It always takes time for new stock to "bed in" so to speak. Reliability should level off at a high level eventually.
But what figure are you using for fleet size? That isn't yet a fixed number as deliveries of 802s is still in progress, and the last 800 was only delivered a couple of weeks ago... Like I said you're taking the published figures - which I agree don't paint the IETs in a great light for reliability - and reading in something that isn't there.
As @TractiveEffort states several units are managing in excess of 900 mile diagrams without issue; and there is (now) becoming a surplus of 80x stock while we wait for the New TT to be introduced - units that are sat spare on NP or SG are going to be contributing zero miles to those run; while still be counted towards fleet size.
Fleet miles run isn't a sensible reliability metric.
Interesting there are spare 80x units, as a few Bristol diagrams were worked by HSTs this week, when they could be covered by 800s.
I'm guessing GWR is getting the most out of their HSTs, as the leading costs are much less than the 80xs
The published data include the total miles run by the fleet in any four week period. Also included is the number of units in the fleet in that four week period and the number of TINs.
Dividing the total miles by the number of TINs gives the MTIN. If I do this I obtain the same value for the MTIN as Modern Railways reports.
So total fleet miles divided by fleet size divided by 28 gives the miles each unit is doing per day. Unless somebody is feeding MR with porkies the arithmetic is correct and this yields a figure which is 200 miles less per day than an HST.
It always takes time for new stock to "bed in" so to speak. Reliability should level off at a high level eventually.
They are indeed. Averaging fleet miles of a fleet that is still in delivery is going to give you some really dud figures.
The last HST workings on GWR are due to finish with effect from the May timetable. If the cl.802 delivery programme continues to progress as it was doing before Xmas, that may come earlier, driver training at Penzance permitting.
The last SX diagrams to finish on the Friday before the T/T change date are a PZ-LA, a LA-PZ and possibly a PZ-PZ, if that hasn’t gone earlier. Both of the first 2 diagrams I quoted involve lunchtime Pullman dining.
But what figure are you using for fleet size? That isn't yet a fixed number as deliveries of 802s is still in progress, and the last 800 was only delivered a couple of weeks ago... Like I said you're taking the published figures - which I agree don't paint the IETs in a great light for reliability - and reading in something that isn't there.
As @TractiveEffort states several units are managing in excess of 900 mile diagrams without issue; and there is (now) becoming a surplus of 80x stock while we wait for the New TT to be introduced - units that are sat spare on NP or SG are going to be contributing zero miles to those run; while still be counted towards fleet size.
Fleet miles run isn't a sensible reliability metric.
Why do people have difficulty with averages? The data published lists the total miles run by each fleet — it makes no difference at all whether the miles run are to Hereford, Penzance or anywhere else.Do your sums make any allowance for the Oxford and Cotswold Line Class 180 and Turbo diagrams that IETs have also taken over in the past 12 months?
Even if it does, a set on a diagram with a couple of London-Worcester and back trips, plus a couple of London-Oxford and back trips, is clocking up 730-odd miles in the course of a single day, never mind the 910 miles that a Penzance-Paddington-Penzance diagram covers.
Though looks like there will be a level of GW fleet-specific problems until the antique 1990s ATP technology is removed from IETs, as Modern Railways says faults with this system account for 28 per cent of all technical incidents and 20 per cent of delay minutes.
Why do people have difficulty with averages? The data published lists the total miles run by each fleet — it makes no difference at all whether the miles run are to Hereford, Penzance or anywhere else.
Why do people have difficulty with averages? The data published lists the total miles run by each fleet — it makes no difference at all whether the miles run are to Hereford, Penzance or anywhere else.
Sets doing almost 0 miles a day seems very unlikely to me.
I have no difficulty with averages but it is pretty clear from points made above that your calculation is based on figures that do not seem to make much sense, such as the number of sets supposedly in service remaining constant over an extended period when extra IETs were entering service at regular intervals. Whatever it is that you are trying to prove in the first place.
We don't have a problem with averages its that your figures don't add up right. For you very low mileage figure to be right, there would have to be a seriously large amount of sets doing almost 0 miles day. Sets doing almost 0 miles a day seems very unlikely to me.
The figures that FGW_DID posted are DIAGRAM (that is, scheduled) miles, the figures I posted are based on the published numbers and give ACTUAL run miles. There is no discrepancy between the two sets of numbers.I appreciate that, however, @coppercapped has stated that the IET's are doing at least 200 miles less per day than the HST's, which to me seems unlikely given that a lot of diagrams have been replaced like for like. Even though there will be sets sat all day, there would have to be a lot for them to bring down the average that much.
The figures that FGW_DID posted are DIAGRAM (that is, scheduled) miles, the figures I posted are based on the published numbers and give ACTUAL run miles. There is no discrepancy between the two sets of numbers.
But possibly lots of questions!
Any chance of posting the actual figures for the MTIN per fleet please so we know what numbers we’re dealing with?
I am loath to quote the complete figures out of the magazine, if you want them I suggest that you buy it.Could you post a link so we can look for our selves?
I am loath to quote the complete figures out of the magazine, if you want them I suggest that you buy it.
However, in addition to the values I posted upthread the published MTIN values for the 800 and 802 fleets are
View attachment 57331
The best units on the railway at the moment are the Class 350 at 61,000 MTIN. Class 142 Pacers come in at around 9,000 MTIN.
Modern Railways (MR) is only publishing the figures for new trains (345(FLU),345(RLU),700,707,800, 802). IIRC MR is only counting TINS due to a fault with the train. I've seen some mention of DfT being the source of these figures but a quick search on gov.uk didn't turn up anything.And what are the MTIN figures for the GWR HSTs over the same period?
Will be interesting to see what the FLIRT MTIN figures are like!
You need to read the January Modern Railway’s, then!Modern Railways (MR) is only publishing the figures for new trains (345(FLU),345(RLU),700,707,800, 802). IIRC MR is only counting TINS due to a fault with the train. I've seen some mention of DfT being the source of these figures but a quick search on gov.uk didn't turn up anything.
These are NOT MY FIGURES!
Modern Railways has been publishing tables of reported fleet sizes, fleet miles run and the number of TINs for several types of new train over the past year. The derivative values, as also published by Modern Railways, are Miles per TIN (MTIN) and the Moving Annual Average of the MTIN time series. The magazine states that the data originate from the Rail Delivery Group which collates the performance of individual fleets for Fleet Challenge within the National Performance Task Force.
Doing simple arithmetic on the published numbers gives the results I posted. On the face of it the miles run per unit per day are a long way below that which even 40 year old HSTs achieve and would be insufficient to meet the demands of the timetable if only IETs were available. Believing these data to be accurate I could not see how it was possible that the GWR would be an all IET fleet by 'Spring 2019'. I thought that such statements had close parallels to Crossrail which suddenly slipped 18 months or so within four months of the scheduled completion date and so thought it was worth posting the result of my arithmetic. I considered the required leap in miles per day figures to be too great to be reached in five or six months as the values had flatlined for the previous three periods.
If anybody doubts the accuracy of the published numbers then this should be taken up with the organisation which collates the data because it implies irregularities in one or all of the reporting of the number of trains in service, the miles they have covered and possibly the number of TINs attributable to the trains. Any incorrect values would affect the published reliability statistics.
The next question is: do the private, internal statistics agree or disagree with the published ones?
If the railway uses questionable statistics for planning and management purposes then I am not surprised that performance is not where it should be.
So the best of the IETs are running some 200 miles per day fewer than the HSTs they are replacing
It is quite obvious that the diagrams are NOT being replaced like for like.
If your initial post had been framed as a question, such as 'do these figures I have come up with on the basis of the tables in Modern Railways make sense?',
SNIP
I've no idea what Crossrail is supposed to have to do with entry into service of GWR IETs - that delay is mainly about infrastructure, getting the central London stations finished off and the railway through the tunnels commissioned. Though looking at Class 345 reliability so far, it will give some useful breathing space to try to sort them out as well.
In his piece about the Golden Spanners in the current Modern Railways, Roger Ford also looks at the apparent dramatic decline in MTIN of SWR dmus - but this seems to be down to how SWR records technical incidents compared with the way that SWT used to do it, which suggests all the figures need to be treated more as a broad guide to the overall situation, not absolutely precise details.
Has anybody else noticed a clunking sound as an IET leaves a station?
Sounds like the doors locking or moving but surely it can't be?
Isn't it the mechanism of the door that pressure seals them?
It is moving, slightly. You can observe it if you look carefully. It's a set of cam locks pressing the door against its seal.Has anybody else noticed a clunking sound as an IET leaves a station?
Sounds like the doors locking or moving but surely it can't be?
Have the 80x been cleared for Castle Cary - Yeovil - Exeter?
Reason I ask is there was an incident at Taunton yesterday, and looking on Twitter there was one doing a Penzance, that passengers were initially told may be diverted, but was instead held at CC for almost 1.5hrs, before taking the normal route through Taunton.