Summer 2015 - Box tunnel closure and the effect on passenger travel

[whole diary]

[grahame]

Summer 2015 will see the most significant engineering works on the Great Western main line in 40 years, as part of the electrification program from London to Swindon, Chippenham, Bath, Bristol and South Wales. For a period of six weeks from 18th July to 31st August, Box tunnel between Chippenham and Bath Spa will be closed, and the only way for westbound trains on the main line beyond Chippenham to carry on will be via the now-single track through Melksham to Trowbridge, which has very limited signaling (so trains cannot follow each other closely) and nowhere at all for them to pass each other all the way to the outskirts of Trowbridge.

The closure is split into two periods.  From 18th July to 31st July, the line from Westbury and Trowbridge via Bradford on Avon will remain open, but thought August this too will be closed, while Bathampton Junction is remodelled. The opportunity is also being taken to undertake works on the track at the aquaduct at Dundas, which has been a tight fit for trains until now and has limited what types of trains can use thay line.  Other opportunities being grasped include other relaying miles and miles of track. As well as contining to move passengers (including commuters) in the area, and freight, some 200 engineering trains will need to arrive and depart from the work sites, from various directions.

On Friday, Phil and I met with First Great Western to learn more of the planning as it develops, and allow us to make inputs to inform the final planning. At this stage, the engineering schedules are you to be finalised and whilst Network Rail are planning their work trains with one eye to passengers, they do have an element of priority in order to avoid the need for a yet longer closure.  So we don't exactly know yet what and when passenger trains will run - but we have a good idea.

From 18th to 31st July, one of the two trains per hour from London to Bristol that usually pass through Box tunnerl will be diverted away from the area and miss Chippenham and Bath, and the second will run from Chippenham to the outskirts of Trowbridge, reversing outside Trowbridge station, and carry on up to Bath.  Most of the TransWilts services will be replaced by buses, however it is expected that there will still be a limited service - in paricular, a peak train into Swindon in the morning and back after work.  This is better than earlier indications which were of complete replacement, and the plan change comes about partly because of the huge rise in passenger numbers on the TransWilts in the last 18 months.

From 1st to 31st August, there are going to be major bus operations from Westbury / Trowbridge / Bradford-on-Avon, and from Chippenham  to Bath Spa (and some other buses too). The hourly train from Portsmouth to Cardiff that usually runs Westbury - Trowbridge - Bath Spa will be diverted from Westbury to Swindon with some (numbers under discussion) stops at Melksham.  For South Wales, there will be a connection at Swindon, with ticket validity extended to allow this route.  London to Bristol trains will run via the South Wales main line, with one an hour extended through Bristol to terminate at Bath Spa from the West.

So TransWilts summary
- 18th to 31st July - a few key trains, mostly buses on the Trowbridge / Melksham / Chippenham stretch.
- 1st to 31st August - served by diverted Cardiff / Portsmouth trains

Note also - Bank Holiday weekend of 23 / 24 / 25 May - complete closure at Swindon.  This is due to the transfer of signalling to the new Didcot centre, and will result in trains being replaced by buses.

[PhilWakely]

Forgive me being very naive, but that arrangement seems particulatly complicated. Surely, all that needs to be done is three routings with a small change to timings.......... Paddington to Bristol via Wootton Bassett; Paddington to Bristol via the Westbury east curve;and Paddington to Chippenham.

This would potentially leave Trans Wilts unchanged and maybe just slight alterations to the Bristol/South Coast service. The powers that be seem to cope with West of England diversions by altering SWT^▸ (South West Trains) services, so why not London to Bristol?

[grahame]

Forgive me being very naive, but that arrangement seems particulatly complicated. Surely, all that needs to be done is three routings with a small change to timings.......... Paddington to Bristol via Wootton Bassett; Paddington to Bristol via the Westbury east curve;and Paddington to Chippenham.

This would potentially leave Trans Wilts unchanged and maybe just slight alterations to the Bristol/South Coast service. The powers that be seem to cope with West of England diversions by altering SWT^▸ (South West Trains) services, so why not London to Bristol?

Some of what you say isn't that far from what's happening - more later.  But you do need to be aware of major flows from Swindon to Bath and from Chippenham to Bath and Bristol, and consider West Wilts and Hampshire to Bath, Bristol and South Wales.   As I say, more anon looking at individual journeys too.

[IndustryInsider]

For a period of six weeks from 18th July to 31st August, Box tunnel between Chippenham and Bath Spa will be closed, and the only way for westbound trains on the main line beyond Chippenham to carry on will be via the now-single track through Melksham to Trowbridge, which has very limited signaling (so trains cannot follow each other closely) and nowhere at all for them to pass each other all the way to the outskirts of Trowbridge.

It's a shame (for the continued development of the TransWilts route) that this lengthy closure didn't result in extra signalling being installed on the Thingley Junction to Bradford Junction section.  Other areas have seen signalling improved as a result of major schemes elsewhere.  For example early in the century when the West Coast Main Line was being upgraded, Banbury to Leamington Spa was upgraded to allow the Chiltern route to be more effectively used as a diversionary route and those improvements are very handy now (when the line isn't closed due to a landslip!) with with 4-aspect colour lights replacing Absolute Block signalling and leading to the closure of Fenny Compton signal box.  Train headways were more than halved as a result.

Closer to home and the recent Swindon to Kemble redoubling will be coming in very useful for when the Severn Tunnel is closed for electrification, and ongoing maintenance, over the coming years.  Whilst electrification of the GWML^▸ (Great Western Main Line) wasn't the only reason for the redoubling of that section, it no doubt helped the case considerably.

So, even if just an intermediate signal in each direction, or even better a passing point, it was probably the best chance for an upgrade that the line through Melksham is likely to get for many years.

[bobm]

So, even if just an intermediate signal in each direction, or even better a passing point, it was probably the best chance for an upgrade that the line through Melksham is likely to get for many years.

Is there a closure date for Westbury PSB^▸ (Power Signal Box)?

[grahame]

So, even if just an intermediate signal in each direction, or even better a passing point, it was probably the best chance for an upgrade that the line through Melksham is likely to get for many years.

Network Rail in their long term strategy are proposing an intermediate signal in around 10 years time.

The government's strategic freight network sees the TransWilts as a major diversionary route for freight from Southampton to the Midlands and north and has the single track section from Bradford Junction to Thingley Junction shown in green - meaning "little or no interference with passenger services" when these diversions are happening.


Rail planning is long term, and errs on the conservative side.  

* We saw this in the summer of 2011 when, for 8 Sundays, an experimental morning round trip was run between Westbury and Swindon.  The first day it was 3 or 4 cars, plans were to cut back to 2 after a week or two and then to a single carriage 153, and it was only done at all as a result of sponsorship being provided.   However, it turned out that the service was quite popular, with up to 68 passengers (and numbers growing) on the 07:30 from Westbury, and the return trip was so busy that the service stayed up at 4 carriages all through.   Even then, we were managing the marketing to ensure we didn't have to turn people away; we got it about right - just a handful denied boarding on one Sunday, and a number of complaints from potential passengers telling us we should have marketed it better because they didn't hear until too late.

* Even after proof that we could get people onto trains (as per above), the next stage had to be / still is the "experimental" service we have at the moment.  And again the setup is such that it's worked on a conservative basis, and there's some surprise in official quarters away from Wiltshire as to how well it has done.  Six days a week there are trains where people are standing, and the busiest section for that is between Melksham and Chippenham, and not on the main line where it could have been argued we were simply abstracting from other trains.

So - disappointed but not surprised at the lack of any improvements on the single line, which I understand is rudimentary in terms of signalling, with a phone call needed for each down train between boxes rather than an automatic handover.  (Will that at least improve with the move of Thingley signalling to Didcot?).

The good news is that there are early shoots of acknowledgement that the current popularity of the TransWilts may be more than a flash in the pan.   But there's inertia in the system and it takes more than just a good year for the service to have it fully cognisant of the fact that there are passengers who want to use the line - and in significant numbers too.

[grahame]

So, even if just an intermediate signal in each direction, or even better a passing point, it was probably the best chance for an upgrade that the line through Melksham is likely to get for many years.

Is there a closure date for Westbury PSB^▸ (Power Signal Box)?

2026 - http://www.signalbox.org/sectionc.php?year=2026

[Timmer]

A page regarding the work taking place at Swindon in May has been added to the FGW^▸ (First Great Western) website:
www.firstgreatwestern.co.uk/Swindon2015

A page regarding the work taking place in the Bath area July/August has been added to the FGW website:
www.firstgreatwestern.co.uk/Bath2015

[phile]

I notice that in the second of the periods Portsmouth to Cardiffs will run to Swindon and for passengers to connect into other services.   I wonder if FGW^▸ (First Great Western) have given any thought as to whether these other services can accommodate the additional passengers..

[ellendune]

I notice that in the second of the periods Portsmouth to Cardiffs will run to Swindon and for passengers to connect into other services.   I wonder if FGW^▸ (First Great Western) have given any thought as to whether these other services can accommodate the additional passengers..

Yes I would suspect that they have.  Given that we are talking about August and they would be joining a westbound Cardiff train from swindon I would not expect a problem except perhaps on the Friday evening before bank holiday.

[grahame]

I notice that in the second of the periods Portsmouth to Cardiffs will run to Swindon and for passengers to connect into other services.   I wonder if FGW^▸ (First Great Western) have given any thought as to whether these other services can accommodate the additional passengers..

Yes I would suspect that they have. 

I can confirm that this has indeed been considered

[NickF]

I noticed today whilst out on a walk a compound has arrived at the eastern portal in Corsham:

Contractors seemed to be building a new access road between the boundary fence and the top of the embankment.

[grahame]

Timetable changes from May 18th 2015 on the TransWilts

On Mondays to Fridays:
The 12:47 from Swindon to Westbury is extended to Frome, where it arrives at 13:43.
The 14:14 from Westbury to Swindon starts at Frome, at 14:04

On Saturdays:
The 15:22 from Swindon to Westbury is extended to Warminster, where it arrives at 16:17
Note - train replaced by buses on 23rd May

On Sundays:
Engineering works effect trains - please check online for your particular Sunday. 

In general, Sunday trains are now scheduled every 2 hours each way from 08:30 from Westbury / 09:26 from Swindon (starting 2 hours later fro September)

From 20th to 31st July 2015

On Mondays to Fridays
A train runs at 07:35 (Westbury), 07:40 (Trowbridge), 07:51 (Melksham), 08:02 (Chippenham) to Swindon at 08:19
Returning at 17:23 from Swindon, 17:40 (Chippenham), 17:50 (Melksham), 18:03 (Trowbridge) to Westbury at 18:10

All other trains are replace by buses during these two weeks.

From 3rd to 28th August 2015

On Mondays to Fridays, trains leave Trowbridge for Swindon at:
06:32, 07m10, 07m56, 09:15, 10m16, 12m16, 13:16, 14m16, 15:18, 16m16, 17:17, 18m16, 19:17, 20m16, 21:19 and 22:20
Trains return from Swindon at:
05m54, 07m19, 18m19, 09:22, 10m19, 13m19, 14:19, 15m22, 16:19, 17m20, 18m20, 19:22, 20m20, 21:37 and 23:18
All trains start from / continue to Westbury
All trains call at Chippenham
Trains marked "m" also call at Melksham

On Saturdays, 19 trains run in each direction of which 9 call at Melksham
On Sundays, 14 northbound and 13 southbound trains run, with 6 (northbound) and 5 (southbound) calling at Melksham

From 1st September to December, Monday to Saturday trains return to their normal timetables.
Sunday trains leave Westbury for Swindon at 10:30, 12:30, 14:35, 16:30, 18:39 and 19:41
Returning from Swindon at 11:28, 13:28, 15:28, 17:28 and 19:55