Design life

Discussion in 'Traction & Rolling Stock' started by jopsuk, 22 Oct 2011.

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  1. jopsuk

    jopsuk Veteran Member

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    There's a lot of talk of the Pacers being over their projected design life. But what was the projected design life for other stock? For example, the first batch of 317s (the "/1"s in service with FCC and /5, /7 and /8 with NXEA- all originally /1) are now 30 years old (introduced 81/82). The 455s are 30 next year (with some trailer cars being older, and much of the traction equipment even older). The 313s are 35 years old. Some Mark 3 carriages are as old as 36. The 319s, which are supposed to be cascaded once Thameslink is done with them, have their 25th birthday next year. Even the "modern" Networkers are 20 this year.

    How long can all these units go on? At what point will the chassis and bodies become untenable?
     
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  3. Class172

    Class172 Established Member Quizmaster

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    The traction equipment on a Class 442 (5-WES) is ancient isn't it, wasn't it taken from the REP(?) units they replaced, even though the actual bodyshell is much younger?
     
  4. ainsworth74

    ainsworth74 Moderator Staff Member Moderator

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    I think I read somewhere that the rule of thumb is 40 years for EMUs and 30 for DMUs. Of course that's speaking generally as some rolling stock will wear out quicker than others (14x vs HSTs for instance).

    Correct the traction equipment of the 442s originally came from the 4-REP units which makes the traction equipment about 45 years old at this point.
     
  5. heenan73

    heenan73 Member

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    15x units are ALL expected to be updated for disability rules which apply from 2020 - by which time they will already be over thirty years old; but they were built well, to solid designs, and the ROSCOs seem confident that they will last long enough to justify the huge cost of new toilets etc.

    Many first generation DMU/DEMUs outlived their official use-by date for many years, but contrary to popular belief, many didn't.

    The 1938 stock on the IOW speaks for itself, of course - I thought they'd grab a few of the 1972 units that the Vic had added to their 1967 base, but not a bit of it.

    As for the pacers, they were expected to last about 20 years (25 years ago), and were built to a much lower specification than, say the 15x units - let alone 180s or HSTs, which were built like tanks.

    Life extension for 14x units would cost much more than any other unit (because the difference between build quality and 2020 requirement is greatest), and the value of any extension would be much lower than any other unit, basically because they're cr*p.

    So far, I have heard no suggestion (outside these forums) that anyone should even spend a penny on painting the things. I don't think I'm alone in suggesting that they should never have been built; it was a false economy.

    ... and all of this in the context of huge numbers of DMU/DEMU being released by electrification. Even the 16x units can (and will) move beyond their western playground. Keeping them all to double the length of every train near Bristol? Dream on! After spending a fortune on electrics for many GW suburban routes, DaFT's generosity will run out long before then! If they keep ten 'spare' units, they'll be lucky. The rest will be used directly or indirectly to retire pacers.

    I'm sure many of all the diesels will find life extension in private ownership, even the pacers. But in their case, not a moment too soon!
     
  6. Peter Mugridge

    Peter Mugridge Established Member

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    At the time the 455s were introduced I was told that the jumper cables on the fronts of the earliest units built were recovered from the class 76s which were being withdrawn at around the same time as 455 production started!

    And one interesting thing... 25 years when the Bakerloo line was still worked with 1938 stock, assuming those units were mainly from the final batches of 1938 stock built they were then the same age as the current 1972 stock on the Bakerloo is now...
     
  7. SouthEastern-465

    SouthEastern-465 Established Member

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    Actually the oldest 'Networker' is approaching 15 years old. The ABB Class 365s were introduced from 1996. Your thinking of the Class 465s that were introduced from 1991 onwards.

    Sorry to be a smart arse!
     
  8. jopsuk

    jopsuk Veteran Member

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    But class 465 ARE Networkers, no? The 365s are "Networker Express".
     
  9. SouthEastern-465

    SouthEastern-465 Established Member

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    Yes 465s are Networkers, so are the 365s. :)

    365s are fastest in the 'Networker' family I assume this is hence the name 'Networker Express'. (Top speed of 100mph compared to 75mph of a 465)
     
  10. A60K

    A60K Established Member

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    I'm afraid you fail though! The Networker name was introduced by Chris Green in late 1987 specifically for the Class 465/466 family which came into service 20 years ago. After completion of the suburban order there was a plan for the rest of the Networker family of units on various sections of NSE. Back then the Class 365 wasn't even planned, and it only came about later because the original plan for replacement of the South Eastern Division rolling stock fell victim to the recession cutbacks. Networker Turbo was the name for the diesel 165/166 units and the only other part of the original plan to be completed.
     
  11. Schnellzug

    Schnellzug Established Member

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    I don't think that rollingstock actually does have a "design life"; things like that only really apply to pressurised aircraft, where a finite number of cycles is factored into the design. (That's why things like DC-3s can go on for ever). There may have been projected estimates of when it was hoped that the next generation of stock might come along when they were introduced, but as we can see with HSTs, they (the coaches, at any rate) can more or less go on for ever.
     
  12. SouthEastern-465

    SouthEastern-465 Established Member

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    I disagree.

    If it wasn't a Networker it couldn't use the name. A good exsample of this is the early build Class 168s these were of a planned Networker design but got built in the privatisation era and got the name Clubman.

    Class 165s/166/465/466/365 are all in the Networker design and family. Only difference being little bits in the name. Like 'Networker Turbo' 'Kent Link Networker' 'Networker Express'.

    So even if it was introduced in the privatisation era its still and Networker, it got the name, it got the design and it looked identical back than to any other Networker!

    My little EMU book describes them as Networker Express!
     
    Last edited: 23 Oct 2011
  13. Peter Mugridge

    Peter Mugridge Established Member

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    The 1992 Combined Volume - the first one in which the 465s appear - describes them as Networkers. Page 295.
     
  14. TDK

    TDK Established Member

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    The compressors on the 455 were built in the 1930's
     
  15. SouthEastern-465

    SouthEastern-465 Established Member

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    I've read some of the traction equipment on 455s were recovered from 4SUBs?
     
  16. dubscottie

    dubscottie Member

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    If i remember right the traction motors on the 455's are from the 4SUBS although I would imagine these have been replaced by newer ones by now. Platform 5 book 1990 says EE507. 2005 says GEC507-20J

    I remember somewhere reading that the life of aluminum bodyshells is still unknown. I believe that there are concerns about the condition of the first 11 Class 158's as some major cracks are starting to show around the door areas.

    Slightly off topic, but when someone mentioned the class 76 jumpers it reminded me of the story that apparently when Crewe tried to fit MU jumpers to the early members of the class the found the could not cut holes in the cab fronts. The story goes that Gorton works had used leftover armour plate from WW2 tank building to construct the cabs!
     
    Last edited: 23 Oct 2011
  17. 142094

    142094 Established Member

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    40 years looks like what everyone aims for - with refurbishment every 10 years or so. Of course design life often is never the same as revenue life - plenty of examples where rolling stock has gone beyond the design life either because it was a decent design or due to the fact there was nothing to replace them with.
     
  18. Eng274

    Eng274 Member

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    I've wondered recently what the design life of the class 86 locomotives are. They are 45 years old now which is nothing remarkable really given the number of class 20s, 37s, 47s etc still in regular service today. Unfortunately they are proving unreliable, according to the (possibly biased, admittedly) class 90 electric loco group forum.

    Does anyone know if Porterbrook and Freightliner would be more keen to overhaul/life extend the 86s, or gradually phase them out and replace with 66s or 90s?

    It would be good to see the 86s continuing in service for many years to come, flying the flag for leckys in the "40yrs+" age group!
     
  19. Schnellzug

    Schnellzug Established Member

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    I don't know if they have much room to talk.

    Anyway, electrics tend to go on for ever, older technology ones anyway. You'll see (or would, until the Economic Downturn) locos from the '50s in regular service on France, Germany, Swizterland etc.
     
  20. Schnellzug

    Schnellzug Established Member

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    or indeed, 1911, like these (re-bodied in the 50's, but still have the original electrical equipment):
     

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  21. apk55

    apk55 Member

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    Theoretically a train or loco could be kept going indefinably if you are prepared to totally rebuild it occasionally replacing all corroded and worn parts.

    However most are scrapped because either modern requirements (such as disabled access or top speed) or a new train offers much lower running costs (such as fuel efficiency and maintenance requirements).

    Many of the long lasting locomotives have done so because they were a good design to start with, are a relatively low stress and conservative design and are often not heavily used. They also still have a use, for which a modern equivalent would not offer any significant improvement. For light freight on low speed lines for example a class 37 could be just as good as a class 66. Often some of scrapped locomotives can be cannibalized to keep others going.
     
  22. Nym

    Nym Established Member

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    Thats primarily because the 86s don't use modern power electronics that only have a lifespan of 30 or so years, the mercury fulfillment arc lasts pretty much forever...

    But power electronics are a damn sight more 'reliable' and efficient so long as the're serviced and replaced properly and regularly.
     
  23. 507 001

    507 001 Established Member

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    Not exactly, eventually there comes a point when things are just uneconomical to repair, for example when cracks start to appear in frames etc. Replacing these parts effectively means that you have a new loco.

    There are several people, including a few drivers who I know from the F&WHR that believe that the end of mainline steam is not too far away as things get more expensive to repair and rebuild, look at Flying scotsman for the most high profile example. There are a few who think that BR era Diesels aren't far behind.
     
  24. apk55

    apk55 Member

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    The mercury arc (or ignitron) rectifier was replaced very quickly from trains as soon as high power silicon rectifiers became available. Mercury splashing around on a moving train is not a good idea. Even for static application such as DC railway substations they have been phased out and replaced by silicon diodes. (Are any still in use today - can anybody answer).

    The Electronics used on 60s and 70s stock is basically simple using small scale integration semiconductors most of which are still available directly or with a close direct replacement equivalent eg op amps. Having worked recently on obsolescence management in the aerospace industry (where support for designs has to be maintained for at least 20 years) the biggest problem is early computer or microprocessor systems.

    The class 86 used tap changer control with a line voltage auto transformer with lots of trappings (38 I think) which fed a step down transformer to power the motors via rectifiers, therefore control was mechanical.
     
  25. Nym

    Nym Established Member

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    Ahhhhhhhh....

    So the power electronics don't control anything on an 86, unlike a 90...
     
  26. Peter Mugridge

    Peter Mugridge Established Member

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    A few years ago it was pointed out in ( I think ) Steam Railway that steam locomotives were designed so that some parts had a 15 year life, some had a 30 year life and the frames had a 60 year life, the idea being that at 15, 30 and 45 years you would replace those bits in the relevant overhauls but at 60 years old you'd scrap it and build a new one.
     
  27. zn1

    zn1 Member

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    what is a maximum service life of a railway vehicle? it depends how much it is needed, the economic cost of keeping it running, the cost of the overhaul - assuming it will have had at its body & underframe overhauls at the specified periodicities. a vehicle can in theory live for as long as there is money to pour in to it....by rights flying scotsman should be razor blades by now as should all the life expired steam and diesels - as long as there is money to finance the rebuilds etc
     
  28. WatcherZero

    WatcherZero Established Member

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    Surely its the life of the frame, you can replace bogies, engines, interiors, even sometimes the walls of the passenger cabins but if the frame is cracked or too heavily corroded its not repairable.
     
  29. yorksrob

    yorksrob Veteran Member

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    I'm guessing that new one that's just been built will be busy then !
     
  30. zn1

    zn1 Member

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    the beauty of steel is it can be cut out - new sections re-welded so it a frame can stay operational

    how much of for example. Mallard, Duchess of hamilton etc is 1930's original steel ? not much i suspect apart from the nameplates !!
     
  31. 12CSVT

    12CSVT Established Member

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    How do you define the design life of a class 31. Some are still in traffic 54 years after they were intoduced yet an entire sub-class (31/0) became extinct (apart from preserved D5500) over 30 years ago.

    The class 14 (D95xx) is another interesting one - some of them barely lasted 5 years with British Rail but some are still providing reliable service in industrial use.
     
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