GRALISTAIR
Established Member
I had not seen that. Thanks for posting.There was some document released with regards to a PWI lecture that revealed the substations being installed east of Leeds (Neville Hill, Micklefield (mid-point), Church Fenton),
I had not seen that. Thanks for posting.There was some document released with regards to a PWI lecture that revealed the substations being installed east of Leeds (Neville Hill, Micklefield (mid-point), Church Fenton),
Some aren’t even that now but just signalling supply points for the 650v supplies from the Auxiliary transformersThe remaining substations of K11 type are no longer true feeders - atleast on the WCML south they're simply track sectioning breakers that allow appropriate switching for isolations etc.
Good to hear they were problematic decades agoSome aren’t even that now but just signalling supply points for the 650v supplies from the Auxiliary transformers
Yes Acton Lane was fully converted to SMOS (structure mounted outdoor switchgear) to cover both WCML and NLL. As for other K11 sites still in use (as TSC's), mostly in the West Midlands area, which technically comes under West Coast South jurisdiction. These being: Coventry, Berkswell, Marston Green, Stechford, New Street, Coseley, Wolverhampton, Gailey and Perry Bar.Seems like Acton Lane was renewed in the 1990s unless the outdoor switchgear is just for the NLL (can't really tell from google earth). So that just leaves Washwood Heath, Willenhall and Stafford as original sites. Unless we take a different view of what counts as WCML South in which case we might count Crewe, Kidsgrove and (soon to be no longer) Speke.




Birmingham TSC is exactly where you suggest it is.Good point, I was just copying how the original map seemed to have labelled that TSC as Roade. But checking google earth, I can see an old building amongst Ashton MPATS.
At Northampton, there is indeed a few old looking buildings opposite the overflow carpark where the viaducts diverge for former line to Blisworth. So a good chance that could be the old TSC. I guess it was made redundant when Kingsthorpe and Hunsbury Hill ATSs came in.
Another thing I noticed scanning some of these sites on google earth is that there are even a few West Midlands substations with podium autotransformers installed and never used. We were talking earlier about ATs on both lines to Manchester but it surprises me how much WCRM thought they would just run AT everywhere. Really makes me think how many more supergrid connections were planned out for the subsidiary routes. At least Nechells (for Washwood Heath) has 275kV present.
I spotted ATs at Coventry, Berkswell, Marston Green, Winson Green, Coseley, Wolverhampton and even on the avoiding route at Aston and Perry Bar. Possibly showing how midway through the project was when it was cancelled, I did not find any at Stetchford, Proof House Jnc, Washwood Heath, Willenhall, Gailey, Galton Jnc or New Street (although I'm not totally sure where New Street TSC is - best guess is the flat building next to the rather retro PSB building.
Yes those are Harmonic dampers and nothing to do with the AT systemOh right okay, so these things resting on podiums are actually nothing to do with the AT system? I've been seeing them all across the North West & Central region and into Scotland. This rather changes a lot of assumptions I've been making...
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I know what you mean! I've been slowly collecting all the insights across the forum on this topic and physically locating them into a rather unwieldly Google Earth project! Finally getting the picture in one place.God, I love this site. I learn so much from it. I wish I could give back and contribute more!

In a nutshell they dampdown( reduce) the level of harmonic frequencies induced into the OLE by the PendolinosCan you (or anyone!) tell me a little more about them? What they do/what problem they addressed?
Were they another part of WCRM that was carried into the NR PSU? Their rollout is quite prolific.
GraphitProjektI know what you mean! I've been slowly collecting all the insights across the forum on this topic and physically locating them into a rather unwieldly Google Earth project! Finally getting the picture in one place.
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GraphitProjekt
Not associated with this thread but have been trying to post a reply to our conversation re early GER electrification. Although only some text it is rejected as "likely to be spam-like or contains inappropriate content" and suggests contacting an admin. However, I cannot find a way to contact an admin. Can anyone show me how.
PeteK
As Elecman says.In a nutshell they dampdown( reduce) the level of harmonic frequencies induced into the OLE by the Pendolinos
I hadn't actually made any particular notes of smaller equipment within TSC sites (some would surely be for the substation's own LV needs), only really the boxes on podiums which I had assumed where a different variety of AT as opposed to the ground mounted ones especially as so many seem to have been unplugged making me assume they were mothballed AT infrastructure. A silly notion in retrospect because most transformers have a distinctive oil tank that of course the dampers don't have.The Auxiliary Transformers at K11 sites you have seen on Google Earth were 650 V Signalling Supply Transformers connected to the main busbar. Back then, the main 650 V supply was provided by the REB (now DNO) with the auxiliary transformer being the stand by supply. Come Solid State Interlocking, these transformers couldn't operate quickly enough with supply variations (25 kV is not just 25 kV you know) to maintain the required output so became defunct over time.
(25 kV is not just 25 kV you know)
I think he means the massive variation seen in the supply voltage from 19kV upwardsIs that the RMS value - root mean square?
Most older SSPs /PSPs in OLE areas are now ussually DNO 400 volt as primary supply and traction derived as secondary back up. The newer ones are the opposite and the DNO is the back up supply.I see, that explains why at least one damper pair I've observed has been removed (Ditton TSC).
I hadn't actually made any particular notes of smaller equipment within TSC sites (some would surely be for the substation's own LV needs), only really the boxes on podiums which I had assumed where a different variety of AT as opposed to the ground mounted ones especially as so many seem to have been unplugged making me assume they were mothballed AT infrastructure. A silly notion in retrospect because most transformers have a distinctive oil tank that of course the dampers don't have.
Does this mean that within Preston and Carlisle signalling areas, 25kV PSPs are more likely to be in use?
The practice of using 25kV to power signalling does strike me as odd. Especially that it's the backup and not the main source. Because surely there are more likely reasons to switch off the overhead line compared to failures of DNO supplies (especially if they're 6.6-11kV sourced as one might expect for a 650V output), so you'd try and use the overhead line source in normal operation. As well as PSPs derived within traction substations, I also have seen many PSPs operating purely off the overhead line circuits as structure mounted transformers, typically with a switch to select between up or down lines.
Furthermore, I can understand it where lines were converted from localised mechanical signalling to an early generation of PSBs, but as far as I'm aware, new electrification schemes to the present day still create PSPs in the same way. I know this is at least true for Core Valley lines.
Wow that is massive.I think he means the massive variation seen in the supply voltage from 19kV upwards
The data logger on 89001 recorded 15 kV when taking power after passing through Garstang neutral section on the northbound test run on 18/03/2026; and the voltage didn't recover to above 20 kV for another five minutes. This was a day of big WCML delays (surely not!) after there had been OLE problems near Leyland, so presumably there were some 'unusual' feeding arrangements in force at the time.Wow that is massive.
15KV is quite remarkable given the standards have a lowest voltage of 17.5kV for a nominal 25kV system.The data logger on 89001 recorded 15 kV when taking power after passing through Garstang neutral section on the northbound test run on 18/03/2026; and the voltage didn't recover to above 20 kV for another five minutes. This was a day of big WCML delays (surely not!) after there had been OLE problems near Leyland, so presumably there were some 'unusual' feeding arrangements in force at the time.
This did however have the benefit of proving that the 89's power limit functionality was working correctly.
Railway electrification using 25 kV, 50 Hz AC has become an international standard. There are two main standards that define the voltages of the system:
The permissible range of voltages allowed are as stated in the above standards and take into account the number of trains drawing current and their distance from the substation.
- EN 50163:2004+A1:2007 – "Railway applications. Supply voltages of traction systems"[6]
- IEC 60850 – "Railway Applications. Supply voltages of traction systems"[7]
Electrification
systemMin.
non-permanent
Min.
permanent
Nominal Max.
permanent
Max.
non-permanent
25 kV 50 Hz 17.5 kV 19 kV 25 kV 27.5 kV 29 kV
Not really considering that BR designed for a "normal" voltage from 16.5kV to 27.5kV with excursions down to 12.5kV for no more than 2 minutes and up to 29kV for no more than 5 minutes.15KV is quite remarkable given the standards have a lowest voltage of 17.5kV for a nominal 25kV system.
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25 kV AC railway electrification - Wikipedia
en.wikipedia.org
That was indeed the source for my cryptic comment in post #169.Hi,
Not really considering that BR designed for a "normal" voltage from 16.5kV to 27.5kV with excursions down to 12.5kV for no more than 2 minutes and up to 29kV for no more than 5 minutes.
It is only since we have adopted European standards that a tighter voltage range is being attempted on new electrification and there is evidence that some in the industry would like to go back to the old values for cost reasons.
Interesting, thanksHi,
Not really considering that BR designed for a "normal" voltage from 16.5kV to 27.5kV with excursions down to 12.5kV for no more than 2 minutes and up to 29kV for no more than 5 minutes.
It is only since we have adopted European standards that a tighter voltage range is being attempted on new electrification and there is evidence that some in the industry would like to go back to the old values for cost reasons.