Didcot-Swindon "getting full" - possible capacity improvements?

[zwk500]

There may not be much capacity potential in this, but closing Stocks Lane LC, then adjusting the OHLE to reinstate 125mph through Steventon would I think help

Are you aware of why they didn't do this first time around?

 

[Snow1964]

Was this section 4-track over a much longer stretch in the past before being rationalised? That might help determine how easy future quadrupling is to carry out.

GWR quadrupled the section through Challow to Wantage Road stations in 1932, so trains could be overtaken in platforms or anywhere between.
There were also quadruple tracks on approaches to both Swindon and Didcot.

Yes there are shorter loops now, and could be extended again, or faster turn outs provided, so electric freight doesn't have to crawl out of the loops, but can accelerate faster.

Potentially the former Didcot power station approach tracks provides lots of room to allow London bound track to be slewed and a prefabricated single track reversible flyover to be installed between the lines, especially if flyover then splits into 2 routes at the top (like the one at Heathrow airport junction), one towards slow lines and one towards Oxford. Think Y shape. This would get rid of flat conflicts at Didcot with trains blocking lines whilst waiting to cross flat junction.

== Doublepost prevention - post automatically merged: 11 Jun 2026 ==

I assume any reopening of the station at Wantage and Grove would be dependant on finding ways to increase capacity on this stretch?

Yes at stated above, rebuilt in 1932 as part of long loops to/from Challow, so trains calling could be passed by fast trains. But always ideal to have loop extend further so train can leave station and be ready to accelerate as soon as signal clears, not start the door closing sequence when signal clears which takes about extra half minute

 

[Dr Hoo]

In 12.00 to 13.00 - _west_ bound there was _one_ freight today. Between 13:00 and 18:00 there were only three _in total_ westbound - and eastbound there were none.

There may be that many _paths_ for freights, but a heck of a lot are 'runs as required' slots (some workings are overlapped with other as required workings), that are rarely used.

Have you seen what it’s like when the ‘Berks & Hants’ via Newbury is unavailable?

 

[fishwomp]

Have you seen what it’s like when the ‘Berks & Hants’ via Newbury is unavailable?

That's obviously going to happen - but have you seen what happens when Penrith is out? Or Weaver Jct? We don't run fewer trains on WCML for the rest of the year, just in case one of those places is out! Out come the buses...

 

[Dr Hoo]

That's obviously going to happen - but have you seen what happens when Penrith is out? Or Weaver Jct? We don't run fewer trains on WCML for the rest of the year, just in case one of those places is out! Out come the buses...

As we saw when Penrith was out for the Clifton bridge renewal and indeed more recent work that has seen Preston-Lancaster closed, the intermodal traffic has to divert to the ECML (because the Settle & Carlisle isn’t gauge cleared). With the ECML being ‘full’ like Didcot-Swindon but over much longer distances this causes significant problems.

Freight can’t get on a bus and thus has to be diverted or lost, probably permanently. There are only two routes to the West of England so the GWML has to be the alternative to the Newbury route (and vice versa).

 

[BrianW]

As we saw when Penrith was out for the Clifton bridge renewal and indeed more recent work that has seen Preston-Lancaster closed, the intermodal traffic has to divert to the ECML (because the Settle & Carlisle isn’t gauge cleared). With the ECML being ‘full’ like Didcot-Swindon but over much longer distances this causes significant problems.

Freight can’t get on a bus and thus has to be diverted or lost, probably permanently. There are only two routes to the West of England so the GWML has to be the alternative to the Newbury route (and vice versa).

Is the route to the West of England Waterloo- Exeter no longer a 'diversionary opportunity'? for some?

 

[brad465]

Is the route to the West of England Waterloo- Exeter no longer a 'diversionary opportunity'? for some?

It has been used in some diversions for B&H services, but there is almost no resilience on the line in its current form. When Taunton was shut a few years ago for a week, some diversions from Castle Cary-Exeter had to take the paths of SWR services in order to fit.

 

[NCT]

Indeed, we need to get away from filling every piece of white space to earn money from it.

Does the industry earn more money from
- 1000 slightly disgruntle passengers, or
- 800 happy passengers?

 

[Dr Hoo]

Is the route to the West of England Waterloo- Exeter no longer a 'diversionary opportunity'? for some?

Bearing in mind that I was referring to large amounts of freight that can't 'get on a bus' I'm not sure. I suppose that Westbury (reverse)-Salisbury-Basingstoke-Reading might be feasible. Perhaps someone more local can comment how often it has been done rather than the more usual Melksham-GWML alternative that causes problems on its own?

 

[The Planner]

Does the industry earn more money from
- 1000 slightly disgruntle passengers, or
- 800 happy passengers?

Or does it lose money from those who choose not to use rail again as its unreliable?

 

[Zomboid]

Bearing in mind that I was referring to large amounts of freight that can't 'get on a bus' I'm not sure. I suppose that Westbury (reverse)-Salisbury-Basingstoke-Reading might be feasible. Perhaps someone more local can comment how often it has been done rather than the more usual Melksham-GWML alternative that causes problems on its own?

Basingstoke to Reading isn't exactly overflowing with spare capacity, with the local, XC and Southampton traffic already. Though it does share tracks with the B&H through Reading West so maybe those paths might extend to Basingstoke.

 

[fishwomp]

As we saw when Penrith was out for the Clifton bridge renewal and indeed more recent work that has seen Preston-Lancaster closed, the intermodal traffic has to divert to the ECML (because the Settle & Carlisle isn’t gauge cleared). With the ECML being ‘full’ like Didcot-Swindon but over much longer distances this causes significant problems.

Freight can’t get on a bus and thus has to be diverted or lost, probably permanently. There are only two routes to the West of England so the GWML has to be the alternative to the Newbury route (and vice versa).

Reality is that there are many important arteries in the system that have terrible or no viable diversionary routes. We can't operate a railway by planning every route to have a diversion that can fit all the normal traffic of the diverted route and its own - and hence run at around 50%!

Am thinking it'd be pretty bad to lose anything at Carlisle or Newcastle.. Port Talbot, or Ely (divert via full WCML?), etc!

 

[Dr Hoo]

Reality is that there are many important arteries in the system that have terrible or no viable diversionary routes. We can't operate a railway by planning every route to have a diversion that can fit all the normal traffic of the diverted route and its own - and hence run at around 50%!

Am thinking it'd be pretty bad to lose anything at Carlisle or Newcastle.. Port Talbot, or Ely (divert via full WCML?), etc!

I am certainly not advocating a 50% utilisation policy on routes that can act as a diversion for a nearby route, in case it is needed as such.
Nevertheless it is a lot easier if a route can at least ‘degrade reasonably’ when needed. E.g. expecting trains to only be able to keep moving at the speed of stoppers or 60mph freights. Contingency plans that can include thinning out or coupling up short 5-car trains can also help. However this is harder to apply to freight traffic.
The other day I was on a 125mph train on the ECML when the brakes came on, on a two-track section. After trickling on for a few miles and dropping back to 9 minutes late we passed a looped non-regular engineering train.
I’m not blaming the signaller, that sort of thing happens when you have a timetable that eats up all the available paths with the mix of regular traffic.

 

[zwk500]

Does the industry earn more money from
- 1000 slightly disgruntle passengers, or
- 800 happy passengers?

Probably 800 passengers, if it's operating costs are lower from running less trains and it's paying out less delay repay.

 

[devon_belle]

Does the industry earn more money from
- 1000 slightly disgruntle passengers, or
- 800 happy passengers?

I guess in some cases it is 800 happy passengers (on more trains) or 800 unhappy passengers (crammed into fewer trains)? The railway isn't exactly reliable as it is, yet we still get lots of passengers. It seems like a question of policy.