Future of Class 91s after introduction of SETs?

Discussion in 'Traction & Rolling Stock' started by absolutelymilk, 16 Nov 2015.

Thread Status:
Not open for further replies.
  1. DarloRich

    DarloRich Veteran Member

    Messages:
    19,207
    Joined:
    12 Oct 2010
    Location:
    Work - Fenny Stratford(MK) Home - Darlington
    I have made a slight addition to the above quote to match my views. I remain concerned that we are potentially binning stock with useful life left without any coherent plan for nationwide train replacements.

    We should have a clear strategy outlining what we as a nation will buy, how many, when and at what cost.

    Whilst I am no fan of the IEP concept (or its costs!) and am fairly certain it will offer less passenger comfort than the replaced trains it does offer us a chance to obtain a widespread base model on which to build our future capacity requirements
     
  2. Mikey C

    Mikey C Established Member

    Messages:
    2,122
    Joined:
    11 Feb 2013
    Hopefully they weren't made of the same steel as the Lancia Betas and Alfasuds of that era...
     
  3. BestWestern

    BestWestern Established Member

    Messages:
    6,736
    Joined:
    6 Feb 2011
    A 'widespread base model' would be truly wonderful; alas the industry appears to favour buying as many completely different types of train as possible!
     
  4. DarloRich

    DarloRich Veteran Member

    Messages:
    19,207
    Joined:
    12 Oct 2010
    Location:
    Work - Fenny Stratford(MK) Home - Darlington
    which hopefully wont talk to each other ;)
     
  5. Philip Phlopp

    Philip Phlopp Established Member

    Messages:
    2,365
    Joined:
    31 May 2015
    (a) we don't do DVTs in the UK anymore, since they waste space - a new build driving trailer standard (or first) coach would be the preferred option.

    (b) you get into a world of pain and hurt (or vehicle dynamic calculations) when you start changing weights and centres of gravity. The consultants fees for that will be astronomical.
    --- old post above --- --- new post below ---
    The coaches are unlikely to be scrapped unless they're not safe or economical to continue in service. That's unlikely but possible. If they can be used, a use will be found for them. The only thing likely to be scrapped is the Class 91 locomotive, and possibly the Mark 4 Driving Van Trailer, which would be replaced by a passenger carrying driving vehicle (or a new build power car of some description).
     
  6. Bletchleyite

    Bletchleyite Veteran Member

    Messages:
    30,680
    Joined:
    20 Oct 2014
    Location:
    Up and down the south WCML (mostly)
    Brake vehicles of any kind seem to be a UK thing (in Europe) - UIC coaches seem to be designed to stand alone, with a screw-down brake in one vestibule of every vehicle, and the guard just wandering around or taking a spare seat/compartment.
     
  7. SpacePhoenix

    SpacePhoenix Established Member

    Messages:
    5,492
    Joined:
    18 Mar 2014
    Which is the best/most appropriate one if one were ever to be preserved as an example of the class?
     
  8. D365

    D365 Established Member

    Messages:
    6,302
    Joined:
    29 Jun 2012
    91131 is the designated unit for the National Collection.
     
  9. sprinterguy

    sprinterguy Established Member

    Messages:
    9,400
    Joined:
    4 Mar 2010
    Location:
    Macclesfield
    91031/91131 is earmarked a place in the national collection as the record holder for a UK domestic passenger carrying train (154mph in 1995) and as the last high-speed locomotive built for British Rail (also the last locomotive built at Crewe).

    91111 has also been allocated a place based largely on its' current commemorative livery, but 91110 would arguably be a more worthy contender, holding as it does the UK domestic locomotive speed record of 162mph (attained in 1989 on a test working).
     
    Last edited: 19 Nov 2015
  10. 43074

    43074 Established Member

    Messages:
    1,425
    Joined:
    10 Oct 2012
    In terms of the future of the 91s, I think Rotherham seems most likely, because there aren't actually many places they would be suitable working: the MML has frequent stops meaning they would offer little or no improvement time-wise on the existing '222s', the GEML seems unlikely as they want new trains, and realistically there aren't many other places which require a high speed electric loco which is slow off the mark.

    The ones which stand out for me:
    91110 - holds the UK speed record for an electric loco on a conventional line (162.2mph in September 1989, although APT-P did 162.7mph somewhere)
    91131 - the last locomotive built at Crewe works and the last high speed electric loco built for BR.

    I'm sure I read somewhere that '11's livery would be preserved as well, but I can't find a source for that.
     
  11. D365

    D365 Established Member

    Messages:
    6,302
    Joined:
    29 Jun 2012
    Here you go! We'd had quite an extensive discussion about it earlier in the year.
     
  12. Mikey C

    Mikey C Established Member

    Messages:
    2,122
    Joined:
    11 Feb 2013
    As they're 25 years old, aren't they at the age when most previous electric locos were tending to be replaced from mainline passenger service anyway?
     
  13. ash39

    ash39 Established Member

    Messages:
    1,212
    Joined:
    8 Feb 2012
    Can't see it myself, there's no wires at Rotherham and I think platform lengths may be a problem :lol:

    Mind you that's still not as ridiculous as whoever suggested trying to convert them to DVT's when there's a load of mk3 DVT's in store and the mk4s becoming free at the same time as the 91's...
     
  14. 43074

    43074 Established Member

    Messages:
    1,425
    Joined:
    10 Oct 2012
    Thanks, knew it was probably on here.

    Well I didn't see that interpretation coming! :oops: :lol:

    Just to clarify, Booths scrapyard at Rotherham!
     
  15. al.currie93

    al.currie93 Member

    Messages:
    381
    Joined:
    27 Jun 2013
    I can't say much for a modern electric locomotive hauled train against a multiple unit equivalent, but I can provide a bit more insight :)

    Traction being centralised (locomotive) or distributed affects the acceleration of a train by affecting both how much the driving wheels of the train can adhere to the rails (adhesion).In short, the more distributed the traction is, the more of the train's weight is over powered axles and the more adhesion the train has, hence the more force can be applied before wheel-slip.

    While top speed and gearing of the train do also affect acceleration, they can actually be ignored when analysing the effects of acceleration to due traction distribution. There's actually a fairly simple calculation that can be done to work this out.

    I'd need more information on the 88 to be able to fully analyse is, but I have previously analysed an Intercity 225 (class 91, nine mk4s and a DVT) and a 9 car Pendolino. Assuming zero gradient, mediocre rail conditions (coefficient of friction of 0.35 for anyone who's interested in that) and zero air resistance.

    - An Intercity 225 has sufficient adhesion to accelerate to 50mph in 39.472 seconds.

    - A Pendolino has sufficient adhesion to accelerate to 50mph in 19.528 seconds.

    If anyone's interested I can message you the calculations, but generally the effect of distributed traction is roughly double the potential maximum adhesion-based acceleration limit. However, I don't believe either train ever accelerates to 50mph in anything less than 40 seconds (do correct me if I'm wrong!), so the reasons why an Intercity 225 cannot achieve this rate of acceleration would be down to reasons other than it being a locomotive hauled train. What's also interesting is that the Pendolino can never achieve its figure of 19.528 seconds, as the total power output of its motors limits its minimum time to 50mph to 22.82 seconds.

    In fact, if any drivers on this forum would be happy to tell roughly how long you take to accelerate your train to 50mph then I'd be very interested to hear! :)
     
  16. CockneySparrow

    CockneySparrow Established Member

    Messages:
    1,012
    Joined:
    14 Aug 2012
    Location:
    Stratford
    In todays day and age it would probably be cheaper to buy new DVTs that mess around ripping the guts out of a class 91
     
  17. Peter Mugridge

    Peter Mugridge Established Member

    Messages:
    9,399
    Joined:
    8 Apr 2010
    Location:
    Epsom
    I love the autocorrect - I have an image in my mind now of zombie DVTs attacking the class 91 fleet; trying to think of a title for the film for it! :lol:
     
  18. Nick82

    Nick82 Member

    Messages:
    329
    Joined:
    20 Feb 2014
    Apologies in advance as this may not be pertinent for this post, I saw the discussion about class 91s so I thought id ask a question.

    I was in Darlington today and I saw a 91 set departing for Kings Cross from Edinburgh. Something I have never seen before is two 91s together pushing it south bound. Does anyone know the reasons behind this and if it will be returning up north as the set originated from Edinburgh.
     
  19. najaB

    najaB Veteran Member

    Messages:
    18,080
    Joined:
    28 Aug 2011
    Location:
    Scotland
    Were they both at the same end, and were both pantographs raised?
     
  20. Nick82

    Nick82 Member

    Messages:
    329
    Joined:
    20 Feb 2014
    Not sure about the pantographs, but the 91 attached to the coaches did not seem to be using power. They were attached at the rear, pushing towards the south.

    91,91,C,C,C,C,C,C,C,C,C,DVT (DVT facing south)
     
  21. TheEscapist_

    TheEscapist_ Member

    Messages:
    150
    Joined:
    18 Nov 2011
    Just a 91 move i think, saves running an extra train from Craigentinny to Bounds Green. Detaches a Kings Cross and goes to Bounds Green light loco.... I think anyway.
     
  22. 61653 HTAFC

    61653 HTAFC Established Member

    Messages:
    8,854
    Joined:
    18 Dec 2012
    Location:
    Another planet...
    Guess would be that the southernmost 91 had broken down and the other was the rescue loco. Only ever seen it before with the rescue loco attached (blunt end first) at the south end.

    Edit: or a loco move as stated above.
     
    Last edited: 20 Nov 2015
  23. sprinterguy

    sprinterguy Established Member

    Messages:
    9,400
    Joined:
    4 Mar 2010
    Location:
    Macclesfield
    It is probable that it's either a handy way of returning a "spare" loco to Bounds Green depot without requiring an extra driver and path for a light engine move, or one of the locos has developed a traction fault and requires assistance (less likely, I would have thought, as there's less chance of a spare class 91 being available at the northern end of the route).

    Either way, it is likely that one of the locos will be removed and go to Bounds Green upon arrival in London.

    I've seen a couple of such moves in the opposite direction heading north "double headed" in the past.
     
    Last edited: 20 Nov 2015
  24. Nick82

    Nick82 Member

    Messages:
    329
    Joined:
    20 Feb 2014
    Shame as I would like to of caught a picture of it on its return up North, Thanks again
     
  25. najaB

    najaB Veteran Member

    Messages:
    18,080
    Joined:
    28 Aug 2011
    Location:
    Scotland
    Sounds like it was a loco move - either due to a failure or for scheduled maintenance. Thanks.
     
  26. EC123

    EC123 Member

    Messages:
    42
    Joined:
    17 Feb 2015
    Was a loco move to Bounds Green via KGX. 91129 was attached to set BN03, with 91116 attached to the end of the set behind 129. 116 was detached at KGX before running to Bounds Green.
     
  27. HMS Ark Royal

    HMS Ark Royal Established Member

    Messages:
    2,811
    Joined:
    2 Sep 2015
    Location:
    Hull
    Why is this - last one built?

    Out of curiosity, can a 91 pull coaching stock without anything on the rear end?
     
  28. najaB

    najaB Veteran Member

    Messages:
    18,080
    Joined:
    28 Aug 2011
    Location:
    Scotland
    Pull, yes. Push, no.
     
  29. jopsuk

    jopsuk Veteran Member

    Messages:
    11,727
    Joined:
    13 May 2008
    well one wouldn't expect any loco to be pushing a train, beyond depot shunting, without a cab on the other end?

    On the compatibility:
    Mark 4s have been run with Class 89 and 90. Presumably they could also therefore work with 86 and 87? And the 91s should be able to work with Mark 3 DVTs and (if in GEML configuration) Mark 2 DBSOs?
     
  30. najaB

    najaB Veteran Member

    Messages:
    18,080
    Joined:
    28 Aug 2011
    Location:
    Scotland
    I know, it was just an attempt to point out a potential problem with using them sans-DVT.
     
Thread Status:
Not open for further replies.

Share This Page