Physicsman

Mike. a quick whizz gives this...

Mike, I see your idea. Of course, even a 1:90 rise to the main viaduct and a 1:90 fall to the branch viaduct could generate a 2cm difference in height. B****y laptop I'm using for the plans is loading updates at the mo, so can't see about moving the river just yet. Keep thinking about it and I'm sure a viable solution will appear. Costs nothing to think! Jeff

Alternatively, behaving Godlike, I can move the river a little, giving a bit more distance between the platform and branch viaduct. Yes, that might work. I will play with the plans...back soon! Jeff PS casual observers, please bear with these musings!

Mike, I'm assuming you are going to suggest a 1:45ish gradient, allowing a 2cm drop for the branch... If the branch only handles traffic in an anticlockwise direction I could go a bit steeper...

Approximately 90cm - shall we say 3 feet in old money...

Will, I assume silly idea number 1 was the curved viaduct! It was actually a great idea and I have to admit that you were the initial catalyst in setting the wheels in motion! Idea number 2 is also a good one - though I haven't a clue how to build one! I'm going to have a re-think about the whole branchline concept and where it crosses the stream. Keep the ideas coming - this thread is open for any discussion, the more the better!! cheers, Jeff

Yes, I don't think I'll go there. I'm almost tempted to scrap the branch line, but I think that would reduce the level of operations on the layout. So I think it'll just be a contrast in size and shape between the two bridges! Jeff

Hi Mike, I can't really make it any lower given that the branchline and mainline leave the station at almost the same place and cross the river very close to each other. That's a real pity as I'd like to have a clear view of both viaducts. Any suggestions? Btw, the single track branch viaduct will be 3 arches and about two-thirds the length of the previous one. Jeff

I am going to base my branchline viaduct on Lunds (S&C). This has a much wider archspan and thicker piers. Lunds is double track, my branch will only be single. My viaduct will also (hee hee) be curved... Hopefully the different style will contrast with the one I've just built. Jeff

Card formers attached to all 6 arches. Plasticard (probably 20thou) will be fitted over the top of these. Pillars need rubbing down and I need to acquire some square cross-section plastic for the boundary between lower pillar and arches. Jeff

Thanks Will. It's been great fun - a few problems to solve, making it even more enjoyable!! The filler seems to have worked well, but it does add a certain "solidity" to the structure (should I say "weight"?). I'm fitting card arch formers today, evening-up the filler and in a couple of days, when the filler is bone-dry, I'll sand it down. I think I'll then move on to the smaller branch viaduct. When that's built I can then do the plasticard bit - probably with Slaters 7mm stone facing. Anyone who thinks railway modelling is boring needs to have a closer look!! Best wishes, Jeff

This should be quite a layout when it's all up-and-running, James! You really do like your Lego, don't you? Btw, am I mistaken - do you live in Canada. I apologise if I'm a few thousand miles out! Cheers, Jeff

Well, I couldn't resist. Here is how the card fits into the pier structure... Jeff

Hi Mike, I've had a look at the arch sections and how to "do" them. It's not feasible to fill them with filler - well, it is, but it would take a hell of a lot of filler and the viaduct is heavy enough as it is. So I've cut some card formers that fit around the arch and I'll then overfit the card with plasticard. The card former is for support. I've just cut a piece to the calculated length and width and it fitted perfectly - beginners' luck? Will fix the card arches on tomorrow. Photos, as usual. Plasticard to follow later. Jeff

Interior of pier pillars now filled with filler. No ingress into the mdf - pleasing, given the amount of PVA I used to seal it. The viaduct is getting heavy, but I can still move it around - just!! Bit of a break now, then I'll think how I'm going to set-up to fill the arch sections... Jeff

A few pics of ply fittings into arch area. Filler being added now - more (exciting) later. Jeff

Interior 12mm ply barrier fitted inside arches and sealed with COPIOUS amounts of PVA. Mike, you'd be proud of me. When the whole thing is completed I'll take some pics. I KNOW some people are aware of these things, but for those who want to see each step - I'm happy to oblige! Other than that, nothing exciting (Andy - I AM considering your canal suggestion). Jeff

Thanks for the advice. I have already coated the mdf in pva on the back of the front fascia and may concoct a ply barrier to avoid direct contact. I will try it behind one arch and see what happens! Jeff

Nick, I'm not a GWR afficianado but I enjoyed seeing Much Murkle in Hornby mag and I'm very glad to see it here. More photos please - the first picture in your opening post is superb! Cheers, Jeff

Change of plans... In consultation with my modelling guru (aka Schubert), I'm reminded (how could I forget - I've used tons of the stuff over the years!!?) that mdf is good at soaking up moisture and might swell in proximity to wet filler. So I'm going for a lighter card/mdf framework - I'll try the idea and see how it works. New to me - no doubt some of you old hands will be shaking your head and thinking "when is he going to get it right?" Photos will eventually follow - even if what I do is disastrous! Jeff

Mike, you are quite right. I'm going to fit some plywood and mdf off-cuts (polite word for rubbish) into the spaces before I add the filler. Weight shouldn't be a problem, but the easier the damn thing is to move around, the better! Ironically, having fitted all that foamboard insulation into my walls, I haven't got a single piece left! Cheers, Jeff

Time to start rubbing down the fascias, especially around the arches. Then the interior of the piers. I was going to try and be clever with more woodwork here, but I've decided to follow the KISS principle and go for simplicity. I'm going to fill the spaces with polyfilla. This will guarantee a very smooth join between the fascias - which is so important when it comes to sticking-on the plasticard. Jeff

Here's a more oblique angle view... The mdf is only fixed for positioning at the mo - I will have to fine-tune that and rub it down - especially round the arch curves (they've only had a first cut, so far). Stanley knives are extremely useful!! Jeff

Rear fascia cut out and temporarily attached (as is the front one) to gauge correct positioning. Photos enclosed... Jeff

Update on progress. Rear fascia drawn out on 3mm MDF. Will start cutting it out tomorrow evening. If I feel inspired I may get the whole thing finished. Then it's a case of fitting inclined walls between the front and back walls - now that could take a while... Jeff