Humped back bridge

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Road over river

Well, seem to have got my mojo back, and with the discovery of Finnboard have decided to try and scratchbuild a road bridge for Ursa Resurgat. As ever, I first looked at Scalescenes stuff for ideas and toyed with the idea of adapting the canal over-bridge, but , having printed out the arch shape reailised that it was too steep for motor vehicles and had to start from scratch. I chose to use John's 'egg-box' bridge construction to give rigidity and work in Random Ashlar [TX 46] from my Scratchbuilder's yard collection.

I took two period[ish] vehicles and tried several contours until I found a shape that didn't ground the rear or the underside of a lorry.










then I set to and cut out some shapes echoing the contours I had chosen. It doesn't show in this shot but the walls lean inwards [batter] at about 1 in 20.




I cut out several parapet shapes, one to go on the outside and two to go on the inside of each wall. As the Finnborad is exactly 2mm thick it scales up to a 24" wall which seems appropriate.




This shows the curved recess between the walls and the parapet pieces which will securely hold the roadway layer…




…and this shows the difference in the radii of the inner and outer wall which will conceal the edge of the arch lining from the outside….




As Finnboard is reputed to be capable of being curved when wet/damp and retains its shape when dry I wanted to try it. I wrapped a piece around a suitable former [ToonaTins!] and I am leaving it to dry for 24 hours.



I chose the largest of the window arches in the TX46 pages, and increased its size by 20% before printing it out several times and cutting out eighty-eight pieces together with two keystones and glued them around each opening. I found UHU solvent-free glue to give the right amount of 'stick and slide'. Note plenty of stiffening pieces inside the armature, if lots of strengthening is good enough for S'Scenes, it's good enough for me!










I have used 6mm balsa to form the vertical components of the butresses. That's it for now, I'll give it a bit more thought before going any further,

Best wishes,

Douglas









Last edit: by Chubber


'You may share the labours of the great, but you will not share the spoil…'  Aesop's Fables

"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin


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Well done Finn for making Douglas not bored!

Great to see top modelling pouring forth from South Devon.

Best,

Bill

At 6'4'', Bill is a tall chap, then again, when horizontal he is rather long and people often used to trip over him! . . . and so a nickname was born :)
 
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Very nice scratch build. Looking forwards to see it progressing!

Last edit: by TeaselBay

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I chose the largest of the window arches in the TX46 pages, and  increased its size by 20% before printing it out several times and  cutting out eighty-eight pieces together with two keystones and glued  them around each opening.


I am sure that would have been "fun"  doing that. Not ideal if your hands have the shakes….

but looking good Doug.

Ron
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Looking good Doug. 👍

Terry
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I'm pleasantly surprised at how well the FinnBoard [FB] conformed to the shape of the cans when it dried out. In fact, I had allowed a little 'spring back' which I would ordinarily do with a wooden laminate, but with this stuff there is no need. In fact, it even retained the shape of the rim of the tin!



Here it is fitted. As a lot of 'end grain' was involved I pre-glued the edges and let them dry so that the glue [Roket Card Glue] would not all be wicked away. A little tidying up with a sandpaper plane gave the result below.



Now, the parapet top needed covering with a coping stone before I went any further. Scalescenes strips of stones are only 10mm wide, so by  copying a couple of strips from the PDF and then pasting them to a photo editor [in my case Microsoft Photodraw] I was able to stretch them sideways until they were 14.5mm wide and cut them out to cover the tops of the parapets.



Once in place I drew a line underneath their edges and in the 'gaps' and darkened the lower edges of some of them, then dented and bruised the lower edge of the overhanging stones in one or two places to reflect the fact that they are built up from random ashlar.







I think that's all for now, the next job is to attach the road surface, but I'm still pondering how first to treat the surface. Hhm, would there be drains or would the water simply run away downhill….

Poop-poop!

D

Last edit: by Chubber


'You may share the labours of the great, but you will not share the spoil…'  Aesop's Fables

"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin


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Great work.

I have a humpback bridge on my layout that I agonized over. And was never happy with.

Thanks for showing how you did yours. With even more spare time now, I might make another attempt

Cheers
Evan
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Thank you all for your complimentary posts, I'm still not too sure what sort of surface to put on the roadway, i.e. cobbles, tarmacadam, hollow to the middle, raised in the middle, drains at side etc. The one thing I'm short of is a photo showing the surface of a 1950 bridge road. Just have to waste a few more electrons Googling…

D

Last edit: by Chubber


'You may share the labours of the great, but you will not share the spoil…'  Aesop's Fables

"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin


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Hi Douglas,

With my boyhood knowledge of Devon and Dartmoor hump back bridges, tempered by a professional life as Chartered Surveyor and PM in the consrtruction sector, the fun humped part would have relied on natural run-off for drainage, then into roadside ditches, since ironwork gratings and underground systems would be seldom seen away from habitated areas.

The road surface for the earliest such structures would certainly have been stone, much later re-surfaced with a sub-base and tarmac. From late 50s to mid-60s, tarmac was the surface of choice for South Devonshire roads and the links below give an idea of condition. In those 'good old days', more council resources may have been used on road maintenance than of late, or more likely the wearing surface lasted longer due to low traffic volumes.

Anyway, a few images to consider:

humpback bridge to Glelands

Small humpbacked bridge that helps walkers and cyclists bypass the water

Bridge with no entry for cars sign

Humpback bridge on a country road



Yes, the above links may be long, but they work                 (Edited links to shrink em, Barchester)    

https://punch.photoshelter.com/image/I0000jZbeNQP0kGo

This last one is just asking to be modelled!

Looking forward to your finished article,

Bill





At 6'4'', Bill is a tall chap, then again, when horizontal he is rather long and people often used to trip over him! . . . and so a nickname was born :)
 
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Hi Douglas,

Rough grass on the edges, no drainage, slightly elevated median, rough gravel on tar. Sign for single lane either side. Large puddles either side when it rained. That long wheelbase lorry will manage it, not sure about an Austin 7 or 12. There was a really good one just outside Highbury on the A361. My Cortina 1600E had 2 replacement sump covers over the years. 


Nigel

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Thanks for that, chaps. Reminds me to weather it with loose gravel in the centre [sorry, median, Nigel!]

'You may share the labours of the great, but you will not share the spoil…'  Aesop's Fables

"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin


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Herewith two pictures before the weathering and fettling starts. Not happy about the 'slabs' on top of the buttresses, doesn't seem to be anything that will work/scale up in S'Scenes textures, these are random ones from the web. Ignore the unrealistic colour of the roadway, that's the sanded down 3mm black foam board used to give a camber effect,






The biggest PITA was working out the wraps for the buttresses which were applied last. Hope it encourages someone else to have a go at a bridge!

Douglas

'You may share the labours of the great, but you will not share the spoil…'  Aesop's Fables

"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin


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See what you mean about the 'slabs' Doug, but I'm afraid I can't offer any suggestions.

Could be a case of live with it, and it'll look OK when in situ.



Ed


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Hi Douglas,On

What about some weathered brick work instead. Plenty of examples. 

Nigek

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The bridge looks great Doug.


Terry
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The slabs will look better once some weathering has been applied but in general, a nice build.

Ron
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With the slabs, would you be able to take off a few corners/maybe split one so there is a visible gap down the middle as it’s cracked? I think once weathered though they will blend in well. 
There is some great modelling going in there! It looks brilliant! 

Last edit: by TeaselBay

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As always Doug, lovely modelling, with wonderful sharp corners.  The Finnboard looks like it was a good investment too.  Enlarging a window for the arch was inspired.  I think the "slab" looks fine, but you could always add a slightly smaller one on top, a little decorative perhaps, but it might trick the eye by being that little bit smaller.
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Hullo chaps, thanks for your encouragement

Below is photo of the tops covered with the TX46 paper and bashed about a bit, not at all convincing, but Chris's suggestion has got me thinking……separate stones?If I can cover the parapets with  S'scenes paper strips stretched sideways, I could use the same to represent a small number of bigger slabs, say 4-6 on each buttress top??




Watch this space.

Puzzling Doofer


Last edit: by Chubber


'You may share the labours of the great, but you will not share the spoil…'  Aesop's Fables

"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin


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Yes, it seems to have worked, thank Chris for sowing the seed. I used three varied sizes of stretched coping stone stuck to a rectangle of Finnboard which I bashed about a bit.










As its 1950, the white marker paint on the buttresses is starting to fade away.

Douglas' 'Troubled Bridge over Water….'

Last edit: by Chubber


'You may share the labours of the great, but you will not share the spoil…'  Aesop's Fables

"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin


In the land of the slap-dash and implausible, mediocrity is king
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