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Post by br7mt on Oct 22, 2019 12:22:07 GMT
ATO reduces the life span of a train by an estimated 10 years apparently. That is not correct - ATO alone does not reduce the life of anything. Regards, Dan |
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Post by Chris M on Oct 22, 2019 18:29:49 GMT
The driver of the Jubilee line train I got home this evening mentioned 12 trains out of service - is that a misunderstanding/misremembering or have 4 more than the first 8 really been withdrawn?
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Post by MoreToJack on Oct 22, 2019 18:41:25 GMT
The driver of the Jubilee line train I got home this evening mentioned 12 trains out of service - is that a misunderstanding/misremembering or have 4 more than the first 8 really been withdrawn? It is possible that there are additional trains are/were already stopped due to other faults or maintenance requirements. Is the mid life refurb still ongoing too? |
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Post by goldenarrow on Oct 22, 2019 19:12:49 GMT
It is possible that there are additional trains are/were already stopped due to other faults or maintenance requirements. Is the mid life refurb still ongoing too? Should be in the single figures by now, 52 was the latest quote a fortnight ago. |
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Post by superteacher on Oct 22, 2019 21:15:04 GMT
ATO reduces the life span of a train by an estimated 10 years apparently. Do you have any evidence for this? The 1967 stock were ATO throughout their entire life and gave 43 years of service. |
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Post by norbitonflyer on Oct 22, 2019 21:53:21 GMT
ATO reduces the life span of a train by an estimated 10 years apparently. Do you have any evidence for this? The 1967 stock were ATO throughout their entire life and gave 43 years of service. And the similar but non-ATO 1972 stock is already at 47 years with little prospect of replacement in the next six years. |
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Post by Chris M on Oct 23, 2019 0:13:45 GMT
The driver of the Jubilee line train I got home this evening mentioned 12 trains out of service - is that a misunderstanding/misremembering or have 4 more than the first 8 really been withdrawn? It is possible that there are additional trains are/were already stopped due to other faults or maintenance requirements. Is the mid life refurb still ongoing too? The phrasing implied it was due to the major defect, but that might just be poor wording (I don't remember the exact phrase used). Other faults are of course possible - indeed around lunch time there was a train taken out of service at Canary Wharf due to a door fault - presumably meaning no pilot light (I'd boarded the second car, the fault was near the rear apparently so I don't know any details). |
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Post by superteacher on Oct 23, 2019 5:01:17 GMT
Do you have any evidence for this? The 1967 stock were ATO throughout their entire life and gave 43 years of service. And the similar but non-ATO 1972 stock is already at 47 years with little prospect of replacement in the next six years. True, but that doesn’t mean that the 67 stock couldn’t have carried on in the same vein. |
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Post by d7666 on Oct 23, 2019 13:18:35 GMT
ATO per se does not decrease train life in terms of total fatigue life.
But the use of ATO has side effects, and you get to the fatigue limit in less time.
ATO allows a higher frequency train service, but from the same fleet size, and higher power + higher braking cycles, all in London where trains are more heavily loaded, and, ever increasingly highly utilised fleets as TPH goes up.
Even adding Night Tube has an effect, as fatigue life is measured in years, if you start putting out trains 7 days and 2 nights per week instead of just 7 days , you will impact expected remaining life when measured in years as you have added more load cycles.
All this is because fatigue is measured in a summation of different load cycles - it is X cycles at load x + y cycles at load Y + Z cycles at load z etc. If you go on increasing XYZ and xyx - which is what ATO allows you to do - you do reduce fatigue life when measured in absolute years, but not in total cycles, you just get through your cycles in less time.
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Post by spsmiler on Oct 23, 2019 18:10:54 GMT
maybe also the different driving styles of different drivers plus their ability to use 'partial power' rather than just 'maximum acceleration' or 'coast' causes less wear and tear? (I've not forgotten braking - this takes place during coasting and again has different 'driver styles' plus application rates).
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Post by underover on Oct 23, 2019 18:21:53 GMT
Maybe I should reword what I said. Automatic operation of a train is harsher on the train that the method of driving normally used by drivers when driving manually. As such, components reach the end of their life sooner. If you drove a car around, ragging it around at 5000 revs everywhere, you would cause more damage/accelerated wear to the engine than driving around at a normal pace.
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Post by jimbo on Oct 23, 2019 23:03:29 GMT
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Post by brigham on Oct 24, 2019 7:45:29 GMT
So, use of ATO doesn't reduce the lifespan of a train...
...it just makes it wear out quicker?
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Post by Chris M on Oct 24, 2019 9:21:50 GMT
So, use of ATO doesn't reduce the lifespan of a train... ...it just makes it wear out quicker? Yes. Basically the main determining factors for the lifespan are (a) (for most components) the distance travelled and (b) (for motors) the number of revolutions*, rather than simply time elapsed. Lifespan in years is just calculated based on the expected usage the train will get per year. For example if you expect your train to last 20,000,000 miles and it does 500,000 miles a year then you can expect it to be in service for 40 years. However if you run that same train 750,000 miles a year it will rack up 20,000,000 miles in a little over 26.5 years. With motors if you run it at 5000 rpm you will get double the life* that you get running it at 10000 rpm. *Very approximately, things like start-stop cycles and acceleration also play a part. |
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Post by dagdave on Oct 24, 2019 10:05:07 GMT
ATO also results in issues with the wheel / rail interface. Accelerating and braking in exactly the same place time after time will have an effect on the rail head.
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Post by d7666 on Oct 24, 2019 11:30:50 GMT
So, use of ATO doesn't reduce the lifespan of a train... ...it just makes it wear out quicker? hehe I see the confusion potential here. It is not ATO per se that is doing this .... but both the effect that ATO allows a more intense peak service, combined with ever increasing general loadings and all off peak services. So the trains do wear out quicker, they may have a reduce lifespan, but it is not ATO itself doing this. The OP who posted that comment has now also posted and amended wording. |
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Post by philthetube on Oct 24, 2019 11:45:34 GMT
ATO does increase component wear on trains, demonstrated on the Met between Finchley Rd and Baker ST.
A driver would motor from Finchley Rd and on reaching 30mph shut off and coast all the way to Baker St. Braking where needed, under ATO there is a lot more acceleration, sometimes changing from acceleration to braking within a very short distance, this must wear out the trains faster.
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Post by brigham on Oct 24, 2019 15:05:28 GMT
ATO does increase component wear on trains, demonstrated on the Met between Finchley Rd and Baker ST. A driver would motor from Finchley Rd and on reaching 30mph shut off and coast all the way to Baker St. Braking where needed, under ATO there is a lot more acceleration, sometimes changing from acceleration to braking within a very short distance, this must wear out the trains faster. ...And increase current demand. All in all, trains operating in ATO cost more to run, but can provide greater service density on the same infrastructure. |
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Post by cudsn15 on Oct 24, 2019 20:19:58 GMT
How much of the original components of a train are still in situ at the date of withdrawal I wonder? - again a lot must depend on actual years in service and working life years...eg How much original on an A or C stock was left compared to a Jubilee 83 stock...??
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Post by aslefshrugged on Oct 25, 2019 7:32:28 GMT
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Post by countryman on Oct 25, 2019 7:52:07 GMT
I wonder whether ATO could, in theory, be programmed to run the trains hard when required in rush hours. Then when the service is less intense to modify the acceleration and braking parameters to cut down on stress and power consumption. Would a new computer control programme be required, or would it require new hardware? Or does it already happen?
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Post by Tom on Oct 25, 2019 8:00:34 GMT
Yes - Seltrac has the functionality to 'turn up the wick' when the service is running late or is disturbed.
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Post by countryman on Oct 25, 2019 9:14:17 GMT
Yes - Seltrac has the functionality to 'turn up the wick' when the service is running late or is disturbed. I was wondering if they could turn down the wick. |
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Post by goldenarrow on Oct 25, 2019 9:38:09 GMT
With the total number of trains now available for service down to the low fifties, trains are still being worked to the existing timetable. I don’t know how sustainable that is in the long term, every third train has a gap up to ten mins in the peaks.
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Post by aslefshrugged on Oct 25, 2019 10:28:38 GMT
With the total number of trains now available for service down to the low fifties, trains are still being worked to the existing timetable. I don’t know how sustainable that is in the long term, every third train has a gap up to ten mins in the peaks. The problem with implementing a special timetable is that it would require a special duty roster for the train operators which if I remember rightly would require 28 days' advance notice by which time more trains might have been withdrawn from service (or a cure for the cracks discovered) making the new timetable as bad as the old. |
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Post by roman80 on Oct 25, 2019 15:35:59 GMT
It would be nice if some attention was given to minimising the gaps in the peaks, and TFL could give an update on the disruption and its length. Canary Wharf is a disaster in the evenings. Every entrance bar one closed, and that forces thousands to queue in the weather from 5pm onwards.
As its half term, there are less people using Canary Wharf but in another week it will be back to normal loadings.
The crowd control is actually so aggressive that trains are leaving westbound in the evening with spare capacity. As entrance is so restricted, passengers cannot enter in enough time to spread along the whole platform.
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Post by Deleted on Oct 25, 2019 15:49:43 GMT
Yes - Seltrac has the functionality to 'turn up the wick' when the service is running late or is disturbed. Not very smooth though |
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Post by spsmiler on Oct 26, 2019 15:00:08 GMT
It would be nice if some attention was given to minimising the gaps in the peaks, and TFL could give an update on the disruption and its length. Canary Wharf is a disaster in the evenings. Every entrance bar one closed, and that forces thousands to queue in the weather from 5pm onwards. As its half term, there are less people using Canary Wharf but in another week it will be back to normal loadings. The crowd control is actually so aggressive that trains are leaving westbound in the evening with spare capacity. As entrance is so restricted, passengers cannot enter in enough time to spread along the whole platform. maybe its because of a desire to leave space for passengers to board at other stations? Or could it simply be that no-one in authority is monitoring the situation and adjusting it to ensure that trains are full without the platforms being dangerously over-crowded? I wonder if the DLR is busier. |
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Post by norbitonflyer on Oct 27, 2019 8:02:30 GMT
Or could it simply be that no-one in authority is monitoring the situation and adjusting it to ensure that trains are full without the platforms being dangerously over-crowded? This can happen on the Big Railway too - I have seen BTP preventing access to Waterloo station from Waterloo Road, with the resulting crowd spilling into the carriageway (thus "exporting the risk" rather than reducing it) because of alleged crowding on the main concourse, only to be able to get to the concourse by way of the Sandell Street entrance to Waterloo East and the linkspan to find the main concourse almost deserted. |
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Post by alpinejohn on Oct 27, 2019 8:49:49 GMT
It is perhaps helpful to return to the issue - they have discovered some cracks in some steel or aluminium components on these trains.
I suspect a debate over the merits of ATO is not high in the minds of passengers - they just want these trains back in service as soon as safely possible.
So what exactly is being done to fix it?
How long will it take?
Who will pick up the bill?
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