Jump to content

Edwin_m

Members
  • Content Count

    5,483
  • Joined

  • Last visited

Posts posted by Edwin_m


  1. 13 hours ago, The Johnster said:

    The two don't mix and cannot be used simultaneously on the same train even if the loco or stock is dual fitted.  A dual fitted loco can work with stock fitted with both types of brake, but only one type at a time,  Dual fitted stock is rare, and the usual arrangement is to have one type of brake fitted and the other, usually vacuum on air braked stock, piped through so that such vehicles can be included in the fitted head of a part fitted freight. rain.

    There are a couple of highly unusual exceptions which just might be relevant here, the carriage of containers to the Far North or West Highland sometime in the 80s (don't recall when or which or maybe it was both), and the "slip and brake" tests that used to be done north of Crewe.  In both cases a dual-braked loco hauled one or more vacuum-braked but air-piped coaches with one or more air-braked wagons coupled behind. 

     

    There are also translator coaches that allow dead multiple units with various electrically controlled braking systems to be hauled and braked by locomotives with a simple air brake, and in theory I guess one of these could be built to convert vacuum into air brake operation.  

    • Informative/Useful 1

  2. 2 hours ago, Compound2632 said:

     

    My recollection from the mid 80s to early 90s is of Cross-Country trains with a guard's compartment at both ends, e.g. BG/FO/RMB/4 x SO/BSO (where all the open carriages were air-conditioned Mk 2, the BG and RMB Mk 1) or WCML BG/n x SO/RB (Mk 3)/n x FO/BFO. I didn't travel much on loco-hauled routes with shorter formations, though I think Class 50-hauled Oxford-Paddington trains were mostly non-air conditioned Mk 2 TSOs with a BSK in the middle.

    Not strictly in line with the formations you have quoted, but worth bearing in mind a lot of Cross Country formations split and joined at Carstairs (and some of these also at Preston) so needed to have two brakes in the formation.  These included the last BFKs (Mk2d) although those were used to segregate the first class passengers from passing plebs rather than anything to do with the brake area.  


  3. 9 hours ago, Aire Head said:

     

    So please forgive what may be a stupid question.

     

    If their was a maximum number of permitted wheel behind a brake why do you see smaller rakes of coaches that are not through portions marshalled with a brake at both ends?

    Going by The Stationmaster's quote, 40 wheels is only five coaches and the gradient rules might reduce this to three or two (at least carrying passengers).  Depending on route many formations wouldn't be allowed to have one brake located at one end and a few wouldn't even be allowed to have one in the middle.  Rules also differed on other Regions and the position of the brake might also have been constrained by any short platforms along the route. 

     

    I believe in 1972 all these rules were swept away and the brake could be anywhere in a passenger train.  

    • Like 1
    • Agree 1

  4. 4 hours ago, The Stationmaster said:

    The number of wheels in effect allowed vehicles to be counted more easily because they came with either four, six, eight, or twelve wheels.  If you counted axles you could finish up with an odd number when vehicles with three axles were involved - counting wheels always involved adding even numbers (even if they don't come out exactly to, say, 40).

    Not sure why counting to 40 in twos should be easier than counting to 20 in ones.  Unless you're Noah.  

    • Funny 3

  5. 1 hour ago, Ian J. said:

    @The Stationmaster I think it's not so far OT. I think my original purpose of this thread was to address how running faster would affect what a line needed to do to meet necessary safety and other regulations (which in my scenario had been a gradual improvement over time), and then more specifically how that would affect the look of the railway (which I can then consequently model). We've raised issues of signalling and automatic warning and braking systems; of what trains could run at any given time; of how much faster the trains could go, given suitable stock. All has been very useful for me, and continues to be so :)

     

    If anyone knows what disability access legislation might do to affect appearance due to the 'commercial' trains running, I'd also be interested to know that as well. I'm presuming modifications to platform edges and access ramps, but I feel there are probably more.

    I imagine for a new commercial service the accessibility rules will apply, possibly subject to exceptions if existing stock is being used and is marginally non-compliant.  The most visible one externally would be colour-contrasting doors to make them more easily identifiable by the partially sighted.  There would probably also be wheelchair spaces and accessible toilets (possibly a longer windowless area?), the door to be used being marked with a wheelchair symbol.  

    • Agree 1
    • Thanks 1

  6. You're also reverse-biasing the LEDs while the DCC current is flowing the wrong way to illuminate it.  This could damage it.  You need a normal diode in parallel with each LED, but in the opposite polarity.  


  7. 10 hours ago, Ian J. said:

    What would be the outward visual impact (if any) of TPWS on a train? I'm aware there's such things as 'toast racks' on the track, and those I could live with being in place (on the model). Would there be any other trackside equipment like cabinets, etc?

    On the train, nothing unless you look underneath an are an expert in the different equipment types, or can see the controls in the cab.  A steam loco needs some sort of electrical power source for AWS, which could power TPWS too, but on a modern conversion I guess this would be hidden somewhere to avoid upsetting the purists.  

     

    Not sure about trackside - I guess probably a junction box near the loops themselves and a cabinet near the signal if there isn't one there already.  

    • Thanks 1

  8. 32 minutes ago, stewartingram said:

    On another thing, mixing freight and heritage. What about Sheffield Tram-Train? If there are H&S concerns between a freight and heritage stock, surely there must be the same concerns between trains and trams? A remote chance of it happening I know, but what is the crash worthiness between a TT and a freight, or even a mu? Surely the similarity can be seen between a freight & a heritage train.

    The crashworthiness risk is indeed more severe, because a tram-train doesn't meet the structural strength standards applicable to trains so would be severely damaged in collision with a freight train.  This is addressed by making the collision less likely.  The most likely cause of such a collision is Signal Passed At Danger (SPAD) so on tram-train routes extra TPWS is fitted and other adjustments are made so a SPAD can't result in a significant collision. 

     

    The same principle could be used to reduce collision risks between heritage and commercial services, but as a SPAD by either type of train could be a cause of collision, it would mean having to fit TPWS equipment to the heritage trains as well as to the signals.  

    • Like 1
    • Thanks 2

  9. 57 minutes ago, Ian J. said:

     

    Agreed. This was something I thought about recently. I have wondered whether it would be possible to 'lock out' many of the intermediate signal boxes during commercial operation? If not, then I may have to concede to colour lights. But it's one more 'nail in the coffin' for the heritage appearance if I do, and a step closer to something that looks a lot like a regular line.

     

    Regarding the freight trains, couldn't they just run at the heritage speed during heritage times? A proviso being that the anticipated fictional oil trains can only run when there's no steam running, so they'd probably be restricted to non-heritage times or overnight (if allowed at all - I'm not wedded to the idea of them but it would be one of the lucrative income sources that would have put in place the line upgrades that allow the commercial passenger service to run with less need of a big profit). As for weekend shopping trains, I think that's a case of the public get something of a service in the 25mph heritage trains and will have to live with that, but I don't see that being a big source of income. The line has a seaside section towards its end and that's a leisure feature that would draw more heritage visitors (as the likes of the Swanage, West Somerset, etc, do now) so shopping traffic is less important for revenue.

     

     

    My worry would be the case of a driver forgetting which timetable type he/she is running. Good training should prevent that but we're all human, and some additional protection might be wanted by the regulator. Perhaps some kind of cue or reminder could be implemented, maybe a light next to the active line speed, with a default of no light = 25mph?

    A box could be locked out unless controlling a level crossing or any pointwork which needed to be worked to run the commercial service.  The railway companies recognized the benefit of being able to do this so many boxes had the facilty, but if one didn't then locking changes would be needed and I think in some cases extra signals (for example if a passing loop was normally uni-directional but operated bi-directionally on one track when the box was closed).  A special lever would be pulled to allow clearance of signals that wouldn't normally be allowed (such as in opposite directions on a single line) and a switch would be operated to interlink the block instruments and bells either side so it became one long block section.  

     

    As to speeds, probably the commercial services would use different locomotives, fitted with AWS/TPWS and otherwise main line certified, so the heritage ones could be labelled as 25mph maximum in the cab.  Similarly a driver would know not to exceed 25mph unless they had the necessary extra training to run "commercial".  If a "commercial" locomotive and driver was assigned to a "heritage" working then I think the driver could be trusted to stick to the lower speed.  There are places on the big railway where certain train types have to observe lower speed restrictions with no signage, just communicated by notes in the Sectional Appendix and relying on the driver's route knowledge to remember this.  

    • Thanks 1

  10. 23 minutes ago, Aire Head said:

     

    BG = Brake Gangwayed - Has facilities for a guard and gangways to access other Gangwayed stock.

     

    GUV - General Utility Vehicle - no facilities for guard, a large van to passenger coaching specifications usually has end doors to facilitate loading of items such as motor vehicles.

    Which makes the point that a parcels train couldn't be formed entirely of GUVs and CCTs.  There had to be a brake coach with guard's accommodation, and by the 80s once all the more antediluvian pre-nationalization alternatives had been withdrawn it could only be a BG or a passenger brake.  

    • Like 2

  11. 4 minutes ago, Aire Head said:

    I remember seeing somewhere something about a passenger service between Leeds and I think Leicester which was composed of about 50% NPCCS for carrying parcels aswell.

    A lot of overnight trains were essentially parcels workings with a seated coach or two tacked on, probably mostly for staff but any passengers for whom the rather random timings suited could use them too.  They died out in the 80s probably due to Sectorisation.  

    • Like 1
    • Agree 2

  12. 6 hours ago, DavidB-AU said:

    I think the discussion is getting hung up on detail about heritage passenger services. There are plenty of prototype examples where commercial operations could generate additional revenue without necessarily requiring higher speeds.

     

    - Revenue freight such as stone to Minehead, MOD to Redmire, coal from Wolsingham and bitumen on the Ribble. I have a recollection spoil trains operated on a preserved line but can't remember the details.

    - Seasonal running of main line DMUs onto preserved lines, for example to Corfe Castle and Bishops Lydeard. Okehampton is a more complicated example but shows how you can mix things up.

    - Main line rail rail tours running onto preserved lines.

    - Storing somebody else's preserved loco and support coach.

    - Charters for film and TV production.

    - Not quite a commercial operation, but some preserved lines have seen the NMT, RHTT and weed spraying trains.

     

    So run more or less whatever you want.

     

    Cheers
    David

    The GCR(N) has freight trains running off the main line at Loughborough to the gypsum plant at East Leake, but not while it is running its own passenger trains.  The Mid-Norfolk has been storing brand new trains for Greater Anglia until they are ready for use, because the existing fleet occupies all the depot space.  

    • Like 1
    • Thanks 1

  13.  

    2 hours ago, corneliuslundie said:

    The other aspect of phone numbers used to be local codes, often two digits. I remember 91 from Swansea, but that was well over 50 years ago and I cannot remember what area it covered. What I do remember is that 9198 circumvented the charging system and if you knew the internal GPO codes you could phone anywhere in the country for free. I never actually needed to do it but it was a challenge one could not resist to try to find out how to route calls to places like Manchester.

    But the point of mentioning this is to ask if these codes would ever have been included on publicity material such as van sides, posters or shop fascias.

    Jonathan

    They were only useable from an exchange that was nearby but not the same one as the destination, and I think the code to get the same destination exchange sometimes differed depending where it was dialed from.  So they would be pretty useless for advertising.  They lasted at least until the late 1980s - I remember if I pressed the first digit too quickly when calling my parents in Newcastle (091) I got a number in Mansfield (91 from Nottingham).  My recollection is that most businesses quoted the name of the exchange, or for shop fronts etc just the local part of the number without the area code (xxx xxxx if in a city with a 3-digit area code).  In the early days of mobiles a colleague of mine had one which would tell you the area code you were in, so as to be able to call those numbers.  

    • Thanks 1

  14. 2 hours ago, Andy Reichert said:

     

    San Francisco now has bendy single deck trolley buses that hold a lot of people. 

    But if you can make a trolleybus that size you can also make a diesel or battery bus the same, less only the marginal extra space needed for engine/batteries which can be above or below and many trolleybuses have that anyway.  Trams can be much longer (depending on route issues such as distance between traffic lights) and a bit wider.  Hence why a tram is more appropriate at high passenger numbers and has little advantage over engine/battery buses at lower numbers.  

    1 hour ago, Philou said:

    For a slightly whacky system : Line T6 just outside Paris (Chatillon - Viroflay) is a tram on rubber tyres - yes really - it's French of course. Single overhead wire with return via a steel wheel (un galet) running in a steel channel. This guides the tram (haven't been on it so I can't say if there is a conventional steering wheel or not). However, they spent an enormous sum on diverting services under the carriageway on the 'tram' alignment and narrowing the carriageway from four lanes to two to create a segregated corridor. They spent even more on a mile-long tunnel (tram only) going from Meudon to Viroflay which was unnecessary as the tyres would have coped with the hilly terrain. All because they didn't want to pay for the rails, they could have saved a good half of the money and had a conventional trolleybus by providing twin overhead and forgetting any diversion costs as the trolleybus is a good hill climber, completely flexible AND will work off battery power too. It really was a waste of public money in this instance. Moi!! Cross?! Non! 

    This is the Translohr.  I sampled another route in northern Paris and I think there's a third one somewhere.  My impression was it was very cramped and rough riding.  A trolleybus might have been better, perhaps with electronic guidance, but an asphalt road carrying identical large vehicles following exactly the same path is prone to rutting so concrete tends to be used for any guided vehicle.  A proper high-capacity transport system also need segregated roadspace, probably with physical measures to prevent use by other vehicles, so the ability to change lanes is also less of an advantage than it first appears.  


  15. 2 hours ago, DY444 said:

     

    I was a senior engineer in BT's Trunk Network Planning department at the time of the 071/081 change and I can assure you that there was no three stage plan in place at that time.  The objective was solely to open up more number levels in London to cater both for growth and the emergence of other licensed fixed network operators after the lucrative City market and the thought was it would give enough number capacity for 20 years.  The project to insert the 1 was conceived after 1990 and was driven by the need to provide more NNG codes to cater for landline growth outside London and for the growing number of mobile operators.   I know from first hand experience that the London business community was very unhappy indeed at two number changes in 5 years and had the 1995 project been known about in the lead up to 1990 then I'm certain that a different approach would have been adopted to avoid the double change.  I'd left before the 2000 project started but I imagine London business would have been equally unhappy about that too.

     

    As you say the decision to dispense with 0171/0181 was because there was a need for a further number level in London and all the 01x1 levels had been taken.   Adopting 020 then made it easier to add new levels going forward.

    Thanks for this update.  So it was moreorless accidental that all numbers beginning with 01 were freed up by the 1990 changes and this allowed us eventually to move to the current system.  I'm not sure though how else this problem could have been solved in 1990.  I do remember talk of some arrangement for businesses in outer London to get themselves an 071 number to make them look more central.  


  16. 55 minutes ago, Joseph_Pestell said:

    I think most of the battery charging in Seville is probably on the longer suburban sections,. the procedure at the city centre stops being just a top-up.

     

    And then there is the Bordeaux system (stud contact in the city centre) which seems to work well now after initial teething problems.

     

    1 hour ago, rue_d_etropal said:

    There has been quite a lot work done using induction charging. OK when you can determine where the vehicle will stop, so easy for trainsand trams , but difficult for buses. Also finding space for batteries can be a problem in British buses, an I think was a small problem with the new Birmingham trams.

    Just because an idea is old does not make it old fashioned . Think 20-30 years ago and tell people trams, and trolleybuses would make a come back, and they would not believe you. Compreseed air engines are being developed for cars, not sure how succesful, but should not be dismissed.

    Another problem with induction charging is that it's not particularly efficient - not a problem for your toothbrush or phone but for a bus or tram it's quite significant.  The APS system as in Bordeaux actually has a live rail but it is split electrically into short sections, each of which is energized only when there is a tram sitting on top of it.  

     

    Trolleybuses occupy a niche between motor buses and trams, but in some ways that niche is getting smaller and may be non-existent in many places.  At high passenger numbers they use more energy than a tram, with more obtrusive overhead, and cost more because they are smaller than trams.  They also have particulate emission from tyres, increasingly seen as a problem.  At low passenger numbers hybrid and battery buses are starting to get the same advantages of performance and no emissions (except tyres) on sensitive parts of the route, without the cost of overhead line.  My own belief is that the trolleybus is a technological dead end, except perhaps in very hilly cities.  


  17. I think the link mentioned one set of bi-directional cars but they needed to duplicate the equipment that heated the air at each end.  

     

    Possibly with modern insulation technology there would be better ways to keep the air warm than having to take on hot water or have a small coal fire in the cab.  

     

    A salt mine in Cheshire has been converted into a large-scale compressed air energy storage, so it's competitive for some applications although obviously very different from a tram.  


  18. 7 hours ago, DY444 said:

     

    I think that article is a little generous in its description of the situation in the early 90s.  It implies a strategic plan to use 071 and 081 in London to free up 01 for subsequent integration into the 1995 number change which in turn created the gaps for the 2000 number change.  Imposing number changes was (and presumably still is) extremely unpopular with customers and in the 1990s at least was a complex engineering undertaking.  Any plan which proposed 3 number changes in London in 10 years would not have been approved.  It evolved into what it became in an almost ad-hoc fashion because of the unpredicted explosion in demand for numbers firstly in London due to the growth in the City and particularly Canary Wharf, then later on through the growth of the cities outside the original 6 director areas and the mobile phone demand.

    I think it was exactly that.  The intention was to add one digit to all numbers and the easiest way was to free up "01" by changing all London numbers.  It had to be done in several stages and there had to be a longish transition between one stage and the next (when both sets of numbers worked) to be reasonably sure that no recipient of a new number would be unduly inconvenienced by it clashing with an old one.  

     

    They could presumably have kept 0171 and 0181, but then would have had to create other "area codes" for London to cope with the increasing demand for numbers, and these wouldn't have been geographic to any part of London as they would have overlapped with 0171 and 0181.  Hence the decision to go to 020 xxxx xxxx for all London landlines.  The same process also allowed the creation of 011x codes and adding an extra digit to the local part of the number for several cities outside London that were running out of numbers.  

     

    Between the start of Subscriber Through Dialling and the 0171/0181 change London enjoyed an advantage.  Not did they have one digit fewer in their numbers than anyone else (01 xxx xxxx when Birmingham was 021 xxx xxxx for example, and most smaller places 0xxx xxxxxx).  But they also had the "1" code which was the quickest to dial on the old pulse dialers! 

    • Like 1

  19. Some years ago I was involved in a feasibility study into the use of a heritage railway to run through trains via its Network Rail connections so the towns in served would have a commuter service to the nearby city.  We concluded that the only way of doing this without the heritage operation having to take on most of the systems, rules and standards of the national network was to have a "time segregation" where the through trains didn't run at the same time as the heritage service.  So at certain times of day the railway would follow national network rules and at others it would revert to heritage rules.  For example we though it would need AWS/TPWS but the trackside equipment could perhaps be hidden under wooden planking so as not to be too obvious.  Stations could have ticket machines inside an imitation lamp hut or similar, and closed off during heritage running hours.  

     

    Because on certain weekdays the railway ran a timetable from mid-morning to late afternoon, the commuter service would be limited to not very attractive hours of operation and wouldn't run off-peak or at weekends.  I guess heritage trains using main-line certified locos and stock could have allowed both types of service to run at the same time, but the railway wasn't interested in doing this and would probably have had to have the considerable costs involved reimbursed by local government.  

    • Like 1

  20. 13 hours ago, jpendle said:

    One other interesting tidbit is that the before the addition of the '1' the STD codes outside the big cities were somewhat in alphabetical order.

     

    For example

    Bolton 0204

    Cambridge 0223

    Carlisle 0228

    Derby 0332

    Doncaster 0302

    Oxford 0865

    Warrington 0925

    Wigan 0942

     

    Of course a lot of others have changed as more numbers have had to be added.

     

    John P

    At the time these were assigned, phones had two or three letters on the dials next to each number, so 2 would have ABC etc.  O or Q was zero.  So at least the first two letters of the codes were meant to match with the place name, and I think the codes within areas such as 021 used something similar.  From your example Bolton would be BO4, Cambridge would be CA3, Carlisle would be CA8, Derby would be DE2, Doncaster would be DO2.  Not sure how this fits with Oxford though!  

    • Like 1

  21. When the 170s first appeared Roger Ford in Modern Railways did an article on how they were narrower than 158s and mused about whether they had been designed for tilt.  However I think he concluded the real reason what that they wanted to have a train that could go anywhere a 158 could go so made them that bit smaller to be sure they would be within gauge.  Presumably following that logic, within a few generations trains would become so small that they disappeared entirely...


  22. The 158 was built in a different material (aluminium) from the Mk4 (steel) and designed and built by a different supplier (BREL vs Metro Cammell).  You may be thinking of the 156, also built by MetCamm and having a similar bodyshell to the Mk4 but not to a profile suited to tilting.  I think also MetCamm were considering buying in the T4 bogie from BREL for the Mk4 but ultimately went for the SIG bogie.  The 158 bodyshell had no provision for tilting.

    • Thanks 1
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.