994-2002
ET New Cross Gate East London 1994-2002
F Hampstead Northern inside former cabin 2008-19
FB Bromley-by-Bow District
FC Plaistow District
FE East Ham District
FF Barking District within manned cabin FB – FG
FF Barking Sidings West District
FF Barking Sidings East District
FG Dagenham East District
FJ Hornchurch District
FM Upminster District within manned cabin FJ – FM
FM Upminster West District
G Golders Green South Northern 2008-19
G Golders Green North Northern 2008-19
HON Holborn Central 1994-2002
JE Willesden Green Metropolitan Jubilee
JL Stanmore Sidings Jubilee 2008-19
JP Rickmansworth Metropolitan within manned cabin JP, JJ
LB Liverpool Street Central in manned cabin in middle of platform 1994-2002
LC Bethnal Green Central in manned cabin in middle of platform 1994-2002
LF Leytonstone Central in manned cabin 1994-2002
LJ Woodford Central in manned cabin 1994-2002
LL Hainault Central in manned cabin Also controlled LL Grange Hill subsidiary area 1994-2002
LP Newbury Park Central in manned cabin 1994-2002
LT Loughton Central in manned cabin 1994-2002
LU Debden Central in manned cabin 1994-2002
LW Epping Central in manned cabin LW, LX 1994-2002
LX North Weald Central in former manned cabin 1994-2002
M Moorgate Northern inside former cabin 2008-19
MAA Marble Arch Central 1994-2002
NN Archway Northern inside former cabin 2008-19
NOA North Acton Central 1994-2002
NOR Northolt Central at end of platform 1994-2002
NP East Finchley Northern inside former cabin 2008-19
NQ Finchley Central Northern inside former cabin 2008-19
NU High Barnet Northern inside former cabin 2008-19
OP Edgware Road Metropolitan within manned cabin 2008-19
OZ Hammersmith Metropolitan within manned cabin 2008-19
QUE Queensway Central at end of platform 1994-2002
RUG Ruislip Gardens Central 1994-2002
TF Green Park Jubilee 2008-19
TG Charing Cross Jubilee at end of platform 2008-19
U Stockwell Northern 2008-19
VE Brixton Victoria at end of platform 2008-19
VF Victoria Victoria at end of platform 2008-19
VG Warren Street Victoria at end of platform 2008-19
VH King's Cross St Pancras Victoria at end of platform 2008-19
VJ Highbury & Islington Victoria 2008-19
VK Finsbury Park Victoria
VL Seven Sisters Victoria 2008-19
VN Northumberland Park Depot Victoria 2008-19
VP Walthamstow Central Victoria at end of platform 2008-19
W Tooting Broadway Northern at end of platform 2008-19
WER West Ruislip Central within manned cabin WER, RUG, NOR 1994-2002
WB West Kensington East District Piccadilly inside former cabin
WC West Kensington West District Piccadilly
X Angel Northern in former manned cabin at end of platform 1994-2002
Y Morden Northern 2008-19
EN Whitechapel District within manned cabin 2021
EC Earl's Court District at end of platform 2022
ED High Street Kensington District 2022
ED Triangle Sidings (Kensington) District 2022
EE Gloucester Road District 2022
EF South Kensington District 2022
EG Mansion House District 2021
EH Embankment District at street level 2021
EJ Tower Hill District in middle of platform 2021
MB Baker Street Metropolitan under platforms 1 & 2 2019
ML Swiss Cottage Metropolitan 2019
OB Aldgate District Metropolitan 2021
OD Liverpool Street Metropolitan inside former cabin 2021
OE Moogate Metropolitan 2021
OH Farringdon Metropolitan 2021
OJ King's Cross St Pancras Metropolitan at end of platform 2021
L King's Cross Northern inside former cabin
J Euston Northern

See also

[edit]

Interlocking

Liverpool Street signal box

References

[edit]
  1. ^ "TfL Behind the scenes: signalling". 24 July 2019. Retrieved 7 November 2019.
  2. ^ "Evening Standard - Underground is in Deep Trouble". 10 April 2012. Retrieved 9 November 2019.
  3. ^ "Westinghouse Brake & Saxby Signalling". Retrieved 9 November 2019.
  4. ^ a b Brailsford, Martyn (August 2024). Railway Track Diagrams Book 5: Southern and TfL (Fifth ed.). Frome: Trackmaps. pp. 40–47. ISBN 9781999627171.
  5. ^ "Transport for London computer system that is used to manage your rail network". Retrieved 7 November 2019.
  6. ^ Jacobs, Gerald (1994). Railway Track Diagrams England South and London Underground. Exeter: Quail Map Company. pp. 37–46. ISBN 1898319073.
  7. ^ Jacobs, Gerald (2008). Railway Track Diagrams Book 5 Southern and TfL. Bradford on Avon: Trackmaps. pp. 37–47. ISBN 978-0-9549866-4-3.
  8. ^ Munsey, Myles (2019). Railway Track Diagrams Book 5 Southern and TfL. Frome: Trackmaps. pp. 40–47. ISBN 978-1-9996271-2-6.
  9. ^ Jacobs, Gerald (2002). Railway Track Diagrams England South and London Underground. Exeter: Quail Map Company. pp. 37–46. ISBN 1898319529.