Possible electrification schemes in the pipeline?

[BerkshireRails]

So it's essentially a 25Kv (only) system, with a fairly long battery extension? (i.e. no DC) That should improve the case, for putting wires all the way between Brent Cross and Acton Wells.

I suspect a static battery fast charging solution (like GWR's 230) would be pushing it, on a higher frequency LO service.

And a DC upgrade (while perhaps desirable for other services) doesn't solve the third rail gap.

If DC Upgrade takes place they will install third rail between Kew Bridge and South Acton. Personally I think they should wire to Brentford if the DC Upgrade takes place so that then there is no need to install third rail in the Kew Bridge area and it would be an extension of the AC & DC system already in use at Acton Central. North London Line services in the Down Direction would pan Down at Acton Central and if they fail to switch they can run on the wires to South Acton and be turned there and Up North London Line services would pan up at South Acton and if they fail to switch they would reverse at Acton Central and stored in a platform at Richmond.

Map from Network Rail which publicly accessible.

== Doublepost prevention - post automatically merged: Yesterday at 04:15 ==

There was a brief mention in that PWI video about how SWR wish to run more Hounslow Loop services but power supply is the most limiting factor. Wimbledon Grid is quite stretched powering everything from Clapham Jnc to Surbiton, Virginia Water and Windsor (and a few other bits) - maybe a new Grid supply in Twickenham (where there is a 132kV substation) would help? Well out of the scope of the LO project though it may have to happen eventually.

They mentioned if they went for Third rail they would have to pay a lot of money to upgrade the third rail.

 

[Bald Rick]

And the power supply issues on the Hounslow Loop as well as rest of Windsor Lines due to Wimbledon grid being at capacity. This means no more electric services than are currently being operated can be operated.

It doesn’t mean that.

 

[GraphitProjekt]

So it's essentially a 25Kv (only) system, with a fairly long battery extension? (i.e. no DC)

That then surely improves the case, for putting wires all the way between Brent Cross and Acton Wells?

I suspect a static battery fast charging solution (like GWR's 230) would be pushing it, on a higher frequency LO service.

I'd honestly suspect that dual electrifying half the of the Hounslow loop is a lot more disruptive and expensive compared to reinforcing the 33kV AC feeder network in the area and running straight dual-voltage EMUs. That latter option also adds resilience and flexibility to part of the Wessex Suburban lines in general

 

[Sonik]

I'd honestly suspect that dual electrifying half the of the Hounslow loop is a lot more disruptive and expensive compared to reinforcing the 33kV AC feeder network in the area and running straight dual-voltage EMUs. That latter option also adds resilience and flexibility to part of the Wessex Suburban lines in general

As I understood it, the AC would end at Acton as it does now, and the WLL trains would use battery from there to Hounslow

Besides lack of DC capacity, the main impediment to a simple dual voltage solution is the gap at Kew and ORR policy against new third rail. So a DC supply upgrade has other benefits, but it's not much help for WLL.

 

[BerkshireRails]

As I understood it, the AC would still end at Acton, and the new trains would use battery from there to Hounslow

Besides lack of DC capacity, the main impediment to a simple dual voltage solution is the gap at Kew and ORR policy against new third rail. So a DC supply upgrade has other benefits, but it's not much help for WLL.

The plan is if they do the DC Upgrade is to do a bit of infill third rail in the Kew area.

 

[MarkyT]

As I understood it, the AC would end at Acton as it does now, and the WLL trains would use battery from there to Hounslow

Besides lack of DC capacity, the main impediment to a simple dual voltage solution is the gap at Kew and ORR policy against new third rail. So a DC supply upgrade has other benefits, but it's not much help for WLL.

I suspect they could make a good case for 3rd rail to the ORR as a short connecting link, if they really wanted to. There's the level crossing risk, but there's already another one electrified 70 metres away along Bollo Lane and battery trains could potentially bridge longer gaps provided for safety. Alternatively, perhaps move the OHLE/3rd rail boundary to South Acton, then continue wires along the connecting line. where the WLO trains could switch over on the move. That could have wider signalling implications however, extending AC closer to more DC railway which uses AC track circuits and point detection widely. Using battery for the DC section and unequipped connection is a sensible compromise. While not used routinely, it might be sensible for the trains to have DC pick up capability, so they could draw DC in an emergency out on the Hounslow line. It should be noted that direct 3rd rail supply can be less efficient overall than the same electricity stored and delivered by a battery because of resistive losses from high current in the supply and return conductors. high voltage AC OHLE is much better in this regard.

 

[BerkshireRails]

I suspect they could make a good case for 3rd rail to the ORR as a short connecting link, if they really wanted to. There's the level crossing risk, but there's already another one electrified 70 metres away along Bollo Lane and battery trains could potentially bridge longer gaps provided for safety. Alternatively, perhaps move the OHLE/3rd rail boundary to South Acton, then continue wires along the connecting line. where the WLO trains could switch over on the move. That could have wider signalling implications however, extending AC closer to more DC railway which uses AC track circuits and point detection widely. Using battery for the DC section and unequipped connection is a sensible compromise. While not used routinely, it might be sensible for the trains to have DC pick up capability, so they could draw DC in an emergency out on the Hounslow line. It should be noted that direct 3rd rail supply can be less efficient overall than the same electricity stored and delivered by a battery because of resistive losses from high current in the supply and return conductors. high voltage AC OHLE is much better in this regard.

TfL would like to close one of the crossings on Bollo Lane. Hounslow Loop should be all Axle Counters as it was resignalled a few years ago to Basingstoke from Feltham. In emergencies the units will be allowed to escape via Whitton and Clapham Junction to reach the OLE at Shepherd's Bush.