RMweb Gold Barry Ten Posted May 25, 2022 RMweb Gold Share Posted May 25, 2022 26 minutes ago, Tony Wright said: An interesting selection of new books this month............. The main bridge on that cover is on the island of Langkawi in Malaysia, where my wife and I had our honeymoon. I found it completely terrifying. (The bridge, not the honeymoon). Al 11 1 Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted May 25, 2022 RMweb Gold Share Posted May 25, 2022 (edited) Picking up on the bridges theme... I've always found them fascinating, not just when railways run over or under them, but in all their manifestations. When I was a child, my maternal grandfather (a lovely man who died nearly 50 years ago) used to read to me from the "Arthur Mee Children's Encyclopedia", a wonderful multi-volume series full of drawings, photos and colour plates. I remember being captivated by the B&W photos of bridges under construction, probably my first appreciation that even the biggest things have to be designed and made at some point. My father was also a civil engineer. Other than being involved in the taking down of Crumlin Viaduct (I think one of his first jobs after graduating from the "South Wales School of Mines") he was full of bridge lore. I particularly remember being driven past the old stone bridge in Pontypridd and my dad explaining that, as my recollection had it, "it kept falling down until they put holes in it": I didn't really understand at the time (how could something become stronger by removing bits?) but the problem was indeed resolved by adding holes: "The final design of the bridge included three cylindrical voids (holes) of 2.7 m (8.9 ft), 1.7 m (5.6 ft) and 1.1 m (3.6 ft) on each side on the bridge.[16] This reduced the weight and pressure on the crown and the bridge is still in operation today, although it is now only used for foot traffic." https://en.wikipedia.org/wiki/Old_Bridge,_Pontypridd Edited May 25, 2022 by Barry Ten formatting 7 1 3 Link to post Share on other sites More sharing options...
ecgtheow Posted May 25, 2022 Share Posted May 25, 2022 3 hours ago, Chuffer Davies said: I have not read anything in the literature from Faulhaber to suggest that they have made changes to their brush gear so the same precautions are still necessary. Remember that model railways are not a significant consumer of such motors which are primarily designed for use in high precision instruments. I sometimes use the analogy that fitting a DCC chip is like relocating your analogue controller to the inside of the locomotive and then sending instructions to it through the rails from another controller. Changing the switch on a Pentroller for different types of motor is the equivalent of modifying the CVs on the DCC chip. In this way each loco is carrying its own dedicated controller optimised for the motor installed in that particular model. Regards, Frank I read some time ago in the modelling section of a magazine possibly the Darjeeling & Himalayan Railway Society magazine or another narrow gauge magazine that coreless motors (I guess small narrow gauge locos often use small coreless motors?) don't like relatively low frequency sampling from feedback controllers so the author, a Hugh Norwood, built one with a much higher sampling rate maybe 10,000Hz. I could be wrong about how high the frequency was, but I bought one from him & in 2014 & it controls Portescap motors on my locos really well. The obvious question if his explanation is correct is why manufacturers of feedback controllers haven't copied what he did. William 2 Link to post Share on other sites More sharing options...
Chuffer Davies Posted May 25, 2022 Share Posted May 25, 2022 35 minutes ago, ecgtheow said: I read some time ago in the modelling section of a magazine possibly the Darjeeling & Himalayan Railway Society magazine or another narrow gauge magazine that coreless motors (I guess small narrow gauge locos often use small coreless motors?) don't like relatively low frequency sampling from feedback controllers so the author, a Hugh Norwood, built one with a much higher sampling rate maybe 10,000Hz. I could be wrong about how high the frequency was, but I bought one from him & in 2014 & it controls Portescap motors on my locos really well. The obvious question if his explanation is correct is why manufacturers of feedback controllers haven't copied what he did. William This sampling rate would not be suitable for more traditional motors widely used in the hobby so unless you want to standardise on coreless motors it would not be appropriate. Regards, Frank 2 Link to post Share on other sites More sharing options...
lanchester Posted May 25, 2022 Share Posted May 25, 2022 On 24/05/2022 at 14:33, Bucoops said: Certainly LNER Truss rod underframes had a deliberate curvature to them, so when the body was added it was level. Not sure the angle iron ones had or needed that. I've probably got this all wrong, but I had the idea that (some?) truss rod underframes had some sort of turnbuckle arrangement so they could be adjusted for the body load (obviously, not for varying loads in traffic, just to be about right for the superstructure) and that this was the whole point of a truss rod (as opposed to a truss made up from angle irons). Of course there is also the well-known case of the prototype glass-fibre bodied carriage (S1000, which I think still exists on the East Somerset Railway?) which flexed to the point that the doors jammed when loaded, despite being perfectly sound in terms of structural strength. I don't know whether such considerations affected wooden-bodied vehicles when they became longer - I can imagine they might to have needed more solid members to avoid undue flexure than were strictly necessary for strength? That would take up usable body width - only a few inches each side, but it matters. (Which would in turn favour steel-skinned vehicles which can take some of the shear loads - a similar evolution to that occurring in aviation, where the metal skin of a Spitfire, for example, is taking load that the fabric skin of a Hurricane can't, (which if I'm right is why the Spit was capable of continuous improvement/ size increase etc. whereas the Hurricane was competitive with the Spit Mk 1 or 2, but couldn't really develop beyond). And of course, over different timescales but for similar reasons, trains planes and automobiles all tended towards monocoque construction. Health warning _ all this could be rubbish - I failed final year Mech Eng at Sheffield not once but twice - so what do I know! (On the other hand, part of the reason for that was that I was Secretary of my Student Union, and my success rate in getting late licences from the magistrates is still revered. I suppose, if I was put on this Earth for a reason, that was probably it!). 1 1 1 2 Link to post Share on other sites More sharing options...
ecgtheow Posted May 25, 2022 Share Posted May 25, 2022 46 minutes ago, Chuffer Davies said: This sampling rate would not be suitable for more traditional motors widely used in the hobby so unless you want to standardise on coreless motors it would not be appropriate. Regards, Frank Frank, That may be why some controllers have a selector function so one can switch between conventional & coreless motors, though if I recall correctly the Finney & Smith Penbit controller senses the motor type & adjusts its output automatically. Wiliam 1 Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted May 25, 2022 RMweb Gold Share Posted May 25, 2022 Purely anecdotal, but I was once waiting by some shops next to the SWML when an HST came through. I could only see the top couple of inches of the train above an intervening building, but there was a definite up-down oscillation in the roofline as each carriage went past, suggesting a degree of curvature, although whether it was a sag or a bow I can't remember. 1 1 Link to post Share on other sites More sharing options...
RMweb Gold john new Posted May 25, 2022 RMweb Gold Share Posted May 25, 2022 1 hour ago, lanchester said: I've probably got this all wrong, but I had the idea that (some?) truss rod underframes had some sort of turnbuckle arrangement so they could be adjusted for the body load (obviously, not for varying loads in traffic, just to be about right for the superstructure) and that this was the whole point of a truss rod (as opposed to a truss made up from angle irons). Of course there is also the well-known case of the prototype glass-fibre bodied carriage (S1000, which I think still exists on the East Somerset Railway?) which flexed to the point that the doors jammed when loaded, despite being perfectly sound in terms of structural strength. I don't know whether such considerations affected wooden-bodied vehicles when they became longer - I can imagine they might to have needed more solid members to avoid undue flexure than were strictly necessary for strength? That would take up usable body width - only a few inches each side, but it matters. (Which would in turn favour steel-skinned vehicles which can take some of the shear loads - a similar evolution to that occurring in aviation, where the metal skin of a Spitfire, for example, is taking load that the fabric skin of a Hurricane can't, (which if I'm right is why the Spit was capable of continuous improvement/ size increase etc. whereas the Hurricane was competitive with the Spit Mk 1 or 2, but couldn't really develop beyond). And of course, over different timescales but for similar reasons, trains planes and automobiles all tended towards monocoque construction. Health warning _ all this could be rubbish - I failed final year Mech Eng at Sheffield not once but twice - so what do I know! (On the other hand, part of the reason for that was that I was Secretary of my Student Union, and my success rate in getting late licences from the magistrates is still revered. I suppose, if I was put on this Earth for a reason, that was probably it!). May be apocryphal but I recall hearing or reading similar stories about the W Region DMUs out of Paddington, the one's LIMA modelled (Became Cl 117s?). 1 Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted May 25, 2022 RMweb Gold Share Posted May 25, 2022 1 hour ago, lanchester said: I've probably got this all wrong, but I had the idea that (some?) truss rod underframes had some sort of turnbuckle arrangement so they could be adjusted for the body load (obviously, not for varying loads in traffic, just to be about right for the superstructure) and that this was the whole point of a truss rod (as opposed to a truss made up from angle irons). The earlier ones were indeed adjustable using turnbuckles, those are the ones I meant by truss rods. There's no adjustment with the angle iron later ones. :) 1 Link to post Share on other sites More sharing options...
Mike 84C Posted May 25, 2022 Share Posted May 25, 2022 Has anyone got any instructions or diagram for an etched SEF Scot chassis? One to build and it would be good to know the best starting point. Thank you in advance and feel free to pm me. Mick Link to post Share on other sites More sharing options...
Steamport Southport Posted May 26, 2022 Share Posted May 26, 2022 17 hours ago, Tony Wright said: In an attempt to sell the few remaining Paul Bromige locos, I've reduced the prices. These now being........... Johnson 3F. £150.00 Motorised Kitmaster 'Pug'. £90.00 Ex-LNWR Coal Tank. £150.00. Ex-MR 1F. £150.00. Plus £10.00 P&P. Anyone interested, please PM me. The L&Y Pug is a RTR Dapol version with what looks like a High Level chassis. Much more sophisticated than the Kitmaster kit. Jason Link to post Share on other sites More sharing options...
RMweb Gold Tony Teague Posted May 26, 2022 RMweb Gold Share Posted May 26, 2022 21 hours ago, Barry Ten said: The main bridge on that cover is on the island of Langkawi in Malaysia, where my wife and I had our honeymoon. I found it completely terrifying. (The bridge, not the honeymoon). Al The very odd thing about that bridge is that there is no bus on it..... 1 1 9 Link to post Share on other sites More sharing options...
FarrMan Posted May 26, 2022 Share Posted May 26, 2022 17 hours ago, lanchester said: Of course there is also the well-known case of the prototype glass-fibre bodied carriage (S1000, which I think still exists on the East Somerset Railway?) which flexed to the point that the doors jammed when loaded, despite being perfectly sound in terms of structural strength. That rings true to me, though I know little about carriage design. Certainly (in Europe at least) The Eurocodes used for building design specify maximum deflection to minimise this risk. So the building should be deigned not only to carry both dead and live loads (i.e. permanent and temporary loads) as specified, but deflection (i.e. amount of hog, bow, sag, whatever terms you want to use,) must not exceed the limit prescribed. Lloyd 1 Link to post Share on other sites More sharing options...
Tony Wright Posted May 26, 2022 Author Share Posted May 26, 2022 6 hours ago, Steamport Southport said: The L&Y Pug is a RTR Dapol version with what looks like a High Level chassis. Much more sophisticated than the Kitmaster kit. Jason Thanks Jason, I thought it pre-dated the Dapol RTR version, and Paul Bromige usually scratch-built his own frames. Regards, Tony. Link to post Share on other sites More sharing options...
Tony Wright Posted May 26, 2022 Author Share Posted May 26, 2022 Just for info' Due to lack of space in the next BRM, my reviews of the illustrated books will be in the one after. Gives me a bit more time............ The book on bridges is fascinating. 1 Link to post Share on other sites More sharing options...
LNER4479 Posted May 26, 2022 Share Posted May 26, 2022 6 hours ago, Tony Teague said: The very odd thing about that bridge is that there is no bus on it..... Nor are there any trains ... 1 1 Link to post Share on other sites More sharing options...
Tony Wright Posted May 26, 2022 Author Share Posted May 26, 2022 (edited) 19 minutes ago, LNER4479 said: Nor are there any trains ... Indeed not. Indeed, most of the hundreds of bridges described in the book do not carry railways, nor cross them, but that makes it no less-interesting. There are some amazing bridges featured, though not all are illustrated - the Forth Bridge, for instance. Edited May 26, 2022 by Tony Wright to add something 3 Link to post Share on other sites More sharing options...
Beechnut Posted May 26, 2022 Share Posted May 26, 2022 1 Link to post Share on other sites More sharing options...
RMweb Gold zr2498 Posted May 26, 2022 RMweb Gold Share Posted May 26, 2022 3 hours ago, Tony Wright said: Just for info' Due to lack of space in the next BRM, my reviews of the illustrated books will be in the one after. Gives me a bit more time............ The book on bridges is fascinating. The bridges book is a follow up to 'An encylcopaedia of British Bridges' by the same author - a book which you gave to me on one of the visits 🙂 1 Link to post Share on other sites More sharing options...
Popular Post Clem Posted May 26, 2022 Popular Post Share Posted May 26, 2022 Good evening Tony et al, I'm close to finishing this little wagon kit. It's a Connoisseur Models PMK LNER Longfit pipe wagon. (There's just the side latches to put on). Jim McGeown stopped producing the 4mm Connoisseur PMK range in 2006 to concentrate on his 7mm business but I've got one or two of these to do on the build list. First of all, I must say it's been a very enjoyable kit to build albeit a bit fiddly in places. Soldering on the individual strapping is pretty straightforward if you're careful. It's generally very accurate although I'm finding that the side latches seem to be a quite bit over scale. (Not unusual for cast white metal parts in my experience from many different sources). Next, I have to source some transfers for it. (e.g.'EMPTY TO STANTON IRON WORKS ILKESTON LNE' ). 24 16 Link to post Share on other sites More sharing options...
Tony Wright Posted May 26, 2022 Author Share Posted May 26, 2022 1 hour ago, Clem said: Good evening Tony et al, I'm close to finishing this little wagon kit. It's a Connoisseur Models PMK LNER Longfit pipe wagon. (There's just the side latches to put on). Jim McGeown stopped producing the 4mm Connoisseur PMK range in 2006 to concentrate on his 7mm business but I've got one or two of these to do on the build list. First of all, I must say it's been a very enjoyable kit to build albeit a bit fiddly in places. Soldering on the individual strapping is pretty straightforward if you're careful. It's generally very accurate although I'm finding that the side latches seem to be a quite bit over scale. (Not unusual for cast white metal parts in my experience from many different sources). Next, I have to source some transfers for it. (e.g.'EMPTY TO STANTON IRON WORKS ILKESTON LNE' ). Nice neat work Clem, Thanks for showing us. Regarding transfers for it, have a word with John Isherwood of Cambridge Custom Transfers (he posts on here regularly). He's been very helpful to me in the past, producing several 'one-off' transfer sheets for LB which are excellent. Regards, Tony. 1 Link to post Share on other sites More sharing options...
Clem Posted May 26, 2022 Share Posted May 26, 2022 59 minutes ago, Tony Wright said: Regarding transfers for it, have a word with John Isherwood of Cambridge Custom Transfers (he posts on here regularly). He's been very helpful to me in the past, producing several 'one-off' transfer sheets for LB which are excellent. Thanks for the info Tony. I've also managed to learn of some others already produced, courtesy of Jonathan Wealleans who recently made one of these wagons for Grantham. John Isherwood will be my next port of call. I have certainly been impressed by the results and realism of transfers applied to the stock on Little Bytham. cheers Clem. Link to post Share on other sites More sharing options...
cctransuk Posted May 26, 2022 Share Posted May 26, 2022 7 minutes ago, Clem said: Thanks for the info Tony. I've also managed to learn of some others already produced, courtesy of Jonathan Wealleans who recently made one of these wagons for Grantham. John Isherwood will be my next port of call. I have certainly been impressed by the results and realism of transfers applied to the stock on Little Bytham. cheers Clem. Clem, Tony, It is true that I have, exceptionally, produced bespoke transfers for personal friends, but I have always made it clear that this is not a service that I can make generally available. For the avoidance of doubt, I repeat this fact here. Though I am retired, I still manage to produce my standard list of transfers as listed on the Cambridge Custom Transfers website, but I do like to do my own modelling as well. Precision Labels and Railtec offer a bespoke service - I would direct prospective clients to those companies. I would ask those whom I have assisted in the past NOT to suggest, especially on a public forum, that I am able to do the same for one and all. John Isherwood. 1 4 Link to post Share on other sites More sharing options...
Clem Posted May 26, 2022 Share Posted May 26, 2022 1 hour ago, cctransuk said: Clem, Tony, It is true that I have, exceptionally, produced bespoke transfers for personal friends, but I have always made it clear that this is not a service that I can make generally available. For the avoidance of doubt, I repeat this fact here. Though I am retired, I still manage to produce my standard list of transfers as listed on the Cambridge Custom Transfers website, but I do like to do my own modelling as well. Precision Labels and Railtec offer a bespoke service - I would direct prospective clients to those companies. I would ask those whom I have assisted in the past NOT to suggest, especially on a public forum, that I am able to do the same for one and all. John Isherwood. Hi John, Thanks for the clarification. No harm done. Tony was simply trying to give me a lead . In fact I've used your transfers with great success in the past. Cheers Clem 3 Link to post Share on other sites More sharing options...
Popular Post Edmund Kinder Posted May 27, 2022 Popular Post Share Posted May 27, 2022 (edited) 12 hours ago, Clem said: Good evening Tony et al, I'm close to finishing this little wagon kit. It's a Connoisseur Models PMK LNER Longfit pipe wagon. (There's just the side latches to put on). Jim McGeown stopped producing the 4mm Connoisseur PMK range in 2006 to concentrate on his 7mm business but I've got one or two of these to do on the build list. First of all, I must say it's been a very enjoyable kit to build albeit a bit fiddly in places. Soldering on the individual strapping is pretty straightforward if you're careful. It's generally very accurate although I'm finding that the side latches seem to be a quite bit over scale. (Not unusual for cast white metal parts in my experience from many different sources). Next, I have to source some transfers for it. (e.g.'EMPTY TO STANTON IRON WORKS ILKESTON LNE' ). Lovely work there Clem. I've also very nearly finished a Connoisseur Models 4mm BR Brake Van that I purchased nearly two decades ago. It all went together very well, and I had to exercise extreme care not to put too much solder on the iron tip when soldering on the strapping and other fine detail. There was an interesting article on building the kit by Steve Banks in BRM February 2002, and I also fashioned and put in plasticard inlays for the ends as he'd done. Regards Edmund Edited May 27, 2022 by Edmund Kinder 16 10 Link to post Share on other sites More sharing options...
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