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I started to assemble my SS80 Ratio viaduct kit which will form a representation of Monsall Head viaduct on the Peak District line. The viaduct needs to go on a double track curve to suit the radius of 34" inside curve and 36" outside curve. I can accommodate 5 arches, the height from the track bed to bottom of the valley is 23cm although this can be raised using scenery. I am thinking of constructing the kit in sections which will be wider at the back and will be filled with plasticard. The supporting pillars will need modification. I am using the article in Nov 2015 Railway Modeller as my starting point.

 

Is it best to persevere with the kit or use a flexible piece of ply, scratch build  and cover with plasticard?

 

Any advice will be greatly appreciated. Will post some photos shortly which show progress so far. 

 

Many thanks, Rob 

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It you curve the whole structure you will run into problems with the materials for the arches not fitting correctly. You end up with a rather complex shape. If you just curve the pillar areas by making one side longer than the other you will get away with this. It might limit the curve of your viaduct however and you might find that it is not wide enough to allow for 2 tracks. 

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I hadn't appreciated the problems with curved viaducts until I got involved in our Club one.

 

There are two ways to make a curved viaduct work, only one will work with the Ratio sides, either the piers have to be wider on one side than the other, or the arch needs to be wider, but not higher, so the arch on one side is 'flattened'. This then makes the underside of the arch 'interesting'.

 

If you are happy to widen the piers from one side to the other then you could hack the Ratio about, but I think on balance you will get a better finish by starting from scratch.

 

We started with the trackbed, supported on timber 'piers' for structural support. We then made the two sides in  mdf, and then when satisfied filled in the gap between to make up the piers. The odd shaped underside of the arch was completed in balsa.

 

post-18627-0-15364800-1457515856_thumb.jpg

 

post-18627-0-33159300-1457515859_thumb.jpg

 

Once complete the whole thing was clad in resin sheets I cast, but card would be equally good, with Arch details added to suit the two different arch profiles.

 

post-18627-0-90208100-1457516373_thumb.jpg

 

It's a pain in the bum, but well worth it, and I think that hackng Ratio kits about will end up looking like just that, for not much less effort.than a scratch-build.

 

post-18627-0-71378700-1457516376_thumb.jpg

 

 

Peter

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I started to assemble my SS80 Ratio viaduct kit which will form a representation of Monsall Head viaduct on the Peak District line. The viaduct needs to go on a double track curve to suit the radius of 34" inside curve and 36" outside curve. I can accommodate 5 arches, the height from the track bed to bottom of the valley is 23cm although this can be raised using scenery. I am thinking of constructing the kit in sections which will be wider at the back and will be filled with plasticard. The supporting pillars will need modification. I am using the article in Nov 2015 Railway Modeller as my starting point.

 

Is it best to persevere with the kit or use a flexible piece of ply, scratch build  and cover with plasticard?

 

Any advice will be greatly appreciated. Will post some photos shortly which show progress so far. 

 

Many thanks, Rob 

 

34" radius is very tight for a line on a viaduct.

 

Is it a stay-at-home layout? If so, you don't need to worry too much about the appearance of the side that won't be seen. So you could optimise the side that you will see to match the Ratio kit and then adjust the other side to match.

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34" radius is very tight for a line on a viaduct.

 

Is it a stay-at-home layout? If so, you don't need to worry too much about the appearance of the side that won't be seen. So you could optimise the side that you will see to match the Ratio kit and then adjust the other side to match.

Jo,

 

Thanks for your reply. This is a stay at home layout although the boards are designed to come apart and are correctly aligned with alignment dowells secured by M6 wing nuts and bolts.

Think it may be best to adjust the pillars on the longer side to somehow match up with the arches. Will let you know the outcomes.

 

Best regards, Rob 

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Hi Rob.
It's important to start with the track bed. The track centers and over hangs of the stock need to be clear and I think your Ratio pillars wont be wide enough.
My viaduct build is shown here

Also I'd encourage a scratch build as a closer likeness to the real one can be achieved.

 

Interested to see how you get on what ever route you take, viaducts are great to watch trains on!!

 

Regards Shaun

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I hadn't appreciated the problems with curved viaducts until I got involved in our Club one.

 

There are two ways to make a curved viaduct work, only one will work with the Ratio sides, either the piers have to be wider on one side than the other, or the arch needs to be wider, but not higher, so the arch on one side is 'flattened'. This then makes the underside of the arch 'interesting'.

 

If you are happy to widen the piers from one side to the other then you could hack the Ratio about, but I think on balance you will get a better finish by starting from scratch.

 

We started with the trackbed, supported on timber 'piers' for structural support. We then made the two sides in  mdf, and then when satisfied filled in the gap between to make up the piers. The odd shaped underside of the arch was completed in balsa.

 

attachicon.gifJPEG Image (1474716).jpg

 

attachicon.gifJPEG Image (1474755).jpg

 

Once complete the whole thing was clad in resin sheets I cast, but card would be equally good, with Arch details added to suit the two different arch profiles.

 

attachicon.gifJPEG Image (1493493).jpg

 

It's a pain in the bum, but well worth it, and I think that hackng Ratio kits about will end up looking like just that, for not much less effort.than a scratch-build.

 

attachicon.gifCopy of DSCF2246.JPG

 

 

Peter

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Hi Peter,

 

Your pictures look fantastic and this is just the design I need. You are right, as I do not want to be constrained by the limitations of the Ratio kit so am now going to scratch build it. In fact I did some experiments at my club (High Wycombe) last night where I took a sheet of thin ply and cut 4 out of 5 arches with the band saw. The rest I will finish at home and sand to shape. The wood also bends to the shape I want it to.  One of my colleagues suggested mounting card which can also be cut to shape with a scalpel and easily strengthened. This sounds like a good idea too. I will be making the supporting pillars out of wood and clad with plasticard. As for the track bed, this needs to be cut to the shape I want as the track is already laid on 6mm birch plywood. 

Will post some pictures of my progress . You can see the images of Monsall Head viaduct on google images.

Thanks once again, Rob 

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Just to add my thoughts. I understand from someone with a better knowledge of these things than myself, arches must be parallel and the pillars tapered. I real life this makes little difference visually, particularly as you can only see one side at a time. On my layout i have a curved viaduct using the Will's kit. I curved it by inserting a 4mm section of Plastruct™ on the back of each pillar. Also, being a fairly gentle curve, I have been able to assemble each section straight without it looking angular.

post-15-0-31294200-1457858178_thumb.jpg

post-15-0-99678500-1457858187_thumb.jpg

 

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Just to add my thoughts. I understand from someone with a better knowledge of these things than myself, arches must be parallel and the pillars tapered. I real life this makes little difference visually, particularly as you can only see one side at a time. On my layout i have a curved viaduct using the Will's kit. I curved it by inserting a 4mm section of Plastruct™ on the back of each pillar. Also, being a fairly gentle curve, I have been able to assemble each section straight without it looking angular.

attachicon.gifv1.jpg

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Thanks for this. Am having a go with scratch build due to the tighter radius on my layout (34 and 36" radius).  Am thinking about laser cut components which should give accurate arches. Your viaduct looks really good especially the railings at the top. Do you have any side views of the viaduct?

 

Rob 

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Some latest photos of the viaduct. I managed to curve it round the track bed . At present it is made from mounting card which will be clad in Plasticard. The supports are in wood which will need to be be angled on the final left hand arches.

 

Today I visited the Alexandra Palace exhibition where I bought some 1mm birch plywood form one of the traders. This could be an alternative to use on the fascias instead of the card. I also bought the dressed stone sheets made by Slaters Plasticard. I opted for 4mm instead of 7mm which in my opinion was a tad too large.

 

Another discussion at the club tomorrow night to decide the best way to proceed with the project but am pleased with my findings so far.

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post-26417-0-54969000-1458514922_thumb.jpg

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On Lostock Junction, Mike made a model of Arten Gill viaduct. The video is of the grand opening.

 

 

The construction uses large lumber and the surface is Hydrocal castings. The base of the viaduct goes over the top of the operating pit.

Not exactly what you were asking, but what can be done. There are still a few bits to be done.

Edited by BR60103
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Latest progress pictures. Spent the afternoon fixing stone plasticard to the underside of the viaduct.  Used impact adhesive which stuck the materials thoroughly. Slight issues encountered namely the pier sides are not long enough hence the sheets have lack of support in the middle and tend to bend. Will correct this over the next few days. 

 

Have added a sheets to the side of the viaduct and scored the sheet to form a 90 degree bend. Slight cracking on the edge which will be filled with filler or das clay om completion. Need to correct a couple of mistakes but generally happy with my first attempt.

 

 

post-26417-0-45352800-1459460920_thumb.jpg

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Hi Rob

 

Interesting pictures and great to see the progress coming along.  I made a curved viaduct for my layout a few years ago but went along the plywood frame and thin ply/hardboard sides clad with plasticard.  From an old Model Railway Constructor magazine there was an article entitled "A Way through the Mountains" from the Chatham and District MRC with a scale drawing of Appersett viaduct near Hawes.  I used these dimensions along with many photographs of Ais Gill viaduct to make the model.  Also, as the layout was designed for exhibition and had to be in sections, the viaduct had to be removable and "plug-in" to the rest of the layout when being assembled.

 

Anyway, a few pictures

 

post-7537-0-49827700-1459583509.jpg

This is how it all started with plywood legs and top

 

post-7537-0-23833300-1459583571.jpg

The sides of the viaduct have been made and I've started to cover them with Wills plasticard stone sheet held in place with a suitable adhesive

 

post-7537-0-15042500-1459583878_thumb.jpg

Eventually the viaduct was finished and painted.  What you see here is the stage before the scenic covering was applied under the arches.

 

Best regards

Edmund

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I am watching this thread with interest as I am planning to have a curved viaduct on the layout I am building. What I have seen so far has been most useful. Thanks.

 

Slightly OT, but still connected, I am struggling to cut the ply track bed accurately. How do people manage to cut such neat curves in plywood? Any tips?

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I am watching this thread with interest as I am planning to have a curved viaduct on the layout I am building. What I have seen so far has been most useful. Thanks.

 

Slightly OT, but still connected, I am struggling to cut the ply track bed accurately. How do people manage to cut such neat curves in plywood? Any tips?

 

Slowly, very slowly with a scroll saw. 

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Hi Rob

 

Interesting pictures and great to see the progress coming along.  I made a curved viaduct for my layout a few years ago but went along the plywood frame and thin ply/hardboard sides clad with plasticard.  From an old Model Railway Constructor magazine there was an article entitled "A Way through the Mountains" from the Chatham and District MRC with a scale drawing of Appersett viaduct near Hawes.  I used these dimensions along with many photographs of Ais Gill viaduct to make the model.  Also, as the layout was designed for exhibition and had to be in sections, the viaduct had to be removable and "plug-in" to the rest of the layout when being assembled.

 

Anyway, a few pictures

 

attachicon.gif035.JPG

This is how it all started with plywood legs and top

 

attachicon.gif051.JPG

The sides of the viaduct have been made and I've started to cover them with Wills plasticard stone sheet held in place with a suitable adhesive

 

attachicon.gif052.jpg

Eventually the viaduct was finished and painted.  What you see here is the stage before the scenic covering was applied under the arches.

 

Best regards

Edmund

Hi Edmund,

 

Excellent work on your viaduct. The finished product is great and I particularly like the piers and stonework. Have had another go with the inside of my arches as the plasticard was not supported well and tended to bend inwards. Glued some 1mm plywood inserts to form the arches and then matched up the plasticard to go with it. Will post some more photos tomorrow so you can see the progress.

 

Can you let me know what materials were used to show the stonework fascias at the top of the outside arches as I need to replicate this. The Wills kit has these but would be difficult to cut and put in place 

 

Your scenery levels are what I will be doing too albeit mine might be slightly steeper as I am modelling Monsall Head viaduct in Derbyshire which is on google images

 

Best regards, Rob 

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Hi Edmund,

 

Excellent work on your viaduct. The finished product is great and I particularly like the piers and stonework. Have had another go with the inside of my arches as the plasticard was not supported well and tended to bend inwards. Glued some 1mm plywood inserts to form the arches and then matched up the plasticard to go with it. Will post some more photos tomorrow so you can see the progress.

 

Can you let me know what materials were used to show the stonework fascias at the top of the outside arches as I need to replicate this. The Wills kit has these but would be difficult to cut and put in place 

 

Your scenery levels are what I will be doing too albeit mine might be slightly steeper as I am modelling Monsall Head viaduct in Derbyshire which is on google images

 

Best regards, Rob 

 

Hi Rob

 

For the stone on the arches I used individually cut pieces of 40 thou plasticard on the front and then underneath I used a much thinner 10 thou individual piece to make it look as one block.  The reason for the thinner piece underneath was unlike the sides where I left a space between the edge of the stone sheet and the curve of the arch, I put the thinner piece straight onto the Slaters brick plasticard underneath.  The top stones were individual pieces of very thick plasticard  (60 thou +), cut out and shaped individually.  I've put some more pictures up so hopefully this makes sense.

 

Best regards

Edmund

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post-7537-0-32604900-1459751156_thumb.jpg

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Hi Rob

 

For the stone on the arches I used individually cut pieces of 40 thou plasticard on the front and then underneath I used a much thinner 10 thou individual piece to make it look as one block.  The reason for the thinner piece underneath was unlike the sides where I left a space between the edge of the stone sheet and the curve of the arch, I put the thinner piece straight onto the Slaters brick plasticard underneath.  The top stones were individual pieces of very thick plasticard  (60 thou +), cut out and shaped individually.  I've put some more pictures up so hopefully this makes sense.

 

Best regards

Edmund

Hi Edmund,

 

Thanks for the advice as this is something I will use. Did you use the same technique for the piers as they have a raised level at the bottom of the arches? I am informed that the plasticard I am using is 7mm dressed stone. I thought it was 4mm but am sure on viaduct I am building, won't matter too much. The suppliers are out of stock for a couple of weeks. My friend at my club has been doing some painting experiments for me which I am collecting later on.

 

Your photos look great and I can see the Settle-Carlisle influence.

 

Best regards,

 

Rob

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I am watching this thread with interest as I am planning to have a curved viaduct on the layout I am building. What I have seen so far has been most useful. Thanks.

 

Slightly OT, but still connected, I am struggling to cut the ply track bed accurately. How do people manage to cut such neat curves in plywood? Any tips?

The neatest way is to cut with the scroll/band saw outside your lines then put it in the vice and sand down to the pencil line by eye. I use my belt sander! The band saws used in cabinet shops are usually too big to cut thin ply. A nice fine Swiss blade in the jig saw is best and the work piece is best clamped down!

 

Cabinet making is all about drawing things out full scale, so when that technique is applied to layout construction it becomes much more interesting.

 

Regards Shaun.

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Hi Edmund,

 

Thanks for the advice as this is something I will use. Did you use the same technique for the piers as they have a raised level at the bottom of the arches? I am informed that the plasticard I am using is 7mm dressed stone. I thought it was 4mm but am sure on viaduct I am building, won't matter too much. The suppliers are out of stock for a couple of weeks. My friend at my club has been doing some painting experiments for me which I am collecting later on.

 

Your photos look great and I can see the Settle-Carlisle influence.

 

Best regards,

 

Rob

Thanks Rob

 

Yes, the raised stone around the base of the arches is actually some square plasticard rodding that I slightly sanded down two edges of to round them slightly and then with a fine saw, made small cuts on 3 sides to represent the gaps between the stones.  These were trimmed, and glued in position with any gaps finished with plastic putty and then shaped etc.

 

I've put some more pictures on that may illustrate this further

post-7537-0-17193100-1460206127_thumb.jpg

post-7537-0-56425200-1460206167_thumb.jpg

post-7537-0-14540300-1460206173_thumb.jpg

post-7537-0-96901600-1460206178_thumb.jpg

 

Finally, although not the viaduct, this picture of a tunnel mouth under construction on the other end of the layout shows what I did with the large plastic rodding shaping and with saw cuts.

post-7537-0-72949500-1460206159_thumb.jpg

 

 

Best regards

Edmund

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