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Table of Contents

SimSig Cambridge
Sim Versions
Geographical Summary
Electric Traction
Location Specific
Train Service
Main Movements
Timetable locations
Hints and Tips
Known Problems
Splash Screen Photos
Pilotman Working
Known Issues
Reference Section
Platform Lengths

SimSig Cambridge

Dedicated to the memory of Danny Goodrum, died February 2006, who provided me with invaluable help in developing this simulation.

Sim Versions

Version Status Scroll/Views Published Comments
v2.201 Donationware V 12/11/09 No longer available for download
Rel 2.0 Donationware V 29/06/09 No longer available for download
v2.105 Donationware V 14/08/07 No longer available for download
v2.104 Donationware V 21/05/06 No longer available for download

Click on the Version to see any known issues


Title Published Author Comments
Cambridge 1985 v7.21 12/07/07 KurtDS Available from Download section and bundled with v2.201
Cambridge 1985 v7.21 0600 start 12/07/07 KurtDS Bundled with v2.201
Cambridge 1977 v1.1 23/07/07 Peter Bennet Available from Download section and bundled with v2.201
Cambridge Summer 2003 30/08/09 TBC Bundled with v2.201
Cambridge 1985 v7.2 TBC Peter Bennet Available from Download section
Cambridge 2005 Summer SX TBC Noisynoel Available from Download section
Cambridge 2006 SO V2 beta TBC Rushey_platt Available from Download section
Cambridge mixed traction mainline gala, fictional ADD ON 14/06/12 Trainmad091 Available from Download section

Manual – version 0.2 beta Last modified 2006-03-21



This is my first major SimSig simulation (Royston having been a relatively simple one). As my home territory it was an obvious one to start with.

Despite the apparent simplicity of the layout, it’s actually a far busier simulation than it appears. Cambridge is split on to five screens and includes the entire area of the real Cambridge Power Signal Box, plus the Royston area of King’s Cross.

Cambridge is the first simulation to have a large number of AHB, MWL, and telephone crossings. It is also the first to feature “one-touch” routes, where pressing the entrance button is sufficient to set the route; there is no corresponding exit button. Obviously these only appear where there is only one route from a signal.

Legal Stuff

SimSig is for personal entertainment use only and must not be used for any commercial use, including the training of signallers etc. Those who are interesting in the commercial application of this software should look at

SimSig is protected by copyright. No SimSig file may be distribution by any other website, by CD ROM or other media without express written permission from G. Mayo. The only exception is when SimSig files are transferred between private individuals where no charge, fee or profit levied.

This software and is offered as-is, “what-you-see-is-what-you-get”. Errors, omissions, faults or other problems are not covered by any warranty of any kind. Problem reports may be emailed or posted on the forums but action may or may not be taken by the authors, a decision which is up to said authors. SimSig accept no responsibility for any damage that may be caused to computer systems by the software.


SimSig Cambridge attempts to match the real experience as far as possible. Signal, points, and track circuit numbering are all taken from photographs of the real panel and therefore are accurate, as are matters such as overlap locations and available routes. Speed limits are taken from the Sectional Appendix. In particular, the availability or otherwise of “auto” buttons on signals directly matches the prototype.

In general the simulation replicates the situation as of 2005. Any discrepancies from reality are listed in this manual.

Geographical Summary


The area covered by SimSig Cambridge follows the majority of the Great Eastern Railway main line from London Liverpool Street, starting near Stansted and running via Cambridge to Ely and thence towards Peterborough, King’s Lynn, and Norwich (though the control area ends at Manea, Littleport, and Shippea Hill respectively). It also includes three branch routes: the Cambridge to London King’s Cross line as far as Baldock (where it connects to SimSig King’s Cross), the Newmarket branch as far as the passing loop at Dullingham, and the western part of the line from Ely to Ipswich.

The simulation covers the main route on views 1 to 4, while view 5 covers the assorted branches, and view 6 is a simplified representation of the route from Manea to Peterborough. On all views the Up direction is leftwards and the Down direction rightwards.

A quick guided tour follows. It is advisable to open SimSig Cambridge and follow this tour.

View 1

This consists of four stripes making up the 20-odd miles from Stansted North Junction at top left to Shelford at top right. Apart from the reversible platform at Audley End, the loops at Great Chesterford and Whittlesford, and the sidings at the latter and Duxford, the layout is plain track and, you would have thought, be easy to operate. However, this section also has 13 separate level crossings, 6 of which have to be operated for each train, and it is easy for a beginner to find themselves dealing with calls from delayed trains.

View 2

The main part of this screen shows Cambridge station itself – with the famous long platform and central scissors crossover – and the associated sidings and yards. In order to fit the layout on sensibly, the adjacent junctions (Shepreth Branch Junction for the line to Baldock and Coldham Lane Junction for the Newmarket branch) had had to be “folded” into the corners.

View 3

Another screen divided into “stripes”. At the top is Chesterton Junction yard and the connection to the Fen Drayton branch, actually a glorified long siding. In the centre is the long run through the fens from Cambridge to Ely. Finally, the bottom section covers Ely station itself, with the connection to the Ipswich line sneaking in from the bottom left. While most of the activity will be at Ely, the level crossing at Chesterton Fen should not be forgotten.

View 4

The last section of the main line and the complex of junctions north of Ely. Here the line branches into three: towards Manea and thence Peterborough and the ECML, towards Littleport and King’s Lynn, and towards Shippea Hill, Thetford, and Norwich. The Ely loop allows trains to run between the first and the other two while avoiding Ely itself (though few trains do so) and there’s also the connection into Papworth’s sidings. Note the potential for conflicts at the single lead junctions, and be prepared to find that the signalling hinders rather than helps.

View 5

This screen covers the three main branches. At the top we have Chippenham Junction to Ely via Soham, partly double track and partly single and with two private sidings at Snailwell. In the middle is the Newmarket branch as far as Dullingham, with nearly 10 miles of single line and 5 more level crossings (4 on this screen: 2 controlled and 2 AHB). Finally, the two bottom sections are the “branch” – but in fact just as important – line to Royston, Baldock, and King’s Cross, with the Barrington Light Railway and the final controlled crossing at Foxton, and the busy layout at Royston.

View 6

The final view presents a simplified overview of the line from Manea to Peterborough (exclusive), which in reality is controlled by half a dozen mechanical boxes before Peterborough PSB takes over. As this section is included primarily to allow chaining with Peterborough, the little used sidings & crossovers at Manea and Whittlesea are omitted, as are all level crossings on the route, and all signals shown simply as automatics in the appropriate places. The exception to this is March, where a set of Goods loops and sidings exist on both sides of the line, and a triangular junction leading to the TMD and various other yards.


It is beyond the scope of this document to list all the speed limits in the simulation, but they are mostly in the 60 to 90mph range with frequent changes. Several sections have differential limits for passenger and freight trains. Cambridge and Ely station areas are mostly 40mph, while crossovers are mostly 15mph or 20mph.

Electric Traction

The standard 25kV overhead equipment powers much of the area and many of the trains will be using this. Both routes from London are electrified as far as Ely and then towards Littleport. In general, running lines are wired but sidings are not; details are given in the specific locations. The lines to Manea, Shippea Hill, Dullingham, and Chippenham Junction are not electrified.

Location Specific

Stansted North Junction

This is one of the two main entry points from the south. The three Stansted junctions form a triangle joining the airport branch to the main line, but this factor can be ignored for simulation purposes.


Elsenham is the first controlled level crossing in the simulation. Unlike most of the others, it is worked by a local gate keeper. This means that the Cambridge signaller can simply set routes across it well ahead of time (or use the Auto button on the Down line) and not have to worry about delaying road traffic; when the keeper has closed the crossing the signals will clear. This arrangement is replicated in the simulation. The simulated gate box will close the crossing in any of the following circumstances:

  • Either of the track circuits between signal 19 and the crossing are occupied.
  • A train is approaching signal 19 from Stansted North Junction and the route is set from the signal over the crossing.
  • Any of the three track circuits between signal 22 and the crossing are occupied.
  • Any of the six track circuits between signals 32 and 22 are occupied and the route is set from the latter.

Audley End

Down trains can use the up platform, though this does not happen in the provided timetable. The lack of Auto buttons mean this station can’t be ignored.

Great Chesterford

The Up Goods Loop is 512m long (PF) and fully wired. Note that there are no signalled moves over the facing crossover; it can only be used by instructing a driver to pass a signal at red. Ickleton Road crossing at the north end has a parallel underpass for road traffic, so it is normally only used by the few vehicles which can’t fit through the underpass but do fit under the catenary. This means it can be closed early for trains without disrupting road traffic.

CIBA-Geigy Duxford

The shunting neck is only a few metres long. Despite this, there is a separate indication on the signal and a separate button on the real panel to set a route from 527 shunt signal in to the neck. Because it is so short, there is no corresponding exit signal.


The Down Goods Loop, 512m long (PF), and the crossovers are wired but not the sidings or spur. Again, there are no signalled moves over the facing crossover; it can only be used by instructing a driver to pass a signal at red.


When a 4-car train is stood at Shelford station the driver cannot see signal 99 protecting Granhams crossing.

Shepreth Branch Junction

This is the junction for the two routes to London. The “approaching” berth has no equivalent on the real panel but is provided to allow easier management of the junction without continually flipping between views. A description will appear in it when the corresponding description reaches signal 93 (which will be once the train passes signal 91 and approaches Sawston Road crossing). The right-pointing arrow is a duplicate of signal 99, allowing a route to be set from Shelford.


The Cambridge station area is by far the most complex section of the simulation.

The Charringtons and Coalfields sidings were abolished a few years ago but I had the full signalling details and decided to include them in the simulation. The remainder of the layout is as shown on the real panel.

The following lines are electrified:

• The main Up and Down lines, which in the station area form the Platform and Through lines.

• The four bay platforms (2, 3, 5, and 6).

• The Down Passenger Loop at the south end and the Down Goods Loop at the north end.

• The Up and Down Goods lines, and Reception Lines 1 and 2 (but not 3 to 5).

• The Loco yard and Engine siding by platform 6.

• The Headshunt, Arrival Line, and Carriage Sidings 1 and 2, but only as far as shunt signals 735/737/739.

• Carriage Sidings 3-5, 6, and 7-8.

• All lines and crossovers connecting these.

There are a number of alternative routes at the south end of the station (for example, there are three routes from platform 1 to the limit of shunt on the Down Main); the appropriate one will be selected automatically depending on the state of the various sets of points.

The platforms can each hold an 8-car EMU (160m) or equivalent length train; platforms 1 and 4 can each hold 230m. All platforms are permissive .

Technical limitations with the simulation mean that the main platforms require careful use.

• There is no penalty for using platform 1 instead of 4 or vice-versa.

• Drivers will take a clear signal at the middle of the station as an instruction to continue and a red as an instruction to stop there.

Therefore if you want a train to stop in the half before the central scissors, do not set a route from the central signal (either into the other half or over the scissors to the Through Line). Conversely, if you want them to run through platform 1 into platform 4 (or vice versa), do clear the central signal.

• The Through Line counts as “arrived” once a train has passed the central scissors.

Platform working at Cambridge is an art as much as a science. It probably won’t matter if you put a train into 4 instead of 1, but sometimes you’ll find a conflict at the scissors if you do so. Similarly, there is a certain amount of “double docking” in the bays and it is important not to get this wrong. The worst disaster, of course, is to put a through train into one of the bays. At times platform space can be tight and it can be a mistake to bring a train past signals 147 or 149 too early.

Platform lengths

Plt Len Notes
P1 247m PP-A
P2 207m PP
P3 166m PP
P4 220m PP-A
P5 167m PP
P6 145m PP

When setting a route up to the scissors crossover, using the signal as the exit point will set an unrestricted route with the overlap shown on the diagram. To request a Warning route, use the yellow triangles as the exit point; the overlap will then extend over the scissors crossover only. The overlap will swing automatically as needed (unlike on the real panel). There is also an automatic warning route from the scissors crossover to signal 175 at the north end of platform 4; this will be used if a route is set in or out of platform 5 or 6.

The two triangles either side of “Goods Lines” can be used to call a loco on to the front of a stationary train. The left hand triangle is used as an exit from shunt signal 659 and the right hand one from shunt signal 710. The route can only be set if the corresponding goods line is occupied. Note that the “stops on through line” flag will need to be set for both the main train and the attaching loco. Loco joins should also work in the platforms, but there are technical problems with doing them on the Through Line.

Several sets of points in the station area have “time of operation locking”. This means that the points cannot be moved – even to swing an overlap – when a train is occupying the adjacent track circuit. The lock times out after approximately 30 seconds.

The platforms, the Through Line, and the Goods Line count as “Cambridge” for timetabling. The Reception lines are “Cambridge TC (reception)”.

Carriage Sidings 1 and 2, and the Arrival line, are each 300m long. The Headshunt is 220m and the breakdown siding 180m. The Up spur and the Engine siding are each 100m.

Carriage Sidings 1 and 2 (or, in a pinch, the Arrival line) should be used to store trains that will be going back into service. Trains signalled into sidings 3 to 8 will leave the simulation. Normally trains heading into Cambridge station will appear in sidings 3 to 5 and those heading to Ely in sidings 6 to 8, but it is possible that a train will come from the “wrong” place and need to reverse.

The DSL is 729m long.

Coldham Lane Junction

The main line continues on to screen 3, while the Dullingham and Newmarket single-line branch is on screen 5.

DGL is 570m long (PF)

Barnwell Junction

Once upon a time there was a line from here to Soham. The line and junction disappeared decades ago, and all that is left is the Shell-Mex siding on the branch alignment. In reality this is controlled from a ground frame with a release on the panel, but it has been shown here as if it were fully signalled.

Chesterton Junction

Trains leaving the Fen Drayton branch, and those standing at shunt signal 752 on the Down Line, can only be signalled to the Up Line (signal 212) even if they are then proceeding into one of the sidings or towards Ely. Only trains leaving the sidings can be signalled to the Limit of Shunt opposite Barnwell.

Fen Drayton

The Fen Drayton branch is now officially closed and is due to be converted to a misguided bus route, but it remained legally open for many years after the last train ran (when trains did run, the several level crossings along it were all Trainman Operated). The signalling to allow trains on and off the branch is still shown on Cambridge panel and is replicated here. The branch itself is operated under One Train regulations; trains will work it themselves and no intervention is necessary. The symbols looking like red signals with a grey background are the marker boards for OT working and do nothing. The identity of the train on the branch is shown on the simulation (but not on the real panel).

Waterbeach and Bottisham Road AHB

“Stop/Non-Stop” control are in place on the Down Line at Bottisham Road AHB (nothing special applies to Up trains). The crossing “strike-in” controls are south of Waterbeach and so, if a train stopped at the station with signal 235 off, it would take so long to reach the crossing that there would be a serious risk of road users thinking the crossing had failed. Therefore the signal only clears when the berth track circuit has been occupied for about 30 seconds or the non-stop button has been pressed. This must be done separately for each train.


The three platform lines and the Reception sidings are electrified; the Up Goods Loop and its links to the Up Line are not. Normally platform 3 is used for trains reversing south-to-north (e.g. services between Peterborough and Norwich). All platforms are 256m long, and permissive working is permitted (PP-A).

Both lines from here to Ely North Junction are fully reversible. Trains heading to Manea and Peterborough must depart on the Down Line; those to Littleport, Shippea Hill, and Papworth Sidings can use either line.

The Reception sidings and the Up Goods Line are separate locations for timetabling purposes.

Ely North Junction

You will quickly discover that this junction is very awkward to use. Nearly all moves need to run over the one bidirectional section of track, resulting in endless conflicts.

Double-blocking is in use at the junction. This means that signals 295, 306, 800, and 908 will stay red until the next signal has cleared (or, for trains going clockwise around the loop, until the route is set and a train has occupied the berth track circuit for a sufficient time).

The lines between Ely and Littleport (and thus only one track through the junction) are electrified, but no others.

When reversing a train to go into Papworth Sidings from the north, there is room for a 320m goods train to stand between signals 298 and 303 or between signals 296 and 305; longer trains must be signalled across Kiln Lane crossing to bring their rear inside the latter, or must be signalled directly in from signal 771.

Ely West Junction

Signals 780, 914, and 910 on the Down Line, and 301 on the Loop, have been locked out of use on the real panel ever since they were installed. This means that the crossover cannot be used and the loop becomes clockwise-only. However, the signals have been made operational in the simulation to provide more variation.

Ely West Junction only needs to appear in timetables for trains using the Ely Loop.

Manea to Peterborough

The line between Manea and Peterborough is controlled by several mechanical signal boxes. This has been simplified in the simulation to automatic colour lights, to allow chaining with the Peterborough simulation at Whittlesea. March is the only location to be simulated in detail, and two types of autoworking have been provided for ease of operation: 'Main Line' continuously resets the main line routes through the station, while 'Auto FCFS' makes an attempt to route trains to the various locations around March. Please note that, unlike full ARS , it will make no attempt to regulate trains- they are dealt with on a First Come-First Served basis.

Littleport, and Shippea Hill

These are the two other entry points from the north, from King’s Lynn and Norwich respectively. The line to King’s Lynn in fact becomes single just north of Littleport, but this will not affect operation of the simulation.

Chippenham Junction

This is the entry point for trains from Ipswich and Bury St.Edmunds towards Ely. The line shown heading up and to the right is in fact the Dullingham and Newmarket branch to Cambridge, but trains running that way will not appear on this part of the simulation.


There are two separate sets of sidings at Snailwell: Firmin Coates and King’s. In reality these are, once again, controlled by a ground frame with a simple release on the panel (not distinguishing between the two). However, as at Barnwell, they are shown as if fully signalled.


This is where the double line becomes single for the last section to Ely. The triangle to the right of Middlemere AHB is the exit point for the route from signal 495 towards Ely.

Particular care should be taken when setting routes for trains in opposite directions. If the route from 495 is set with an Up train still between Middlemere and Mill Drove crossings, the former will operate falsely (this will happen in real life as well).

Cherry Hinton and Fulbourn

The two level crossings at Cherry Hinton both involve busy roads and therefore they should not be closed too early.

The sidings and ground frame just east of Fulbourn AHB were closed and removed in 2004. I have omitted them from the simulation.


Dullingham station is the fringe box for this line – it consists of a passing loop before the line reverts to single track for the run via Newmarket to Chippenham Junction. In reality the loop points and the three signals D1 to D3 are operated by Dullingham signal box, with Cambridge panel having a slot on D2. For simplicity this is not replicated in the simulation. Instead D2 is treated like a normal signal, while the route will be set automatically from D3 into the loop whenever a train is signalled up to it.


Unlike the other two lines on screen 5, Baldock is the other main entry point from the south and the line carries a frequent and fast service.

The Cambridge simulation may be chained to the King’s Cross one at this point.


The section of the simulation from Baldock to just north of Royston is actually part of King’s Cross PSB, not Cambridge, and the signals all have a K prefix.

The layout here reflects that of around 1980; most of the sidings have since been lifted, though sometimes small stubs remain. The two running lines and the crossovers between them are electrified, but not the sidings. It is common for trains to join or split at Royston, and the signalling is set up to allow this. It is also practical for a train to run “wrong line” through the station in either direction, and the supplied timetable contains examples of this. Also keep an eye open for the occasional Royston reverser, usually running with an R headcode. Both platforms are permissive.

In order to provide a more accurate simulation of Cambridge, the Royston area can be put into automatic mode using the button above platform 2. When this is turned on, the routes straight through the station will be set automatically as trains pass. Automatic mode can be turned off by right-clicking on the button or by cancelling any of the 7 routes.


“Stop/Non-Stop” controls are in place on the Up Line at Shepreth AHB. See Waterbeach for a full description.

If you are reversing a train from the Up Line to go back to Foxton, signal 110 should be replaced to red to stop the AHB operating spuriously.


As with Elsenham, Foxton level crossing is managed by a separate gate box. This again means that the Cambridge signaller can simply set routes across it well ahead of time and not have to worry about delaying road traffic; when the keeper has closed the crossing the signals will clear. This arrangement is replicated in the simulation. The simulated gate box will close the crossing in any of the following circumstances:

• The track circuit between signal 114 and the crossing is occupied.

• Any of the four track circuits between Harston AHB and signal 114 are occupied and a route is set forward from the latter.

• Any of the four track circuits between Shepreth Branch Junction and Harston AHB are occupied, a route is set forward from both signals 116 and 114, and the train occupying those track circuits is not timetabled to stop at Foxton. If the train has not passed signal 118, the route must also be set forward from this signal.

• Any of the eight track circuits between signals 109 and the crossing are occupied and a route has been set forward from signal 113.

• Either of the track circuits between signals 105 and 109 are occupied, a route is set forward from both signals 109 and 113, and the train occupying those track circuits is not timetabled to stop at Shepreth.

• Any of the shunt routes over the crossing are set.

As a point of interest, the line to the cement works is actually an independent railway – the Barrington Light Railway – and not part of Network Rail.

Train Service

The supplied timetable is based on the workings of July 2003. It runs from 03:00 to 02:30 the following day (shown as 26:30), though the last timetabled move ends at 26:04.

There are a total of 480 schedules in the timetable involving 319 trains entering the simulation, 15 divides (one of them a 4-way divide), and 33 joins. The entry points are:

Baldock 77
Stansted North Junction 61
Manea 58
Shippea Hill 37
Littleport 24
Chippenham Junction 23
Cambridge Carriage sidings 20
Dullingham 11
Papworth sidings, Ely 4
Coldham Lane Depot 2
Snailwell Sidings 2


Standard railway descriptions (headcodes) are used in SimSig, as always. The first digit is the class of train. The second character is a letter, which usually denotes the route taken by the train. The remaining two digits simply give each train its own identity.

The train classes are:

The speed of classes 1,2,3 and 5 are determined by the train type. 75mph, 90mph, and 100mph stock is found in the timetable. The route letters found in the timetable are as follows. They are only a guide; always check the actual destination of the train. Furthermore, light engines and empty coaching stock normally use the same last three characters as the related service train, even if they don’t follow the route implied by the letter.
1. Express Passenger Train
2. Local Passenger Train
3. Priority Empty Coaching Stock (in this timetable)
4. Freight Train (75mph)
5. Ordinary Empty Coaching Stock
6. Freight Train (60mph)
7. Freight Train (40mph to 45mph) (not in this timetable)
8. Freight Train (35mph or less) (not in this timetable)
9. International Services (not in this timetable)
0. Light Locomotive
A Trains from Cambridge to Harwich (via Dullingham)
B Not used
C Trains between King’s Cross and Cambridge
D Trains to Leeds/Bradford/York
E Trains to Eastern Region via Peterborough, and ECS to Hornsey
F Not used
G Not used
H Trains between Liverpool Street and Cambridge or King’s Lynn
I Not used
J Not used
K Not used
L Trains via Peterborough to Norwich, Ipswich, or Stansted Airport
M Trains to London Midland Region (mostly via Peterborough)
N Trains to London Midland Region via Peterborough and Stamford
O Trains to Southern Region
P Trains from Cambridge or March to Norwich
Q Not used
R Trains between King’s Cross and Royston
S Trains to Scottish Region
T Trains between King’s Cross and King’s Lynn (or Ely)
U Not used
V Not used
W Trains between Cambridge and Ipswich via Dullingham
X Out-of-gauge trains
Y Not used
Z Special trains

Main Movements

Passenger Services

Great Northern

First Capital Connect (WAGN until 31st March 2006) run 100mph EMUs between King’s Cross and King’s Lynn. The fast service is the “Cambridge Cruiser” – non-stop (except in the peaks) between London and Cambridge every 30 minutes, with alternate trains running to King’s Lynn. Fitting between these is a stopping service between London and Cambridge, plus a few Royston reversers in the morning peak.

West Anglia Electrics

ONE Trains run 100mph EMUs between Liverpool Street and Cambridge, extending to King’s Lynn in the peaks.


A variety of diesel services run through Ely. Most of these run via Manea and include services between Norwich and the Midlands (reversing at Ely), trains between Stansted Airport, Cambridge, or Ipswich and Peterborough, and a service between Cambridge and Norwich. Keeping these untangled at Ely North Junction can be interesting.

Finally there is an irregular service between Cambridge and Ipswich via Dullingham. Outside the immediate Cambridge area these require no attention.

Freight Services

There are a number of fast (class 4) freights between the Ipswich area and the Midlands, running via Chippenham Junction, Ely, and Manea.

Slower (class 6) freights run on a number of routes:

• between the Ipswich area and the Midlands;

• between Papworth Sidings and the Midlands – these need to reverse at Ely North Junction or Ely Reception sidings, the latter involving a loco run-round;

• between Norwich or King’s Lynn and the Midlands via the Ely Loop or reversing in Ely Up Goods Loop (with a loco run-round);

• between the Midlands and Stansted North Junction;

• into and out of Snailwell sidings; this also involves some light loco running.

Timetable locations

This section lists the internal codes (which in many cases are TIPLOC codes) for the timetable locations in the simulation, and also provides a brief description of the less-obvious locations. These codes are used when using the timetable converter.

When a train enters the simulation a different code – an entry point code – is used. These codes are shown in italics following a » symbol. In general, the entry location should not be the first location in the train’s timetable as well.

STANNJN Stansted North Junction » ESTAN
ELSENHM Elsenham
AUDLEYE Audley End
GTCHSFL Gt. Chesterford UGL; Up Goods Loop signals 64 and 521
GTCHSFD Gt. Chesterford; station, including behind signal 524
CAMB515 Gt. Chesterford CA515; south of Fairheads MWL crossing
CAMB519 Gt. Chesterford CA519; use for reversing on the Up Main
CAMB528 Duxford (reverse, CA528); use for reversing into Ciba-Geigy
WTLESFD Whittlesford; station
CAMB531 Whittlesford (reverse, CA531); use for reversing on the Up Main between the station and the sidings
WTLEDGL Whittlesford DGL; Down Goods Loop
WTLEFDR Whittlesford sidings; behind signal 533 » EWHITS
CAMB540 Whittlesford N (reverse); behind signals 540 and 84, use for reversing on either line
CAMB534 Whittlesford shunt spur
SHELFD Shelford
SHPRTBJ Shepreth Branch Junction
CAMB147 Camb. S (CA147 DL); Down Loop use both for trains waiting to enter Cambridge and those reversing
CAMB149 Camb. S (CA149 DM); Down Main
CAMB645 Charringtons » ECHAR
CAMBCGF Cambridge Coalfields » ECOAL
CAMB657 Cambridge shunt spur; south of the station
CAMBDSJ Cambridge south junction; signals 148, 647, 643, and 653 approached from either direction, and 655 and 659 approached from the south.
CAMBDGE Cambridge; station, Through Line, and Goods Lines. A train will only “arrive” on the Through Line once it has passed the central crossover.
CAMBGTC Cambridge TC (reception); the five reception lines east of the Goods Lines» EREC4D or EREC4U (to depart northwards or southwards respectively)
CAMBDHS Cambridge loco sidings » ELOCO
CAMB706 Cambridge engine spur
CAMB180 Cambridge N (CA180); between signals 180 and 733 on the Up Line, including approaching 180, but not 733, from the Carriage Sidings
CAMB708 Cambridge N (CA708); can only be approached from the north, and not be used for reversing trains
CAMBDNJ Cambridge N (CA721); trains approaching from the north to reverse must not be routed towards sidings 6 to 8
CAMBDCS Cambridge carriage sidings"; includes the headshunt, the Arrival Line, and sidings 1 to 8. Note that a train can be timetabled to move between sidings 6 to 8 and the remainder. » EESSO (3-5), ECS6 (6), or ECS7 (7-8)
CAMBTMD Coldham Lane TMD » ECLDA, ECLDB, or ECLDD (the last letter indicates the specific track where the train will appear)
CAMB734 Cambridge breakdown siding
CLDHMLJ Coldham Lane Junction; use for reversing on the Down Goods Loop as well as all through movements
BRNWJRP Barnwell Jn. (reverse); use for reversing south to north at signals 211 and SMX1
BRNWJBP Barnwell Jn. Shell-Mex siding; use for both the siding and for the Up Line between the siding points and the Limit Of Shunt
CESTRTJ Chesterton Junction; on the Down Line, represents the crossover points but only for trains coming from signal 211; on the Up Line, between signals 212 and 751
CAMB752 Chesterton Jn (CA752); use for reversing on the Down Main
CESTRTB Chesterton Jn (Ballast) » ECHSJU2
CESTRTR Chesterton Jn (Redland) » ECHSJU1
CESTFHH Chesterton Jn (FHH) » ECHSJD
CAMB758 Chesterton Jn (spur)
FNDRYTN Fen Drayton; far end of the branch » EFEND
WATBECH Waterbeach
CAMB253 Ely S CA253 (reverse); use for reversing at signal 253
ELYYRCS Ely Reception south; signals 254, 255, 256, 257, 760, and 761
ELYYREC Ely Reception; signals 273, 762, 764, and 765
ELYYDLN Ely Dock Junction;
• on the Down Main, the trailing crossover from the Up Main (but only for moves along the Down Main)
• on the Up Main, the facing points to the Soham branch
• on the Up Goods Loop, behind signal 262
ELYYUGL Ely Up Goods Loop; signals 270 and 287 (but not from the Engineer’s Siding and signals 272 and 769)
CAMB766 Ely Cripple Siding » EECRIP
ELYY Ely; station (the three through platforms)
CAMB288 Ely north (reverse); use for reversing at signals 288 and 290
ELYYNJN Ely North Junction; signals 296, 298, 303, and 305; for moves to and from the Ely loop,
the diamond crossing with the Down March;the Line codes GL, ML, and SL all refer to Papworth sidings
ELYYPHS Ely Papworth headshunt
ELYYPAP Ely Papworth Sidings; » EPAPW The codes ELYYFHH and ELYYPAW may be used to represent this location as well, but the simulator will only generate ELYYPAP
ELYYWJN Ely West Junction; signals 780 and 917 on the Down March (use for reversing at signal 780), and the facing points on the Up March
CHTISHM Chettisham; the track circuits at the AHB
CAMB776 Ely North Jn (reverse); use for reversing at signals 776 and 778
LTLPORT Littleport » ELPT
SPHL Shippea Hill » ESHIP
ASHWELC Ashwell & Morden
K977245 Royston S K977/245 (reverse)"; use for reversing behind K977 on the Down or K245 on the Up
ROYSSHR Royston Sherriff's siding » EROY249
ROYSLP Royston Down Loop; can be entered at either end » EROY244 to depart towards Baldock or EROY253 to depart to platform 2
K246 Royston S K246 (reverse); use for Down to Up reversals
K247 Royston Up Siding » EROY247
ROYSTON Royston; station
MELDRTH Meldreth
SHPRTH Shepreth
CAMB551 Shepreth north (reverse); use for reversing from the Up to the Down line
FOXTRC Foxton Cement (Barrington LR) » EBLR
CAMB554 Foxton shunt spur
FOXTON Foxton; station, including reversing via signal 556
DULNGHM Dullingham » EDULL
CHPNJN Chippenham Junction; do not use for trains via Dullingham » ECHIPJ
SNLWLS Snailwell (sidings) » EFIRM or EKING depending on the siding
SNLWLRV Snailwell (reverse); use for reversing into the sidings
SOHAM Soham; the double-to-single line points

Hints and Tips

- Interpose the next working into the train describer as soon as possible. It is a good habit to do so as the inbound train is arriving, or even as soon as you have set the route into the terminating platform.

- Keep an eye on the level crossings on screen 1 and Chesterton Fen on screen 3; it is easy to forget a train and leave it waiting at a red signal.

- Up trains at Shepreth Branch Junction will be going towards Royston if they have C or T headcodes and towards Stansted if they have H or L headcodes.

- Watch the platform workings at Cambridge.

- Take advantage of the bidirectional tracks north of Ely, but beware of locking yourself up. Trains into and out of platform 1, and trains to Manea or Papworth Sidings, have to use the Down Line. If a train is timetabled for the Up Line it’s probably for a good reason. As a rule of thumb:

• E, M, and N headcodes are running towards Manea.

• H and T headcodes will be going towards Littleport or Cambridge;

• L headcodes will be going towards Shippea Hill, Cambridge, or Soham.

• P headcodes will be running towards Shippea Hill

but always check the timetable just in case.

Known Problems

The following problems are known about in this beta release.

• The timetable analyser will report “Reverses at Ely North Junction but has “passing time” ticked” for certain trains. This will happen for trains that run via the Ely Loop, and can be ignored.

• It is possible to set warning routes up to signal 161 and 164 simultaneously (using the yellow arrows) and then swing the crossover so that both routes are sharing an overlap.

Splash Screen Photos

A brief description of the various “splash screen” photographs.

The Barrington Light Railway – the exchange sidings taken from the Cement works end and looking towards Foxton.
A ONE service to Cambridge in the northbound platform at Whittlesford.
Whittlesford station, showing the turnout into the Down Goods Loop, the sidings, and the rear of signal 82.
Signal 527 at the exit from CIBA-Geigy, seen from the far side of the main line.
The section of Cambridge panel covering the area just north of the station, showing the Down Goods Loop, the main lines, and Carriage Sidings 1 to 5.
The section of Cambridge panel covering Ely station. At top left is Brannolds AHB and at top right the CCTV for Ely station level crossing. The line along the bottom is the Ely-Ipswich branch, showing the points at Soham.
A view over Cambridge station from the signal box. The reflected lights at the top are actually on the signal panel. Trains are visible on platforms 1 and 2 and Reception Line 1; the old Coalfields sidings are in the foreground.
The main Carriage Sidings, with signal 721 in the left foreground. The line at front centre links sidings 5 and 8; it is not signalled and not shown in the simulation.
The north end of Cambridge station, with signal 710 in the foreground, platforms 4 and 5 at top left, and the loco sidings at top right.
Looking north on platform 3 at Ely; signals 283, 285, and (on the right) 287 are visible. The line is closed by an engineering possession.
Another view of signals 283 and 285. The station level crossing barriers are visible on the left, either side of the OHLE support.
A ONE service from Ipswich runs into platform 3 at Ely. Signals 274 and 276 are visible in the foreground, and 270 and 272 in the background.
The central scissors crossover at Cambridge with an Up train in platform 4. Signals 161 and 163 are visible in the foreground, and trains are stabled on Reception Lines 1 and 2.
A service to Ipswich is about to depart platform 6 at Cambridge. Signal 171 is showing yellow plus “M” for the Main Line (to Coldham Lane Junction).
Littleport signal box, the fringe box on the line to King’s Lynn.
A train to King’s Cross sits in platform 1 at Royston, with signal K253 – at the exit to the Down Loop – in the foreground.


For those interested, here are some statistics about the simulation.

Signals and points

In the following table, the four columns are:

CA controlled by Cambridge PSB
K controlled by King’s Cross PSB
Other controlled by other signal boxes
GF controlled by ground frames in the area
CA K Other GF
Controlled signals (240) 217 17 1 5
Main without subsidiary 110 5 1
Main with subsidiary 36 5
Fixed red plus subsidiary 1
Shunt signal, always shown 3 1
Shunt signal, can be hidden 67 6 5
Automatic signals (111) 76 16 19
Aspect shown with emergency replacement button 52 5 5
16 2
Aspect greyed out 10 9
Limit of Shunt, can be hidden 6 1
Distant / Repeater 18 5
“A” (automatic working) buttons 63 1
Yellow (warning route exit) arrows 4
Grey (route exit not at a signal) arrows 33 4 3
Grey (additional route exit) arrows 22
Routes (611) 563 40 1 7
Main 214 12 1
Calling-on 47 4
Warning 9 5
Shunt 293 19 7
Points (171) 150 17 1 3
Single-ended 44 1 1 3
Crossovers 53 8

The signal with the most routes from it is CA147, with 19 different routes to 8 destinations, followed by CA149 with 14 routes to 7 destinations. The signals with the most destinations reachable from them are 171, 173, and 175, each with 13 routes to (the same) 12 destinations.

Track Circuits

There are 548 track circuits displayed in the simulation; of these, 50 in the Royston area are not shown on Cambridge panel. 3 of these track circuits are split 3 ways on the ground (that is, 3 track circuits are shown as a single one on the panel) and another is split 2 ways. There are a further 21 track circuits from the King’s Cross simulation that are used for chaining, and 46 other locations within the simulation that can hold trains but do not have their status displayed (for example, within sidings).

Train Describer

There are 290 train describer berths shown on the screen (one shown in two places). In addition there are three hidden berths and the 5 “on duty” indications.

Pilotman Working

The Cambridge simulation contains a scenario called Sawston Blockage, which requires the use of pilotmen. Essentially, the Down Main line is blocked at Sawston, so all trains between Whittlesford and Cambridge must use the Up line. A knock-on effect of this is that trains to and from Royston must use the Down Main between Cambridge and Shepreth Branch Junction.

To ensure safety on the temporary single line, pilotmen are used. Each train must be dispatched by the pilotman onto the single line, which makes a head-on collision impossible. The pilotman may travel with the train onto the single line, or he may allow it to depart and wait for a second train. It is your job to ensure that he is at the correct end of the line to keep delays to a minimum.

Receiving calls from the Pilotman

When a train arrives at the end of the single line that the pilotman is at, he will phone you. The responses are:

Proceed on single line with train Travel to the other end of the single line on this train
Dispatch train and wait here Allow the train to proceed on the single line, but wait here for another train. NOTE: The following train may be allowed onto the single line immediately if it is travelling 'right line' (in the direction that the line is normally used in), since the normal signals maintain a safe distance bewteen trains. However, if the train is going 'wrong line',it must be held until the first train has cleared the single line section.
This train does not need a pilotman To be used only when the train is shunting and will not enter the single line section
Travel to the other end of the SLW Leave the train there and travel by road to the other end of the single line. Note that it is almost certainly faster for the pilotman to travel in the train than by vehicle.
Call back in x minutes What it says!
Go to other train Go to the other train that can enter the single line at this location (see sections dealing with specific lines below

Placing calls to the pilotman

You may phone both pilotmen:

Where is the pilotman? Where is the pilotman at the moment?
Ask pilotman to call back The pilotman will call back, which will allow you to tell him to travel by road to the other end of the single line. See below for journey times

Down Line

Down trains will wait at signal 123 for the pilotman, and routes for the train should be set as normal. Signal 123 will clear when you have given the Pilotman permission to send the train to Cambridge. Down line trains can wait at either L152 or L154. If there are two trains waiting, you may tell the pilotman when he phones up for one of them to go to the other train and deal with that one first. All points on the single line must be manually set: if a train encounters a point set against it, it will display a "Run out of valid track" error. The pilotman takes 10 minutes to travel from one end of the single line to the other by road.

Up Line

Down trains from Great Chesterford will wait at signal 83 for the pilotman. Note that there is no route allowed between signals 83 and L531- the crossover points and points to the loop must be set manualy. Trains from Whittlesford sidings, or that have otherwise shunted onto the Up line via signal 540 will wait at signal L531. If a train is waiting at both locations, it is possible to send the pilotman to deal with the other train first. Note that you do not have to take any action level crossing-wise for Down trains. Up trains will phone from signal 148, which will clear when the pilotman is told to allow a train onto the single line, and routes must be set as normal for these trains. Note that Cambridge shunt movements at signal 647 are still allowed, provided no train is approaching on the single line in the Down direction. The pilotman takes 20 minutes to travel from one end of the single line to the other by road.

Known Issues

  • Royston and March main line ARS don't work. March FCFS works fine.
  • March reception lines/goods loops - locations for reception lines and goods loops are reversed. Route trains vice versa to these locations. Fixed for next release.

Reference Section

Cambridge Signal Number Plan Speed Limit 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 .

Signal Prefix Codes

Box on the Ely- Peterborough line, all main line signals visible but not contollable.
Code Box
CM Chippenham Junction*
D Dullingham*
K King's Cross*
KD King's Dyke
L Liverpool Street*
L Littleport*
M Manea
ME March East
MS March South
P Peterborough
S Stonea
SH Shippea Hill*
THS Three Horse Shoes
W Whittlesea

*Fringe Box, signals not controlled by this sim.

Non-prefixed signals are controlled by Cambridge (CA)

Platform Lengths

Location Platform Length (m)
Ashwell & Morden Down 168
Up 167
Audley End All 248
Cambridge 1 247
2 207
3 166
4 220
5 167
6 145
Dullingham Down 103
Up 94
Elsenham Down 167
Up 165
Ely All 256
Foxton Down 84
Up 105
Great Chesterford All 167
Littleport All 86
Manea Up 42
Down 49
March Down 194
Up 115
Meldreth All 128
Newport Down 167
Up 168
Royston 1 236
2 169
Shelford All 180
Shepreth Down 91
Up 97
Shippea Hill Down 147
Up 132
Waterbeach Down 86
Up 90
Whittlesea Down 45
Up 62
Whittlesford All 254

Source: Network Rail's Timetable Planning Rules .

Last edited by Steamer on 27/06/2020 at 11:34