Redhill to Tonbridge power supply questions

[Colin1501]

A few questions about the traction current supply arrangements on the Redhill to Tonbridge line, electrified in 1994.

1 - I'm aware of the location of the seven substations, but where is the grid feed for the route?

2 - What is the grid feed voltage? Is it the same 'budget' 11kv of the earlier Weymouth and South Hants electrifications, or 33kv?

3 - Is the supply controlled from the Paddock Wood electrical control room, or some other location?

Grateful for any information.

Colin

 

[Bald Rick]

A few questions about the traction current supply arrangements on the Redhill to Tonbridge line, electrified in 1994.

1 - I'm aware of the location of the seven substations, but where is the grid feed for the route?

2 - What is the grid feed voltage? Is it the same 'budget' 11kv of the earlier Weymouth and South Hants electrifications, or 33kv?

3 - Is the supply controlled from the Paddock Wood electrical control room, or some other location?

Grateful for any information.

Colin

3) some from Paddock Wood, some from Brighton.

Would need to check the diagrams for your other questions, and I don’t have them to hand.

 

[contrex]

The Kent Traction Power Supply Upgrade planned to enable the December 2018 timetable included "Outer Kent resilience: Grove Hill and High Brooms substation upgrades (conversion to 33kV)" on page 46 of this document https://flua.org.uk/documents/NR CP5 Enhancements Delivery Plan September 2017.pdf

 

[Nicholas Lewis]

A few questions about the traction current supply arrangements on the Redhill to Tonbridge line, electrified in 1994.

1 - I'm aware of the location of the seven substations, but where is the grid feed for the route?

2 - What is the grid feed voltage? Is it the same 'budget' 11kv of the earlier Weymouth and South Hants electrifications, or 33kv?

3 - Is the supply controlled from the Paddock Wood electrical control room, or some other location?

Grateful for any information.

Colin

Having been the project engineer for it this is what I recollect.

1. It has a power infeed at either end off existing 33kv HV distribution system and a 33kv feeder was run from Dormansland Grid via Dormans Stn on E.Grinstead line upto Crowhurst Jcn Switching stn (near former Crowhurst Jcn). At each infeed its stepped down to 22kV. Some years back a new 33kV s/stn was installed on E.Grinstead lines and I suspect this feeder was diverted to run via that location.

2. Power is distributed at 22kv to each s/stn then stepped down and rectified. The W.London line is the same. The other lines were don at 11kV because it was a more cost effective voltage to buy equipment for compared to 33kV and basically we didn't have much money in the 80's. The irony of the line is it was designed to support 6800A Class 92's on freights but they've never run along there on the juice. Instead we get a single class 377 pootling over it and the odd 8 car 375 when Hastings line are on diversion.

3. My recollection is most of it was on Brighton ECR with Paddock Wood just controlling upto Haysden TPH but might be wrong.

 

[Colin1501]

3) some from Paddock Wood, some from Brighton.

Would need to check the diagrams for your other questions, and I don’t have them to hand.

Thanks.

Having been the project engineer for it this is what I recollect.

1. It has a power infeed at either end off existing 33kv HV distribution system and a 33kv feeder was run from Dormansland Grid via Dormans Stn on E.Grinstead line upto Crowhurst Jcn Switching stn (near former Crowhurst Jcn). At each infeed its stepped down to 22kV. Some years back a new 33kV s/stn was installed on E.Grinstead lines and I suspect this feeder was diverted to run via that location.

2. Power is distributed at 22kv to each s/stn then stepped down and rectified. The W.London line is the same. The other lines were don at 11kV because it was a more cost effective voltage to buy equipment for compared to 33kV and basically we didn't have much money in the 80's. The irony of the line is it was designed to support 6800A Class 92's on freights but they've never run along there on the juice. Instead we get a single class 377 pootling over it and the odd 8 car 375 when Hastings line are on diversion.

3. My recollection is most of it was on Brighton ECR with Paddock Wood just controlling upto Haysden TPH but might be wrong.

Thanks for this, Nicholas - really helpful. I was aware that the electrification was carried out with Class 92 operation in mind, and it's indeed ironic that they've never worked over the line. Wasn't this because of interference with the signalling equipment?

One other question - there seem to be a lot of substations for the length of the route, and they're fairly closely spaced. Was this also a factor in providing sufficient capacity for the Class 92s?

 

[Nicholas Lewis]

Thanks.


Thanks for this, Nicholas - really helpful. I was aware that the electrification was carried out with Class 92 operation in mind, and it's indeed ironic that they've never worked over the line. Wasn't this because of interference with the signalling equipment?

One other question - there seem to be a lot of substations for the length of the route, and they're fairly closely spaced. Was this also a factor in providing sufficient capacity for the Class 92s?

The signalling interference issue was with the reed track circuits installed under the Brighton Line resignalling scheme and they were in the plan to be replaced but can't recollect why it got stalled although ironically one of my last acts before retiring was to get them converted so other than an expensive safety case from the loco owners (DBS/GBRf) they could run now but i believe they rarely run on DC now. Not for this topic but freight through the tunnel has been and remains a personal disappointment in that what I constructed never got used as intended. All other electrification schemes I worked on produced a great impact on passenger usage though.

Substation spacing was optimised for the class 92's and used intermediate TPHs to keep costs down. On the BTR1/2 routes we converted TPHs to s/stns so the distance between substations was around 1.5miles but it was more cost effective then a complete power system rebuild.

 

[Colin1501]

The signalling interference issue was with the reed track circuits installed under the Brighton Line resignalling scheme and they were in the plan to be replaced but can't recollect why it got stalled although ironically one of my last acts before retiring was to get them converted so other than an expensive safety case from the loco owners (DBS/GBRf) they could run now but i believe they rarely run on DC now. Not for this topic but freight through the tunnel has been and remains a personal disappointment in that what I constructed never got used as intended. All other electrification schemes I worked on produced a great impact on passenger usage though.

Substation spacing was optimised for the class 92's and used intermediate TPHs to keep costs down. On the BTR1/2 routes we converted TPHs to s/stns so the distance between substations was around 1.5miles but it was more cost effective then a complete power system rebuild.

Thanks again - interesting stuff.