Marylebone - Banbury North/South Signalboxes

Introduction

Banbury in real life consisted of two signalboxes in the older eras, north and south. Both were mechanical lever frames, although the South signalbox also had an entrance-exit panel controlling the Aynho Junction area. In SimSig the two signalboxes are joined to form one signaller control area as we have the advantage of automatic routesetting and entrance-exit routesetting throughout. The layout is also simplified slightly with additional track circuits to show occupancy by trains that would normally be seen by looking out the signalbox windows - a luxury one cannot have in a remote signalling centre!

In later eras the area is covered by West Midlands SCC with the layout enhanced significantly.

Locations

Fenny Compton

Trains will appear/disappear here and should thus be used for timetabling purposes. Until a few years ago this area was controlled by a lever frame signalbox but it is now controlled by a Westcad in the West Midlands Control Centre.

Fenny Compton does not have a station but does have MOD sidings as well as a passing loop for freight trains. These are not shown as the area is not controlled by Banbury.

Banbury North

The Down Goods Loop, between BN84 and BN34, is used frequently to turn back trains from both Marylebone and Oxford. It can also be used to recess freight trains that are being overtaken by passenger trains without taking up valuable platform space.

A ground frame (BN35) controls access to and from the Reservoir Sidings. In a multiplayer game the host acts as the ground frame operator - the connected clients can only act as signaller to release the frame while the host operates the levers.

Signal BN39 has a route towards the neck adjacent to the Down Main. This allows a longer train to pass the signal and get clear of the ground frame pointwork. As a train heading that way does not clear the track circuit immediately beyond signal BN39, there is no need for a signal or route to go back into the Down Goods Loop.

Banbury

Three through platforms, a north-facing bay, and a south-facing bay provide passenger facilities. Due to the nature of the bays, both cannot be used for terminating service trains, but can be used for departing service trains.

The two signals, BS27 and BS33, at the south end of the Down platforms did not exist until a few years ago. These were put in place to allow First Great Western trains from Paddington to turn back to the south after avoiding Reading station during the blockade when the entire station was closed. It is one of the rare instances of brand new semaphore signals being installed on a main line railway!

Banbury South

As previously mentioned, this signalbox has both a mechanical interlocking frame, which controls the station area, and a panel which controls the Aynho Junction area.

Aynho Junction

The facing crossover, from the north direction, was only installed a few years ago. This meant that the reversible Down Bicester was not accessible without reversing first at Aynho (twice). Nowadays trains can be signalled at relatively high speeds from the Up Main to both the Up Bicester and Down Bicester lines.

A goods loop is also available. The signal sections towards the south (towards Heyford and Oxford) are a few miles long so a slow freight will delay a fast passenger train behind. Check the timetable and regulate accordingly.

Signalling Notes

Signal BS83's overlap will never time out - trains must therefore proceed beyond BS83 before a train heading towards Kings Sutton/Aynho Jn can leave platform 1 or 2.
Both BN68 & BN89 have fixed distants - therefore even if BS19 is 'off', the distant at either of these two signals will still be 'on'.
Semaphore symbols are used where they exist in real life in Banbury North/South. Main plates show red or green for on and off respectively. Distants show grey when not appropriate (e.g. the signal itself is not showing a proceed aspect), yellow if on, and green if off. Shunt discs are shown as ordinary shunt signals with grey for on when associated with a main aspect, red when on and not associated with a main aspect, and white for off.
Several signals will operate a time out if cancelled manually, even if no train is approaching. These are usually where, in real life, there is no track circuiting and thus no way of determining whether a train is approaching.

Train Describer (pre-2016)

Banbury North and South boxes, in real life, did not have a train describer. As SimSig uses ARS and has track circuits in places that the real life train describer doesn't, SimSig's version is more comprehensive to that in real life. Despite that, the TD will still only handle common moves. Where shunt routes are used, and intermediate signals don't have a TD berth, route must generally be set all the way through at the time of the train passing the first shunt signal in order for the TD to step correctly. For example, getting from the location known as Banbury North SB to the North Bay requires routes BN84 to BN25, BN25 to BN23, and BN23 to the North Bay, otherwise the TD will not step. In any case, it is good practice to set those routes in reverse so that a train has a clear route into the platform without stopping at intermediate shunt signals.

Both the bays can only handle one inbound and one outbound train each. In practice this means that sending a second train in will result in the first outbound train coming out wrongly described as ARS hasn't found any room to interpose the next working of the second train. Thus, when signalling a train into an occupied platform, check the train descriptions and manually update them carefully.

Marylebone Contents

Last edited by Steamer on 30/07/2020 at 14:45