Surely just improving those journey times a little bit would allow 2tph to run. It’s not difficult to beat the 171’s current acceleration but also would it not be cheaper to make improvements to the linespeed rather than laying down long stretches of new rails? Potentially you could widen the junction at Appledore to allow a faster approach into the station. With a second tph, you can alternate stops at Three Oaks and Winchelsea again which would further improve on the current journey times.
The answer may be that battery plus third rail electric trains are the best solution for ending the use of diesel trains on the Uckfield and Marshlink lines but I wish the Government would decide on the solution and implement it. I wish the Government would either install electrification and run third rail or dual voltage electric trains or order and run new battery plus third rail electric trains on these two lines.
The diesel rolling stock currently used for the train services on the Uckfield and Marshlink railway lines will not last forever so whichever branch or agency of Government is responsible (I assume it will be Great British Railways) will eventually have to make a decision on replacing the rolling stock. Otherwise there will then no longer be a train service on the Uckfield and Marshlink railway lines.
but with NwR's inexperience in this field, the TOC's lack of commitment to the future and UK rolling stock procurement as inept as it usually is these days, surely allowing for (say) a 4-year lead time would be sensible?
Thats why I think that there will be a desision made to reduce the amount of deisel traction with the introduction of a new class of EMU, that has battery,3rd rail, and overhead capability, and it will be rolled out across every region, that has electrification, but still has pockets of unelectrified lines, most likily built by Alstom at Derby, based on the existing ElectroStar design, the class could be used by GWR, southern/ SE, great northern, in fact anywhere across the uk,
The Class 171s were built in the early 2000s, so just over 20 years old. The various members of the Sprinter family are 30-40 years old and only just being considered for replacement. So perhaps in a decade’s time at the earliest you would look at retirement on the grounds of being life expired.
For 2tph on any single track section you need a runtime =< (15 minutes - Reoccupation Margins - Resilience time). The standard margins for Sussex would be Depart 1 after conflicting arrive/pass or Pass 2 after conflicting pass, although for a single line additional SPAD protection is likely to increase that to 3.
I'd agree about the potential savings for using battery trains over full electrification as a general statement. But what this rather assumes is that the current service pattern remains for now and doesn't consider future. With the population centres on both routes on the increase, the return to 2tph may be necessary at some point - including the introduction of 2tp to Uckfield. Full electrification allows for the consideration of splitting/joining at Oxted or Hurst Green, whereas a BEMU microfleet would require services to be kept forever separate (unless compatibility between MUs can be engineered.) Do you think the latter would be considered with the production of such a fleet?
BEMUs can attach to EMUs. There's zero problems with that if they're appropriately specified. Or you order a bigger BEMU fleet and use that interchangeably with EMUs.
Why would there be any splitting/joining involved? The service pattern wouldn’t be any different to pre-pandemic rush hour, and the East Grinstead/Uckfield branches have separate established flows to different termini.
Electrostars haven’t been built since 2017. Alstom’s current product is the Aventra. Nothing is impossible, but interoperability between different train families isn’t usually seen as a priority.
That was my reaction to "If a BEMU is based on an existing type, already used across the network, such as the ElectroStar family, then they could work in multiple with other types of the same family" as well.
It could be an option for streamlining services if a second train ph to/from Uckfield was required. Rather than having to find a new path it could attach to the train running in the xx.53 slot at Oxted.
It doesn’t need to “find” a new path it is already there but not being used. You would need to do a lot of gymnastics to harmonise the timings on the Uckfield and East Grinstead branches and it probably wouldn’t be possible with the demands of the single track sections.
So you're telling that there's already a spare path that a second Uckfield branch train could use? That is interesting. And on your other point, that is why the line should IMHO be re-doubled, or have the loops lengthened.
The top line speed used to be 85mph, so this shouldn't be too difficult to reinstate. I would do it in conjunction with BEMU introduction though, as even though the gaps between stations on that line are not the shortest, a 171 won't spend much time at 85mph on an all stations (except Doleham) calling pattern.
Ore-Doleham is only 40mph, so this is probably the low hanging fruit for line speed improvement, along with removing the 25mph speed restriction over the level crossing at Winchelsea (i.e. upgrade or close it).
When was the line speed reduced from 85mph? Could the ‘Thumper’ DEMUs even get up to that speed? I suspect that factors like level crossing and foot crossing safety these days would tend to militate against ‘shouldn’t be too difficult’.
Both the Class 205 and 207s could do 75mph apparently. If no 90+mph derivative existed then I wonder why the line speed was that high. I believe it was reduced in 1979, alongside the rationalisation that singled sections of the line.
85 was the steam-era default on the SR - I don't have the 1960 appendix to hand, but fairly certain there would have been some specific lower limits.
It may be possible to get a worthwhile journey time saving by going back to the 85mph speed limit from the current 40mph limit. You're probably looking at a Rye to Winchelsea dynamic passing loop. The position of the turnback siding at Ore might prevent full double tracking, along with the clearance in the Ore tunnel. This would reduce the single line running time to 11 minutes. Based on the southern region 2 minutes for a station call, I get a run time of 21 minutes between Rye and Ore based on 2D03 the 06:13 Ashford International to Eastbourne service, which could be reduced to 15 minutes by running non stop and might be able to get it down to 14 minutes by removal of the pathing which would require all trains to run non stop. A better solution might be to run a three-train every two-hour service.
A Rye to Winchelsea dynamic loop would be an option considered in the scheme development. It's certainly feasible. Regarding Ore Turnback siding, it would be slued or removed and terminating trains cut back to Hastings if necessary (Ore would of course now be getting Charing X calls so the loss of Victoria trains would be annoying from a Gatwick/East Croydon perspective but not the absolute end of the world).
