Electrification system islands.

[zwk500]

I don't think there are any locos that are fitted with the KVB signalling system fitted in St Pancras (HS1). I believe one of the freight operating companies has a safety case exemption to allow its class 66 to work there without protection under special protection for special purposes. I think that any traction unit/ mu going from HS1 to the UK electrification systems has to have a system for selecting different heights of the overhead wire between the two systems.

I make no claim to accuracy but here's where I saw it: https://www.kentrail.org.uk/st_pancras_orient_express.htm

 

[Mag_seven]

Not any more, the depot was fully wired ready to plug into the Mainline scheme only to be dewired later.

So it was actually wired at one point - I knew I wasn't imagining it!

However for the purposes of this thread as it no longer is wired I withdraw it as a valid entry.

 

[Bald Rick]

Slows lines out of Platforms 9 & 10 at Euston to Primrose Hill Tunnel seem to have managed okay for the last 50+ years.

Indeed - it’s usually ok if the D.C. traffic is relatively light - ie short trains or low frequency, or both.

 

[norbitonflyer]

The North Clyde Line running from Helensburgh / Balloch / Milngavie to Springburn / Airdrie via Glasgow QS Low Level was a 25kv AC island until 1979, when the Argyle Line re-opened that links with electrified Lanarkshire suburban lines and the WCML.

Before the WCML was electrified between Crewe and Glasgow in May 1974, Cathcart Circle and Inverclyde Lines were also an electrified island.

In fact, there were two electrified railway islands in Glasgow!

Manchester to Bury line back in its BR days was also an electrified island, but it wasn’t majorly a big deal as it used the unique side contract 1200v DC 3rd Rail. The trains were Class 504 two-car EMU. This was the line became part of the Manchester Metrolink in 1992.

I was under the impression that the Glasgow Union Line (Shields Junction to Bellgrove) was electrified to allow empty stock movements between north and south Clydeside, but Google Street view would suggest otherwise (unless the wires were removed at some point in the last 42 years, since the Argyle line opened)

 

[Mag_seven]

I was under the impression that the Glasgow Union Line (Shields Junction to Bellgrove) was electrified to allow empty stock movements between north and south Clydeside, but Google Street view would suggest otherwise (unless the wires were removed at some point in the last 42 years, since the Argyle line opened)

The Glasgow City Union line has never been wired.

 

[Greybeard33]

Slows lines out of Platforms 9 & 10 at Euston to Primrose Hill Tunnel seem to have managed okay for the last 50+ years.

Indeed - it’s usually ok if the D.C. traffic is relatively light - ie short trains or low frequency, or both.

There are of course other places around London where the AC and DC systems overlap. I did not say it could not be done, just best avoided if possible.

 

[swt_passenger]

Slows lines out of Platforms 9 & 10 at Euston to Primrose Hill Tunnel seem to have managed okay for the last 50+ years.

They have ‘managed’, but they don’t meet present day standards of earthing and corrosion prevention.

 

[Greybeard33]

Manchester to Bury line back in its BR days was also an electrified island, but it wasn’t majorly a big deal as it used the unique side contract 1200v DC 3rd Rail. The trains were Class 504 two-car EMU. This was the line became part of the Manchester Metrolink in 1992.

And the Manchester to Altrincham line, now also Metrolink, was an island of 1500V DC OLE for many years, never linked to the 1500V DC lines to Sheffield on the opposite side of London Road station (now Piccadilly).

 

[matchmaker]

The Glasgow City Union line has never been wired.

Stock transfers were loco hauled. The main proviso was that the loco had air brakes so some Class 20s were fitted with these at quite an early date. I have also heard that in the early days ex Caledonian steam locos were used as some still retained their Westinghouse brakes.

 

[edwin_m]

I don't think there are any locos that are fitted with the KVB signalling system fitted in St Pancras (HS1). I believe one of the freight operating companies has a safety case exemption to allow its class 66 to work there without protection under special protection for special purposes. I think that any traction unit/ mu going from HS1 to the UK electrification systems has to have a system for selecting different heights of the overhead wire between the two systems.

Eurotunnel's Krupp diesel locomotives have operated into St Pancras at least once (hauling a Postal TGV). I presume this was done under signalling rather than under possession.

 

[Snow1964]

Prior to being connected to the GWML was North Pole an island of 25kv?

Old Dalby test track is an island of (IIRC) 25kv, 750 dc and LUL style 4th rail. I believe there is similar at Litchurch Lane, Derby.

Waterloo and City Line has been an isolated island of electrification on both BR and London Underground.

If GWML is connected to North Pole, and North Pole is connected to West London Line, and West London is connected at Willesden, is GWML an island ?

Or is North Pole no longer connected to West London line. However if you start including disconnections must have been dozens over the years where maintenance required temporary removal of a section

 

[paul1609]

Eurotunnel's Krupp diesel locomotives have operated into St Pancras at least once (hauling a Postal TGV). I presume this was done under signalling rather than under possession.

I don't think the special arrangements are possessions as such. The signalling and interlocking is working correctly its just that the train doesn't have protection. From how I understand it the "outer home" is held at red which causes the TVM interface to display a stop/AWS/ TPWS ensures a stop. The signaller sets the route to the buffer stops with no possible conflicts. The driver is then authorised to proceed at a reduced speed. I think there were similar arrangements at Ashford to allow 374s to call before KVB was fitted.
From what I hear the KRUPPs were down to under 25 km/h hauling a Eurostar on the incline through North Downs Tunnel so I don't think it would be done in normal operation.

 

[alangla]

The North Clyde Line running from Helensburgh / Balloch / Milngavie to Springburn / Airdrie via Glasgow QS Low Level was a 25kv AC island until 1979, when the Argyle Line re-opened that links with electrified Lanarkshire suburban lines and the WCML.

Before the WCML was electrified between Crewe and Glasgow in May 1974, Cathcart Circle and Inverclyde Lines were also an electrified island.

In fact, there were two electrified railway islands in Glasgow!

Manchester to Bury line back in its BR days was also an electrified island, but it wasn’t majorly a big deal as it used the unique side contract 1200v DC 3rd Rail. The trains were Class 504 two-car EMU. This was the line became part of the Manchester Metrolink in 1992.

It was more extreme than that in Glasgow originally- the city centre bit of the North Clyde and (I think!) the Cathcart lines were originally 6.25kV with 25kV further out.

 

[Mag_seven]

If GWML is connected to North Pole, and North Pole is connected to West London Line, and West London is connected at Willesden, is GWML an island ?

I've already asked that question in post #14. As you say it may dependent on whether there is an isolation between the wires leading out of the depot and the WLL itself.

 

[Bald Rick]

There are of course other places around London where the AC and DC systems overlap. I did not say it could not be done, just best avoided if possible.

I agree entirely!

 

[nlogax]

I nominate New Cross Gate Depot - iirc there's 25kV test track amongst the sea of third rail. Used to be aligned through the carriage wash but was moved in 2015.

 

[matchmaker]

It was more extreme than that in Glasgow originally- the city centre bit of the North Clyde and (I think!) the Cathcart lines were originally 6.25kV with 25kV further out.

The whole Cathcart Circle and Parkhead - Westerton/Yoker were 6.25kV.

 

[Highlandspring]

The Glasgow City Union line has never been wired.

Hasn’t stopped a few drivers and signallers having a go over the years...

 

[Bald Rick]

I nominate New Cross Gate Depot - iirc there's 25kV test track amongst the sea of third rail. Used to be aligned through the carriage wash but was moved in 2015.

If we’re going down that road, then Three Bridges depot and Litchirch Lane must qualify.

 

[paul1609]

If we’re going down that road, then Three Bridges depot and Litchirch Lane must qualify.

and Selhurst I believe

 

[themiller]

Not forgetting the Hitachi assembly plant at Aycliffe! 25kV test track. There used to be a length of overhead line at Derby RTC as well.

 

[zwk500]

Not forgetting the Hitachi assembly plant at Aycliffe! 25kV test track. There used to be a length of overhead line at Derby RTC as well.

On that note, I believe the Hitachi Depot at Ashford has a brief 25KV test track (Not connected to the OLE in the station).

 

[59CosG95]

and Selhurst I believe

Both Selhurst & Three Bridges seem to have their installations literally "in-house" as I can't find any photos of them outside the buildings!

 

[61653 HTAFC]

Not forgetting the Hitachi assembly plant at Aycliffe! 25kV test track. There used to be a length of overhead line at Derby RTC as well.

Healey Mills yard had an isolated stretch of overhead for years. At a guess this was there for training purposes, as even when the depot was open and had locos allocated none of them would have been electric for obvious reasons. Tbh I'd be surprised if those wires were energised at the full-fat 25kv if at all (though if they were indeed used for training I could see the advantage of having the wire energised at a significantly stepped-down rate).

Anyone happen to know the story behind those?

 

[LNW-GW Joint]

If we’re going down that road, then Three Bridges depot and Litchirch Lane must qualify.

And the Old Dalby test track?
And the newly funded Welsh test track at Onllwyn if it is actually built.
Government backs Global Centre for Rail Excellence in Wales | Rail Business UK | Railway Gazette International

Facilities would include a 6·9 km electrified outer loop for testing trains at up to 175 km/h, an electrified 4·5 km inner loop for testing infrastructure and equipment, including a two-platform station environment.

 

[kieron]

Indeed - it’s usually ok if the D.C. traffic is relatively light - ie short trains or low frequency, or both.

Do you know if the crossover in Hunts Cross caused any problems in that respect? I'm thinking that the CLC line may be electrified at some point, and I'd expect there to be a crossover somewhere if they did that.

 

[61653 HTAFC]

One of the reasons the DC bay is where it is at Hunts Cross is that there was originally the intention of reopening to Gateacre. No idea if those plans could be revived but if there's little or no chance of it, it would probably be worthwhile to move the Merseyrail platform to the other side in the event of wiring the CLC.

 

[Bald Rick]

Do you know if the crossover in Hunts Cross caused any problems in that respect? I'm thinking that the CLC line may be electrified at some point, and I'd expect there to be a crossover somewhere if they did that.

I don’t know but I’d be very surprised unless it had a frequent service of D.C. trains over it.

 

[HSP 2]

The Glagow subway is the only 3rd rail system in Scotland.

and always will be, due to two factors, 1] it's a tube system. 2] it's 4' gauge. I'm not sure if Broomlaw has a standard gauge rail connection, or if all the gear has to go in by road.

 

[Greybeard33]

I don’t know but I’d be very surprised unless it had a frequent service of D.C. trains over it.

Hunts Cross West Junction (where the Merseyrail DC line crosses the CLC main line) has 8tph of Merseyrail DC trains over it (4tphpd).