Diagrams in Wiltshire - how one train forms the next service.

[whole diary]

[grahame]

Can I get a quick sanity check.  Do I have anything wrong here?

a) The 08:13 from Temple Meads gets to Swindon at 09:04, and then forms the 09:54 to Cheltenham.  This train is followed into Swindon, 6 minutes later from Temple Meads, by the 08:30 from there, which has missed out Keynsham and Oldfield park, but otherwise made the same stops.

b) The 16:42 arrival at Swindon from the Golden Valley line remains in Swindon until 17:54, when it returns up the Golden Valley

c) The 16:28 arrival at Westbury from Bristol and beyond (Great Malvern?) forms the 17:08 to Warminster, and then the 17:28 back, carrying on at 17:38 to Great Malvern.

d) The 17:56 arrival at Westbury from Bristol and beyond forms the 18:38 back to Cheltenham Spa

e) The 11:36 arrival at Westbury from Bristol and beyond forms the 13:38 from Westbury to Bristol (Parkway).

f) The 21:01 Frome to Westbury terminates there are parks up overnight

g) All of the trains mentioned above (with the exception of the 08:30 Bristol to London) are normally formed of 2 cars - 158 or 150 units.

Once I'm sure of my facts ... I'll carry on 

[Rogang]

So far, you are spot on. Interested to see where this is leading to.....

[devon_metro]

Likewise, the world of diagrams is a magical place and there are so many factors that leads to this that and the other!

[grahame]

So far, you are spot on. Interested to see where this is leading to.....

Rogang, this should come not entirely "left field" to your folks who have a headstart on most of these ideas, nor the other folks who have an interest in the operation of the service on the TransWilts line. I'm particularly looking at the late afternoon situation, where a previous suggestion would have caused an issue with a near-zero turnaround and a couple of other unacceptable negatives, so I wanted to make sure I knew the groundworks before I wasted weeks (and missed a deadline in the process.) ....

We've been campaiging for an appropriate service and it was looking as is the minimum 'step up' was adding a 153 diagram, but on encouragement at the very highest level have looked for an option that's severely lower cost.   I'm feeling nervous about, as an amateur, making suggestions that have silly mistakes in them, but at the same time slightly flattered that I / we have been asked to make them.

w.i.b.n.i.f .....

wouldn't it be nice if ....

a) 08:13 Bristol to Swindon - current path to Bath, then diverts to Westbury. Leaves Wesbury at 09:02 for Swindon, arriving there 09:44 (2 hoursish  behind the 07:02 / same pathing between regular interval 125s.  Bristol to Bath peak flow service unaltered. Passengers from Oldfield park and Keynsham to Swindon change at Bath, and arrive 10 minutes later (Chippenham) or 6 later (Swindon)

b) New services - approx 11:45 Westbury to Swindon, approx 12:35 Swindon to Westbury. Using 11:36 arrival / 13:38 departure unit.

c) New service - 16:32 Westbury to Swindon using 16:28 arrival. Approx 17:20 into Swindon and forms 17:54 onward to Cheltenham

d) New service - 16:45 Swindon to Westbury, using 16:42 arrival. Approx 17:25 into Westbury, forming 17:38 to Great Malvern.

Services (c) and (d) pass at Chippenham, single line is clear for approx 10 minutes between them. Both may be retimed / delayed by up to 10 minutes with no great issues.

e) 21:01 Frome to Westbury extended to Swindon.  Return service provided at approx 22:35.

f) New service - 18:08 Westbury to Warminster and 18:28 Warminster to Westbury, which carries on as the 18:38 to Cheltenham.  Both calling at Dilton Marsh.

g) Extra stops at approx 17:00 at Dilton Marsh on Cardiff - Portsmouth and Portsmouth - Cardiff service; 17:08 Westbury - Warminster and 17:28 Warminster withdrawn.

** Summary service after proposed changes - Northern TransWilts.

Westbury -> Swindon: 07:02, 09:02, 11:45, 16:32, 19:35 and 21:33
Swindon -> Westbury: 06:15, --:--, 12:35, 16:44, 18:44 and 22:35

Advantages. 

1. ZERO round trip commuter options into Swindon from West Wiltshire replaced by TWO such trips - 07:44 arrival to 16:44 departure (9 hours) and 09:44 arrival to 18:44 departure (also 9 hours).   Only current option provides for 11 hours (TOO LONG!) in Swindon.

2. Access from South and West Wilts to Chippenham for a working day, with early starters and late finishers catered for. Only current option is an 07:27 arrival for a 19:00 departure from Chippenham.

3. Middle of the day round trip for half day traffic ... also provides longer distance journey options, off peak fare opportunities, etc;  very marketable in association with the other trains.

4. Evening servivce for late returners / with the 16:32 / 16:44 trip, also provides evening out, and provides later London return.

5. Dilton Marsh gets back a return peak service for evening peak; passenger numbers there dropped by 1/3 when the current service gap was introduced.  With the extra 17:00ish stops, current traffic still catered for too.

6. No extra stock needed. So should be a "low cost" option but with huge benefits / marketable service level.

7. Enough TransWilts service to seriously market and grow the line and get Community Rail Partnership running

Limitations.

1. No 08:xx into Swindon, 17:xx departure.  But with both morning and afternoon "bracketed", there would be a lot of potential users / anyone who's job can be a bit flexible.  Note that this timetable adjustment should cost < 10% of the cost of a complete extra diagram, with unit hire and staff costs.

2. Huge gap in southbound service from Swindon in morning - Chippenham to Salisbury would still be "change at Bath" and Melksham to Salisbury for morning / leiure would be ruled out.  Southbound for work may be practical for a few people sing the 06:15 off Swindon as there would be return options.

3. Any possible penalties on FGW^▸ (First Great Western) if the new trains are delayed?  Can we get some sort of derrogation I wonder on delays to these new services by up to (say) 20 mins.

Notes - this in NOT an all - or - nothing type bid.   Clearly, service (e) is the most marginal and only makes sense if most of the others are provided.

[Btline]

Having read this, it does make you think whether the stock is being used fully.

Why not send this to FGW^▸ (First Great Western) to see what they say?

[devon_metro]

Graham, I havn't read your whole post, however I did notice that a 09:44 arrival into Swindon wouldn't be possible. Running times from Chippenham are roughly 18/19 minutes in a 75mph DMU^▸ (Diesel Multiple Unit), which would clash with the 09:25 HST^▸ (High Speed Train) to London.

[grahame]

Graham, I havn't read your whole post, however I did notice that a 09:44 arrival into Swindon wouldn't be possible. Running times from Chippenham are roughly 18/19 minutes in a 75mph DMU^▸ (Diesel Multiple Unit), which would clash with the 09:25 HST^▸ (High Speed Train) to London.

Should probably have read "09:48" ... supposed to be being the 09:25 ex Chippenham.  Thanks, and there may be other line this - I am tring to get it as accurate as possible.

Why not send this to FGW^▸ (First Great Western) to see what they say?

A lot of this won't come out of the blue to them

[John R]

Graham

Other points you may want to consider if you haven't already are occupation of platform space at Swindon (probably the bay), and whether there will be any confliction with down South Wales services at Wootton Bassett.

Given the excellent CBR^▸ (Cost Benefit Ratioi (1/BCR)) of a service which requires 1 unit, I would have thought a service which requires no additional units would have a superlative CBR.

The hordes of people who get off at Swindon in the morning from Bath and Chippenham would indicate that there must be a significant untapped market from West Wilts.



 

[grahame]

Graham

Other points you may want to consider if you haven't already are occupation of platform space at Swindon (probably the bay), and whether there will be any confliction with down South Wales services at Wootton Bassett.

I think we're OK with the bay.  We can slide a few minutes on some services / others are at same exact time in hour of a current or a previously validated time and as S Wales and Bristol are clockface, that should not be a problem.   We may have problem with frieght paths.

Given the excellent CBR^▸ (Cost Benefit Ratioi (1/BCR)) of a service which requires 1 unit, I would have thought a service which requires no additional units would have a superlative CBR.

Ah - you been reading the GWRUS^▸ (Great Western Route Utilisation Strategy) 

The hordes of people who get off at Swindon in the morning from Bath and Chippenham would indicate that there must be a significant untapped market from West Wilts.

It's listed in one of the top (forget how many) flows, yes.  BUT FGW^▸ (First Great Western) have found that a lot of Trowbridge / Westbury passenger will endure a Bath change, so they're getting a lot of the income anyway.  Many of these are stories for other threads, though ... I'm looking to see if there are any showstopping 'sillies' in my proposals / timings.

[bemmy]

If I've understood it correctly Graham you have a couple of units swapping over, which would affect the crew and stock diagrams for the rest of the day. Could that make it problematical?

[grahame]

If I've understood it correctly Graham you have a couple of units swapping over, which would affect the crew and stock diagrams for the rest of the day. Could that make it problematical?

There are a number of issues that I can't answer / are beyond the information I have available - crewing being the major one. I can't answer you on route knowledge for any of the journeys proposed, whether it would effect rest breaks, and whether it would leave crews out of position. 

I believe that all of the units concerned are in the same pool so the swap there shouldn't be a problem, and having the 09:54 Swindon to Cheltenham and subsequent journeys in reverse order shouldn't be a problem either as these trains don't need to be "first class at the front".  Fuel capacity - I think checked through an earlier post, unless we end up putting two short ends togther and two hugely long ends (and a stop overnight away from a fuelling point) together.  Frieght paths on the single line I can't answer for either.   

I think we're probably OK on the SLC^▸ (Service Level Commitment), but would need to check that Bristol to Swindon which *may* be in there now - a lot of things have crept into the SLC which seem far more presecriptive that they were at first - FGW^▸ (First Great Western) are now required to have the a TransWilts train arrive at Swindon between 20:00 and 20:30, for example - that's not a problem because the existing services remain - but there may be other things in there which seem oddly pedantic and perhaps even peverse.

[grahame]

I would be really happy to hear back on the above - especially the elements that I have had to guess at such as staff rota effects  - either here, by p.m. or email - graham@wellho.net .

[devon_metro]

Graham, just showed your post to somebody "in the know":

service e) would not be viable, as the set goes on the 22.33 Westbury-Bristol
also the service from Bristol-Swindon is normally standing at Oldfield Park and was over 3/4 full from Chippenham
You can't stop the 15.22 PMH-CDF^» (Cardiff - next trains) at Dilton as it is already tightly timed in Bristol area
Nearly all crew PNB^▸ (Personal Needs Break)'s are taken in these service 'gaps' and fresh crew would be needed for the 11XX trip
 an 08.13 Bristol-Westbury would clash with the 08.22 BRI^» (Bristol Temple Meads - next trains)-PMH as well

[grahame]

Graham, just showed your post to somebody "in the know":

service e) would not be viable, as the set goes on the 22.33 Westbury-Bristol
also the service from Bristol-Swindon is normally standing at Oldfield Park and was over 3/4 full from Chippenham
You can't stop the 15.22 PMH-CDF^» (Cardiff - next trains) at Dilton as it is already tightly timed in Bristol area
Nearly all crew PNB^▸ (Personal Needs Break)'s are taken in these service 'gaps' and fresh crew would be needed for the 11XX trip
 an 08.13 Bristol-Westbury would clash with the 08.22 BRI^» (Bristol Temple Meads - next trains)-PMH as well

Many thanks for this ... useful feedback.

Service (e) is / was the least critical ... we can look around for other options there, but it's not a vital part of the plan.

The 08:13 from Bristol to Bath wouldn't change ... and there's a whole host of other follow up issues with that particular service that take into account the issues with the BRI-PMH service following (like ... it wouldn't need to stop much if at all between Bath and Westbury) and the Chippenham - Swindon section, where (at present) it mops up the early birds for the HST^▸ (High Speed Train) that gets to Swindon 6 minutes ahead.

The option is described as "low cost" rather than "no cost" - and the crewing issue is not a surprise - in fact I wonder(ed) whether it's an issue for some of the other services too.

As I say, great to have the feedback.   Did your "person in the know" make any comments along the lines of 'what about xxxxxx"?