Copyright: SignalBox Application - version 42.70 (7-Apr-2006)


Introduction

The application '!SignalBox' is a full, accurate simulation of a mechanical signalbox. What does that mean? When I say simulation I do mean a full, accurate simulation, not like some of those on the market! In the simulation, you see the signal box lever frame, block shelf and instruments and track diagram in one window. The working timetable showing the trains that will run is available separately but the train register book, which records the trains that pass from box to box, is shown on screen in another window. The track circuit indicators on the box diagram and the train register are both displayed and kept updated by the computer.

All interlocking, both mechanical and electrical, is fully implemented using original technical data as source data. Context sensitive help messages lead an inexperienced user through the process and the level of difficulty can be selected. The points and signals on the track diagram may be operated by a simple mouse click over them (and signals and points move to show they have been operated). If interlocking is not free a helpful message is given explaining why the lever or electric lock cannot be operated.  When a box is operated as a ground frame, then the mechanical locking, below the operating floor, can be viewed as the levers are operated – this is included for all boxes where the data are available and excludes those currently in operation.

As trains move from track circuit to track circuit, lamps light up on the track diagram, and an image of the train concerned moves over the track diagram on both track-circuited and non-track-circuited lines showing the position of every train continuously. A right-mouse-click (‘ADJUST’) over an occupied track will give a menu permitting the engine to be reversed or the stock uncoupled. Context-sensitive help messages will give additional information about whatever the mouse pointer is pointing at. Simulation speed can be adjusted at any point and the simulation paused.

Full simulation is implemented of both Kidderminster Station (SVR, circa 1998) and Exeter West (circa 1964 but using a train service based on Summer 1982).  Full simulation gives a choice of timetables, but in the ‘free’ version only a limited number of train movements are included. Also provided are Morlais Junction, Radyr Junction (as at 1961 and 1987) and Bewdley North (1956), which may be operated as a ground frame (animated mechanical locking is provided for all three boxes, Radyr Junction 1987 only).

In the full (purchasable) version Rotherwas Junction, as well as the other SVR boxes, may be operated as ground frames and many alternative timetables are provided for Exeter West and Kidderminster Station including gala timetables and over six hours of timetabled trains and shunting.  In addition, further boxes may be purchased as data files that will operate under the full version:  currently available (or in development) are Acton Yard, Oxford Station North, St Austell and Resolven East (these complete with animated 5-bar locking); Penwithers Junction (with mechanical locking, not animated) and Neath & Brecon Junction and St Erth (available with box diagram but not mechanical locking).

The following steps provide some basic information to get you started:

Installing and running

What happens in a signalbox

Novice – how to get started

Purchasing the full version

Copyright notice

This is version 42.70, updated on 7th April 2006.


Copyright

Copyright notice

This application is copyright (c) C.K.Hall 1995.

This product has been compiled with BBC BASIC for Windows.

Acknowledgments

Severn Valley Railway Signalling & Telecommunications Department.

Exeter West Group.

Developed with Silicon Vision's RiscBASIC compiler.

Back to Introduction


Installing and running

Once the application has been extracted from the 'zip' file, this should produce an '.EXE' file and a sub-directory 'SIGBOX' containing the resources needed.  Use 'Run' from the 'Start' button to run the programme (the application is named ‘SignalBox.exe’).  The necessary data files are stored in a sub-directory ‘SIGBOX’ and contain all the information needed for the both the ‘free’ version and for the full, purchasable version.  The full version requires a licence key which is linked to a user name and address.  Instructions on how to obtain the key by e-mail or post will be provided if the full version has been purchased and are repeated below.  Once the full version has been purchased and the key entered and saved, then additional signal boxes may be purchased.  At any time a later version may be downloaded from the internet and the key re-entered and saved making upgrades simple.  Data files for additional signalboxes will only function with the personal key for which they were created and are thus not transferable.

On start up, the opportunity is given to enter and store a user name and licence key to access the full version, to display this help file or to select your choice of signal box from a list.  Depending on the box selected, there may be a timetabled sequence of trains to select (Exeter West and Kidderminster Town) - the simulation will start up in ‘paused’ mode, waiting to see if you take the initiative.  If you do not, then the booking boy will step in and show you how to do it!  Simulation speed may be adjusted and the simulation paused, slowed down or speeded up.  Other boxes may only be operated as ground frames.

The simulation works best in at least 1024x768 with 256 colours (1280 by 1024 is recommended), but 16 colour mode is perfectly acceptable. In smaller screen modes it is difficult to use.

It will run under Windows NT4.0, 2000, ME and XP (it has also been tested on Windows 98-SE). It runs at an acceptable speed on 1600MHz processors and probably on slower processors. If the processor is too slow to keep up with the selected simulation speed, then its actual speed will also be shown.

When the application starts (by selecting a particular timetabled sequence for either Exeter West or Kidderminster) it will open two windows as follows:

* the signal box diagram plus the lever frame and block shelf;

* the train register.

Window sizes are automatically selected according to the screen mode.  If a box diagram/lever frame is enlarged so that only part of it appears within the screen window, then it will automatically scroll left, right, up or down as the mouse pointer approaches the edge of the window.  It may be scrolled left, right, up or down more quickly by typing ‘PageDown’, ‘PageUp’, ‘Ctrl-LeftArrow’ or ‘Ctrl-RightArrow’.  Interactive help messages describing the different functions are displayed in 'tool tip' windows. Almost every item in each window provides an individual help message: levers, electric locks, points, signals, track circuits, the score display, etc.

During a sequenced timetable of trains, they will move across the diagram. Shunting movements (a single engine or a train being propelled) will stop behind shunting signals and be ready to shunt back - if you want it to continue the shunt further, then click with the right-button (‘ADJUST’) on the mouse and select 'Reverse (engine)'.

Back to Introduction	-	What happens in a signalbox


Purchasing the full version

Sufficient is provided in the free version for a full simulation of both Kidderminster and Exeter West boxes, including a service of timetabled trains with a choice between tables A or B or a Winter service at Kidderminster. At Exeter West a selected sequence of trains (twenty of the eighty-seven provided in the full version) from a very busy August 1982 Saturday is provided. These two boxes may also be operated without a train service to explore the locking, operating the box as a ground frame.

A complete demonstration mode is provided for Exeter West and Kidderminster Station.  Both boxes are fairly complicated and so the booking boy will intervene to pull all the levers for you if, after a short delay, you do not start pulling levers yourself.  The complete sequence of timetabled trains will proceed completely automatically and without error! Just listen and watch as the bells jangle, the trains move across the diagram and the train register is updated.  The most interesting mode of operation is to allow the booking boy to deal with the levers and bells but to make all the regulating decisions yourself.  This is done by allowing the auto pilot to start, clicking over the box ‘Auto pilot – click to interrogate’ and then selecting ‘Manual’ – each movement will then start but does not proceed until you click ‘Resume’ at each ‘hold point’.  In the free version, this may only be used in the Kidderminster simulation and for the last two trains in the Exeter West simulation.  Each wrong decision will then cause delay – you can of course make every lever movement yourself manually to get out of it, but then you probably won’t find the ‘auto pilot’ of much use from then on!

Three further boxes are also supplied in the free version, Morlais Junction, Radyr Junction (1987) and Bewdley North (1956), with authentic mechanical and (except for Radyr Junction) electrical locking (but with no train service) – these boxes may thus be operated only as ground frames.  As the levers are operated the movements of the mechanical locking can be seen on screen.

The full application includes a complete set of the timetabled trains for these two boxes, which includes table C and D services for Kidderminster as well as two Gala timetables for the enthusiast. For Exeter West a full service over two and three quarter hours on a busy Saturday in 1982 is provided (eighty-seven movements) as well as a full service over six hours on a busy Friday in 1982 (a hundred and twenty-five movements).  A full demonstration mode is provided for these to prove that it can be done without error!

The full version is available for £25 from the following address:

Please specify whether you require the Archimedes (RISC-OS) or IBM-PC compatible (Windows) version.

3, Rockleaze Court, Sneyd Park, Bristol, BS9 1NN.

Cheques should be made payable to C.K.Hall. No credit/switch cards accepted.

In addition, further boxes may be purchased as data files that will operate under the full version:  currently available (or in development) are Acton Yard, Oxford Station North, St Austell and Resolven East (these complete with animated 5-bar locking); Penwithers Junction (with mechanical locking, not animated) and Neath & Brecon Junction and St Erth (available with box diagram but not mechanical locking).  The price for these is £7 each (for those with animated locking) or £4 each (for those without animated locking) when purchased with the full version and price £15 for any three purchased separately (please quote your user name and key).  Note Acton Yard box diagram is still slightly 'unfinished'.

The full application is made up from a data generation programme (not supplied) which creates the necessary data files (over thirty thousand lines of BASIC) plus the application itself (over ten thousand lines of BASIC) supplied in compiled form as an ‘.exe’ file.

There are some known bugs which are gradually reducing in numbers and the development history of the application is described.

Back to Introduction	-	Copyright notice


What happens in a signalbox?

A number of levers are provided, numbered sequentially from the left, each operating a signal, point, facing point lock (or another function). The levers are coloured to show their function (red is a stop signal, black is a point, blue is a facing point lock, yellow is a distant signal, blue plus black is a motorised point and FPL, red plus brown is an interlocking lever giving a release to another box). A plate on the lever shows the number of that lever and (if there is space to do so) describes its function and lists the other levers that have to be pulled in sequence to release it. Where the lever is electrically locked (in addition to the mechanical locking provided) then an electrical plunger may be fitted just above the lever. Alternatively (at Arley and for some levers at Bewdley South and Kidderminster for example) electrical locking may be effected by a circuit controller or by passing contacts which operate the electric lock as the lever is moved.

The location of the points and signals is shown on a track diagram above the lever frame, which may also contain lamps to indicate (when lit) that a train or vehicles is standing on a particular section of track. These lamps are driven by track circuits and the occupation of track circuits may be used as part of the electrical locking. Where signals cannot be seen from the box, then a repeater on the block shelf provides confirmation that the signal has responded correctly to the lever - in this simulation, repeaters are not currently provided.

Trains may only be despatched on the 'absolute block' system after communication on the bells with an adjacent signalbox - the signal giving permission for trains to leave 'station limits' is normally provided with an electric lock which can only be released from the box in advance. To signify this the lever has a white stripe. A train register is provided in which all bell signals are recorded, giving the beats on the bell, the running line, the direction and the time. Each message has a unique combination of beats on the bell and each bell (one for each pair of running lines) has a unique tone. Exeter West has six block bells, as there are six pairs of running lines (Main lines in each direction, Southern, Middle, Goods and Relief).

Interlocking between the levers ensures that conflicting routes cannot be set, signals can only be cleared if the route is set and the route cannot be disturbed while the signals are 'OFF', i.e. cleared. The interlocking is effected in three ways - mechanically through the lever frame, electrically through electric locks on the lever and mechanically remote from the signal box.

All of this is accurately simulated in this application.

Back to Introduction	-	Novice – how to get started


Novice - How to Get Started

When the application starts, the desired signalbox and train service may be selected. In the free version some timetables are not available. Several windows will open, including one showing the levers and block shelf - this will show 'Simulation paused' and note that the auto pilot will start after a short time if not started manually. Either click over 'Slow' to start or just wait for the demonstration mode to start.

There are therefore two options:

•	click over 'Slow' or 'Fast' or the space between them to resume the simulation - the inset box will disappear and you are on your own - the booking boy leaves you on your own in the box;

•	just wait and if, after 20 seconds, you have not resumed the simulation, the booking boy will pick up the duster and give you a commentary as he pulls the levers for you.

If you choose to operate the box yourself then you will need to know a little more about how it operates:

Operating the levers

Using the block bells

Watching the track diagram

Mechanical locking

How long is the shift?

What does the score mean?

Brief description of the Signalling Regulations

Local instructions at Exeter West

Brief history of changes at Exeter West

The booking boy will pull the levers and operate the block instruments (everything except answer the telephone), making the best job of regulating the trains that he can. As each train in the timetabled sequence initiates, an entry will appear in the inset box giving a description of the train and its next movement. The next movement will appear in red until a decision is made that this movement should proceed, at which point it turns black and the necessary levers and block instruments will be operated by the booking boy.

Each point where a movement is allowed to proceed is a regulating decision and you can let the booking boy make all these decision, the best he can. Alternatively you can elect to make all the decisions and just let him do the work. However you cannot change your mind again. To make the decisions yourself, click on the box ‘Click here to interrogate auto pilot’ and then click the button ‘Manual’ to make your own decisions on regulation from then on.

In manual mode, where you make the regulating decisions, movements may be allowed to proceed by clicking over the red text (you can also click over the red text in 'auto' mode to make individual decisions but this is not without risk). There are a number of conflicting movements which need to be regulated. The fundamental purpose of the signalman is to regulate the trains safely and to minimise delay. Not all delay can be avoided as some compromises are made in the timetable (especially on summer Saturdays!). The score, which is continuously displayed, contains penalties for late running and for operation outside the regulations, with penalties differing according to the severity of the error.

In the free version, you can therefore choose to watch a demonstration of the whole sequence of trains proceed, with someone else pulling all the levers and operating the block bells. You see and hear the result, with a commentary scrolling up explaining what is happening. The score stays at 100% as no mistakes occur! To operate the simulation yourself, just click on the 'Simulation Speed' box within the first 20 seconds and you are on your own!

In the full version, the demonstration mode is more complex, with many movements operating in parallel - again you can just watch a demonstration or you can operate as a supervisor, just making the regulating decisions, leaving the details of pulling the right levers and sending the right bell codes to a menial. A taste of how this works is provided for the last two movements in the free version where you choose in which sequence they depart.

Back to Introduction	-	Purchasing the full version


Operating the levers

Clicking with SELECT (left mouse click) over a lever will operate the lever, if it is mechanically free to move and the electric lock plunger (where fitted) has been clicked on to release the electric lock. This is an exact simulation of a real signalbox.

To make it easier the lever will also operate (if it is free to do so) by clicking with SELECT over the relevant point or signal on the track diagram.

If an attempt is made to move a lever that is mechanically locked, or to operate an electric lock plunger that is not free to operate, then an error message is generated, the error message is helpful indicating (one of) the reasons why the lever is locked.

A context-sensitive help message is generated if the mouse pointer is over a lever or electric lock plunger which also indicates whether the lever is free to operate. The lever lead - a brass plate giving the lever number, its function and the pulling sequence - is only shown where the lever display is large enough to accommodate it. The text can be more easily read by clicking ADJUST (right mouse click) over the lever which causes a larger version to appear in a separate window.

Where a timetabled sequence of trains is operating, the trains will obey the signals and follow the lie of the points.

Back to Introduction	-	Using the block bells


Using the block bells

These are shown on the block shelf below the track diagram but only if a timetabled sequence of trains has been selected - that is they are not shown where the box is being operated as ground frame.

A block bell is provided for each pair of running lines - to 'call attention' of the signalman at the remote end, click with the left-button over the block instrument. Most bell codes are sent after calling attention, but there are exceptions. A menu of the available bell codes is obtained by clicking on the brass plate on the block shelf (or by clicking again over the block instrument) - then select the relevant bell code from the menu. This menu is context-sensitive and will only show appropriate bell codes, only those that are appropriate are available (in black) to be chosen.

If you receive 'call attention' then several things will happen - you will hear the bell (of the correct tone for the box or line to which it applies) and you will 'see' it vibrate. Click with SELECT (left-button) on the block instrument to acknowledge call attention and listen to the bell code you will receive. Clicking SELECT on the block instrument again will then bring up a menu of the bell codes you might wish to use to reply, clicking ADJUST (right-button) will bring up a menu allowing you to send call attention.

The Signalling Regulations are briefly described in a separate chapter.

Back to Introduction	-	Watching the track diagram


Watching the track diagram

When the box is being operated as a ground frame (i.e. with no sequence of timetabled trains), then the individual track circuits may be switched from 'occupied' to 'free' by clicking over them.

During a sequence of timetabled trains, the track circuits will be lit whilst they are being occupied by a train or vehicles. As trains move from track circuit to track circuit, the lamps light and extinguish on the track diagram and an image of the train moves across the diagram.  For the novice this is useful but the experienced user can remove these ‘sprites’ by pressing ‘F5’.  However with no window to look out of, you cannot see where each train is and so pressing ‘F5’ again allows you to ‘look out of the window’. A right-mouse click over an occupied piece of track (whether a track-circuited or not) pops up a menu to allow uncoupling or to change their direction of movement. Selecting 'Reverse' will change the direction of movement of the items coupled together (if there is no engine, just vehicles, this would do nothing). Selecting 'Uncouple X from Y' will cause it to uncouple (except where the train is still on its journey from or to the remote signalbox). If a train moves onto a section of line where another train is standing, then they will couple together (except where one is still on its journey, in which they will just buffer-up).

Simulation speed can be adjusted at any point and either Kidderminster Station (SVR) or Exeter West can be chosen as the subject of the simulation.

Back to Introduction	-	Mechanical locking


Mechanical locking

Mechanical locking between the levers follows six main principles:

.	a signal lever cannot be reversed unless the point levers are set correctly;

.	a signal lever cannot be reversed unless levers controlling facing point locks, where provided, are set for the safety of the train;

.	signals levers for conflicting movements cannot be reversed simultaneously;

.	distant signal levers cannot be reversed unless all relevant stop signals have been cleared;

.	point levers are locked by other point levers so that conflicting routes cannot be set;

.	signal levers lock each way trailing points in rear.

Mechanical locking is effected by tappet locking - the initial movement of the lever is prevented unless all of the levers which affect the relevant function are in their correct position. This initial movement of the lever then locks these levers in their correct position and only as the lever is placed in the fully reverse position does it release other relevant levers. The locking is converse - that is if lever A locks lever B, then lever B locks lever A.

The signalling system never assumes that the equipment on the ground has operated correctly, for example a point or signal having correctly responded to the lever. Interlocking is therefore provided outside the signal box to ensure that:

•	a signal cannot be cleared unless facing points have responded correctly to the lever;

•	facing points on passenger lines are provided with a facing point lock (FPL) which is secured so that as the train passes over the points they cannot be moved even if the Signal is replaced to Danger.

The FPL is held engaged either mechanically by a fouling bar between the signal and the point or by an electric lock on the FPL lever operated by track circuits. The FPL is driven via the fouling bar and engagement of the FPL is proved by means of a mechanical slide driven sideways at the FPL engages. The ends of the point blades also drive mechanical slides and only if all three slides line up in the correct position may the signal be cleared. This is either by means of a mechanical slide in the wire run to the signal or by means of electrical switches which allow the electric lock on the signal lever to be released (and provide indication in the signal box).

The mechanical locking below the operating floor may be displayed (when operating a box as a ground frame, but not during a timetable sequence) so that the movements of the mechanical locking can be seen as levers are operated.  Both a diagrammatic representation (known as a dog chart) and an actual view of the locking (with the covers removed!) are available from the menu.  On slower processors this can move quite slowly and so can be turned off by selecting either ‘Dogchart’ or ‘Actual locking’, whichever is ticked.  Selecting the unticked one changes between diagrammatic and actual.

Back to Introduction	-	How long is the shift?


How long is the shift?

The working timetable is shown in a window which appears if the box marked ‘Auto pilot – click to interrogate’ or ‘Simulation speed’ is clicked.  The train register notes the times all bell signals are sent and when each train arrived and departed. These are shown in separate windows and the register is updated to show the running of the trains, minutes late etc.

The movements which are not included in the free version are shown on the working timetable but are 'greyed' out.  The full application includes all trains shown and includes the additional timetables 'Table C' etc. for the Kidderminster simulation.

At the end of the shift, the train register is extended to give a report on all the errors made and shows a final percentage score.  It may be saved as a bit-map by following instructions on screen.

Back to Introduction	-	What does the score mean?


What does the score mean?

The score is made up of four elements - the cumulative late running of trains, the number of minor signalling errors per hour, plus the total of other more significant signalling errors. The score is updated frequently and the break-down into the four components is shown in a context-sensitive help message.

The score will reduce as significant signalling errors are made, it will rise or fall as the 'average lateness' of trains gets better or worse and it will rise or fall as the number of minor errors per hour improves or deteriorates.

Back to Introduction	-	Description of the Signalling Regulations


Brief description of the Signalling Regulations

The box in advance controls entry of trains into a block section - the section of line from the last stop signal of the box in rear to the first stop signal of the box in advance. Trains may not approach until permission is given. This can only be done by the exchange of bell signals whilst the block section is clear of any trains (although there are exceptions to this for the Up passenger lines at Exeter West). Trains may not leave until offered forward and accepted.

In the case of Kidderminster, there is only one block section, that to Bewdley South.  A context-sensitive list of bells codes may be obtained from a MENU produced by clicking (with any button) over the brass plate on the block shelf for the relevant block section. Call attention is sent by clicking over the block instrument/bell.

The procedure that will be followed when a train is ready to approach is that a single beat on the bell is received ('call attention'), which should be acknowledged (by clicking over the block instrument/bell which stand on the block shelf just above the brass plate), after which a code is received which indicates the class of the train which is approaching. This may either be accepted, ignored or a train offered instead in the other direction.

To accept, it may be necessary to reverse an acceptance lever (at Kidderminster lever number 1 is the acceptance lever from Bewdley South and at Exeter West there are acceptance levers for wrong road movements down the up lines). To reverse the lever click on the button above the lever to release the electric lock and then click on the lever itself to reverse it. Repeat the same bell code in acknowledgement to accept the train.

When the approaching train passes the previous signalbox, the code 'train entering section' (2) is sent. This must be acknowledged. When the train has arrived clear of the section, the acceptance lever may be restored and the appropriate bell code (e.g. 'train out of section' (2-1)) sent. The train out of section bell signal will not be acknowledged.

When a departing train is offered (e.g. from Kidderminster to Bewdley), it will always be accepted in this simulation. This will release the section signal, 57, for a single pull. If this signal is put back to danger then it cannot be released again. In this case, or if a train is not to proceed, then the acceptance of the train may be cancelled by a special bell code. After sending 'call attention', the menu of bell codes obtained by clicking on the blue square or on the brass plate will contain an option 'cancelling' (3-5). Once acknowledged, a train may then be offered in either direction.

Working of Exeter West is complicated and some knowledge of the Absolute Block Signalling Regulations would be helpful. Alternatively why not visit the Heritage Centre at Crewe (the 'Railway Age') where the Exeter West signalbox has been recreated and full signalling simulations are enacted alternate weekends so you can see the object of the simulation being operated as it would have been twenty or thirty years ago.

Back to Introduction	-	Local instructions at Exeter West


Local Instructions

Method of Working

The Up and Down Main, Up and Down Middle, Down Main Platform and Up Relief lines between this signal box and Exeter Middle are worked in accordance with Regulations for Train Signalling on Double Lines by the Absolute Block System, specially modified to allow more than one train to occupy a platform (in the Up Direction only) at any one time.

The Up and Down Main lines between this signal box and City Basin Junction are worked in accordance with Regulations for Train Signalling on Double Lines by the Absolute Block System.

The Up and Down Central lines between this signal box and Exeter Central 'B' are worked in accordance with Regulations for Train Signalling on Double Lines by the Absolute Block System.

The Up and Down Goods lines between this signal box and Exeter Goods Yard are worked in accordance with modified Regulations for Train Signalling by the Permissive Block System. Block bells only are provided between this signal box and Exeter Goods Yard and are to be employed for description purposes only. The 'Train Out of Section' bell signal will not be sent or received on these lines. Under normal circumstances Passenger trains are not allowed to run over these lines, and should such a movement be required working by the Absolute Block System must be instituted.

Special Bell Signals

Down Line Received	Code

Class A train not booked to stop at Exeter 	3-3-3

Down Line Received and Sent

Freight train for City Basin 	1-2

Freight train for Alphington Road 	4-3

Down Line Sent

'Is Line Clear?' for:

Class A train not booked to stop at Newton Abbot for:

Plymouth line 	3-3-3

Paignton line 	3-3-1

Up Line Received and Sent

Class A train not booked to stop at Exeter	 	3-3-3

Freight Train from City Basin 	1-2

Received and Sent between Exeter Central 'B' and Exeter Middle

Southern Region Passenger Train 	1-4-1

Southern Region Freight or Ballast Train 	3-4-1

Southern Region Parcels or Perishables Train 	4-2-2

Southern Region Light Engine (other than assisting) 	1-5

Southern Region Assisting Engine 	1-2-4

Southern Region Empty Coaching Stock 	7-2

Southern Region Breakdown Train

   or Light Engine going to assist disabled train 	7-3

Interchange Engine (SR to WR or vice versa) 	5-1

Received and Sent between Exeter West and Exeter Middle

Light locomotive from or to Shed

  or Riverside Yard	2-3-4

Light locomotive not running through 	2-3-2

Locomotive with vehicles attached 	2-2-4

Local Instructions

Absolute Block Regulation 1

In accordance with clause (e) of this regulation, the ‘Is Line Clear?' bell signal for trains not booked to call at Exeter West must be forwarded immediately upon receipt. For trains on the Up Main line booked to call at Exeter, the ‘Is Line Clear?' signal should be forwarded as soon as possible after receipt if City Basin Junction Box is in circuit. When this box is switched out, the ‘Is line Clear?' signal should be forwarded on receipt of ‘Train Entering Section' from the box in rear.

‘Is Line Clear?' must be sent for Down trains booked to call at Exeter when the train is ready to depart.

The ‘Train Approaching' bell signal will be received and acknowledged to Exeter Middle on the Down Main line, and will signify that a Class A train not stopping at Exeter has just passed Cullompton. The �Train Approaching' bell signal will be received at this box before the ‘Is Line Clear?' signal for such trains, and Signalmen must make every effort to clear traffic so that ‘Is Line Clear?' may be acknowledged as soon as possible.

Absolute Block Regulation 4

For the purpose of accepting Down trains booked to call at Exeter, the following modified clearing points will apply:

Down Main Platform

The line must be clear into the down siding as far as points 106 and points 107 secured correctly in position.

Down Main

For trains booked to stop the line must be clear to signal 98/99, points 112 set in the normal position. For trains booked not to stop the standard clearing point will apply. In both cases the detonators worked by lever 110 must be in position on the rail until it is possible to clear the signals for the train.

Down Middle

The line must be clear to signal 117, and trap point 114 at the end of the platform must be closed.

Down Central

The ‘Is Line Clear' bell signal must not be acknowledged to Exeter Central ‘B' for a Down train until the route is set for an unoccupied line and ‘Line Clear' has been received from Exeter Middle.

Absolute Block Regulation 4A

The provisions of this Regulation are applicable at this signal box, as necessary, for trains on the Down Main line.

Absolute Block Regulation 5

In connection with the working of light locomotives from Exeter Central ‘B', if ‘Line Clear' cannot be obtained from Exeter Middle for such a movement, it may be accepted in accordance with Regulation 5, providing that the line is clear beyond signal no. 87 as far as signal no. 37.

Absolute Block Regulation 31

The provisions of this regulation are applicable to the lines between this signal box and Exeter Middle.

Absolute Block Regulation 32

The provisions of this regulation are applicable to the lines between this signal box and Exeter Middle.

Working of Up Lines Between this Box and Exeter Middle

Should a train require to enter one of these lines when it is already occupied, the ‘Is Line Clear?' bell signal will not be acknowledged, but the bell signal 2-4-2 sent and acknowledged. The movement must be brought to a stand at the signal controlling the entrance to the occupied line, and the appropriate ‘Calling On' signal lowered.

A second train may be allowed to enter an occupied platform for connecting purposes only, and only if there is sufficient room for the second train to stand clear. During fog or falling snow a Handsignalman must be positioned in the rear of the first train and exhibit a red handsignal before the second train is allowed to enter.

Shunting on Up and Down Central Lines

Owing to the severe gradient on these lines, shunting moves should not be made onto them unless absolutely necessary. This will not apply to locomotives running around trains or travelling to the Up Central Spur.

Fog Marking Point

The Fog Marking Point for this signal box is Signal 117 (Up Central Starting).

Working of the Incline between Exeter St. David's and Exeter Central

For special instructions in connection with this working, see ‘Instructions to Western Region Employees when working over the Southern Region'.

Not more than four engines, including the train engine, must be attached to any passenger or freight train. Only fully fitted trains are permitted to have two assisting engines in the rear.

When 'Line clear' has been obtained for a train to depart over the Up Central line, signal 117 must be lowered, but no further action should be taken until the Distant signal for Exeter Central 'B', situated below signal 117, has been seen to move to the 'Clear' position. Signal 118, 119 or 120 may then be lowered as appropriate.

Working of Cattle Pens Siding Ground Frame

The Ground Frame operating the crossover connection leading from the Down to Up Goods Line and connection leading to the Cattle Pens Sidings together with the Disc for backing movements along the Down Goods Line as far as the Cattle Pens Ground Frame, is controlled from this signal box and is worked in accordance with the Instructions for Working Ground Frames operated by Interlocking Lever at Signal Box and Key Release Instrument at Ground Frame.

Telephone communication is provided between the Ground Frame and this signal box.

Working of engines to and From Locomotive Shed

Telephone communication is provided between this signal box and the Running & Maintenance Yard for the purpose of regulating the passage of engines.

Engines Arriving

The operation of admitting engines to the Running & Maintenance Yard must normally be confined to the Turntable Road. If this is not possible the Running & Maintenance Foreman must communicate with the Signalman at this signal box and come to a clear understanding as to what is required to be done.

Engines Departing

Upon receiving a telephone advice that an engine or engines are ready to leave the Yard, the Signalman at this box must, if circumstances permit, immediately set his points and lower the signal for the engine to leave the Yard. If he cannot permit the engine to leave the Yard straight away, the Fireman must be so informed by telephone.

On each occasion that an engine or engines leave the Yard, the Signalman must satisfy himself as to the destination and order of the movements to be made.

Shunting within the Running & Maintenance Yard

An electric switch controlling the points worked from this signal box leading to the Running & Maintenance Yard is provided in the telephone box in the Yard. When it is necessary for a shunting move to be made across the connection leading from the yard to the Main Line the person in charge must obtain permission from the Signalman in this signal box for the move to be made. If the Signalman gives his permission the switch will be placed from ‘Right for Signal Box' to ‘Right for Yard' which will electrically lock the points in the ‘Normal' position.

Upon completion of shunting, the Signalman will be advised and the switch must be restored to the �Right for Signal box' position.

Working of Points leading from Engine Shed to Up Goods Line

The points leading from the engine Shed Sidings to the Up Goods Line must be kept padlocked and the key, when not in use, retained in this signal box. When the Siding is to be used the Signalman must hand the padlock key to the Running & Maintenance Foreman who must arrange for the working of the points. A lever collar must be placed on the lever of the Up Main Inner Home to Up Goods Signal, and no Up trains or engines must be admitted into the Goods Yard until the Key has been returned and the Signalman is assured that the line is clear and the points are properly locked in their normal position.

Working of Freight Trains over Up & Down Goods Lines

When Exeter Goods Yard Box is switched out, all Freight Trains entering or leaving Riverside Yard must as far as possible do so at Exeter East Box.

In the event of a Freight Train requiring to enter or leave Riverside Yard along the Goods Lines while Goods Box is switched out, the Signalman at this box and the Yard Inspector must come to a clear understanding as to what is to be done. A competent person must accompany the movement in order to handsignal the train past the Goods Yard Box Home Signal and across Exwick Level Crossing.

Accommodation Crossing between Exminster and Starcross

Arrangements have been made for the City of Exeter Fire Brigade, in the event of their being called to a fire at the Turf Hotel, to telephone Control, from which it will be understood that an appliance with trailer pump equipped with winders has left the Exeter Fire Station by road and that in approximately 20 minutes time it will require to be taken over (or delivery pipes taken under, if adjoining fields are flooded) the Accommodation Crossing at 199m. 35ch. between Exminster and Starcross.

Immediately upon receipt of this telephone message, Control will instruct the signalboxes in circuit on either side of the crossing to warn all trains until the message is received from the Fire Brigade that the fire Party have cleared the crossing which will be passed on to the signalboxes concerned. When the Fire Brigade have completed operations, a further message will be passed on either side of the crossing to warn all trains until the advice is given that the Fire Party have returned back over the crossing.

Back to Introduction	-	Brief history of changes at Exeter West


Brief history of changes at Exeter West

A new locking frame was installed on 18 April 1959 - a GWR 5-bar vertical tappet frame at 4" centres with 131 levers. This is implemented as "Exeter West (1959)". The layout at West box was unchanged since at least 1935 but by 1959 the station throat between the river bridge and the platforms had been track circuited and fouling bars replaced by track circuit locks, some ringed arms had been replaced by 3ft arms and some backing signals replaced by discs. The scissors crossing between the Down Main and the Down Main Platform, controlled by Middle box, had been removed in October 1952. Exeter St. Thomas box was closed the following day.

The timetabled sequence of train movements assumes that S.R. trains terminate at St. David's as it is based on Summer 1982. The 1959 layout would not therefore be suitable for this service.

Exeter St. Thomas Up Distant (below City Basin Junction's Up Starting signal) became West box Up Distant and similarly the previous St. Thomas Up Starting signal became the Up Home, a new signal being installed as the Inner Home and the Home signal bracket became the Up Starting signals. A period of decline in the early 1960's accelerated when the Western Region was given the chance on 1st January 1963 to pay off old scores as the ex-Southern lines were transferred to W.R.

By 1964 S.R. trains to Central could depart from platform 4, a replacement signal with a route indicator was installed and the necessary facing point lock provided. This is implemented as "Exeter West (1963)" which reflects the position as at January to June 1964 except that it shows ringed arms rather than 3ft arms on signals 77 to 80 (actually replaced in January 1959).  Later in 1964 signals 79, 80, 15, 35 and 102 were renewed as discs.

In 1966/67 the connection to the engine shed was simplified making movements on and off shed to and from the Down side much more complicated. In 1968/69 the spur siding off the Up Central line was taken out of use and points 89 converted from spring to normal operation, by which time the Cattle Pen Ground Frame had been removed. This is implemented as "Exeter West (1970)" and reflects the position between January 1970 and July 1972.

On 22 February 1970 Exeter Central 'B' closed (meaning that trains to Central could be allowed to proceed before seeing the Central 'B' distant drop). On 18 November 1973 Exeter East was abolished making use of Regulation 4A unnecessary as West box would then control a distant signal 2300 yards away (previously Exeter East Down Distant, beneath Cowley Bridge Junction Down Homes). On 27 February 1978 Goods Yard box closed and the Goods Lines and sidings were severed at Exwick crossing.

Back to Introduction


Known bugs

A list of the known bugs is included below – those which have been corrected are also shown with the relevant version number where it was corrected.

Bug number	rectified?	Description
1		Not clear how wrong road moves on Good Lines are signalled. Hence none are provided for.
2		Permissive block on Goods Lines not yet implemented. Otherwise use of block bells on Goods Lines to describe trains is implemented, TES and TOS not being used.
3	SigBox41B6	Add hard spaces to lever leads. Avoids having TO UP & DOWN MAIN all on different lines on lever lead.
4	Gen291	Corrections to EW 1970/1959 not yet done.
5	Gen41DX	KR to be made smooth curves. This will take a lot of work and is not high priority.
6	SigBox340	'Down train ready to depart' annunciator. This will replace the telephone call 'Down train ready for departure' with a buzzer and a light identifying P1/P3/P4/P5/P6.
7	SigBox340	Telephone concentrator. All telephone calls will light a lamp and wait for a click to open a window with 'telephone message'.
8	SigBox300	Cannot close mech. lkg. table or ECT windows. This must be something simple...
9	Gen291	Remove second BB and AF t.c. at KR.
10	SigBox292	Initial simulation speed value is wrong.
11		Add S.R./special bell codes 141 341 15 124 72 51 234 232 224. This may be a little tricky to implement, especially the special bell codes, however 2-3-2 is partially implemented. For now just BR (WR) bell codes apply.
12	Gen38ZE	Add detonator placer, treat as red signal both ways, show on diagram. At present detonator placers can only be identified from the lever lead and it is not clear where they are located!
13	Gen41DX	Add limit of shunt board and remove fudge. Shunts are stopped at no. 3 signal at EW but no symbol on diagram.
14		Add white stripe to levers, and black stripe for relief line.
15	Gen400	Footnotes require engines going onto shed normally to use the turntable road. At present all engines coming off shed also use the turntable road. Engines coming off shed should use the shed road.
16		Provide pilot engine for sundry shunting? At present only train engines are available. Principal problem is that certain trains arrive in the Goods Sidings and then 'vanish' until wanted again - if a pilot engine was standing there it would not be handled properly at present.
17	Gen320	Add 'R' superscript to ECT [BN29(N)L 2R ON].
18	Gen320	BN Rock to be 13, P3 to be 9.
19	GenTab290	Up trains at EW routed P4 uncouple. Solved by marking them as departures (where they continue to Middle) before they reach the end of the platform (where the engine would uncouple).
20	SigBox315	Rules for acceptance of trains (Regs. 4, 4a and 5) are not quite in line with footnotes as follows: Reg. 5 authorised for LEs on Down Main/Main platform/Middle. Reg. 5 allowed on Down Goods (bug).
21	SigBox300	Add CRC check of data surrounding name and address. To improve security.
22	SigBox292	Cancelling clears Perm%() but 323 does not. Had effect of leaving section 'occupied' after train withdrawn.
23	SigBox292 (partly)	Distinguish between wrong route and shunting. Shunting movements are not permitted beyond EW122, EW117, EW20, KR57. Departing trains signalled past these signals will give a 'wrong route' error whereas attempted shunt moves should produce a less serious error.
24	SigBox292	Correctly identify passenger trains passing 10/11 signal. Although not entering a block section, this still represents a 'wrong route' error.
25	Gen291	Up goods track section number wrong. This had the effect of preventing freights passing EW20 as they were not recognised as departures.
26		At present signal EW20 is regarded in the same way as EW117 and EW122. Consider treating this as EW4 so that any train may pass (including shunts) but cannot proceed 'off the diagram' until recognised as a departure. At present freight trains standing at EW20 will cause a 'wrong route' error if EW20 is cleared before its scheduled departure time. Freights standing in advance of EW20 must then be recognised as ready to depart.
27	Gen291	Check all differences in section nos between smooth and diagrammatic.
28	SigBox292	Redraw of trackwork occasionally displaced.
29	SigBox340	Redraw of levers occasionally fails. Effect is to partially redraw or not redraw a lever after clicking on a point or signal on the diagram.
30	(not relevant for PC version)	Can !Run file ask for font cache to be at least 250k?
31		Failing to ack TES - treat as sloppy until TOS.
32	SigBox362	Failing to ack TES - resend 2 beats.
33	(not relevant for PC version)	Add !Licence text to directory.
34		Error 'rev acc lev before ILC' is in both sloppy and reg?
35	SigBox300	Improve 'Many errors cancel or OK' message. This error message allows an interpreted BASIC programme to be interrupted at the point of error to examine contents of variables. However the initial error message allows this as well. To be cleaned up, especially for compiled applications.
36		Add signal repeaters, point repeaters, lock indicators. As there is no physical equipment, indicators have not been provided, and in 'novice' mode points and signals move to show their position. The primary reason to do this was to show the signals that were automatically replaced to danger. In due course an indicator will be provided to do this...
37		'Minutes late' display inconsistent? This is for odd factions of a minute.
38	GenTab9CY	Consider adding a shunt to/from Down Sidings at EW.
39	SigBox208	At EW only 1, 81-84, 131 are short levers.
40	SigBox313	Add '%' to all integer variables.
41	SigBox300	'Wrong route' error appears in register, suppress after first. Currently each attempt produces 'Wrong route' which fills the 'description' column, leaving no space for other items.
42	SigBox320 Gen320	Running lines that are not track circuited should be grey/orange(goods)/blue(sidings). At present all are light blue.
43	SigBox300	Change '70' to 'ew_aa%', kr_aa%, bs_22t%, toBS%, DnBR%, kr_yd% etc. At present there is a mixture of constants and variables.
44	SigBox300	'1210 Barn' added to register twice, overflowing 'description' column. Permissive accounting breaks down when engine hooked off (inevitable) and run round (as engine reintroduced from Middle this could be corrected). Also stock introduced with 3-3-2 breaks down as 'wrongly described' when departing as a side effect of permissive accounting having affected BC%().
45		5-2 bell code sent both ways without C.A. Not very easy to cure this one.
46	SigBox340	Add context sensitive train speeds to KR.
47	SigBox289	Add context sensitive train speeds to EW. Restrictions: RiverBridge 25/30, Goods Lines 15, SR 15, P4 10, P1/P3 25. Linespeed on main lines except passing Up Distant at caution - 20.
48	SigBox26I	Suppress green/red/pink T.C. surround colour in all but 'Novice' modes.
49		Add strike-in bell for KR AB TC.
50		City Basin Jcn switching in & out not implemented.
51	SigBox300	Help text does not explain 'cheat mode' where individual timetable sequences can be manually terminated as 'complete'. This is done by clicking ADJUST or MENU over the Working Time Table window coloured text additions. Not available in the 'restricted' version.
52		Permissive block does not yet permit cancelling to be sent as individual trains are withdrawn. This would require the accounting method to count trains not just items of stock. At present therefore cancelling is only permitted once the section is empty. Cancelling is not possible if a train has beEn accepted under line occupied acceptance, but not put on line, even once the section is empty.
53	SigBox300	Certain error messages are obscure, but are only useful to identify bugs during testing. These errors will be revised to say 'Please use e-mail to report the following error: 'internal error ff at line gg at time tt' so that it can be fixed. The offending error messages were poorly described (now included in this Help file).
54	(not relevant for PC version)	When terminating a simulation sequence (e.g. by closing the main window) this allows a complete restart. All timetable information should be erased at this point to avoid later conflicts.
55		When reopening a box diagram window, all levers and indications should be restored to 'normal'.
56	SigBox314	Change use of 'LOCAL' to conform to ABC Compiler usage. Ensure that LOCAL ERROR is last item made LOCAL.
57	SigBox314	Improve CRC checking.
58	SigBox41.PJ	Some telephone messages not well formatted.
59	SigBox315	Accepting a train under Reg. 4A or Reg. 5 gives wrong sound effect.
60	SigBox315	Help messages that are too long cause a fatal error due to a bug.
61	GenTab330	Friday timetable: 1310 Waterloo (1632 arr.) – engine runs round but cannot shunt stock clear for 1643 arrival. Mixing 'engine arrived' and 'line occupied acceptance' confuses simulation. Solution is to delay departure of engine (seq. 128) until 1646 to Exeter Central has completed.
62	GenTab330	Seq. 128/129 incorrectly shown as engine off 0910 Waterloo not 1310 Waterloo.
63	GenWTT320	WTT should include list of shunting: Friday: 1231 arr in P4 to shunt clear to P3 for 1253 arrival. 1411 arr in P4 to shunt clear to P3 for 1432 arrival once 1418 dep. clear. 1432 arr in P4 to shunt clear to P3 for 1511 arrival once 1456 dep. clear. 1456 arrives in Gds Sdg. Shunt to P6 once 1710 dep. clear. 1632 arr in P4 to shunt clear to P5 for 1658 arrival. 1632 shunt in P5 to shunt to P4 for 1749 arrival once 1710 dep. (freight) clears. This means that 1450 arr in P6 and 1643 arr in P4 will probably need to enter an occupied platform. Saturday: 1234 arr in P4 to shunt clear to P3 for 1301 arrival. 1306 arr in P1 to shunt clear to P6 for 1331 arrival. 1421 arr in P4 to shunt clear to P3 for 1432 arrival.
64		Add more freights to make regulation that bit more challenging!
65	Gen330	Make track elements join without black line between them - needs bounding lines to be drawn separately from fill colour.
66	SigBox330	Ensure that RiscBASIC version is used on Virtual Acorn to conserve memory (i.e. on all versions prior to RISC OS 3.50) and that ABC version runs on Iyonix.
67	Gen330	Minor bug in drawing curved points.
68	SigBox332	Distinguish between interpreted and compiled versions showing 'Int', 'Cru', 'RB' and 'ABC' to show interpreted, crunched interpreted, RISCBasic compiled and ABC compiled respectively.
69	SigBox332	Cancelling sometimes caused an incorrect train register entry, corrected.
70	GenTab332	Minor bug in train identification (1305 Exeter SD).
71	SigBox335	Occasional memory problem on Iyonix appears when drawing complicated mechanical locking. Caused 'abort on data transfer' errors and was finally traced, with the assistance of Castle, to a 'feature' of the ABC compiler where real array elements cannot be used as RETURN parameters.
72	SigBox336	Minor drawing bug prevents vertical lines in electrical control table being drawn.
73	SigBox338	Same drawing bug prevents track circuit indications from working.
74	SigBox339	When accepting a train under reg.5 or reg.4A, sound effects are not quite correct.
75	SigBox339 LkgDrawA0Q SourceA0D	Improve mechanical locking display.
76	SigBox339	Improve help messages on non-track circuited lines.
77		Assisting engine bell code not yet implemented.
78	SigBox362	Telephone concentrator stops ringing during pause.
79	SigBox362	Train-on-Line not forced on block instrument once relevant track circuit drops.
80	SigBox362	Score not updated continuously. Clock face not perfectly drawn.
81	Gen39ZK	Radyr Junction (1961) still under development, further information (lever leads) required.
82	SigBox394	Drawing of track circuits EW1970 HK and EW1959 AH & HK improved (does not affect free version).
83		Track circuits at Morlais Junction not shown on box diagram.
84		Acton Yard - tidy up box diagram and improve detail of colour light signals.
85	Gen39VP GenTab39Z	Exeter West platform track section numbers prevent all possible positions being listed - this affects Friday departures 1623 and 1720 which have to be shunted away from platform 6 before they are 'seen'.
86	GenTab39Z	Exeter West Friday departure 1648 (P1) announced as ready before 1646 (P4) causing delay.
87		Subscript out of range error (untraced) at 1815 on Friday service at Exeter West. Not recurred.
88	Gen41XU	Draw file for train register has wrong offset when opened in !Draw.
89		Exeter West Friday service can run out of space in the train register!
90		Consider keeping a hidden event/error log in detail for chasing out those last few bugs.
91	SigBox39VM GenWTT399	Regulation 4A now applied correctly on Down Main (advance block section should be block normal or Line Clear, not just Line Clear). Demonstration mode now implemented. Most (all) track sections at Exeter West are shown as descriptive and not just arbitrary numbers. WTT for Saturday now has tidier boxes to show minutes late for each train. Exeter Central 'B' and City Basin Junction are now not both summarised as 'CB'.
92	SigBox3BL GenTab3BJ Gen3BK	Demonstration mode improved, allowing novices to regulate trains without having to understand how to operate the box.
93		Cannot send 'call attention' whilst a wrong road movement is approaching.
94	SigBox41B1	IBM-compatible version created but boxes may only be used as ground frames so far. Free version 41.Z5 (PC) includes Kidderminster Station, Bewdley North (1956), Exeter West (1963), Morlais Junction and Radyr Junction (1961 and 1987) Note: Morlais Junction and Radyr Junction mechanical locking included but electrical locking omitted.
95	SigBox41B8	Improve first line of text in auto-pilot window.
96	GenTab41B8	Make sequence numbers appear in numerical order ‘cast in order of appearance’
97	SigBox41DZ	Some movements are jerky – SR to P4; 13 signal to P4/P5; either side of (BS)30; movement over pointwork not related to point position.
98	SignalBox41YE	Clock numerals corrupt slightly. (PC version only)
99	Gen41DX	Remove second ‘BC’ track circuit lamp at Kidderminster.
100		Improve sound of block bells (at present bell tones are arbitrary rather than tuned to what was actually provided)
101		Improve sound of platform buzzer. (PC version only)
102	SigBox41DZ	‘Ready to depart’ and telephone concentrator bulbs show odd colours. (PC version only)
103	SigBox41B8	‘Press F4 to save train register’ is not implemented. (PC version only)
104	SigBox41E3	Telephone bell not working and concentrator light fails to extinguish when message box closed. (PC version only)
105	SigBox41E3	Obscure bug in conversion to PC version that caused acceptance lever to become mechanically locked if restored while train in section. (PC version only)
106	SigBox41E4	Line spacing of text on lever leads incorrect. (PC version only)
107	SigBox41.JF	Kidderminster BD track circuit indication omitted. (PC version only)
108		Bug reported that right-click fails to bring up MENU selection:  cannot replicate bug. (PC version only)
109	SigBox41.P4	Animated mechanical locking has some minor detailed drawing errors associated with the conversion from Acorn ‘draw’ module operations to Windows API vector drawing functions.  Mechanical locking is not shown ‘in motion’ at present, only updated when lever movement has stopped as the drawing routines have not yet been optimised. (PC version only)
110	SigBox41.ME	Sound generation adjusted to wait until quiet (rather than last beat sent) but then found not to work on some versions of Windows. (PC version only)
111	SigBox41.QD	Vector drawing routines did not work on Windows ME, now corrected to use only 16bit graphics units.
112	SigBox41.W8 SigBox41V	"Click MENU here to adjust zoom" message removed on PC version. Help message for Down 'ready to depart' indication (for Exeter West) removed from Kidderminster. Auto-answer for telephone message improved on Acorn version. Box diagram details improved
113	SigBox41.WC Gen41WT SigBox42.08	Capability to add additional signal boxes as separate add-ons but file open dialogue looks at last opened directory.
114	SigBox41.WP	Help messages occasionally gave error.  Sound buffer usage improved.  (Acorn only).
Note: Current version is SigBox41WP (Acorn, advertised as 42.8), SigBox41YE (PC, advertised as 42.70), Gen41XU, GenDat41N9, GenWTT41F0.

Still looking for another box to simulate - needs full dog charts, lever leads, ECT, box instructions, explanation of regular shunting movements, timetable with LE/ECS moves and platforming.

C. K. Hall 7th April 2006.


Development History

The development history of !Signalbox is as below:

Date	Version	Developments included
May 1994	1.01	Draw levers and simple track diagram. Spidery screen display and slow redraw.
June 1994	2.20	Bewdley South and Bewdley North. No iconbar menu Basic data structure robust.
July 1994	3.40	Generalise data input. Add Kidderminster.
October 1994	5.00	Click on point/signal now works. Electric locks and track circuits being added.
March 1995	8.0zz	Track layout finished. No moving trains.
November 1995	2.0p	Compiled application. Sequence of trains Electric locks and operating track circuits.
May 1996	2.70G	Realistic clock face.
February 1997	5.00	Exeter West added.
May 1997	9.00	Substantially complete.
February 2000	9.9G	Improved interlocking. Enhanced screen display including platforms and signalbox. Proper clock display with smooth movement. Continuously displayed score, adjusted at every error. Three levels of difficulty 'Novice', 'Moderate' and 'Expert'. Work around (after a long period of thought) to avoid a RISCBasic bug which introduces 'data abort' errors.
February 2001	13.0	Animated mechanical locking. Fringe boxes for Rotherwas Junction etc. Allowance for more track circuit elements (22) and levers (800). Proposed Bewdley North relocking. Rotherwas Junction added.
April 2001	14.7	Bugs corrected (5-bar second tray). Radyr Junction, Acton Yard and Morlais Junction added, plus fringe boxes. Array dimensions increased to accommodate new boxes. Lever leads improved. Mechanical and electrical locking tables improved.
August 2001	15.1	Array dimensions made variable for future changes. RadyrJn and Exeter West split into earlier and later layouts.
September 2001	15.4	Electrical control table now shows 19(NR)L and 34NR. Bugs corrected (n_items%). HTML mechanical locking table produced for external use. Electrical control table improved (use of nr%; 'ON', 'R' in small caps; approach locking). Bewdley North relocking corrected.
November 2001	16.2	Selection of period date for Exeter West and Radyr Junction improved. Bugs fixed (wrong road moves; runaway; simulation start time; approach locking). WTT display misaligned with text. Cheat mode added to allow sequences to be aborted. TRegister now saved as a 'Draw' file. Maximum number of sequences increased from 88 to 145. Scale of electrical control table reduced to 50% and content improved. Bewdley North data improved. WTT display improved to show data about sequences more clearly.
November 2001	16.3	Train arrived message suppressed at Up Inner Homes. Ready to depart message suppressed Eastbound from pfms 4,5,6. Cheat mode (aborting trains) suppressed on saleable versions. Forces correct leading on WTT display so text lines up correctly. Exeter West now has a Friday service in place of a Saturday service, with up arrivals adjusted.
December 2001	18.1	Cheat mode corrected to allow for gaps in numbering. Clock now shows grey when paused. ForceRedraw now has proper extent values. Minor errors now counted per hour. Train register updated on game over. Train 'ready to depart' limited to down trains. Electric locks now time out too quickly during pause. Bugs with Goods Lines corrected. Window extents now set correctly. Some bugs with train register entries corrected. Non-track circuited lines now identified by name on coupling. Both Friday and Saturday services now available for Exeter West.
February 2002	18.B	Add 'A' and 'B' to detection in electrical control table Bug on zoom value corrected (affected app. lkg. indicators). Electrical control table window added. Locking tray max. channels increased from 10 to 11. Bug corrected (large dog charts overwrite memory). Percent display adding during loading of dog charts. Third Exeter West version (1970) added. Passenger trains that pass EW10/11 now flagged as wrong route. Hourglass display added as application starts up. Trains don't start until platform starter clears. Some error messages now treated as dialogue. Lever lead (adjust click) relocated to top LH corner.
February 2002	20.0	No change, version numbers now aligned.
February 2002	20.1	Help file changed to StrongHelp.
March 2002	20.8	Lever leads improved. Exeter West 1970 data improved. Minor data errors corrected. Last major development of 'free' version.
April 2002	24.0	Box diagram now centralised and boxed. Exeter West box diagram now drawn using smooth curves in 'full' version.
May 2002	24.8	Bewdley North (1956) data added and included with 'free' version. Minor data changes. Menu options now sorted into order.
July 2002	26.0	Improved visibility of track circuits. Seperate 'lever' and 'diagram' windows that can be zoomed independently. Automatic scrolling of windows as mouse approaches edge. Clicking at the edge of a window adjusts its size or zoom. Lever leads can be more easily read, enlarged in a seperate window.
August 2002	27.0	Train speeds at EW improved. More responsive and better use of faster processors. Close window bug corrected, register and WTT can now be reopened. Line occupied acceptance on up lines. Icon menu options now shown ticked.
September 2002	29.2	Line occupied acceptance bugs corrected. Train lengths and speeds adjusted to give correct track occupancy times. Up trains passing the up distant at caution go more slowly. Cancelling remains limited to times when the advance block section is clear. Two additional light engines at start of service at Exeter West on the Friday. Audible thump as bell codes are sent. Help messages improved.
October 2002	30.0	CRC check of user details – causes abort if details have been altered. Error reporting improved. Permissive accounting bug fixed. Some constants given names, not just numbers. 'Wrong route' message improved. Help text over WT improved.
November 2002	32.0	CRC check improved. Help messages that are too long are now handled tidily. Reg. 5 acceptance now aligns with footnotes. All integers are now handled as integers, LOCAL usage amended to conform to ABC compiler limitations and relevant compiler directives added. Alternative run images (RISCBasic compiled, ABC compiled or crunched interpreted BASIC) provided to allow 32 bit compatability with or without GDraw/DitherExtend functionality. Non-track circuited running lines now shown in correct colour (grey/orange).
January 2003	33.5	Minor bugs within ABC compiler overcome, 32-bit aware version of !StrongHelp now bundled.
March 2003	33.9	Minor drawing bug prevented vertical lines being shown on the electrical control table and track circuit indications from showing correctly - cured. Help messages and mechanical locking display improved.
April 2003	36.0	Telephone concentrator and 'ready to depart' annunciator added. Lever redraw bug corrected. Context-sensitive train speeds added to Kidderminster. Help messages for concentrator and ready to depart annuniator added. Error display improved to indicate line number and Wimp_Poll reason code. Data file format revised. Redraw routines for clock and score etc. improved. Train 'ready to depart' simplified.
April 2003	36.2	Telephone concentrator improved - now rings until answered and 'MENU' shows last message. Score is now continuously updated and clock display no longer has 'debris' from last time displayed. Train-on-Line is now correctly forced as the home signal berth track becomes occupied, if train entering section was not acknowledged. Unnecessary 'train arrived' messages suppressed and 'green' track circuit indication (train ready to depart) now removed. Minor corrections to help messages and timetable data.
June 2003	39.1	Track circuit drawing improved. Data file format changed to suit. Radyr Junction and Exeter West (1970) track diagrams improved and corrected. Radyr Junction (1984 & 1987) added to freeware version.
July 2003	39.4	Radyr Junction 1961 mechanical locking and lever leads improved (still under development). Buffer size increased. Exeter West 1970 & 1959 track circuit drawing bugs removed.
November 2003	41.1	Major enhancement to include a demonstration mode for the WTT services at Kidderminster and Exeter West, which operates the full service of trains, bells jangling, filling the train register and making no errors!
February 2004	41.Z5	IBM-compatible PC version implemented but so far only allows boxes to be operated as ground frames.
May 2004	41.B8	IBM-compatible PC version improved to allow timetabled sequence of trains.  All features implemented.
August 2004	41.DZ	Kidderminster now smooth curves – box diagrams include all relevant detail correctly. Limit of shunt boards and stop boards provided. Phone is now answered automatically after a 20s delay and closes after a further delay. A few levers were drawn with incorrect colours, now corrected. PC version now makes sprites optional so press ‘F5’ to ‘look out of the window’.
December 2004	41.E4	PC version minor bugs corrected.  Lever leads improved. Telephone concentrator now works correctly on PC version.
January 2005	41.JF	PC version files tidied up and a single version distributed with facility to enter a licence key to upgrade to full version.
January 2005	41.ME	PC version now includes animated mechanical locking showing a view below the operating floor.  This may also be displayed in diagrammatic form in what is called a ‘dog chart’. Bug in use of ‘PlaySound’ routine that caused block bells to stay silent on some versions of Windows corrected.
March 2005	41.QD	Animated locking improved on PC version.  Still slow (on PC version) in assessing which locks should move.
April 2005	41.Q6	Pre assessment of which locks should move makes lock movement near immediate.
November 2005	41.W8 (PC) 41.V (Acorn)	Box diagram detail improved, including colour of running lines. Some redundant help messages removed. Acorn version updated for A9Home computer Acorn version auto-answer of telephone corrected.
December 2005	41.WC/42.0 (Acorn) 42.08 (PC)	Capability to add additional boxes as separate add-ons.
April 2006	41.WP (42.8) (Acorn) 41.YE (42.70) (PC)	PC version can now show mechanical locking table and electrical control table. PC version now shows movements of points and signals on the box diagram as the lever(s) are operated. Further additional boxes have been added: Neath & Brecon Junction, Penwithers Junction, St Austell and Oxford Station North.
7th April 2006.