RMweb Gold russ p Posted December 20, 2019 RMweb Gold Share Posted December 20, 2019 20 minutes ago, Titan said: A demonstration of the effectiveness of sanding stopping a sliding train on a 1:16 down hill grade: https://youtu.be/mgfzdvkcCao?t=405 I don't think I would have liked to have been in the cab of that! Sad to see its last run a scene now lost forever in the uk , hope the lads got what they wanted in terms of redundancy or new jobs 2 2 Link to post Share on other sites More sharing options...
RMweb Gold 4630 Posted December 20, 2019 RMweb Gold Share Posted December 20, 2019 1 hour ago, Titan said: A demonstration of the effectiveness of sanding stopping a sliding train on a 1:16 down hill grade: https://youtu.be/mgfzdvkcCao?t=405 Thanks for showing that. It's also a timely reminder that 'Big K' closed 4 years ago this week - 18th December 2015 - the end of deep coal mining in the UK. 2 Link to post Share on other sites More sharing options...
jim.snowdon Posted December 20, 2019 Share Posted December 20, 2019 7 hours ago, david.hill64 said: Actually the reverse. Sand improves adhesion which allows the braking force to be transmitted through the contact patch without causing the wheels to slide. Wheelflats are caused by a locked wheel leaving an area of low adhesion and entering one of normal adhesion. The sliding friction at the interface then causes a metallurgical transformation of the steel in the wheel. The resultant compound, martensite, is hard brittle and cracked. It then spalls from the wheel leaving a depression that becomes a flat under the rolling action of the wheel. It is perfectly possible to have a flat on only one wheel of an axle if only one rail is heavily contaminated but flatting both is more likely. Sanding, for both acceleration and braking has been normal for modern trams for as long as I can remember. But, tramways do not normally have track circuits and signal engineers to cope with. The trains I had responsibility for on the Docklands Light Railway, which were more like trams, did not have sanding, and did suffer from flatting, usually as a result of the ATO equipment getting confused. It's where I came across the martensite problem. The friction at a sliding contact patch not only heats the wheel locally but is enough to cause the metal to smear, creating a flat spot. The resulting scar on the tread is a martensite patch that will them flake out leaving a deeper scar, making the flat even worse, as well as being a pain to turn out. The real oddity was finding narrow martensite trails right round the treads. Getting back to sanding, It was forbidden on the London Underground after a District Railway train disappeared from track circuits near Ealing Broadway a very long time ago (1912 comes to mind), and although every BR loco had sanding, it is something over which signal engineers do seem to get rather apprehensive. The growth in the number of multiple unit trains, with the capability to have sanding distributed over the whole train, combined with the move away from tread braking, probably would not have helped. Jim 1 2 Link to post Share on other sites More sharing options...
RMweb Premium uax6 Posted December 20, 2019 RMweb Premium Share Posted December 20, 2019 Were the Eastern regions 'Abrasive Fines' that were used instead of sand conductive? (They were some sort of slag from blast furnaces I believe. Andy G Link to post Share on other sites More sharing options...
Zomboid Posted December 20, 2019 Share Posted December 20, 2019 Presumably not a problem for axle counters though? Link to post Share on other sites More sharing options...
david.hill64 Posted December 20, 2019 Share Posted December 20, 2019 2 hours ago, Zomboid said: Presumably not a problem for axle counters though? No, which is one of the reasons why axle counters find favour. Neither track circuits nor axle counters are required with ETCS 2/3 but are provided for back up. 2 Link to post Share on other sites More sharing options...
david.hill64 Posted December 20, 2019 Share Posted December 20, 2019 2 hours ago, Zomboid said: Presumably not a problem for axle counters though? No, which is one of the reasons why axle counters find favour. Neither track circuits nor axle counters are required with ETCS 2/3 but are provided for back up. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted December 20, 2019 RMweb Gold Share Posted December 20, 2019 (edited) 20 hours ago, russ p said: Years ago its was frowned upon for some reason to use sand to retard a slide I was used especially when loose shunting heavy rakes of wagons with a 350 Or with class 9s in poor rail conditions. We were taught to pulse the sand to help clear blockages and save sand and air Exactly so Russ. On the Welsh Valleys sand was used basically to improve (or in many cases achieve) adhesion for the traction unit and principally when hauling on some valleys because when used for braking it could simply lead to skidding (hence pulsing the sand in order to also avoid a continuous trail of it on the rail head). Don't forget (I'm sure you won't) that with loose coupled trains on incline working the bulk of the friction to retard movement comes from the wagons and they are basically running on dry rail because it has been 'cleaned' before most of them reach it. Incidentally one point which had not been mentioned when I drafted this response - Jim has raised it since - is that applying sand can lead to track circuits failing to detect a train (depending on the type of track circuit) and this was a major concern in the early days of track circuiting on the GWR often with Instructions to Drivers not to use sand when on track circuited sections of track. With low unsprung weight it is, I suppose, a possibility that this could happen nowadays on a train applying sand. Edited December 20, 2019 by The Stationmaster Link to post Share on other sites More sharing options...
RMweb Gold beast66606 Posted December 20, 2019 RMweb Gold Share Posted December 20, 2019 Great Moulton 20 December 2019 755328 on 5Q66, 13:39, Ipswich - Norwich C.PT. T.&R.S.M.D (14:23) - unit under test 6 1 Link to post Share on other sites More sharing options...
RMweb Gold beast66606 Posted December 20, 2019 RMweb Gold Share Posted December 20, 2019 Great Moulton 20 December 2019 37611, Pegasus, and 745103 on 5Q09, 11:50, Parkeston H.S. - Norwich C.PT. T.&R.S.M.D (13:27) - unit move Weather was horrendous, torrential rain, lots of standing water, I had to cross two Fords caused by field run off, was diverted due to a bad smash but a 37 under load was worth it. 11 Link to post Share on other sites More sharing options...
Satan's Goldfish Posted December 21, 2019 Share Posted December 21, 2019 It's almost like deja vu; see your excellent pictures on Facebook, then see them here I don't know if it's because I'm used to seeing the 755/4, but the 755/3 still look a bit... odd. Nothing wrong with them, just different. 2 1 Link to post Share on other sites More sharing options...
Siggie in the east Posted December 21, 2019 Share Posted December 21, 2019 3 hours ago, Satan's Goldfish said: I don't know if it's because I'm used to seeing the 755/4, but the 755/3 still look a bit... odd. Nothing wrong with them, just different. I'm the same. When the 755/3 was testing on the sudbury a few nights back I got a photo of it from the psb and all I could think was, I need to add another carriage or my OCD is going to kick off! 3 Link to post Share on other sites More sharing options...
RMweb Gold russ p Posted December 21, 2019 RMweb Gold Share Posted December 21, 2019 You would think a small single cabbed loco at one end of the train would have been a better idea than that pod thing, at least they could be swapped over to increase flexibility 2 1 Link to post Share on other sites More sharing options...
Wild Boar Fell Posted December 21, 2019 Share Posted December 21, 2019 Regarding sanding discussed earlier, GMRT 2461 (IIRC) is worth reading to understand current thinking along with its briefing notes. This includes the location of sanders too. 1 1 Link to post Share on other sites More sharing options...
Titan Posted December 21, 2019 Share Posted December 21, 2019 2 hours ago, russ p said: You would think a small single cabbed loco at one end of the train would have been a better idea than that pod thing, at least they could be swapped over to increase flexibility I do wonder if it is future proofing, will just removing the pod and one bogie create a straight electric, with very few new parts and minimising waste? 1 1 Link to post Share on other sites More sharing options...
Zomboid Posted December 21, 2019 Share Posted December 21, 2019 I remember reading that that was the idea. Take the engine module out (and one of the bogies) and it's an EMU. Doubt that ever happens, but a good general idea. 1 1 1 Link to post Share on other sites More sharing options...
RMweb Gold russ p Posted December 21, 2019 RMweb Gold Share Posted December 21, 2019 Can't ever see any of the Norfolk branches getting wired, still seems a waste to me having all the local fleet bimodes 2 Link to post Share on other sites More sharing options...
Zomboid Posted December 21, 2019 Share Posted December 21, 2019 In another universe, Felixstowe to Peterborough & Nuneaton would get wired for freight purposes. Not going to happen in this one though. I would say that there's enough electric mileage on the routes that these will run that it's worth having the electric stuff on a DMU. (Braintree/ Harwich/ Walton? as well as Ipswich to Stowmarket and Stansted to Ely). And if they end up with a different operator who wants pure electrics then that's a viable option for the future. 1 1 Link to post Share on other sites More sharing options...
RMweb Gold russ p Posted December 21, 2019 RMweb Gold Share Posted December 21, 2019 6 minutes ago, Zomboid said: In another universe, Felixstowe to Peterborough & Nuneaton would get wired for freight purposes. Not going to happen in this one though. I would say that there's enough electric mileage on the routes that these will run that it's worth having the electric stuff on a DMU. (Braintree/ Harwich/ Walton? as well as Ipswich to Stowmarket and Stansted to Ely). And if they end up with a different operator who wants pure electrics then that's a viable option for the future. They just seem very complicated and probably expensive for a local train Link to post Share on other sites More sharing options...
Zomboid Posted December 21, 2019 Share Posted December 21, 2019 They probably are a bit over the top in some ways, but if you want to take it to the other extreme you end up with a pacer, and I think it's probably a good thing that they're showing a bit more ambition than that. 3 Link to post Share on other sites More sharing options...
RMweb Gold ruggedpeak Posted December 21, 2019 RMweb Gold Share Posted December 21, 2019 8 minutes ago, russ p said: They just seem very complicated and probably expensive for a local train Be careful what you wish for, if they don't get the Stadlers to work on the branch lines we'll end up with these: 2 3 Link to post Share on other sites More sharing options...
RMweb Gold russ p Posted December 21, 2019 RMweb Gold Share Posted December 21, 2019 6 minutes ago, ruggedpeak said: Be careful what you wish for, if they don't get the Stadlers to work on the branch lines we'll end up with these: At least these seem to work Link to post Share on other sites More sharing options...
RMweb Premium newbryford Posted December 21, 2019 RMweb Premium Share Posted December 21, 2019 41 minutes ago, russ p said: They just seem very complicated and probably expensive for a local train They probably said the same when a Met-Camm replaced a tank loco and a couple of suburban coaches! 2 Link to post Share on other sites More sharing options...
RMweb Gold TravisM Posted December 21, 2019 RMweb Gold Share Posted December 21, 2019 4 hours ago, Zomboid said: In another universe, Felixstowe to Peterborough & Nuneaton would get wired for freight purposes. Not going to happen in this one though. Unless capacity is a issue, if it went all electric traction, just send it down the GE mainline and round London. If they did wire up from Ipswich to Nuneaton, a high number of Intermodal stuff from Felixstowe goes north via LIncoln, so they’d have to wire that up as well. Link to post Share on other sites More sharing options...
Pete 75C Posted December 22, 2019 Share Posted December 22, 2019 (edited) 13 hours ago, ruggedpeak said: Be careful what you wish for, if they don't get the Stadlers to work on the branch lines we'll end up with these: I'd be very happy with one of those shuttling between Sheringham and Cromer at the moment. Edited December 22, 2019 by Pete 75C 1 1 Link to post Share on other sites More sharing options...
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