LNER ground signals; route setting

[micknich2003]

Richard, do you have the Locking Chart? If so, it may reveal why the locking is such. Mick.

[LNERGE]

I can do a dog chart for St Neots where the ladder is similar but it is a Duplex tray.

[micknich2003]

I can do a dog chart for St Neots where the ladder is similar but it is a Duplex tray.

Your locking chart sounds interesting. The frame is pressumably an 1888 or 1905 version of Saxby & Farmer "Duplex" frame, the H&B had several of the 1888 version. Mick.

[RailWest]

There were several places on the Southern (and maybe on other railways too) where, when a pair of ground signals which read for 2 different routes was replaced by a single signal reading for both routes, they kept both the original levers in use. So the one signal was worked from two levers, the signalman using whichever lever was necessary for the required route - saved altering the locking.

 

To apply this to your model situation, for design purposes you assume that there are in fact two signals. You then build the relay system for each of your two routes, but use the outputs from those two routes to work the same actual signal. Each individual route relay package therefore can be simpler by being dedicated to one route only - the fact that signal it operates is actually the same as the signal operated for another route is immaterial.

 

I'm not sure if I've explained that well enough, but I hope you get the idea !

[micknich2003]

Over thirty years ago, my first box had a disc worked by 2 levers,

15 Backing Down Main to Up Main 16,

18 Backing Down Main to Goods Yard 19.

Picture attached of the interesting bits.

I always pressumed there had originaly been two seperate signals, but not so, it was installed as such 1911/12.

There is also the other set up, when two signals are worked by one lever and the "Lie" of the points selects which signal clears. Mick.

[micknich2003]

On reflection, possibly M&H/NERly went for this option to simplifie the interlocking. Two discs would have required a piece of Conditional Locking: 15 rel by 18 w 16N. Mick.