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Interlocking messages

Interlocking messages

The following is a list of Interlocking messages you may encounter when attempting certain actions, such as setting a conflicting route . Thanks to Clive Feather for the original list.

Message Meaning
[number of] seconds approach locking To prevent a collision in case a train passes a signal at danger, some signals are fitted with a time out when you cancel the route. This is normally 30 seconds for shunt signals or 120 seconds for main signals, but specific signals can be longer (e.g.: 240 seconds). This message does not necessarily mean you cancelled the route in front of a train. examples
A slot is required for this route You need to obtain permission before you can set the route, usually by clicking a slot button (white roundel) in the view window. In certain locations or on certain simulations you may need to make a phone call to a yard or depot for the slot. examples
Another signalbox has collared the exit signal
Automatic working not available for this route You have clicked the "automatic working" button on a manual signal, but the route currently set cannot be used in automatic mode
Call-on route set from the signal in rear You tried to set an exit route (from the departure end of the station) while a call-on route is still set, i.e., the train being called-on (into a station already containing a train) is still in motion, moving into the station. The green signal of the exit route might be mistaken by the driver of the call-on train as a green through signal if the other train is obscured by poor visibility. This is an example of Huddersfield Control . Note that this error message will occur even if there is no train at the platform. examples
Cannot overset a different route A route is already set from the signal; may also be associated main/warner routes.examples

Cannot release ground frame The required conditions to release the ground frame have not been met. For example, a protecting signal has not been returned to danger via an Emergency Replacement Switch . See individual simulation manuals for more detail. examples
Cannot swing overlap The points in the overlap are locked, therefore the overlap cannot be swung. Points often become locked as the train approaches the red signal.
Conflicting slot given You have given a slot on one line that will cause a conflict if this slot is given. For example, signalling one train onto a single line, then trying to give a slot so that a train can come the other way.
Conflicting subroute(s) You have attempted to set a route that crosses a route that has already been set.
No overlap available There is no overlap currently available for that particular route. Could be because another route is set, occupied or points are locked preventing the overlap being set. examples
No route between selected signals There is no valid route between the two chosen signals. Routes are usually set from main signal to main signal. Check that you are not trying to set a route over a main signal. examples
No route set from signal You have pressed the "automatic working" button on a manual signal, but no route has been set
One or both signals are collared One or both of the signals has a General or Traction Isolation reminder applied.
One or more signal(s) collared One or both of the signals has a General or Traction Isolation reminder applied.
Part of route already locked by another route You have attempted to set a route that crosses a route that has already been set.
Points locked normal/reverse by another route A set of points within the route you are trying to set are either manually locked, or are locked by another route that has already been set. examples

Preset shunt signal is collared The preset shunt signal has a General or Traction Isolation reminder applied.
Preset signal already working in preset mode You have attempted to set a route to a preset shunt signal
Preset signal(s) already have a route set
Route locked by token apparatus
Route not available This message may have several meanings depending on the Simulation. Please see the relevant manual .
Route set from the exit signal - call-on not allowed You are trying to set a call-on route for a train to enter a platform at which another train is already waiting and for which an exit route has already been set. This is not allowed due to the possibility of the driver of the train being called-on to enter the platform misinterpreting the distant signal of the exit route as a sign that the platform is empty. This rule, known as Huddersfield Control , arose from an actual accident. Note that this error message will occur even if there is no train at the platform. examples
Subroute locked in opposite direction You've attempted to set a route onto a track that already has a route set in the opposite direction
The exit signal is collared The signal you are attempting to set a route to has a general/traction reminder applied.
Track circuit(s) isolated The route you've attempted to set includes track circuits that are under an engineer's possession
Via buttons are mandatory for this route There is more than 1 possible route between these signals, and you have to click the via buttons to tell the interlocking which one you want to set.

TODO Move further ARS-related messages to separate ARS message page (created)

TODO Add further messages and meanings

TODO Create example pages with screenshots to expand these explanations

TODO Add any other links to things on usertrack:glossary:[x] in suitable places. Keep the links to the first reference of it within the meanings column.

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