Signals for Bradford North Western

[clecklewyke]

One of the important aspects of my project is operation and this demands working signals. I think it is important that the functions of driver and signalman are separated and that the drivers, as far as possible, simply need to read the signals in order to know whether they are safe to proceed. I have now reached the stage on my layout where this is possible, apart from a few shunting moves, which we are happy to imagine the signalman authorises with the wave of a green flag - so far imaginary, but we’ll see!

 

I am trying to standardise on a way of installing signals which allows them to be removed without having to unscrew baseplates or disconnect mechanisms. In my experience signals are very liable to damage from shirt cuffs etc. when working on track. So I use telescopic square-section brass tubing to allow the signal to slide into a slightly larger cross-section tube soldered to a baseplate which is firmly anchored to the baseboard, and therefore can be permanently disguised with ballast etc. I find that friction is quite enough to hold the signal in place. The operating mechanism consists of a striking plate attached to a crank which pushes the signal push rod “offâ€, with a small spring to make the signal return to “onâ€. Because I am an old codger, unable (or willing) to learn new tricks I use solenoids from MSE to move the crank. Sophisticates will no doubt use servos and build in “bounceâ€.

 

I am attaching a few photos demonstrating this approach. The signal is from a Gibson kit of an ex-LMS lattice UQ signal - probably not very appropriate for Bradford NW but a nice change from the ubiquitous LNWR LQs. It’s mounted on the side of a temporary, non-scenic connection between Clecklewyke and Bradford NW but it functions as BNW’s home signal, so is important in preventing trains entering station limits until there is a suitable route for them. This unusual method of mounting also allows the innards to be seen easily when the plywood shield is removed.

 

 

The diagram is a cross section of the base of a signal.

 

The parts shaded brown are fixed - the baseboard, the mounting plate and the larger section brass tube soldered to the mounting plate.

 

Those in green are the signal - the post at the top soldered into the smaller section tube, with the joint reinforced with a short length of the larger tube. Part of the tube is cut away to give access to the innards in order to adjust and solder in place the end stops.

 

The red parts are the moving parts - the push rod, made of hard brass wire; the two end stops made of small diameter copper tubing soldered to the push rod and which control how far the signal arm moves; and the crank and striking plate, which transmit the movement of the solenoid to the push rod.

It will be seen that the blue and green components can be removed from the brown components without having to dismantle anything.

 

This all works well with simple single-arm semaphores but will need development for multiple arms and gantries. I think the principle will work if I use separate tubes for each of the push rods.