Electrical Control Rooms

[matchmaker]

Any chance of a screenshot, I don't think any of us can view this unless we apply to enter the group its from (not that the denied screen tells us what group To join!)

It's a public Facebook group called "BR: The last living employees of British Rail and British Railways" so should be viewable if you are on FB.

 

[GraphitProjekt]

On every link I click on associated with that facebook group, I'm entirely blocked from seeing anything. Interesting if I'm the person for whom this is the case. However, I can sort of view content on that group by way of google images so it's probably this picture? (Shame because I'm sure the comments will be interesting on the actual post)


== Doublepost prevention - post automatically merged: 2 Aug 2026 ==

Going back to the discussion on LUL, I just found this article in the Railway Gazette (vol 115, iss 20, p573) about a substation modernisation programme in 1961. The work was mainly to replace dc motor-generators with rectifiers which would be able to work off both 33.3Hz and 50Hz for the imminent change of frequency but lots of complex civils went on as well. However it does mention that modernised substations were to be moved into centralised control rooms (plural!) at Aldgate, Baker Street and Cromwell Curve (I knew there was something going on there!).

 

[Falkland Yard]

The picture in post 32 is found on page 24 of a booklet called Glasgow Electric (link to Railway Archive site) and shows the original mimic board of the Cathcart ECO with the North Electric & Cathcart Circle lines. Also the Youtube video Wires over the border - 1974 also has shots of inside Cathcart ECO (at about 13min 38sec).

 

[Nicholas Lewis]

There is also this very much substation looking equipment at the entrance to North Pole depot.
View attachment 206566
Not sure how this fits in to the story as there are definitely two bigger sized transformers, and I don't think this is OOC FSs as I'm pretty sure that site was situated on the other side of the area between Old Oak Common Ln and the Central Line.

Thats the DC substation that was installed in early 1990s when North Pole Depot was home to Eurostars. It fed the exit roads from the depot and the West London Line which is still in use for London Overground service.

 

[GraphitProjekt]

Thats the DC substation that was installed in early 1990s when North Pole Depot was home to Eurostars. It fed the exit roads from the depot and the West London Line which is still in use for London Overground service.

Thanks for this, makes sense now I think about it although it does look like a much more substantial installation than the other DC substations on the WLL (Olympia, Chelsea). Nonetheless, UKPN open data insists that they still operate a 26.5MVA 132/25kV transformer connected to a "North Pole BR". It must just be derelict even though it could maybe offer a useful third source for Acton Lane FS, it's got a higher rating than those two. You can kind of see 3x single phase transformers at the Grid side area of Acton Ln FS from google earth but I'm not entirely confident about that.

 

[bramling]

Thanks for this, makes sense now I think about it although it does look like a much more substantial installation than the other DC substations on the WLL (Olympia, Chelsea). Nonetheless, UKPN open data insists that they still operate a 26.5MVA 132/25kV transformer connected to a "North Pole BR". It must just be derelict even though it could maybe offer a useful third source for Acton Lane FS, it's got a higher rating than those two. You can kind of see 3x single phase transformers at the Grid side area of Acton Ln FS from google earth but I'm not entirely confident about that.

ISTR seeing in a diagram somewhere there’s a “Stabling Sidings Switching Station” somewhere there. Not sure if that’s attached to North Pole Substation, or something else.

 

[GraphitProjekt]

What I think I know is is:
- The HEX system was normally fed by Hayes 66/25kV
- OOC No.1 FS (controlled by Rugby) received a 25kV BR owned interconnector from Acton Ln FS allowing power to be shared from one of the two WCML supplies.
- OOC No. 1 FS also received a different and separate 25kV supply from UKPN that must originate from that 3rd transformer at the "Willesden BR" grid site.
- This suggests two cables going between largely the same places but owned by the different authorities
- OOC No. 2 FS (controlled by Slough, later Romford) actually sectioned the OLE on the GWML and was connected by a single circuit to OOC No. 1 (I imagine these two were right next to each other geographically)
- North Pole depot had no track connection to the GWML (at least no electrified one) probably until well into the IET/GWEP era
- There was and still is a neutral section at Scrubs Ln where the lines into North Pole connect to the a final stretch of OLE coming down from West Ldn Jnc

What I conjecture

ISTR seeing in a diagram somewhere there’s a “Stabling Sidings Switching Station” somewhere there.

- The third 25kV DNO supply at Willesden actually went to this mystery "Switching Station" within North Pole and possibly was under local control or Rugby's control
- That DNO supply normally fed the OOC depot area before GWEP connected it to the GWML
- This would make sense since North Pole depot and OLE is different and slightly older than the HEX project
- This switching station also had a cable to OOC No.1 FS allowing that supply to be sent to OOC No.2 and power the GWML which was the N-1 scenario for a loss of Hayes.

Another piece of evidence that might support this is this great big list of NR standards that has an explicit standards document for:

"NR/DIST C16m Isolation and Earthing at Old Oak Common Feeder Station No 1 Including Cables to North Pole Depot and Interconnector Cables to Old Oak Common Feeder Station No 2 and Acton Lane and their Isolators"

So it could be that when North Pole depot was put in, they went all out and supplied it with it's own 132/25kV transformer situated at the Willesden site which explains why all grid sources refer to it as "BR North Pole". But when HEX came along, they decided to wanted to be able to connect both the North Pole "feeder" and Acton Ln.

 

[Nicholas Lewis]

Thanks for this, makes sense now I think about it although it does look like a much more substantial installation than the other DC substations on the WLL (Olympia, Chelsea).

It was a double rectifier substation along with a 22kV switch room which had the incoming feeder from Acton Lane LEB switchroom also a DC switchboard module. The site also provided supplies for the North Pole Depot complex. The other WLL locations were only single rectifier substations with 3 panel 22kV and 5 panel DC switchboards

Nonetheless, UKPN open data insists that they still operate a 26.5MVA 132/25kV transformer connected to a "North Pole BR". It must just be derelict even though it could maybe offer a useful third source for Acton Lane FS, it's got a higher rating than those two. You can kind of see 3x single phase transformers at the Grid side area of Acton Ln FS from google earth but I'm not entirely confident about that.

Someone else has answered the question with more knowledge on the above but my recollection at the time was this was initially provided for the OLE within North Pole but may have been sized to cover the Heathrow Express electrification as well as that was authorised not long after the Channel Tunnel works had been approved.

 

[GraphitProjekt]

Going back to the LUL side of things. I asked some questions around the District Dave forum and it turns out there were a rather large amount of electrical control rooms between the start of the LPTB era until the ~1970s before they all came under Leicester Square. This information is fairly vague and not likely to be hugely accurate but it gives a lot to look into.

Aldgate:
- Eastern side of the Sub-Surface lines (at least substations: Whitechapel, Moorgate, Surrey Docks)
Cromwell Curve:
- Western side of the Sub-Surface lines including Acton Town - Rayners Lane and down to Hounslow.
- replaced an earlier control room at Alperton
Neasden:
- for most parts of the Met line and Stanmore branch. Built around the time of Amersham electrification and closure of Neasden power station.
- Replaced and earlier control room at Harrow (on the hill).
Wood Green:
- for the Piccadilly Line northern extension
East Finchley:
- for the top end of the Northern Line
Charing Cross:
- for Northern Line's central and southern sections and Bakerloo line
Wood Lane:
- for the core part of the Central Line
South Woodford
- for the Central Line eastern extension at and beyond Bethnal Green
- there is actually detailed information about this ECR in a 1949 article in The Engineer available online (Aug 1949, vol 188, p178)
Old Oak Common
- for tube lines over former/technically GWR tracks since the GWR would have installed the electrification
- firstly the Hammersmith branch of the Met
- but also the western parts of the Central Line, Wood Lane to West Ruislip. (Not sure how the Ealing branch worked with regards to Cromwell Curve)
Dagenham Heathway
- for the eastern part of District beyond Campbell Road substation as the line was electrified by the LMS

Chiswick/Stamford Brook
- for trams and then trolley-busses but still part of the wider LPTB power system.