Miniature lever frame interlocking

[RRU]

I am building a layout with 3 aspect colour light signals controlled by a miniature lever frame.
I would like to know the correct interlocking for the passage of a through train.

The signals involved are;-

Outer Home
Inner Home
Platform Starter
Section Signal

Could the Panel tell me which lever is locked to what and when each is unlocked again?

Assume section is clear and line clear given.
 

[TheSignalEngineer]

Simplisticly putting it. In Absolute Block working where sequential locking is provided the signals would be pulled in order through the section. Each colour light would be replaced to Red by passage of the train. All of the levers would have to be placed to the Normal position before starting the sequence again. To ensure that the levers could not be fully replaced before the train had gone through a check lock would be provided which usually requires the track circuits operated in sequence or a time having elapsed with the train stopped at the signal. 

To bring the train into the platform before a Line Clear was obtained the levers of the Outer and Inner Homes could be pulled but the signals would not clear until the respective berth track circuits were occupied for a time to ensure that the driver had time to see the signal clear. 

[RRU]

Thank you for that information. I will design the interlocking with that in mind.

[jamie92208]

I've no connection to Modratec apart from being a satisfied customer but a Modratec frme would do this for you and build the interlocking into it.  Have a look at Modratec.  You then download the free software, design your trackplan and interlocking on it, then Modratec generate a locking table and send you a quote for a lever frame kit to do that. The kit has tappets and locking bars and works just like the real thing.

 

Jamie

[The Stationmaster]

Unless things have changed I understand that Modratec can't offer either conditional or sequential locking  (although such locking could be superimposed electrically but not then on teh movement of the levers themselves).

[Eggesford box]

Would you even need sequential locking on the levers? Two boxes that I work on odd occasions have colour lights on the running lines and there is no sequential locking on the levers. These are full size levers, ex GWR but the colour lights would have been put in by the LMR.It is AB between the two boxes. I have no knowledge of miniature frames but if you can happily 'restroke' a route on a full size frame I cannot see it would not be possible on a miniature frame. Probably depend a lot on who put the frame in and when.

 

One of the boxes the controls on the signals are different on the up and the down. On the down if you replace the lever (lets call it home 1) for home 1 and clear it again after the train has passed the overlap T/C then the signal will clear once the train has passed the overlap of home 2 regardless of the position of the home 2 lever. You can do the same on the up but home 1 will not clear until the home 2 lever has been replaced in the frame.

 

Bit long winded and possibly OP but I am just pointing out that you could have different controls/locking on parts of your miniature frame depending on when alterations have been made. We have even had some of the backlocking removed recently on one of the frames to speed up working.

[RRU]

Would you even need sequential locking on the levers? Two boxes that I work on odd occasions have colour lights on the running lines and there is no sequential locking on the levers. These are full size levers, ex GWR but the colour lights would have been put in by the LMR.It is AB between the two boxes. I have no knowledge of miniature frames but if you can happily 'restroke' a route on a full size frame I cannot see it would not be possible on a miniature frame. Probably depend a lot on who put the frame in and when.

 

One of the boxes the controls on the signals are different on the up and the down. On the down if you replace the lever (lets call it home 1) for home 1 and clear it again after the train has passed the overlap T/C then the signal will clear once the train has passed the overlap of home 2 regardless of the position of the home 2 lever. You can do the same on the up but home 1 will not clear until the home 2 lever has been replaced in the frame.

 

Bit long winded and possibly OP but I am just pointing out that you could have different controls/locking on parts of your miniature frame depending on when alterations have been made. We have even had some of the backlocking removed recently on one of the frames to speed up working.

Very interesting. It seems there is no hard and fast rule.

[TheSignalEngineer]

Would you even need sequential locking on the levers? Two boxes that I work on odd occasions have colour lights on the running lines and there is no sequential locking on the levers. These are full size levers, ex GWR but the colour lights would have been put in by the LMR.It is AB between the two boxes. I have no knowledge of miniature frames but if you can happily 'restroke' a route on a full size frame I cannot see it would not be possible on a miniature frame. Probably depend a lot on who put the frame in and when.

 

One of the boxes the controls on the signals are different on the up and the down. On the down if you replace the lever (lets call it home 1) for home 1 and clear it again after the train has passed the overlap T/C then the signal will clear once the train has passed the overlap of home 2 regardless of the position of the home 2 lever. You can do the same on the up but home 1 will not clear until the home 2 lever has been replaced in the frame.

 

Bit long winded and possibly OP but I am just pointing out that you could have different controls/locking on parts of your miniature frame depending on when alterations have been made. We have even had some of the backlocking removed recently on one of the frames to speed up working.

With all signals colour lights and full track circuiting the sequential locking would often be done as electrical circuits and not as bars in the frame. In your second paragraph I assume that lever 2 would have to be replaced and pulled again before its signal would clear. Here the sequential element will probably be somewhere in the way that the signal circuits work, ensuring that the trains are properly separated. Without knowledge of the actual location and control tables I can't accurately say.

[The Stationmaster]

With all signals colour lights and full track circuiting the sequential locking would often be done as electrical circuits and not as bars in the frame. In your second paragraph I assume that lever 2 would have to be replaced and pulled again before its signal would clear. Here the sequential element will probably be somewhere in the way that the signal circuits work, ensuring that the trains are properly separated. Without knowledge of the actual location and control tables I can't accurately say.

I can't see any point at all in retaining mechanical sequential locking on a frame once the levers have got circuit controllers/electric locks and full track circuiting has been provided - in fact it would usefully get rid of mechanical locking which is increasingly difficult to maintain and obtain spare parts for.

 

There is I think always a potential problem when looking at alterations which have been made when colour light signals and electrical controls have been superimposed on a mechanical frame as alterations carried out to plans from different designers at different times working to changing standards and Instructions can create anomalies even, sometimes, on the same frame as indicated in the earlier post.  And of course the two in that instance might be different for perfectly good operational reasons.

[TheSignalEngineer]

On jobs I was involved where colour lights were provided throughout the only time we would leave in mechanical sequential locking was if there were no other mechanical locking alterations. Fitters were scarce enough without greating extra work which could be avoided. For w wholesale change the sequential element would be incorporated in the circuitry. For a miniature lever frame as everything was worked electrically there would be little point in providing mechanical sequential locking if doing it electrically didn't generate a lot more relays.