Could bimode EMUs to run from Heathrow to Gatwick without any need for diesel?

[showchaser]

Moderator note: split from

Acton Main Line to Acton Wells Jct electrification

19/05/25 Poplars Acton Wells to Horn Lane bridge. 1747670141 Bank viewed from Down Relief through Horn Lane bridge. Poplars adjacent to Acton Main Line

www.railforums.co.uk

Hello, sorry to ask a stupid question, will the current electrification work allow, theoretically, for bimode EMUs to run from Heathrow to Gatwick without any need for diesel?

 

[The Planner]

Hello, sorry to ask a stupid question, will the current electrification work allow, theoretically, for bimode EMUs to run from Heathrow to Gatwick without any need for diesel?

No. There would still be a section without wires.

 

[Class15]

Hello, sorry to ask a stupid question, will the current electrification work allow, theoretically, for bimode EMUs to run from Heathrow to Gatwick without any need for diesel?

Yes but you would need to reverse at Willesden Junction High Level.

 

[zwk500]

Hello, sorry to ask a stupid question, will the current electrification work allow, theoretically, for bimode EMUs to run from Heathrow to Gatwick without any need for diesel?

A dual-voltage EMU couldn't run direct, it would need to reverse somewhere. If at Willesden Jn High Level as @Class15 suggests, it'd need to use the siding and therefore couldn't do the reversal in passenger service. If wanting to stay in Passenger service it'd need to go at least to Gospel Oak (or get special permissions to reverse of a shunt signal).

A Bi-Mode Multiple Unit by definition carries an alternative power source, so would be able to bridge the gap between Acton Wells Jn and Willesden West London Jn and run direct. Not that any such service would run because of the difficulty of getting off the Brighton Slows at Balham.

Small technical point of pedantry (not a criticism of you specifically by any means) - a Bi-Mode and an EMU should really be mutually exclusive categories, as 'EMU' is one mode. It's a bit of a frustration I have that press reports have referred to 'tri-modes' when they actually mean 'Dual-voltage Bi-Mode' because I've never seen a Class 700 (say) referred to as a Bi-mode.

 

[showchaser]

A dual-voltage EMU couldn't run direct, it would need to reverse somewhere. If at Willesden Jn High Level as @Class15 suggests, it'd need to use the siding and therefore couldn't do the reversal in passenger service. If wanting to stay in Passenger service it'd need to go at least to Gospel Oak (or get special permissions to reverse of a shunt signal).

A Bi-Mode Multiple Unit by definition carries an alternative power source, so would be able to bridge the gap between Acton Wells Jn and Willesden West London Jn and run direct. Not that any such service would run because of the difficulty of getting off the Brighton Slows at Balham.

Small technical point of pedantry (not a criticism of you specifically by any means) - a Bi-Mode and an EMU should really be mutually exclusive categories, as 'EMU' is one mode. It's a bit of a frustration I have that press reports have referred to 'tri-modes' when they actually mean 'Dual-voltage Bi-Mode' because I've never seen a Class 700 (say) referred to as a Bi-mode.

Thank you for this masterful, and entirely welcome explanation. I do not interpret it as criticism!

Please may I ask, would an imaginary service through Gospel Oak be able to continue onward and somehow enter the Thameslink core?

 

[Bald Rick]

Please may I ask, would an imaginary service through Gospel Oak be able to continue onward and somehow enter the Thameslink core?

Not without further electrification and two reversals, or a very lengthy detour via North, East, North, West and South London.

Also any train to/from Heathrow via the GWML must be equipped eith ETCS L2 signalling.

 

[jfowkes]

Please may I ask, would an imaginary service through Gospel Oak be able to continue onward and somehow enter the Thameslink core?

You can't get there via Gospel Oak, not without either going up to Harringay via the GOBLIN and reversing, or through Camden Road, onto the ECML and reversing.

 

[zwk500]

Not without further electrification and two reversals, or a very lengthy detour via North, East, North, West and South London.

Point of order M'lud - Gospel Oak to the ECML via the North London Incline is already wired, and there are reversing signals on the Down Slow 2 at Hornsey such that the move could be made by an EMU with one reversal. (I'm fairly sure the wrong-direction signal on the Down Slow at Copenhagen junction can't be used to reverse but may be wrong).

Obviously this would never be a regular service as it'd be a sure fire way to knacker the performance of the entirety of London's network in one easy swoop.

Also any train to/from Heathrow via the GWML must be equipped eith ETCS L2 signalling.

indeed.

 

[Class15]

Point of order M'lud - Gospel Oak to the ECML via the North London Incline is already wired, and there are reversing signals on the Down Slow 2 at Hornsey such that the move could be made by an EMU with one reversal. (I'm fairly sure the wrong-direction signal on the Down Slow at Copenhagen junction can't be used to reverse but may be wrong).

Yes, you are 100% correct - you can do it with one reversal and there is OHLE - from the diagrams it looks possible to reverse at Copenhagen Jn on the Down Slow but I might be wrong.

 

[zwk500]

Yes, you are 100% correct - you can do it with one reversal and there is OHLE - from the diagrams it looks possible to reverse at Copenhagen Jn on the Down Slow but I might be wrong.

I mean, it's fairly academic as you'd never get the path, hence saying about K440 on DSL2 for the flyover back. There's a wrong-direction signal at Copenhagen junction but it doesn't mean you can reverse there - there may be interlocking or operating restrictions given how close it is to the crossover and tunnels. K440 can definitely be used to reverse. However the flyover is not passenger-rated so you'd need Authority to pass the train in passenger service.

 

[Bald Rick]

Point of order M'lud - Gospel Oak to the ECML via the North London Incline is already wired, and there are reversing signals on the Down Slow 2 at Hornsey such that the move could be made by an EMU with one reversal. (I'm fairly sure the wrong-direction signal on the Down Slow at Copenhagen junction can't be used to reverse but may be wrong).

Objection upheld!