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Table of Contents

Watford Junction
Up Fast Approach
Emergency Replacement Switches 182 / 766 and 183 / 768
Available Routes and Via Buttons
Watford Yard Ground Frame (4002)
Watford North Ground Frame (4003)
Crossovers at Watford
Line Speeds
Entry Points
Signal Box Prefix Codes
Version History
Version 1.1 (released 01 / 08 / 2014)
Version 1.0 (released 18 / 07 / 2014)

Watford Junction


Watford Junction PSB opened during 1964 as part of the resignalling of the southern end of the West Coast Main Line. Originally controlling from Bushey (fringing with Willesden PSB) to Cheddington (fringing with Bletchley PSB), the box's area has been cut back substantially to the area between Bushey and Apsley. This simulation represents its last days as an independent signalbox before it is scheduled to be resignalled and recontrolled from a new panel in Wembley Main Line signalbox. The latter will then fringe to Rugby SCC (to the ironically-named Watford desk) at roughly the same location as Watford Junction PSB.

An important location on the busy four track West Coast Main Line from London Euston to the north, this area sees the fast trains flying through, only being on your panel for a few minutes, before passing to the next signalbox. However, incidents can occur which rely on you doing some regulation in order to keep the trains moving as best as possible.

The St. Albans Abbey branch is included but apart from entering the train onto the branch in the morning and taking it off in the evening, there is not a whole lot to do! There are no train describers on the branch so Sticky Notes should be used to keep track of which headcode is currently in operation.

The simulation is suitable for one-person operation and is fairly easy so is suitable for those new to SimSig. Chaining is possible to the following:

  • Wembley Main Line
  • Wembley Suburban
  • Rugby SCC


Up Fast Approach

A slightly unusual indication on the real Watford Junction panel is the track through Apsley platform 2 on the Up Fast. The approaching tracks are combined into one indiction such that it becomes occupied when a train is approaching either of signals WT3134 or WT3138. The TD berth will still step through the two signals.

Emergency Replacement Switches 182/766 and 183/768

Each of these switches replace both signals indicated.

Available Routes and Via Buttons

Not all theoretically possible routes are provided, as per the real interlocking. For example, the only route from WJ2009 is along the Up Fast to WJ2007. It is not possible to get from platform 9 at Watford Junction into the Neck.

Via buttons must be used when there is a possibility of using either crossover between the Up Fast and the Down Slow. These routes are:

  • WJ2004 to WJ744
  • WJ756 to WJ744
  • Both routes can be set via B or via C.

Watford Yard Ground Frame (4002)

Lever Operates Notes
1 Release Once the signaller releases the ground frame, this lever can be reversed to operate the ground frame
2 Branch Points This controls the point between siding 1 and the St. Albans branch
3 Signal WJ752 Once the signaller has operated the co-operative control on signal WJ752, this can be operated to show a proceed aspect on that signal
4 Hand Points 3-7 This hand point gives access to sidings 3-7. It is simulated in the frame for easy access but does not require a release to operate.

Sending a Train on to the Branch

With a train approaching signal WJ759, first (as the signaller) operate the release for ground frame 4002 by left-clicking on the green F circle. As a shunter, take the release by reversing lever 1. Reverse the point towards the branch by reversing lever 2. Set a route from signal WJ759 to the exit triangle near signal WJ2002. Note that there are no train describer berths on the branch line. The train will proceed onto the branch, disappearing momentarily as it traverses the non-track-circuited section.

Once the train has arrived complete at platform 11, normalise the branch points by normalising lever 2. Normalise lever 1 to give the frame back to the signaller. The signaller can then right-click on the white F roundel to restore the ground frame to normal.

Getting a Train off the Branch

With the train at a stand at platform 11, as a signaller release the ground frame by left-clicking on the green F circle for ground frame 4002. As a shunter, take the release by reversing lever 1. Reverse the point from the branch by reversing lever 2. As a signaller, left-click the co-operative plunger next to signal WJ752. As a shunter, give the train a proceed aspect on signal WJ752 by reversing lever 3. As a signaller, when ready, set route from signal WJ2002 to the train's next location. Once the train is clear of the trackwork the shunter may restore the ground frame by normalising levers 3, 2, and 1 in that order. The signaller can then take back the frame by right-clicking on the white F roundel.

Watford North Ground Frame (4003)

Lever Operates Notes
1 Release Once the signaller releases the ground frame, and a 3 minute timeout has expired, this lever can be reversed to operate the ground frame.
2 Branch Points This lever operates the points leading off the running line into the sidings.
3 Siding Points This lever operates the points determining which siding to access.
4 Signal WJ50 This lever operates the subsidiary aspect on signal WJ50. The branch points must be reversed before this lever can be pulled.
5 Top Siding Handsignal This gives the driver of a train in the top siding a handsignal to indicate it is safe to proceed. As this is a handsignal, it is not interlocked with the frame so be careful using it!
6 Bottom Siding Handsignal This gives the driver of a train in the bottom siding a handsignal to indicate it is safe to proceed. As this is a handsignal, it is not interlocked with the frame so be careful using it!

Crossovers at Watford

The single lead ladder immediately south of the platforms was removed during the Watford blockades in August 2014.

Pending renewals, most of Watford North Junction was taken out of use during the same period on 18 August 2014, with only the Down Slow to Up Slow trailing crossover (3034/3035 points) remaining operational. On 7 April 2015, that remaining crossover was taken OOU as well, with the whole junction remaining inoperative until further notice.

The connection to the St. Albans Abbey line was also remodelled in August 2014, with it now directly branching off the connection to platform 10, however this change is currently not modelled within the simulation.

Line Speeds

  • The Fast lines are 110mph throughout, plus EPS-enhanced limits of 125mph south of Bushey and north of Kings Langley.
  • The Slow lines are mostly 90mph with a 75mph restriction through Watford Junction and an 80mph restriction near Bushey.
  • Watford South Junction is rated at 50mph fast to slow and vice versa on the double lead, and just 15mph on the single lead.
  • Watford North Junction is rated at 50mph fast to slow and vice versa.
  • The St. Albans Abbey branch is 50mph once north of Watford North.

Given the linespeed of the single lead junction immediately to the south of Watford Junction, it would be better to use the faster Watford North Junction instead if crossing from fast to slow or vice versa.


Down fast/slow trains should enter at the Wembley Central departure/passing time. Down DC trains should enter at the Watford High Street departure/passing time. Up fast/slow trains should enter at the Bourne End Junction passing time.


Name TIPLOC ID Notes
Bricket Wood BCWD
Bourne End Jn BONENDJ
Garston GRSTH
Hemel Hempstead HEMLHMP
Harrow & Wealdstone HROW
Kings Langley KLGL
Kings Langley Loop KLGLLP
Wembley North Jn NWEMJN
Park Street PKST
St. Albans Abbey STALBNA
Watford High St WATFDHS
Watford Jn WATFDJ
Watford North WATFDN
Watford North Jn WATFDNJ
Watford Yard WATFDY
Watford South Jn WATFJSJ
Watford Neck WATFNCK
WJ2001/WJ2009 WJ2001 For reversing at signals WJ2001 or WJ2009
WJ2016/WJ2018 WJ2016 For reversing at signals WJ2016 or WJ2018
Wembley Central WMBY

Entry Points

Name Entry Point ID Notes
Down Suburban EDNSUB
Watford Yard EWATYRD


ID From To Notes
R2001AS S2001 S765
R2001BS S2001 S767
R2001CS S2001 S769
R2001DS S2001 S754X
R2001ES S2001 S2002X
R2002AS S2002 S2003X
R2002BS S2002 S746
R2002CS S2002 S744
R2003AS S2003 S765
R2003BS S2003 S767
R2003CS S2003 S754X
R2003DS S2003 S2002X
R2004AS S2004 S2003X
R2004BS S2004 S746
R2004C1S S2004 S744
R2004C2S S2004 S744
R2005AS S2005 S761
R2006AS S2006 S2004
R2006BS S2006 S744
R2006CS S2006 S2005X
R2006DS S2006 SWS74
R2007AS S2007 S765
R2009AS S2009 S2007
R2016AS S2016 S756
R2016BS S2016 S758
R2016CS S2016 S2006
R2018AS S2018 S750
R2018BS S2018 S756
R71AS S71 S71X
R72AM S72 S183
R73AM S73 S183
R748AS S748 S2003X
R748BM S748 S746
R748CM S748 S744
R74AC S74 S73
R74AM S74 S73
R74BM S74 S72
R750AM S750 S746
R750BM S750 S744
R754AS S754 S2003X
R754BM S754 S746
R754CM S754 S744
R755AM S755 S759
R755AW S755 S759
R756AS S756 S2003X
R756BM S756 S746
R756C1M S756 S744
R756C2M S756 S744
R757AM S757 S761
R757BM S757 S767
R757CM S757 S754X
R758AM S758 S748
R759AM S759 S765
R759BM S759 S767
R759CM S759 S769
R759DC S759 S754X
R759DM S759 S754X
R759ES S759 S2002X
R761AM S761 S765
R762AM S762 S750
R762BM S762 S758
R764AM S764 S750
R765AM S765 S775
R767AM S767 S775
R767BM S767 S777
R769AM S769 S777
RWS309ES SWS309 S761
RWS77EM SWS77 S761


Although every effort is taken to check external content, the links below are provided without any claims of quality or appropriateness.

Signal Number Plan

These are Adobe Acrobat PDF files. If you don't have Adobe Acrobat Reader installed on your computer you can get a free download of the latest version from the Adobe website . When checked during June 2014, it had reached v11 and the download size was just over 70MB.

Signal Box Prefix Codes

Code Box
WM Wembley Mainline*
WS Wembley Suburban*

*Fringe Box, signals not controlled in this simulation.

Non-prefixed signals are controlled by Watford Junction (WJ)



Peter Bennet's photostream Detailed panel photos of Watford Junction PSB


Class 86 Action x 9 @ Watford Jn, 02-10-13 YouTube video taken on the platforms at Watford Junction
87005 London Euston - Watford Junction Driver`s Eye View YouTube video taken over the driver's shoulder
St Albans Abbey to Watford Junction *Drivers Eye View* Video taken from secondman's position on a 321.


Many thanks to PP (Guts) for his help in ensuring the simulation is as realistic as possible. Thanks also to Peter Bennet, Stephen Fulcher, and the ICT group for testing and timetabling.

Version History

Version 1.1 (released 01/08/2014)

Ticket number Summary
11301 Watford North GF release not prevented by TC occupancy
11156 Sig 2002 & 2003 should have opposing locking ommitted
11139 Adjacent Boxes not labelled
11132 Train finds buffer stops from WJ752 over ground frame
10842 WJ182BR should be tri-state

Version 1.0 (released 18/07/2014)

First release. No known issues.

Last edited by GeoffM on 15/09/2016 at 03:00