SECTIONAL APPENDIX  BATH GREEN PARK


Introduction

This simulation is a remake of the original Bath Green Park heritage simulation.
Development of the heritage simulations over the last years means that it is now possible to create a simulation which is much more closer to the reality as the original one. Features introduced now are, for instance, separate FPLs, multiple distant signals, distant signals slotted by other boxes, proper working of groundframes, green flag shunt locations etc.
Another very interesting feature of this new simulation is the proper working of banking engines returning from Combe Down after banking freight trains out of Bath.

The standard timetable is new, based on the 1951 timetable. There are two versions of this timetable.
One version has extensive notes and full details for all empty stock workings.
The other version is for experienced users. It has far fewer notes and empty stock workings are not detailed but must be organized by the player.

Note that the additional timetables as released for the original simulation will not work with this updated version. These additional timetables will be converted to the required format and will be released separately.

General and History

The Midland Railway opened its branch from Mangotsfield to Bath in 1869. At first, the line terminated south of the river Avon but one year later, the new station which was the terminus for this branch was completed. The new station was situated on the north bank of the river and was known as Bath Queen Square, named after a local square nearby. The name was changed to Bath Green Park in 1951.
The station was a modest affair with just two single-sided platforms, and the two platform tracks plus two sidings in between. The platforms almost ran up to the river Avon. Goods yard and locomotive shed were across the river.

Meanwhile, two separate companies were building a line from the south coast to the Bristol area.
The Somerset Central Railway opened its first section of line, from Highbridge to Glastonbury, in 1854, and reached Templecombe, the junction with the Salisbury & Yeovil Railway, in 1862.
The Dorset Central Railway completed its first section from Whimborne to Blandford in 1860. At Whimborne, this line connected with the railways along the south coast. In 1863, the final section between Blandford and Templecombe was completed and the gap was closed. One year earlier, the two companies had amalgated into the Somerset & Dorset Railway.
The purpose of the line was to cater for through traffic from the south coast to the west and north, but the anticipated traffic never materialised and soon the company was in financial trouble.
As a last attempt to avoid the inevitable, the company set out to build a branch from Evercreech Junction to Bath. This branch was completed in 1874.The S&D branch connected with the Midland line at Bath Junction,about  a mile from the station. An agreement was reached with the Midland Railway for shared use of their station and goods facilities. This joint use provided for good connections to the north, for both passenger and freight trains. However, both companies had their own locomotive depot. This brach was indeed succesful, with a large amount of traffic generated by the quarries and collieries in the Radstock area. However, the financial burdon of the cost of building the branch proved too much, and the company started looking for purchasers. In 1875, a deal was completed with the Midland and LSWR railways which took over the company as a joint enterprise, and the line became the Somerset & Dorset Joint Line.
After grouping, the S&D became a joint enterprise of the LMS and SR. It was operated mainly using Midland or LMS engines.
After nationalisation it became part of the Southern Region, but in 1958, the northern part (north of Templecombe) was transferred to the Western Region. Despite this, the line kept its Midland engines, and near the end of its working life, the S&D had some of the oldest working Midland engines.

The passenger services to Bath and on the S&D to Evercreech Jn, Templecombe and Bournemouth were only a modest affair, and on weekdays there was only one through service from the North (Manchester) to Bournemouth. On summer saturdays, however, it was different world, with a large number of express services from the north to the south coast and back.
Freight was the life line for the S&D. The collieries and quarries at the north end of the line provided a large amouth of traffic, most of which was handled through Bath Yard. There was also a good flow of traffic from the west which came onto the S&D at Templecombe.

The S&D and the Midland branch to Bath did not survive the Beeching axe. All passenger traffic to Bath and on the S&D were terminated in March, 1966. Goods traffic from Mangotsfield lasted a little longer, this included goods services to the Bath Coop sidings, just outside Bath on the line to Midford. But all traffic ended in 1971, and all lines were lifted.

The station itself, however, survived and is now a shopping centre and offices, and the former railway bridge over the river Avon is also still in use for road access to the station area.

Adaptations
                          
Bath Junction.
All lever numbers for Bath Junction are as per original.
Signal 20A was added to comply with the simulation requirement to provide a single exit signal. However, to have operations of the approaching signals as close to reality as possible, all route settings to signal 20A (from signals 1, 4, 8 and 20) require Line Clear to be obtained from Weston.
Signal 33 was slotted by Bath Station (lever [1]34). Slotting of main signals is not supported by the simulation, and it would not add to the operation, so this slotting is not included and this signal is operated by lever 33 only.
Levers W11 and W12 (at west end of Gaswork Sidings) are provided to operate switches which in reality were manually operated.
The sidings to Bath Coop are not included, these were located on the line to Midford, to the south of the Bath Junction home signals.

Bath Station.
All lever numbers for Bath Station are as per original, but with 100 added to that number.
Signals W6, W7 and W8 are substitutes for a single signal ([10]6) which controlled all three lines.
Levers W1 and W2 (at east end of Gaswork Sidings) and GS (at Gas Sidings) are provided to operate switches which in reality were manually operated.
There were two entries to the S&D depot. The most westerly exit started at points [10]9, and the exit was controlled by signal [1]10. The second exit started at a manually operated point between [10]9 and [1]19, the exit was controlled by signal [1]11. For the simulation, this has been reduced to just a single exit. Signals [1]13/22/23 controlled both lines at the Gas Sidings. In the simulation, these signals have been moved to the single track between pts. [1]18 and GS, with flag positions provided for the two Gas Siding lines.


Local instructions
                              

Shunt locations

At many signalboxes there were a number of locations in the area where trains could reverse for shunt workings, with permission to proceed to reverse provided not by signals but by instruction from the signalman, usually by showing a green flag. At Bath Green Park and Bath Junction, this applies for a number of locations as shown in the diagram. Permission for trains to proceed at these locations can be given through a series of buttons, displayed next to the levers. When a button is selected, a green flag is shown at the appropriate location, either the signalbox or the groundframe. Available routes from these locations and the related locking details are shown in the locking table. Note that these permissions operate in the same way as for signals, in that when permission is granted, all related switches are locked and other routes which would conflict with the permission are also locked.

Special intructions

Bath Station  platform 2
Platform 2 at Bath Station is split by the switch which is provided for engine release.
Short trains (upto 8 coaches plus engine, or 7 coaches if an engine exchange is required) must stop clear of the switch to allow the engine to be released. Long trains must run through to the buffer stop.
The platform line between the signal and the switch is allocated to the main Bath location.
The section between the switch and the bufferstop is located to a separate location, Bath PE [Bath Platform End].
Short trains must be booked to stop at Bath, Long trains must be booked to stop at Bath PE.
Shunt position P2F must be cleared separately for all moves to the end of the platform, so both for through trains as well as for shunt moves. This position can be cleared for through moves when signal 105 is cleared. It can be cleared for shunt moves when groundframe A is released.
Motive power depots
Both original Midland and S&D depots survived until the withdrawel of passenger services in 1966.
After reconstruction in the 1930s, the only turntable at Bath Green Park was accessed through the exit to the Midland depot. However, there was only limited storage space at this location, so most engines were first sent to the former Midland loco depot for turning, and then to the former S&D loco depot for storage. Only some engines for workings on the Midland Main line were stored at the former Midland loco depot.
Freight train engine release
All tracks in the goods yard were dead-end tracks, there were no engine release or run-round facilities in this area. Therefor, all freight trains were stopped on the Up Shunt Line (at signal 114/115), where the engine would be detached and sent to the loco depot. A yard pilot then backed up to the train and propelled it into the goods yard.
Banking engines
All freight trains to Midford were banked as far as Combe Down, approx. 2 miles from the Bath Junction home signal. The engines would leave the train at this location and return to Bath. There were no signals controlling this move.
The simulation includes these banking engines as these return to Bath.
Note that the banking engine cannot actually be attached to the train, the engines are assumed to be attached when the train exits from the goods yard. Information on the banking engines is shown in the train notes.
When the freight train reaches Combe Down, the banking engine leaves the train and this now becomes a light engine, returning to Bath.
When the freight trains clears the line at Midford, OOS will be send by Midford box but this cannot be acknowledged until the banking engine also has cleared the line.

Token exchange
Token exchange of the single line tablet for the branch to Midford was done through automatic token exchange equipment (Whittaker apparatus). There was therefor no need for trains to stop for the token exchange. Banking engines, however, obtained a special tablet from the Bath Junction signalman, which could not be exchanged through the automatic equipment. On the way back to Bath after banking, the engine had to stop opposite the Bath Junction signalbox in order to hand back this tablet. In the simulation, returning banking engines will therefor have a short stop on the section between signal 17 and points 16.
Shunt position STR
The shunt position STR, on the Straight Road, only needs to be cleared for shunt moves reversing at this location. For through routes from signals 104, 108 and 114 to Straight Road, Platform 2 or Dock, this position is cleared automatically and need not be set manually.


Fringe boxes

Distance to fringe boxes (distances from Bath Junction box) :
Weston (to Bath Junction)  : 0m 31c
Midford (to Bath Junction) : 3m 68c
Distance between Bath Station and Bath Junction is 41c.


General instructions

Rules to caution trains.
For semaphore signalling, the rule (rule 39A) applied that for a sequence of signals which had no intermediate or combined distant signal, if the last signal in this sequence could not be cleared, all preceding signals had to be kept at 'danger' at the approach of the train and could only be cleared if the speed of the train was sufficiently reduced. For the simulation, the speed must be reduced (to about 10 mph on approach). The speed while passing the signal must not exceed 15 mph.
See the locking details for the list of signals and conditions where and when trains must be cautioned. Note that the cautioning does not always apply for shunt moves which are wholly within the station area.

Locking rules.
For locking rules please see locking table.

FPL.
Facing Point Locks (FPL) have been provided where these were installed - see Locking information for details.
FPL's normally stand 'in', i.e. the normal position of these levers is 'normal', in this position the linked switches are locked. To operate the switch, set the FPL lever to 'reverse'. Once the switch is thrown, return the FPL lever to 'normal'. FPL levers are locked in 'normal' if a route is set over the switch on which they operate, or when this route is occupied. If an FPL is in 'reverse' position, all routes over the related switch are blocked and signals can not be cleared.
Note that if an FPL operates on a switch which is part of a crossover, these rules generally also apply to the other switch of this crossover even if the FPL does not work directly on this switch; some shunt moves are exempt from this rule.

Notes on shunting
The 'shunt' command must be used if a train is to reverse at a particular signal. It is good practice to issue the shunt command before clearing the last signal which leads to the location where the train is to reverse, this in order to avoid 'overshoot' when the shunt command is issued too late for the engine to brake in time, which will result in the engine running past the reversal point up to the next signal.
The 'shunt' command can be issued for a train waiting to depart as issuing this command does not affect the timed departure of this train. However, the shunt command must NOT be used for a signal which is beyond a booked station stop before the train has come to a stand for that specific station stop. Setting the shunt command before the train has stopped will cancel out the station stop, and will lead to an error on missed station stop.
 
If an engine is to be attached to a train, it has to be terminated before it can do so.
If the engine is terminated in the same location as the train to which it is to be attached, it will stop short of this train. After the engine has terminated and is redescribed to a 0Z** number, it can be moved onto the train using the 'proceed' command, and can then be coupled to the train using the 'couple' command.
If the engine is terminated in another location and is moved onto the train while it already has a 0Z** number, it will move up to the train and can then be coupled using the 'couple' command.


Section lengths

The list below details the lengths of platforms and sidings etc.
The length is defined in units, each unit equals an engine, a passenger coach, or 3 wagons.
For sidings which are allocated to a specific location, this is indicated in the list below.
For all dead-end platforms and sidings, deduct 1 unit from maximum length if engine is to be attached to take train out of platform or siding.
                          
Platform 1 (within D2 crossover)          :  8 units
Platform 1 (from signal 140)              : 14 units
Platform 2 (betw sig 135 and pts. A1)     :  9 units
Platform 2 (betw sig 135 and buffer stop) : 11 units
Platform 2 (betw pts A1 and buffer stop)  :  1 unit

Straigt Road (betw sig C6 and pts A1)     :  7 units (location Straight Road)
Long Siding (betw sig D3 and buffer stop) :  6 units (location Long Siding)
Long Siding (betw pt 144 and buffer stop) : 14 units

Gaswork Sidings 3                         : 11 units (location Gaswork Sidings)
Gaswork Sidings 2                         : 11 units (location Gaswork Sidings)
Gaswork Sidings 1                         : 10 units (location Gaswork Sidings)
Gaswork Sidings betw. Sigs 4 and W6       : 13 units

Gas Sidings 1 amd 2                       :  6 units (location Gas Sidings)

Down Passenger (betw sigs 1 and 103/104)  :  7 units
Up Passenger (betw sigs 20 and 108)       : 16 units
Up Shunt (betw sigs 8 and 114/115)        : 16 units

Spur                                      : 10 units (location Spur)

Down Branch (betw sigs 17 and 10)         : 25 units

Note : line Sidings Road is the section between sigs. 107 and 113/122/123.


Speed Restrictions

Up and Down Main                 : 75 mph
Up Passenger and Down Passenger  : 60 mph
Arrival line and Departure line  : 40 mph
Branch (see note below)          : 30 mph
Up Branch                        : 40 mph  
Down Branch and Up Shunt         : 40 mph

All other sidings, switches etc. : 10  20 mph

Note : Down Branch freight trains are restricted to 20 mph to reflect the impact of the gradient on this section of line.
                                                                                                    
Train Reporting Numbers

Train reporting numbers only came into use in later years, and also changed over the years. See timetable information for details.

Acknowledgements

Thanks to PCRail-Test team for their help in testing this simulation, and as ever to John Dennis for providing the basic program for the heritage simulations.





                          
