34theletterbetweenB&D Posted January 21, 2018 Share Posted January 21, 2018 I mentioned the Holden 4-6-0's (B12) a few pages back. A mixed traffic version with smaller wheels would be useful, perhaps even as a 2-6-2? Except as already mentioned that the GER built the smaller wheeled version as the D81 0-6-0 classified J20 by the LNER. (Presumably the 2-4-0 T26/E4 design did all that was required in mixed trafficness on the GER?) https://www.lner.info/locos/J/j20.php It is an interesting loco. Many other pre-group companies would likely have built a goods locomotive with 29,000lb TE as an 0-8-0 following the LNWR's lead, if the lack of a leading truck was no concern for the class of work it was intended for. Very long six coupled wheel base at 18' 10" (long enough for eight coupled) and yet surprisingly light on the frame length this demands at 54 tons, (The slightly later J38/39 on 17' wheelbase came in at 57 to 58 tons) but it must have worked sufficiently well as they saw service to the end of steam on the ex-GER lines. Was there a longer wheelbase six coupled loco in the UK? 2 Link to post Share on other sites More sharing options...
RMweb Premium Northroader Posted January 21, 2018 RMweb Premium Share Posted January 21, 2018 See above. I can’t find any reference to any British locomotive using an auxiliary tender in scheduled revenue service.Would this count? 4 Link to post Share on other sites More sharing options...
rockershovel Posted January 21, 2018 Share Posted January 21, 2018 Would this count? 17B8A9E4-F77D-4B8B-93ED-DFED3CC28AFF.jpeg #prototypeforeverything..... Link to post Share on other sites More sharing options...
rockershovel Posted January 21, 2018 Share Posted January 21, 2018 (edited) Yes the issue we are trying to solve is these monster locos' coal consumption, so sacrificing some water space in the main tender and having a water cart. If you have a wye, this isn't an issue, but if you are restricted to turntables, to avoid having to build very very long ones, the water cart could work. The only water tender in the UK as you say was built to go with 4472 (subsequently Bittern) after the demise of water troughs and water columns. I didn't know they had kept the corridor though! Having the same connections at each end makes sense as: a) the loco can still operate without the water tender (albeit with reduced water capacity) b) the turntable doesn't need to be very very long c) the tender can be uncoupled and recoupled to different locos depending on need/direction If the goal is increasing coal capacity, and the overall length of the loco plus at least one tender is a constraint (otherwise you could have bogie-type tenders of any length you wanted) I would imagine that the two tenders would differ radically, with the leading tender incorporating mechanical stoking But, since locos like the Gresley eight-coupled types seemed to be reaching the operational limits of maximum train size, and the LMS didn’t consider 4-6-4 or 4-8-4 designs worth progressing after study, I’d guess that the real answer was that British steam locos had reached their maximum useful size by the 1930s Edited January 21, 2018 by rockershovel Link to post Share on other sites More sharing options...
DCB Posted January 21, 2018 Share Posted January 21, 2018 You're right, it would need to drive to the second axle, maybe like the J20 which used the B12 boiler, cylinders and motion. In this case the connecting rods would need to be longer to get to the 2nd axle? I'll adjust them to give it a bigger/higher cylinder cover like the J20. https://www.lner.info/locos/J/j20.php The 4-8-0 is based on a King rather than a 4700, with the 4 cylinder front end layout (see comparison below) - this is what I meant by it being a Collepelon rather than a Chapelward The centre point of the first axle is in the same place as the King, so it could drive on the 1st and 3rd axles instead of 1st and 2nd? GWR-4-8-0 vs King.jpg The GWR 4 cylinder locos have the inside cylinders placed well forward and drive on to the front axle - see animation below. Churchward kept the inside and outside connecting rods the same length to keep the valve timing simple, Stanier didn't bother with the Duchess despite still using one set of valve gear for both inside and outside cylinders. I reckon 2nd axle drive with the cylinders directly under the smokebox would have worked but the rocking levers would have to be behind the cylinders not in front and there would be nowhere to put an access hole in the frames to oil the inside motion. Maybe outside walschaerts would be the answer? either as well as inside or instead like the Duchess? Link to post Share on other sites More sharing options...
RMweb Gold Regularity Posted January 21, 2018 RMweb Gold Share Posted January 21, 2018 Would this count? That’s the LMS (ex-CR) version. The LNER (ex-NB) had an identical idea: 3 Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted January 21, 2018 RMweb Gold Share Posted January 21, 2018 (edited) But, since locos like the Gresley eight-coupled types seemed to be reaching the operational limits of maximum train size, and the LMS didn’t consider 4-6-4 or 4-8-4 designs worth progressing after study, I’d guess that the real answer was that British steam locos had reached their maximum useful size by the 1930s Except as already mentioned that the GER built the smaller wheeled version as the D81 0-6-0 classified J20 by the LNER. (Presumably the 2-4-0 T26/E4 design did all that was required in mixed trafficness on the GER?) https://www.lner.info/locos/J/j20.php Yes, but if we take that line with every 'what if'? Then the whole thread and discussion just becomes 'Q: what if x designer made this?' - 'A: they didn't because they had this already/there was no need for it' and you just end up drawing something that already exists. Of course there is no need for any of them. Churchward kept the inside and outside connecting rods the same length to keep the valve timing simple, Stanier didn't bother with the Duchess despite still using one set of valve gear for both inside and outside cylinders. I reckon 2nd axle drive with the cylinders directly under the smokebox would have worked but the rocking levers would have to be behind the cylinders not in front and there would be nowhere to put an access hole in the frames to oil the inside motion. Maybe outside walschaerts would be the answer? either as well as inside or instead like the Duchess? Right, but why would I need to drive the 2nd axle if I can drive 1 and 3 with and adjust the valve timing to suit, surely that's easier than designing a whole new front end when the 'Star' type works so well? If Stanier didn't bother having equal length coupling rods, then if these were built in the 1930s, Collett could have mimicked what Stanier did and reversed it? By moving the cylinders you just create more problems as you say. EDIT: Sorry, I'm not trying to be overly defensive, I'm just not sure why you keep suggesting I change it when I think it would work. Edited January 21, 2018 by Corbs 1 Link to post Share on other sites More sharing options...
Satan's Goldfish Posted January 21, 2018 Share Posted January 21, 2018 Yes the issue we are trying to solve is these monster locos' coal consumption, so sacrificing some water space in the main tender and having a water cart. If you have a wye, this isn't an issue, but if you are restricted to turntables, to avoid having to build very very long ones, the water cart could work. The only water tender in the UK as you say was built to go with 4472 (subsequently Bittern) after the demise of water troughs and water columns. I didn't know they had kept the corridor though! Having the same connections at each end makes sense as: a) the loco can still operate without the water tender (albeit with reduced water capacity) b) the turntable doesn't need to be very very long c) the tender can be uncoupled and recoupled to different locos depending on need/direction I think then, the 2 tender types would be very different. The tender permanently connected to the loco for (mostly) coal could be quite short (3 axle) so it would still fit on conventional turntables. The symmetrical tender for just water could then be a much longer vehicle (2x 3 axle bogies). The next challenge is creating an aesthetically pleasing design that works with the 4-8-4 design... 2 Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted January 21, 2018 RMweb Gold Share Posted January 21, 2018 I think then, the 2 tender types would be very different. The tender permanently connected to the loco for (mostly) coal could be quite short (3 axle) so it would still fit on conventional turntables. The symmetrical tender for just water could then be a much longer vehicle (2x 3 axle bogies). The next challenge is creating an aesthetically pleasing design that works with the 4-8-4 design... It could even be van shaped and painted in coaching stock livery! 2 Link to post Share on other sites More sharing options...
RMweb Premium Coryton Posted January 21, 2018 RMweb Premium Share Posted January 21, 2018 It could even be van shaped and painted in coaching stock livery! At one point didn't they paint the Flying Scotsman's second tender in coaching stock blue and grey? Link to post Share on other sites More sharing options...
Satan's Goldfish Posted January 21, 2018 Share Posted January 21, 2018 Not the most graceful, i'll keep trying with different engine designs! 4 Link to post Share on other sites More sharing options...
Zomboid Posted January 21, 2018 Share Posted January 21, 2018 And the main tender was a Vanderbilt, the water cart could be a fairly standard tank wagon and follow the same lines, aesthetically speaking. Though any such things would probably have been freight locos, as by the time engines were getting anywhere near that kind of size, streamlining was fashionable for big passenger locos. The only large passenger engines which might have wanted multiple tenders in reality would have been those on the Southern, if they had wanted to run something non-stop to Exeter and a 5 minute engine change at Salisbury/ Wilton was not acceptable - I guess the competition with the GWR never quite reached that level. Troughs being provided everywhere else kind of negates the requirement. 1 Link to post Share on other sites More sharing options...
BernardTPM Posted January 21, 2018 Share Posted January 21, 2018 There were plenty of water troughs in steam days, so auxilliary water tenders wouldn't really be necessary. Flying Scotsman had two tenders because by the late '60s many of the troughs were out of use, reducing the opportunities for pick-up water en route. Of course, you'd need rather more substantial scoops to pick up coal on the move.... Link to post Share on other sites More sharing options...
RMweb Premium Compound2632 Posted January 21, 2018 RMweb Premium Share Posted January 21, 2018 Mind you, if the next step from water troughs is collecting coal on the move, why not simply collect the power on the move from an overhead electric cable? ... 1 Link to post Share on other sites More sharing options...
rockershovel Posted January 21, 2018 Share Posted January 21, 2018 It could even be van shaped and painted in coaching stock livery! I suspect there would be a requirement to balance the weight distribution. The accompanying text states that the Flying Scotsman water tender has quite small tanks. I’d guess that having a second tender significantly heavier than the leading one, would cause stability problems. It might be instructive to know how the two water tenders were managed in use? Link to post Share on other sites More sharing options...
Satan's Goldfish Posted January 21, 2018 Share Posted January 21, 2018 Bit better. Might work in Coaching stock livery. Vanderbilt next... (Don't get bogged down with the real infrastructure details, embrace the imaginary!) 4 Link to post Share on other sites More sharing options...
Zomboid Posted January 21, 2018 Share Posted January 21, 2018 Makes you wonder why they didn't just convert the troughs to enable diesel to be picked up on the move... 1 Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted January 21, 2018 RMweb Gold Share Posted January 21, 2018 I suspect there would be a requirement to balance the weight distribution. The accompanying text states that the Flying Scotsman water tender has quite small tanks. I’d guess that having a second tender significantly heavier than the leading one, would cause stability problems. It might be instructive to know how the two water tenders were managed in use? Interesting. Doesn't one of the main line operators these days have a water cart disguised as a carriage? Link to post Share on other sites More sharing options...
rockershovel Posted January 21, 2018 Share Posted January 21, 2018 Makes you wonder why they didn't just convert the troughs to enable diesel to be picked up on the move... https://m.youtube.com/watch?v=DXBJnyjgbGw 2 Link to post Share on other sites More sharing options...
DavidB-AU Posted January 21, 2018 Share Posted January 21, 2018 Makes you wonder why they didn't just convert the troughs to enable diesel to be picked up on the move... And for anyone who saw last week's episode of The Grand Tour... Cheers David Link to post Share on other sites More sharing options...
Satan's Goldfish Posted January 21, 2018 Share Posted January 21, 2018 And Vanderbilt. that looks very purposeful for a heavy fast freight engine! I can imagine a 4-8-4 streamlined P2 would work quite nicely with an LNER style Vanderbilt too (anyone got a side shot of a streamlined P2 to doctor?) Ref the effect of tenders on the engine; that makes sense for single tenders as they're 'fixed' to the locomotive, but if the second tender is connected with conventional draw gear would that not just appear as train-load to the locomotive? 3 Link to post Share on other sites More sharing options...
rockershovel Posted January 21, 2018 Share Posted January 21, 2018 Not the most graceful, i'll keep trying with different engine designs! post-898-0-76948100-1516370057_thumb.jpg The first requirement is to get the relationship between the firebox, cab and trailing bogie correct. The bogie needs to be under the firebox, that’s its function. Then the appearance of the cab and tender comes into focus Link to post Share on other sites More sharing options...
Satan's Goldfish Posted January 21, 2018 Share Posted January 21, 2018 The first requirement is to get the relationship between the firebox, cab and trailing bogie correct. The bogie needs to be under the firebox, that’s its function. Then the appearance of the cab and tender comes into focus I was just tinkering with previous pictures by Corbs (Thanks Corbs), I take no credit for the original design. (I thought it looked alright, it was the additional tender I thought was off, but my Steam knowledge is lacking). Link to post Share on other sites More sharing options...
RMweb Premium Compound2632 Posted January 21, 2018 RMweb Premium Share Posted January 21, 2018 Dillicar? Link to post Share on other sites More sharing options...
RMweb Premium Compound2632 Posted January 21, 2018 RMweb Premium Share Posted January 21, 2018 Ref the effect of tenders on the engine; that makes sense for single tenders as they're 'fixed' to the locomotive, but if the second tender is connected with conventional draw gear would that not just appear as train-load to the locomotive? Any tender is load not contributing to the adhesion, surely? Except for us modellers, as anyone who has tinkered with a Triang Lord of the Isles or Caley single in an effort to get them to pull a train will know! Link to post Share on other sites More sharing options...
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