Bathtub effect - trains will get less and less reliable

[whole diary]

[grahame]

The "bathtub effect" is well know to the Train Operating Companies.  The graph of the reliability of rolling stock against time is like a bathtub - with high unreliability in the early days of new trains being commissioned as teething troubles are sorted out.   You then get a progressively more reliable period, but after a period of say 15 to 20 years, there's a quite steep increase in unreliability.

Naturally, good lifetime maintainance, well engineered trains, trains that were robustly constructed in the first place and major refits can extend that 15 to 20 years but in the end it is inevitable that stetching the life of stock may be s short term expedient that - in the long term - costs more.   And then you have to consider the detrimental effect on your passengers morale when trains fail in service.

Coming back up from Weymouth yesterday, we were on a "Transpennine" 3 car class 158 unit which arrived at the terminus less that 5 minutes before it was due to depart.  "Late off depot" I understand, with no explanation of why, nor any explanation of why just 3 cars (the route can take 5 and it's the busiest train of the day) nor where the 2 x 150 that had been in Weymouth on Saturday night had gone.

But anyway - I suspect some maintainance was responsible for the late start and slightly short formation. The train ran well enough - but the station stops were prolonged. Partly due to the flow on and off of the crowds, and partly because of faulty doors on the rear coach that were taking an age to close each time they were opened.  We were 10 late off Castle Cary - no big deal, save that we had an 8 minute connection there.   With a big group, though, we had arranged for the train to be held in case of delay.

"Get the conductor to phone ahead" I had been advised, and indeed I did so - and he came back with bad news.  Westbury had a platform blocked by a broken down train, services of Cardiff / Portsmouth had a number of delays, and the operational staff might have to go back on the promise made to hold the train.  We were only talking 5 minutes, damn it!  And it's a usual operation on a Sunday evening to have both trains at Westbury at the same time - it SHOULD not have been a platform issue ....

As it turned out, the Swindon train WAS held at Westbury. How much (or how little) influence our party had over the decision I simply can't tell.  But I can tell you that there were a considerable number of other people who made that change too.  The ex-Weymouth left first, and a delayed (?) 125 then drew in to the plaform vacated before we set off.

Why am I telling this story under "bathub effect"?  Because the root cause of the delays / issues was faults with older rolling stock.  If the doors had worked properly.  If the train hadn't broken down.  No issue.  The clapped out old stock is turning what should be a clockwork operation into an eventful adventure all too often, and with no modern replacements in site, I can see it only getting worse rather than better. Can someone re-assure me that my analysis is incorrect?

[Jim]

But even new stock fails sometimes, so it isn't that fair on our units!

[grahame]

But even new stock fails sometimes, so it isn't that fair on our units!

I agree tha everything fails from time to time, Jim - in fact very new stock is more prone to failure than stock that has "bedded in" ... but then it tends to get less reliable with age.  Everything fails sometimes, but I've see statistics of "once every 40,000 miles" for some items, and "once every 2000 miles" for others - that's a 20:1 ratio.

[BandHcommuter]

Historically, passenger rolling stock has had an operating life of 30 - 40 years, so it is entirely possible that classes 150/158/165/166 will be around for another 20 years. We have another 8 years before HSTs^▸ (High Speed Train) are replaced, so they will be 35-40 years old.

Interestingly, (according to something I read in Modern Railways magazine a couple of years ago), the old slam door trains on the Southern region were some of the most reliable on the network when they were withdrawn, and they were pushing 40 years. Not much to go wrong on these I suppose. The same article showed that units of the same type and age could have very different reliability results on different TOCs^▸ (Train Operating Company) (I think the example was Silverlink and Great Eastern). This suggests that maintenance regimes are more effective in some areas than others.

It would be interesting to see how FGW^▸ (First Great Western)'s rolling stock reliability compares with other TOCs running similar stock types.

[simonw]

The replacement of HST^▸ (High Speed Train) trains has been postponed a number of times for financial reason, not operational reasons.

The idea that a train fleet can justifiably be kept for 35-40 years is laughable. I am not qualified to provide an expected lifespan for rolling stock, so I will not try and guess, but,

• Train design regarding safety has trained dramatically in the past 40 years. What would the accident toll have been in Cumbria if Virgin had used an HST?
• Environmental efficiency of 40 year trains compared to modern trains is not good.
• Maintenance costs of older stocker are significant.
• Refurbishment can address many issues, but there is a limit to improvements that can be made for the money available

Many people have a nostalgic view of old trains, but should this have any part in a modern rail network? I think not!

We need a reliable, fast, clean rail system. Old rolling stock suffering from continued breakdowns, power failures, heating failures, air conditioning failures, non-working doors is not the way forward.

[Lee]

But anyway - I suspect some maintainance was responsible for the late start and slightly short formation. The train ran well enough - but the station stops were prolonged. Partly due to the flow on and off of the crowds, and partly because of faulty doors on the rear coach that were taking an age to close each time they were opened.  We were 10 late off Castle Cary - no big deal, save that we had an 8 minute connection there.   With a big group, though, we had arranged for the train to be held in case of delay.

According to the FGW^▸ (First Great Western) Changes To The Service Level Commitment letter (Page 38 of the link below) , it is proposed to increase the station dwell times to provide realistic station allowances on the Weymouth line.
http://www.saveseverntunnel.co.uk/FirstGW%202007%20Draft%20Timetable%20for%20comments.pdf

The clapped out old stock is turning what should be a clockwork operation into an eventful adventure all too often, and with no modern replacements in site, I can see it only getting worse rather than better.

Quote from a recent DfT^» (Department for Transport - about) press release (link below) :
http://www.gnn.gov.uk/environment/fullDetail.asp?ReleaseID=302338&NewsAreaID=2&NavigatedFromDepartment=False

"Major improvements include 1,300 new carriages for the busiest trains across England and Wales. This will include extra carriages on services in the Bristol area."

No info as to when they will be delivered / how many there will be and on what services they will be deployed. FGW didnt seem to know anything about it when I asked them , and they said that they await the details with "considerable interest."

Interestingly, (according to something I read in Modern Railways magazine a couple of years ago), the old slam door trains on the Southern region were some of the most reliable on the network when they were withdrawn, and they were pushing 40 years. Not much to go wrong on these I suppose.

I remember SWT^▸ (South West Trains) saying that their slam door trains were effectively "boxes on wheels" with none of the complex technology that could go wrong on the newer trains.