Footbridge for the Caradon Branch

  • Thread starter Thread starter Alec K
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Alec K

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It may be snowing outside but the Moorswater shops are busy fabricating a new footbridge for the Caradon Branch. The prototype did not run to such niceities, preferring accomodation crossings that were to prove a legal nightmare, but that's another story...
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After much photo research, I've settled on a compromise design that avoided complex latticework but seemed to me at least to look reasonably authentic. The raw materials are Slaters Plasticard in 60 and 80 thou sheets, and Plastruct I girders in two sizes. A scale 'concept' drawing was made first on two elevations, after test measurements on the line's rolling stock were completed, and the components for the track span were measured and cut from this. The outsize L piece in the picture is a trial for the eventual fitting of a correctly proportioned L girder along the top edges to 'finish off'. Supporting brackets were cut from individually shaped and drilled Plasticard; the girders are used prototypically- at least I hope so.
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The angled step sections at either end of the track span are measured and cut per the scale drawing, with a lattice spacer/reinforcer for the girders fixed as shown. The steps are cut and plastic-welded individually. A smoke deflector from scrap Plasticard is fixed centrally to the underside of the track span.
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One angled step section has now been completed and fixed to the track span. The next task is to replicate this for the other side, and commence work on the approach steps. I hope to add further photos as these stages are completed.

Alec K





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Thanks, Mel - I could do with a bit of encouragement: the cutting out of the risers and treads for the steps is numbing my mind! I daren't count how many more are needed....

As ever

Alec K
 
Further progress this afternoon, with the platforms at the head of both main flights of steps now constructed. The extended stanchions on which the supporting brackets are eventually fixed can be seen: later tonight I intend to add the side plates, brackets and attach these structures to the span in the picture.
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All the best,

Alec K
 
Both landings at the head of the main flights of steps have now been completed and attached.
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The side support stanchions are made from three pieces of shaped Plasticard, seperately applied. To ensure that the whole span is structurally square, I've had to insert some very small fillet pieces that, hopefully, will be invisible once model filler and paint coats are in place.
Another visit to Stratford Upon Avon is called for post-Christmas as I will need more Plastruct I girders for sure, and some lengths of L girder to reinforce the top edges of the side panelling.

I was considering saving myself a considerable amount of work by not modelling the intermediate platforms on the two flights of access steps, which I have included on my scale drawing, but this will, I think, detract from the balance and overall solidity of the structure. Additionally, it is an awful lot of steps to climb in one flight for my staff and passengers!

Kind regards

Alec K
 
I did decide to include half-way platforms on both flights of steps, having looked at my assembled photos of prototypes once again. I have this evening completed two such platforms, and these are shown below.
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This is probably time to pause in the construction of the footbridge, as I now definitely don't have enough Plastruct I girder lengths required to complete the four flights of steps. I have also opted to model the supporting structures using circular columns with ornate capitals, and these will require a visit to the shop in Stratford for sure! I will also have a few days in which to work out how to connect the flat cross bracing to the round tube, so more prototype pictures are called for. If I have understood the process correctly, lugs were cast integrally with the columns on similar real structures, but on a plasticard model this isn't going to be very strong as small fillets would have to be plastic-welded. Maybe a slot cut into the tube? We'll see.

Happy Christmas, all.

Alec K
 
And I'm still cutting and welding Plasticard girders! However, while the end is not exactly nigh -well, not of this project anyhow - the footbridge is taking shape steadily.
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For those who are minded, it is possible to see the structure of the vertical supports and connecting flights of stairs in this shot. The vertical columns are cut from Plastruct tubing of 7mm diameter, which were then bunched tightly together and filed carefully with a flat rasp file at the cut ends to ensure that they would be, as far as possible, of identical lengths. I found it tricky to cut tubing with precisely parallel ends, despite using masking tape positioned to measured marks.

Lattice girder units were cut and drilled from single pieces of plasticard and the four sets of upright supports assembled, then welded to the cross H girders that support the landings at either end of the transverse walkway. Work has now started on the four flights of steps. The structure of these is identical to the short flights for the landings, although there is less leeway for 'adjustment', shall we say?

Back to cutting risers and treads....

Alec K


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Wow.:thumbup:
 
Double WOW!!

It will be an anticlimax when it's completed though - I just love "work in progress".
 
Proud rightly you should be Alec
 
First class workmanship. This would make an excellent article for thr G.Scale Journal.
 
Thank you, one and all!

One lesson I have learned pretty quickly is that this sort of structure - just like the real ones, I guess - lends itself to casting the common components (steps, side panel outriggers, lattice girders). I would then have made one good master from Plasticard for each component and ensured exact replication. As well as Mel's great thread on this process for his own building construction, there's an excellent article in the latest Railway Modeller on DIY cold resin casting of 7mm loco parts.

However, with all your kind encouragement, I will press on.

All the best

Alec K
 
Only two more flights of steps to go... I started to count how many ****** individual components I'd cut from Plasticard for this project until I realised I was about to turn the corner to a place where counselling was called for.
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Forgive the customary standard of photography, please. Filling and adjustment continues on the completed assemblies, and, seeing the light at the end of the tunnel (pun intended), I can now think about paint colours. It would be tempting to go for a base colour like cream/light stone with stanchions and cappings in a darker colour like brown/dark stone, but in reality I think overall green is more likely - just like the Airfix kit to which Mel referred earlier. All ideas gratefully received.
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All the best, as ever,

Alec K



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A truly impressive structure.


Alec K said:
I started to count how many ****** individual components I'd cut from Plasticard for this project until I realised I was about to turn the corner to a place where counselling was called for.
Click to expand...

Anyone good at g-scale men in white coats?
 
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