Il Grifone Posted August 25, 2011 Share Posted August 25, 2011 Having got around to some of the various coaches requiring completing, I'm assembling two K's 40 ft luggage vans, which will be a K15 and a K16, covering the variations by one having duckets and one on 8' American and the other on 8 ' 6" Dean bogies. K's supplied a 1.5mm slab of plastic for the roofs, which is obviously too thick, but a search through my library failed to reveal the correct thickness, though drawings seem to suggest about 20 thou./1½". I am sure someone here knows the correct value and also possibly the width of the planks used. Would this have been a universal dimension? I have a roofless Roxey LSWR van (sorry for the heresy! ) staring at me as well. Link to post Share on other sites More sharing options...
chrisf Posted August 25, 2011 Share Posted August 25, 2011 This intrigued me and I went burrowing through my library too. Sadly neither Mr Russell nor Mr Harris had the answer but some thoughts arise. I would agree that the K's roof is on the thick side but consider how long ago it was made. Plastic moulding technology has advanced considerably since then! The prototypes date from 1903 so are a hangover from Dean and just pre-date Churchward's revolution in design and construction. Logically, [dangerous I know] the thickness of the wood used for the roof would depend on the design. That roof profile would need some support over and above the partitions forming the guard's compartment. Harris does tell us that Dean used Polish oak and mahogany for bodywork. The former was easily steamed to shape but presumably it is easier to shape thinner wood than thicker. I would be surprised if the roof timbers were thicker than two inches but then life is full of surprises. The only other crumb I can offer is that prior to the 1920s the roof would be covered with canvas, typically modelled with toilet tissue Mek-Pakked to the plastic roof. I wonder if the collective wisdom of the GWR modelling e-group would know? The discussion would be so much better than the recent bitching about Hornby Hawksworths! Chris Link to post Share on other sites More sharing options...
buffalo Posted August 25, 2011 Share Posted August 25, 2011 Not quite a K15/16 and not a direct answer, but these photos of a K14 being restored at Didcot may help. From the ventilation lamp hole in the second photo, I wouldn't put the timber thickness higher than one inch. Nick Link to post Share on other sites More sharing options...
bertiedog Posted August 25, 2011 Share Posted August 25, 2011 I think 2 inch thick would be the max, mainly going from seeing re-builds at preserved sites of mainy vans and utility coaches etc.. One inch would really be too thin, although there are support arches, and with more arched formers, thinner wood could be used. Some vans are double skinned, an outer with canvas and an inner tongue and grooved wood interior skin. For models, use 1mm ply glued with superglue over wood formers, or properly plank the lot with real wood. I use oak, old parquet floor wood, which is stable, sawn in to 1mm thick planks,with a band saw fitted with a fine toothed blade, and then glued to the profiled formers with Superglue and PVA mixed, an excellent quick setting combination. The superglue is put on one part and PVA on the other, they set in moments, the PVA acts as filler. The advantage of any roof made this way is the profile will be as good as the formers, elliptical and compound curves are easy to achieve. Model boat suppliers sell pre cut planks in thin wood, or real wood veneer can be used, laid in planking over a plywood base.The veneer cuts with a scalpel or very sharp craft knife. The 1mm solid planks can be sanded to about .7mm to smooth the curve, finish the lot inside and out, with a coat of sanding sealer dope, and sand, then add a sheet of damp Japanese tissue, (available easily from aero modeller suppliers). This is smoothed over and shrinking dope is added with a mop brush, a couple of coats, without sanding to retain the tissue surface, or sanded and under coated for a smooth paint finish.to be added. With correct formers underneath, and even gluing, the thin wood roofs do not warp, They can be edge thinned by sanding to reach scale thickness on the visible edges, and usually 2 inches is used, .7mm approx.(.69mm) Big advantage is cost, very low if you cut up the wood yourself, and ease of getting correct profile to the roof. Entire coaches can be done easily or just a van roof or two. The key to it working is the superglue and PVA combo glue, it makes it fast enough to be practical to work at reasonable speed, and when set hard is super tough. Stephen. Link to post Share on other sites More sharing options...
Coach bogie Posted August 25, 2011 Share Posted August 25, 2011 If you are looking for a more modern variation on the K's see my post on K15 for the new etches available now. The roof is etched, thinner and fully detailed. I got mine via David Geen Kits http://www.rmweb.co.uk/community/index.php?/topic/37085-is-this-a-gwr-k15-non-corridor-passenger-brake-van/page__st__25 Regards Mike Wiltshire Link to post Share on other sites More sharing options...
kandc_au Posted August 26, 2011 Share Posted August 26, 2011 I wonder if the collective wisdom of the GWR modelling e-group would know? The discussion would be so much better than the recent bitching about Hornby Hawksworths! Chris Chris, I gather you actually mean the gwr-elist rather than the mosdelling group. Khris Link to post Share on other sites More sharing options...
chrisf Posted August 26, 2011 Share Posted August 26, 2011 Chris, I gather you actually mean the gwr-elist rather than the mosdelling group. Khris Correct - my apologies! In respect of the person who started the discussion I am tempted to remark that every village has one but I didn't think that the forum was a village. Chris Link to post Share on other sites More sharing options...
buffalo Posted August 26, 2011 Share Posted August 26, 2011 The roof timber is 1 7/8" thick. Not doubting your word on this, for all I know you might be a carpenter who has rebuilt many a coach roof, but do you have some evidence to support this bald statement, please? Looking back at my second photo of the K14 above, and bearing in mind that the internal width of a K14 (from drawing in Russell) is 7' 6", I would estimate that the roof timbers are no more 7" (perhaps 8" at most) wide. If so, It's difficult to see how they can be 17/8" thick unless the upper surface has been thinned around the lamp area, or the timbers are doubled with the outer one not visible. If in doubt, here's a closeup clipped from the full res photo. Nick Link to post Share on other sites More sharing options...
buffalo Posted August 26, 2011 Share Posted August 26, 2011 Thanks. 6" would probably fit with the planks in the photo, so do the Didcot carpenters know something that John Lewis and the official draughtsperson didn't, or vice versa? Nick Link to post Share on other sites More sharing options...
buffalo Posted August 26, 2011 Share Posted August 26, 2011 Ah yes, that old chestnut. That's not the first time that van has been used to illustrate variability in the restorers' art, though I'm sure there are worse examples both in preservation and in repairs when in service. On the other hand, having seen some of the very high quality work done in the Didcot carriage shed over the last few years, I would be interested to hear the restorers reaction to the implied suggestion that they are bodging to that degree. Unfortunately, I don't have a copy of the Lewis books so can't see the drawings you referred to. The most detailed drawing I have available is in Russell's part 1. It is in an extract from a paper by Churchward presented to the Junior Engineering Society at the GWR Mechanics Institution on 9/1/1896. The drawing shows parts of a clerestory coach though I know not which diagram. My interpretation of the drawing is that it shows two different sections through the clerestory, and end elevations (both ends) of the main body. The roof of the clerestory is a single layer about 1" thick. The main roof appears to be composed of a double layer of battens/planks, each of similar thickness. However, if I am right that this is an end elevation, then the upper layer is in fact the beading at the end of the roof and the actual roof is only a single thickness. Unfortunately, the only dimensions visible on this part of the diagram concern the fixing screws, so I'm forced to estimate the thickness. Nick Edit: see also fig 20 on p20 of Russell part 1 of an accident damaged E1/2, a BG coach of 1876, and two photos of a Metropolitan coach after a large weight fell on it in 1866, one in the first ed of Great Western Way, p49, the other in the BGS Broadsheet No 65. Both early examples, I know, but the K14 dates back to 1898 and K15/16 are only a few years later. Link to post Share on other sites More sharing options...
Il Grifone Posted August 27, 2011 Author Share Posted August 27, 2011 Ah yes, that old chestnut. That's not the first time that van has been used to illustrate variability in the restorers' art, though I'm sure there are worse examples both in preservation and in repairs when in service. On the other hand, having seen some of the very high quality work done in the Didcot carriage shed over the last few years, I would be interested to hear the restorers reaction to the implied suggestion that they are bodging to that degree. Unfortunately, I don't have a copy of the Lewis books so can't see the drawings you referred to. The most detailed drawing I have available is in Russell's part 1. It is in an extract from a paper by Churchward presented to the Junior Engineering Society at the GWR Mechanics Institution on 9/1/1896. The drawing shows parts of a clerestory coach though I know not which diagram. My interpretation of the drawing is that it shows two different sections through the clerestory, and end elevations (both ends) of the main body. The roof of the clerestory is a single layer about 1" thick. The main roof appears to be composed of a double layer of battens/planks, each of similar thickness. However, if I am right that this is an end elevation, then the upper layer is in fact the beading at the end of the roof and the actual roof is only a single thickness. Unfortunately, the only dimensions visible on this part of the diagram concern the fixing screws, so I'm forced to estimate the thickness. Nick Edit: see also fig 20 on p20 of Russell part 1 of an accident damaged E1/2, a BG coach of 1876, and two photos of a Metropolitan coach after a large weight fell on it in 1866, one in the first ed of Great Western Way, p49, the other in the BGS Broadsheet No 65. Both early examples, I know, but the K14 dates back to 1898 and K15/16 are only a few years later. I missed these drawings (How I don't know, I read this paper during my search! ) Investigation using a magnifying glass shows a clerestory roof dimension which appears to be 7/8". It can also be seen that the planks vary in width being narrower around the sharper arc at the sides of the lower deck. This would seem reasonable, as the roof would have to be strong enough to support a man's weight, but would not be wanted to to be thicker (and heavier) than necessary. There is a reference to an article on carriage construction, but this would probably be difficult to get hold of. I've thinned the ends of the K's mouldings and my thoughts were running along the lines of using 20 thou. Microstrip to make the LSWR roof. Obviously lots of cross members will be needed. I'll have to order a pack of 80 thou. X 20 thou., which would be about right for 6" planks. Link to post Share on other sites More sharing options...
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