For curiosity & historical value - 1930s state of the art power control, using wooden insulators

[rjenkinsgb]

This is an English Electric traction controller (ie. electric throttle/brake) from a 1934 tram.

It's built to switch a 550V DC supply to two traction motors through several stages, using different taps on massive open resistor banks, initially with the motors in series (for the first four steps) then with the motors in parallel for the next four steps up to full speed.

The left half is the rotary switch that controls the individual accelerate or brake steps, the upper section of the right hand drum is the forward - off - reverse selector.
The lower section of the right drum is changed to reconfigure the motor connections when the throttle moves between either series and parallel modes or run and brake (I can't remember which offhand).

The mechanism at the very top right (with the stub shaft protruding from the casing) allows one or the other motor to be bypassed and also locks out the top four speed steps, where the motors would be parallel connected.


The large drum switches and the terminal board just to the right of those are built on wood (shellac coated, at a guess).

There are more detailed photos and pictures of the resistor banks and some some original cable etc. in the album here:

https://www.electro-tech-online.com/media/albums/tram.8/

View media item 37

 

[JimB]

A Sheffield tram by any chance?

JimB

 

[rjenkinsgb]

A Sheffield tram by any chance?

Blackpool, in fact

 

[Nigel Goodwin]

I live only a few miles away from the National Tram Museum at Crich, who do all the repairs and refurbishing for most historic trams in the UK (and other countries) - it's quite common seeing Blackpool Trams going through Matlock on transporters on their way to and fro.

 

[rjenkinsgb]

I live only a few miles away from the National Tram Museum at Crich

I've heard a lot about it but never actually been...

This one is being rebuilt on a private site in Blackpool, we are doing the electrical side and another specialist is doing the bodywork.
It was apparently "modernised" in the 60s to look like a flat-front bus & it's now being restored to its original 1930s styling.

 

[Nigel Goodwin]

I've heard a lot about it but never actually been...

It's well worth a visit, and has a reasonable length of track to take a ride on. I must admit, I should probably go more than I do, but it's like anything else when it's on your door step you don't pay much attention to it. It didn't help that where I used to work we used to drive past it multiple times most weeks

The village itself (Crich) is worth a look round while you're there, and it's where Peak Practice was originally set.

There's also Crich Stand next to the Museum, a rather strange lighthouse set just about as far from the sea as you can get.