Any more DMUs?

[The Planner]

Until they change the goalposts where Freight actually makes a meaningful amount to a business case then it isn't going to make a huge difference.

 

[northwichcat]

Well then, if there isn't alot of freight (if any) and the problem is low bridges could the tactics used on that Scottish branch (I can't remember if they banned frieght altogether or just electric freight) be used to avoid bridge works? Alternatively, if raising the bridges would also enhance the freight guage maybe that would strengthen the case?

We seem to be going around in circles here. Network Rail have looked at that and concluded that there would be so many gaps in the wires that it would mean the Crewe-Chester shuttle would have to remain as DMU as there would be no suitable commuter EMU able to operate on the line.

 

[HSTEd]

There is an alternative but is is heresy.

Extend the third rail through to immediately outside Crewe and do the switch on the move.
Use dual voltage units and job's done.

But it would mean dual voltage Pendos would be necessary...

 

[Rhydgaled]

We seem to be going around in circles here. Network Rail have looked at that and concluded that there would be so many gaps in the wires that it would mean the Crewe-Chester shuttle would have to remain as DMU as there would be no suitable commuter EMU able to operate on the line.

I don't think the Scottish scheme I'm talking about had gaps in the wires. I think there was one 'neutral section', under one bridge where physical clearances were suffcient but electrical clearances weren't. The rest of the line I think was managed by planning clearances based on using particular types of EMU, rather than trying to make the route universally available.

 

[HSTEd]

Would singling the line allow electrification to proceed without massive bridge works all over the place?

Its relatively lightly used and dynamic loops should permit the existing timetable to be maintained....

 

[The Planner]

Would require pretty much wholesale re-signalling. Conisidering the plans to get rid of Steelworks and Beeston are pretty well advanced I can't see that getting off the fag packet.

 

[northwichcat]

I don't think the Scottish scheme I'm talking about had gaps in the wires. I think there was one 'neutral section', under one bridge where physical clearances were suffcient but electrical clearances weren't. The rest of the line I think was managed by planning clearances based on using particular types of EMU, rather than trying to make the route universally available.

I thought Network Rail looked at dis-continuous electrification because none of the tried and tested methods would work?

With regards to third rail isn't there an EU regulation forbidding it on overground lines except where it is replacing existing third rail?

 

[HSTEd]

I thought Network Rail looked at dis-continuous electrification because none of the tried and tested methods would work?

With regards to third rail isn't there an EU regulation forbidding it on overground lines except where it is replacing existing third rail?

Nope (otherwise there would be trouble with the new sections of the East London Line et al?), it appears to just be a self imposed restriction on the part of Network Rail.

 

[Peter Sarf]

The main part of the East London line was third and fourth rail originally of course - I mean the ex LUL section. Even the bit North of that from roughly where Broad street station WAS to Dalston Junction was third rail. The Southern end of course always was third rail (as in to West Croydon / Crystal Palace). The latest section to Clapham Junction is of course largely also over Southern tracks.

However I think the main tunnels under the Thames were built to a huge loading gauge so might not have prevented 25kV AC overhead. Then again most of the other routes the 378s use are 3rd rail. Its perhaps only the parts of the NLL that (electric) freight uses that are overhead. I seem to remember that as part of the engineering work done around Highbury and Islington to Camden parts, at least, were converted to overhead ?.

 

[61653 HTAFC]

Would singling the line allow electrification to proceed without massive bridge works all over the place?

Its relatively lightly used and dynamic loops should permit the existing timetable to be maintained....

Would require pretty much wholesale re-signalling.

Would electrification not require extensive signalling alterations anyway due to immunisation? Forgive my ignorance if that's not the case.

 

[Chris125]

The problem with wiring Chester-Crewe is that it's poor value for money - the high infrastructure cost only benefits a relatively small number of services.

The easiest way to justify electrification may be to include as part of a larger scheme - I believe the WAG are putting together a business case for electrifying the NWCL which could do just this.

Chris

 

[swt_passenger]

I seem to remember that as part of the engineering work done around Highbury and Islington to Camden parts, at least, were converted to overhead ?.

The various dual or DC sections of the NLL were rationalised away either before or during the upgrade, units must now be on AC from Stratford all the way through to Acton Central or North Pole (WLL towards Clapham Jn). There are changeovers around Willesden Jn LL but they aren't on the main NLL passenger route.

(The ELL extension section through Canonbury is functionally separate to the NLL.)