Sunday 29 January 2012

Bridge over lumpy polystyrene

I knocked up a girder bridge from the sides of a Dapol turntable and a load of evergreen styrene. I put the bit over the top to try to stop it looking so much like a turntable. Not sure it worked but it is a nice solid structure.

I've been painting it this evening, Codex Grey, only done the first coat but it is a big improvement. I wish I hadn't stuck the track down as it would be easier to paint the bearers without it there. I might rip it off and have a scrape.

I've also finished the Full Truckle cheese rail lorry so I now have a pair that can run back to back. Pictures to follow. Part of my finishing things off before starting anything else plan... however while I was looking for chassis and bits to sell on evilbay to pay for Christmas/car exhaust/vet bills/tesco etc I found the Fleischmann 0-8-0 that I have been hoarding. So then it set me wondering what would look good on it... and then I found the remains of a Hunslet WD 4-6-0 kit and I seem to have started to build another loco... Doh! So far it looks like Doris but with more wheels, I'll have to do something to make it look different but still from the same factory.


Anonymous said...

Nice model, i like it....

Property Facility Management

Michael Campbell said...

That bridge doesn't quite work for me. Maybe as an engineer I am being pedantic. However here are some suggestions that might help:
- The brace over the centre makes it look more like a turntable! I've never seen one on that kind of girder bridge
- A skew girder bridge has the girders offset longitudinally - i.e. the girders should start at the edge of the gap, even if that is not perpendicular to the track
- The girders should be *only just* long enough for the gap, and sit on abutments overlapping by about 12-18" (say 5mm). I suggest building out a brick/stone abutment closer to the edge of the river and then shorten the girders to suit, a couple of "bays" off either end would make it less like a turntable too.
- The girders are rather massive for NG. Given the above points should look OK, but have you considered the PECO NB-39 N-gauge girders? Cheap enough to try!

As always a look at a real girder bridge will be a big help, I believe there are some NG ones in your area! There was a useful book on "Bridges for Modellers" but I'm not sure it is available now.

Michael Campbell said...

Another thought - the bottom of the girders should sit below track level, and there would be cross-members (timber or smaller girders) running accross between the girders at their bottom edge, and under the deck of the bridge. In other words, set the deck about 6-8mm up from the bottom of the girders.

Lord Stoner said...

It is a ludicrously over engineered bridge but I'm growing to like it. It will have proper abutments once I've worked out where it will properly sit. The bit over the top is daft but will also have a decorative thingy in typical Isle of Stoner style. I thought about the PECO bridge but dismissed them as dull. Thanks for the advice.