An interesting evening in the TransWilts

[whole diary]

[grahame]

Looks like an interesting evening in the TransWilts

A Whatley quarry to Oxford freight (the 15:03) left the quarry at 17:46, and was 183 minutes late by the time it got to Chippenham at 19:32 (it had waited at Westbury for 40 minutes instead of 16 - probably so it didn't get in the way of the TransWilts that was due at Chippenham, and indeed made it there, at 19:01)

The late running 17:47 from Wootton Bassett to Merehead left Wootton Bassett at 18:46 and got to Thingley East  at 19:04, where it had to wait until 19:31 to get the single line

The 18:52 TransWilts Passenger train from Swindon was a few minutes late - due off Chippenham at 19:09, it got there at 19:15 but couldn't leave until 19:33 ... then it got stuck at Thingley, eventually leaving there at 19:49.

The 18:00 Paddington to Bristol express was running a few minutes late - it passed Dauntsey at 19:23, but then had to wait in the queue outside Chippenham until 19:37 (23 late) and it eventually passed Thingley at 19:52 - some 33 minutes late.

The 18:30 Paddington to Bristol was running 18 minutes late anyway, so suffered no further delay.

The 19:32 from Westbury to Swindon (due Chippenham at 20:01) had to wait at Trowbridge and was 20 late at Chippenham.  It took 20 minutes between leaving Trowbridge and getting onto the single line at Bradford

The Brighton to Great Malvern train, due to call at Trowbridge at 19:48, was not delayed as it was running about 15 minutes late anyway.

[grahame]

So ... what does this tell us?

Something went amiss in the priority of passenger trains over freight trains.

* An intermediate signal on the TransWilts would significantly increase capacity at time like this where there's more traffic around that scheduled because of late running.

* A loop at Chippenham station (where there's already a platform face available) would significantly reduce delays to main line trains by giving somewhere to get freights and / or TransWilts passenger trains out of the way.

[anthony215]

So ... what does this tell us?

Something went amiss in the priority of passenger trains over freight trains.

* An intermediate signal on the TransWilts would significantly increase capacity at time like this where there's more traffic around that scheduled because of late running.

* A loop at Chippenham station (where there's already a platform face available) would significantly reduce delays to main line trains by giving somewhere to get freights and / or TransWilts passenger trains out of the way.

I agree about extra signalling on the route as well as restoring the loop at Chippenham station.

I would also say we need a passing loop somewhere on the line around the Melksham area.

[TeaStew]

Looks like an interesting evening in the TransWilts
 
The 19:32 from Westbury to Swindon (due Chippenham at 20:01) had to wait at Trowbridge and was 20 late at Chippenham.  It took 20 minutes between leaving Trowbridge and getting onto the single line at Bradford

While on the other hand the 18.32 from Westbury to Swindon ran on time. I noted this as I passed it between Bradford Junction and Trowbridge at 18.39 on the delayed (in theory) connecting 16.50 out of Gloucester

[John R]

Yes, I was on the 1800 PAD^» (Paddington (London) - next trains) to BRI^» (Bristol Temple Meads - next trains) so caught up in all of that, and was going to post similarly.  I couldn't work out why the Southampton train a) didn't wait short of the junction rather than at CPM^» (Chippenham - next trains), as it then prevented the Bristol service at least getting into the station and b) why the further delay of 10 mins when the branch was clear.  So quite a few delay minutes that could have been significantly minimised either by a loop near Melksham or by having holding places clear of the main lines.

[grahame]

A single evening of laterunning freight trains is an indicator, but insufficient evidence to form a quanitative evaluation of what improvements should be made to let traffic and service levels grow between Swindon, Westbury and beyond.

I was struck on Sunday as to just how effetively the South Wales main line was being diverted from Swindon via Kemle and Gloucester, with an unimaginable previous efficiency as trains were passing at speed on the newly-redoubled section.   Even though trains were turing up with various delays on them, that delay was not being bounced back from Westbound to Eastbound by any remaining significant lengths of single track.  There is a comparison to be made in the medium and long term between various options on the TransWilts, and the ultimate solution may well be the "Kemble" one - i.e. redoubling the line all the way, or nearly all the way.   I think that the junction near Stonehouse is still single for a short distance, and I suspect that costwise a similar thing could be required / sensible at the river Avon bridge at Staverton.

The question, though, is wider that just the TransWilts on this story.

Re-instatement of a loop at Chippenham. Railway property still allows for this on the South side, Vision Chippenham is looking to it, Network Rail should be making passive provision in resignalling and electrification to allow for it - i.e. not plonking signals or masts in what would be the trackbed.  This will allow:
* Sidetracking of trains to / from the TransWilts
* A turnback for the Bristol Metro service rather than Batheaston
* Overtaking by London to Bristol express trains of the Oxford to Bristol Regional service
And the Bristol Metro and Oxford to Bristol regional services are both providing a train that can stop at Corsham.

Other possible options / improvements short of full re-doubling include
* An Intermediate signal on the TransWilts to let trains follow at shorter headway
* Re-engineering Thingley and Bradford Junctions back to double junctions with sufficient double track clear of the main lines to hold a long freight train
* Provision of an intermediate passing loop - either fairly short or dynamic

Electrification also come in somewhere here ;-)

Finally on track / operational improvements, I need to add in the request to re-instate the triangle at Bradford Junctions.  That would be superbly useful during next summer's diversions of Chippenham - Bath services to avoid Box tunnel, and I understand that one of the reasons that the curve was taken out in 1990 - the lack of power for power operated points at the junction - would no longer be an issue.

I would love to see it redoubled.  I think the loop at Chippenham is needed for quite other reasons too, and I like the idea of trains being able to wait off the main line for / from the single line without stopping a train going the other way.   I'm personally les convinced about an intermediate loop, simply because of the wide variety of trains and the tendency for them to be a few minutes late - loops are fine on single ended services where 2 passenger trains pass each other every hour, but I'm less convinced for th TransWilts at current robustness levels and think that signal and section end solutions may be better.  I'm not an expert on this and need to learn more to make a properly educated comment.

Looks like an interesting evening in the TransWilts
 
The 19:32 from Westbury to Swindon (due Chippenham at 20:01) had to wait at Trowbridge and was 20 late at Chippenham.  It took 20 minutes between leaving Trowbridge and getting onto the single line at Bradford

While on the other hand the 18.32 from Westbury to Swindon ran on time. I noted this as I passed it between Bradford Junction and Trowbridge at 18.39 on the delayed (in theory) connecting 16.50 out of Gloucester

Yes,  the northbound freight waited at Westbury until it had gone and followed it after a decent interval.  The 18:32 gets to Chippenham just a few minutes before the 18:52 from Swindon heads back the other way - or that's how it's supposed to be - but the pair of late freights got in the way tonight; an effective round trip over the single line of 36 minutes.   An intermediate signal would have cut that to 20 minutes (saving 8 minutes headway between the 2 northbound and 8 minutes between the 2 southbound)  and the loop at Chippenham would have allowed the 18:00 from Paddington to overtake the Southampton train had the Paddington been on time.   Total delay time to TransWilts passenger trains would have been reduced from around 60 minutes to around 20, and the Bristol express, already 18 late, may only have suffered another couple of minutes if that due to conflict movements at Thingley.

[TonyK]

The late running 17:47 from Wootton Bassett to Merehead left Wootton Bassett at 18:46 and got to Thingley East  at 19:04, where it had to wait until 19:31 to get the single line

Have I missed something here?

[grahame]

The late running 17:47 from Wootton Bassett to Merehead left Wootton Bassett at 18:46 and got to Thingley East  at 19:04, where it had to wait until 19:31 to get the single line

Have I missed something here?

It's a train of stone empties - not available to passengers

[eightf48544]

Graham wrote

Finally on track / operational improvements, I need to add in the request to re-instate the triangle at Bradford Junctions.  That would be superbly useful during next summer's diversions of Chippenham - Bath services to avoid Box tunnel, and I understand that one of the reasons that the curve was taken out in 1990 - the lack of power for power operated points at the junction - would no longer be an issue.

I would love to see it redoubled.  I think the loop at Chippenham is needed for quite other reasons too, and I like the idea of trains being able to wait off the main line for / from the single line without stopping a train going the other way.   I'm personally les convinced about an intermediate loop, simply because of the wide variety of trains and the tendency for them to be a few minutes late - loops are fine on single ended services where 2 passenger trains pass each other every hour, but I'm less convinced for th TransWilts at current robustness levels and think that signal and section end solutions may be better.  I'm not an expert on this and need to learn more to make a properly educated comment.

I think you have highlighted the necessary improvments which would greatly enhace the usefulness of the Trans Wilts line.

I have long been in favour of reinstating the Bradford North Chord both for diversionary puposes but also to run a Bristol Swindon/Oxford  and or London stopper serving Bradford on Avon. I think this should have been done before electrification of Box tunnel to remove the need for a blockade.

To make full use of the chord it would make sense to redouble Thingley Trowbidge/Bradford. If not then double junctions with room to get a long freight train off the mainlines at either end would be essential together with  intermediate signals to allow following trains.  A loop in the middle doesn't seem as efficatious as loops at the junctions as shown by the ongoing problems on teh cotswold Line with the two single track sections either end.

The Chipenham loop makes sense, in fact the standard German intermediate station layout is three lines with a bi-directional loop to one side. Usually used by a stopper the get of the way. However, I have been on an IC^▸ (Inter City) which used the loop to overtake a freight train. In fact we weaved in front of two freight trains going the other way one in the station and one outside.

Edited to clarify quoting - Grahame

[Trowres]

There were delays earlier, also.

The 1514 ex-Swindon was delayed between Trowbridge and Westbury (it left Trowbridge on time, contrary to what Realtimetrains reports). The return working, the 1615 from Westbury consequently departed late.

The cause isn't clear - there were two late-running freights off the Berks&Hants, then the Cardiff-Portsmouth was held outside Westbury - the Swindon was behind that.

Does anybody know if this was just congestion (freight standing fould of the junction?) or a failure of some kind?

[phile]

In these days of privatisation freight trains are treated almost the same as passenger trains, i.e. if they have paid for their track access they are entitled to a path.

[eightf48544]

In these days of privatisation freight trains are treated almost the same as passenger trains, i.e. if they have paid for their track access they are entitled to a path.

That was one of the first things the advocates of privatisation and the fragmentation of the railways came up with. I remember hearing a Miniser say if a freight company wanted a path, in the middle of the evening peak, from the North London Line at Stratford to Barking, which involves crossing all 4 GE lines,they could have it!

[grahame]

In these days of privatisation freight trains are treated almost the same as passenger trains, i.e. if they have paid for their track access they are entitled to a path.

That was one of the first things the advocates of privatisation and the fragmentation of the railways came up with. I remember hearing a Miniser say if a freight company wanted a path, in the middle of the evening peak, from the North London Line at Stratford to Barking, which involves crossing all 4 GE lines,they could have it!

From the other evening, the question really is "should a freight train that was already hours late be given priority over a passenger train that was on time?".   The effect giving it that priority was a 40 minute delay to the passenger train, and around 20 minutes to another passenger train stuck behind it.

In general, the current TransWilts service with some apparently odd schedules is based around the freight diagrams - in particular, the 07:32 from Westbury sits in the bay as Swindon for half an hour before returning to Westbury, when it should be heading back south earlier ... (a) to provide a commuter train to Trowbridge and Westbury and (b) to make onward connections to Salisbury and beyond, and to Weymouth.  But, alas, we've not been able to get it earlier because of a freight path for a train that runs very infrequently indeed.   Big shame, as this prevents us servicing a significant market, and it depresses loadings on the 16:15 and 18:32 back up from Westbury in the evenings too.

[Andrew1939 from West Oxon]

Do freight trains pay the same level of track access charges as passenger trains? In the case of pasenger trains I understand that the access charge varies according to the weight and length of trains as the bigger the train, the more wear and tear is made to the track. If so a typical freight would be many times heavier and longer than a passenger train and would, I would have thought, paid much higher track access charges than, say , a 2-car sprinter. 

[Network SouthEast]

Freight trains are charged for their path based on the loco(s) used, along with the type of wagons and the load within those wagons. Not recently, but a while ago I did a crude comparison, and freight does appear to pay a little more in track access charges.

However, I don't think track access charges are at the front of signaller's mind when regulating trains. If they were, then Severn Beach trains would always be delayed for everything else in the Bristol area, when often the reverse is true!

More likely in the bigger picture, a signaler has no choice but to run a freight train through because others are on the way. And there aren't that many places on the network for a freight train to be looped. It's all very well saying to hold a freight train, but all you do is move the problem further back down the line as other freights have to then be looped, or even stopped on the runing lines, then run late themselves and then delay more passenger trains.

Sometimes the solution isn't an ideal one.... it's just the least worst!