Blog @ GVLR

The Golden Valley Light Railway

a 2ft (610mm) Narrow Gauge Railway in Derbyshire

BEV type WR5 "Baby Jane" Wheal Jane 19

Restoration and Recommisioning

a Blog by Andy Kemplen

When tasked with starting the work to bring Baby Jane back to service I examined it in the container and took some photos. Using these photos with the parts book I worked out what was missing from the controller. It was item 3158-0018, the Contact Block Assembly, a block of 4 Sevcon contactors in a fabricated carrier as shown below.

Contact Block Assembly, a block of 4 Sevcon contactors in a fabricated carrier
The Contact Block Assembly

I reached out with this picture using email and social media to other railways that had BEV WR5 locos in the hope of finding any available spares. I received three responses from:

Richard Fellows at the Great Bush Railway (Tinkers Park) was helpful in telling me that their WR5 ‘Titch’ did not have the same controller as ours. It was from new a ‘Yard Shunter’ from a brick works and had a Cableform Pulse-o-matic MK10 electronic controller, similar to a Lansing Bagnall forklift truck. This could be useful as I was able to get a copy of their wiring diagram, which showed how the motors’ field coils were arranged for this type of controller. We have a similar type of controller out of the Cushman/Ezego Titan Truck that we dismantled a couple of years ago. I have sourced from Australia via the internet a wiring diagram for that exact truck so it could possibly be rigged up to work.

Tobey Jones at the Moseley Heritage Museum replied saying they had been forced down the route of fitting a controller from an older BEV locomotive to their WR5 as they could not source spares for our type of controller. He said that the older type was less intricate and easier to make contact plates for. This was again helpful as I realised that it could be an alternate route to go down if spares were that difficult to source as we have a similar controller that came from Roy Etherington – I had noticed that this has been done on other WR5s seen on the internet like the one at the VBT&MS in New Zealand.

Nicholas Harper at the Lea Bailey Railway was most helpful telling me that they have two WR5s but no spare contact blocks. They had sourced some second hand through Alan Keef and commented that they were like hens teeth! Nicholas did advise though that a modern equivalent to the Sevcon contactor was available from Schaltbau and he had considered making a new carrier to hold them, but advised they were expensive. I reached out to Hertford Controls, the UK Schaltbau distributor and was quoted £558.96 for four contactors! Yes they were quite expensive!

Then I had a further e-mail from Nicholas Harper showing me there were some available from the USA on e-Bay. I investigated and bought 4 straight away for only £110 including delivery, a bargain! The new Schaltbau contactors arrived and then with the data sheet for them that I sourced from the internet, and a series of dimensions I took from our control box, I was able to design a suitable carrier to hold these contactors to function as the original Sevcon ones did. I produced CAD models and drawings for the components and from them a ‘G’ code programme was written to mill out the aluminium end plates on a CNC machine. I ordered some Tufnol strips to make the side rails like those that held the original Sevcon contactors (see below). That is as far as I have got for now, due to lock down.

Tufnol strips and new aluminium end plates
The Tufnol strips and aluminium end plates"

When normality returns, I will mark out and drill the side rails, assemble it and have a trial fitting to check the function. Interestingly in my lockdown boredom, from the dimensions I took from the controller to allow me to design the contact block assembly I was able to determine the cam sequence and with the descriptions in the maintenance manual that we have, work out the contactor wiring.

Using that information and my son’s GCSE electronics testing software ‘Circuit Wizard’, I have made some operational diagrams using bulbs as the motor field coils that can be seen below. At notch 1 the bulbs barely glow yellow as the resistor is switched in, at notch 2 they are more clearly visible as the resistor is shorted out and then at notch three they are shining bright being switched into parallel.…. so I think I can wire it all up now when the time comes!

Contactor wiring circuits drawn by the author
Contactor wiring circuits drawn by the author
For larger diagram click here, or on the image above