RMweb Gold lezz01 Posted January 15 RMweb Gold Share Posted January 15 Well the style would depend on when the retaining walls were installed. If they were all done at the same time then they would all be the same style. If one was renewed or rebuilt at a later date then it may be different due to improvements in structural engineering methods. It might also be the case that a weakness was detected and strengthening was added at a later date. However I would make them with a similar style to each other with maybe a slightly difference in detail. Regards Lez. 3 Link to post Share on other sites More sharing options...
Philou Posted January 16 Author Share Posted January 16 Thanks for your thoughts, chaps and chapesses, I agree with your views and I shall go with a similar design to that already done for the retaining wall facing Dymented station. I shall do arches but without batters this time. I finally got to give the wall a waft of varnish this morning and screwed it into place. The fun will now begin as I want to continue the rock face between it and the trackbed of the branchline. As it's darned cold in the railway room and I see no point in putting the heating on for just an hour, I shall tackle the bridge next as I can do it indoors. Milder weather due at the weekend - huzzah! Nevertheless, here's a picture of the wall before fixing in place: ^ Can't believe it's taken me since before Xmas to get this far!! Cheers, Philip 8 Link to post Share on other sites More sharing options...
Philou Posted January 18 Author Share Posted January 18 Hello chums and chumesses, I didn't update yesterday as there wasn't anything to report. I haven't yet figured out why, but I felt a bit in the dumps - quite flat in fact. I think it's simply I can't really get into the barn due to the cold - and it's lasted a week already and more to come! Besides, real life seems to be getting in the way and tripping me up! Anyway, today is better and I have started to create some sketches for the skew bridge - the longest side with be 350mm, the short side (nearest Dymented) is 200mm and the centre span will be 240mm. As the branchline is curved underneath, the skew changes hence the irregular spans. I haven't yet decided what shape to make the plate girders - I'm thinking of a curved top - Rule 1 and all that - rather than a plain rectangle as all the other bridges will be copies of the prototypes and they're in the main, plain. More to come, Cheers, Philip 1 5 Link to post Share on other sites More sharing options...
RMweb Gold lezz01 Posted January 18 RMweb Gold Share Posted January 18 Why don't you get some heating in the barn Philip? You could go with something like those Calorgas heaters with the propane bottle in the rear that way you've already paid for the heat up front or a small electric fan type heater that way the cold weather won't stop you. I have one of the latter in my shed although as I insulated the shed when I built it it gets very little use as a heater, I mainly use it in the summer to give me a bit of air flow. If I'm out there in the colder months 15 mins or so is enough to warm up the shed and then it stays warm with the heater only kicking in occasionally. As for the bridge if it was built at the same time as the other bridges I would say that it would be of a similar style to the others. If the branch was a later addition then sure go with a different style. Rule one notwithstanding a lack of continuity often spoils some layouts. Regards Lez. Link to post Share on other sites More sharing options...
Philou Posted January 18 Author Share Posted January 18 1 hour ago, lezz01 said: Why don't you get some heating in the barn Philip I do have a modern ceramic-type electric fan heater but the problem is that there is 110m3 to warm up! I would prefer gas, but the problem is with any flame based heater (gas or paraffin) it creates condensation which in times of cold weather means that damp will get everywhere - the Velux could be opened but then all the warm air will escape! At the moment, there is no damp in there so I prefer to keep away and work in the warm. The dew point is usually around 7°C (it does vary of course) so once temperatures rise again (we had +13°C yesterday afternoon, down to -2°C today), I shall be out there toot dee sweet. What I ought to do is decide early in the morning if I'm going to the railway room, turn the heater on and then go in the afternoon. At the moment it's just a quick visit, measure and then out again. Cheers, Philip 1 1 7 Link to post Share on other sites More sharing options...
RMweb Premium Andy Hayter Posted January 18 RMweb Premium Share Posted January 18 I am in a very similar situation to Philip. Rather bigger volume to heat but sited over a centrally heated lower floor - not that you would know it. A key thing is that we enjoy significantly colder temperatures than you will in SE England. It is said by the experts that reducing your heating by 1°C reduces your heating bill by 10%, so the obverse is heating your railway room by say 6°C more than you have to (because we start at a lower temperature) means that we are going to need 70-80% more energy to heat the same volume as you do. I do use a little local heating but can really only stand about one hour before the cold sets in. Added to that, glues and paints take a lot longer to cure. 5 Link to post Share on other sites More sharing options...
Philou Posted January 19 Author Share Posted January 19 14 hours ago, Andy Hayter said: Added to that, glues and paints take a lot longer to cure. Hence why I'm waiting as I'm at the stage where glueing and plastering of the scenic areas is to commence. I know that PVA is sensitive to low temperatures and will go off (in a bad way!) and I've a largish area to do. There's mild weather due in few days certainly our way (don't know about you, Andy!). Cheers, More later, Philip Link to post Share on other sites More sharing options...
RMweb Premium Andy Hayter Posted January 19 RMweb Premium Share Posted January 19 Same here. Minus 6 just at the moment but plus double figures forecast for next week. Link to post Share on other sites More sharing options...
Philou Posted January 19 Author Share Posted January 19 1 hour ago, Andy Hayter said: Minus 6 just at the moment Brrrrrrrr ............ just thinking about makes feel cold. Anyone like a nice large friendly dog that needs walkies four times daily? Just got back in - I think it must about 0° but feels like -6°C due to a light North North Easterly wind that's blowing. 3 1 Link to post Share on other sites More sharing options...
Philou Posted January 19 Author Share Posted January 19 Hello chaps and chapesses, I thawed out enough to carry on doing some drawings in SketchUp and here are my plans - there is the decking and all the metalwork below to be done. I haven't gone to the nth in detail - there are no angles nor rivets shown (so you can't count them ;)) ) and the track is laid onto the ballast rather than sunk into it. The drawings are to be considered as general arrangements and the building of the bridge will fill in the details. Here we go: ^ A view from the Dymented side showing the two main outer girders plus the central one. ^ Unfortunately this view won't ever be seen normally as it's towards the rock cutting. A pity as I prefer the look of it. I've included the trackwork on this one. ^ This is the trackwork showing the baulkwork and ties. The model will be laid to a slight curve (24mR) but I wasn't going to do it on the plan as the 3D work becomes more complex - gives the idea. Tomorrow I'll do the bridge deck and all the under gubbins - the bridge will be straight but the track will curve gently over it, like this: ^ Picture copied from the RAIB report into a derailment near Wansted Park, London. Used with permission. My trackwork will not have a walkway covering the tiebars to the baulks. Cheers everyone, More tomorrow and stay warm. Philip 5 1 Link to post Share on other sites More sharing options...
Philou Posted January 21 Author Share Posted January 21 As ever, real life called wanting a day with me and not only Saturday but Sunday as well so very little was done railway-wise. I have tinkered with the General Arrangement drawing in 3D and I have set out the deck. Tomorrow (out in the woods cutting trees notwithstanding) I shall tackle the girder work underneath. In finishing the top part, I did note that the baulks could be shortened slightly and that has been done. I could also see that the central beam could do with beefing up a bit and this I want to raise by about 4mm making it a nadger's worth under 12mm above railhead height. I'm sure if I can do it in one go on the drawing as the only facility I can see will stretch it and not add to it (if you see what I mean) and may deform the span - we'll see. Here is a modified drawing: ^ The baulks have been shortened but as you can see, the central span needs beefing up height-wise. Generally, I'm happy with the GA. More tomorrow, Cheers, Philip 7 Link to post Share on other sites More sharing options...
RMweb Gold lezz01 Posted January 21 RMweb Gold Share Posted January 21 Looking good Philip. What are going to build it with, plastic or card? Regards Lez. Link to post Share on other sites More sharing options...
Philou Posted January 22 Author Share Posted January 22 10 hours ago, lezz01 said: What are going to build it with, plastic or card Hello Lez, I ought to do it in plasticard, but there are no suppliers nearby so it'll be in card (I know there are internet sales, but I like to have a look at it especially the channels and beams). I have a lot of good quality card in varying thicknesses and some not-quite-as-good that does take a nail-punch to form rivets. The latter card will be OK for forming cleats and angles. Once all glued together it forms a quite sturdy model. There was, years ago, a scale model in 4mm of the original Brunel Tubular bridge over the River Wye at Chepstow, in card, it was extremely well done and it was quite amazing how strong it was. Lord and Butler had it for sale at a price that was very, very reasonable, but I couldn't make use of it at the time. I hope it went to a good home! More this evening, Philip PS: No lumberjacking this morning due to rain - maybe this afternoon :( . 3 Link to post Share on other sites More sharing options...
Flying Fox 34F Posted January 22 Share Posted January 22 Interesting about the Brunel bridge made from card. I recall an article in maybe RM many years ago of someone building the Saltash bridge from card, as originally designed with double track. Paul 1 Link to post Share on other sites More sharing options...
Philou Posted January 22 Author Share Posted January 22 Well chums and chumesses, Rain p*ssed on my parade today and so any thought of cutting down trees came to a halt - was I disappointed? Oh no I wasn't! It meant I could stay in the warm and dry and carry on with this 3D model, that is now complete. I just hope that when I start cutting the card it'll be as accurate as the drawings: ^ The bridge deck. ^ The under girder work. There are things that I don't know in how its constructed - for example, the supporting girders under the running lines, do they touch the deck (which I assume they must do)? If so, what form are the cross-girders? I've shown them as 'I' beams with large flanges but in real life are they an inverted 'T' shapes? I'm probably over-thinking this as once it's all fabricated you're not going see much detail on the underside! ^ The underside as seen from the branchline - I reckon it'll do despite my lack of detailed understanding of how it's built. ^ The whole thing in Technicolor (sic). Tomorrow I start cutting out card and I just hope it'll look vaguely similar - perhaps 'inspired by ......' I did manage to beef up the central girder without distortion - 30 second job - well pleased with that. Thanks to @lezz01 for giving me the idea and getting the bits of trackwork out to me. Cheers, Philip 4 1 1 Link to post Share on other sites More sharing options...
Philou Posted January 23 Author Share Posted January 23 Hello chaps and chapesses, Not a lot happened as I was rostered to do kitchen work today as we're having our tenth (yes - 10th!) and last, Christmas lunch until the end of 2024, tomorrow. I have managed to cut to shape the bridge deck out of 2.5mm card - I'll need to trim it to size once I start the plate girders. I have the dimensions of these and once I find my 1mm card, they will take little time to cut out as I have curved templates already to suit (co-incidentally the same as some of my trackbed curves). More update on Thursday, Cheers, Philip 4 Link to post Share on other sites More sharing options...
JeffP Posted January 24 Share Posted January 24 Card? Well I'm disappointed. With the standard of the other work going on, I was expecting mild steel plates, genuine steel sections, (girders to those who don't come from a steel town), and scale steel rivets.🙂 1 3 Link to post Share on other sites More sharing options...
Philou Posted January 24 Author Share Posted January 24 @JeffP Steady on there ...... you can have the rivets and the sections but it won't be in steel or wrought iron :)). I may have mentioned already that I have a nail punch that (if I can find it) gives a reasonable impression of a rivet head on card when tapped with a small hammer. I'm going to have a revisit (when I find it) of the effect as it might be overscale. I have a choice off using it as intended and have overscale heads spread further apart or find a smaller punch (probably unlikely) or not bother and say 'they're too small to see - ahem'. How big are these rivets anyway? 1"? 1.5"? I haven't any plate girder bridges around these parts to measure as they're mostly stone arch. I think my nail punch makes a rivet head 1mm wide - which is 3" - =80 !! I shall do a test run tomorrow (if I can find the punch) and let you know how I get on. This was my first (and only) card bridge to date. The photo shows the nail punched rivets. Do you think it would pass muster - especially when viewed from 600mm away? : ^ There really should have been a fourth row of rivets - but I think I only want to give the impression of rivets and not necessarily count them! ;) Cheers everyone, More tomorrow, Philip PS: My 'new' ECoS arrived today by hand from Cardiff - so something else with which to play! 5 1 Link to post Share on other sites More sharing options...
RMweb Gold GWR57xx Posted January 25 RMweb Gold Share Posted January 25 Railtec Transfers now do rivets: Railtec Transfers Rivets Would be a lot easier than punching individual rivets... 3 2 Link to post Share on other sites More sharing options...
Philou Posted January 25 Author Share Posted January 25 (edited) @GWR57xx Thanks for the heads-up. I had a look and I may have to get some in as I finally found my nail punch and had a go. Read on ...... I found the punch in the last place I looked after about an hour. I had a play with some card I had at hand but it's not what I had before and the results were definitely NOT as was shown in the photo above. The punch did what it was supposed to do and punched right through the card! A lighter tap with the pin hammer didn't make enough impression. I shall have to find other grades of card to have a go, otherwise it'll be as GWR57xx has suggested, Railtec Transfers. I did manage to cut out the side and central girders with their curved tops. I've also marked them ready to place the flanges later: I'm not sure of how the central girder would have been constructed. I'm musing on this as to whether it would have been a box girder so to avoid flanges being cut into the bridge deck. It makes no odds really, but an inquiring mind just wants to know. Next step will be to cut the vertical plate flanges to length and then the ends followed by the top and bottom flanges. The last bits will be the angles between all the various parts. I did it once and I shall do it again - hopefully to a better standard this time. Toodle pip, More tomorrow, Philip Just to add, the punch is only about .33mm wide so makes a rivet of about 1" diameter. Edited January 25 by Philou Added info 3 Link to post Share on other sites More sharing options...
RMweb Gold 5BarVT Posted January 25 RMweb Gold Share Posted January 25 23 minutes ago, Philou said: I'm not sure of how the central girder would have been constructed. I'm musing on this as to whether it would have been a box girder so to avoid flanges being cut into the bridge deck. It makes no odds really, but an inquiring mind just wants to know. I’m not a structural engineer or a bridge designer, but my gut feeling is that if there were a central girder it would have been two separate bridge decks, one each side. Paul. 1 Link to post Share on other sites More sharing options...
Philou Posted January 25 Author Share Posted January 25 (edited) 1 hour ago, 5BarVT said: if there were a central girder it would have been two separate bridge decks, one each side. @5BarVT Mmm, yes my model is going to be just that - two separate decks. I expressed myself badly in my musing. I'm trying to get my head around of just how the deck would be supported on the central girder if there are flanges every six feet (say). Regarding the two outer girders their outer faces would have flanges (they're usually the sides we can see from a road, for example) but I have assumed (probably wrongly) that the inside face has no flanges and just rivetted plates at each joint (I have a photo that may bear this out). But what happens when there's a central plate girder? The few photos that I have tend to show flanges, but the decks are big corrugated channels within which the sleepers are placed with a bit of ballast and an angled plate from the girder down to the channel presumably to stop the ballast falling out of the channelling (does this make sense?). How is all supported? I suppose the channel rests on the bottom flange of the girders. (I think this 'flange' is actually the web). ^ This photo shows a central girder but I can't see what's under the angled plate at sleeper level. This bridge has the corrugated channelling under the sleepers and having looked at the dimensions from this side and externally, it seems that the sleepers are partially inside the channelling. In my case, I'm having a flat bridge deck without ballast and the rails on baulks - how is the deck supported along its edges? Perhaps it isn't and is supported by the longitudinal 'I' beams below that are then supported by the steel sections. Are there cut-outs in the decks at each flange? I was in highway design but never did bridgeworks and even then our office only did concrete or concrete/welded steel composite. Plate girder construction is probably very old hat - but I'm curious - surely the Victorians didn't use skyhooks - or did they? :)))) The bridge that I used as illustration from the RAIB report above, appears plated but no rivets were used in its construction - its all nuts and bolts and unfortunately as the inspection concentrated on the damaged track and baulks, there are no details regarding the bridgeworks itself. I know I'm probably overdoing this thinking lark, but if you don't ask, you don't find out. Edited January 25 by Philou Web added, picture added 1 Link to post Share on other sites More sharing options...
RMweb Gold lezz01 Posted January 26 RMweb Gold Share Posted January 26 I've seen 3D printed nuts and bolts in 1/72nd scale on eBay. Regards Lez. 1 Link to post Share on other sites More sharing options...
RMweb Gold lezz01 Posted January 26 RMweb Gold Share Posted January 26 Here you go Philip. https://www.ebay.co.uk/itm/185987213176?var=694006084897 Regards Lez. 1 Link to post Share on other sites More sharing options...
RMweb Gold 5BarVT Posted January 26 RMweb Gold Share Posted January 26 (edited) Hi Philou, Although not GWR/LNWR, the RAIB report R01/2010 for a bridge collapse near Stewarton G&SW shows construction details for a skew centre girder bridge and shows details of what went on below ballast level. Link here https://assets.publishing.service.gov.uk/media/5a7f5fe7e5274a2e87db5784/100203_R022010_Stewarton.pdf From fig 7 p16 it looks like there was no ‘deck’ as such when the rials were laid on baulks. A timber deck was added when the bridge was ballasted. It may be that there was a light timber deck sufficient to support foot traffic before the bridge was ballasted. King Edward bridge across the Tyne seems to have some sort of infill to,prevent stuff dropping through. Paul. Edited January 26 by 5BarVT Added bulk bridge and KEB comment. 2 3 Link to post Share on other sites More sharing options...
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