The latest planning session and John's progress on cutting some of the pier apertures certainly makes for some positive vibes on this project. Apart from starting to 'look' right and give encouragement that the final product will match our ambitions for it, getting down with the actual pieces and doing 'trial fits' is a good catalyst for brainstorming and coming up with solutions for the more 'macro' construction issues.

We know from the derived table of dimensions for each pier where the apertures are, and how much of each pier/plinth is exposed above ground level. This is enabling decisions on how far the scale plinths continue below ground on the model, and design concepts for the 'base' of the viaduct - probably stepped in a series of benches just under the scenery rather than a continuous floor with many 'piers' being, like icebergs, largely hidden from view.

The whole thing including approaches is 7m long. We discussed for a while how many sections to divide it into for transport, this being a compromise between minimising joins and getting it into a car. Eventually we settled on five sections of 1.4m each, which is three essentially identical 10-arch sections in the middle and two more of 3/4 arches plus approaches at each end.

Then, where to make the join? At a pier or half way across an arch? Initially we favoured the latter, with detachable balustrades and bricked sections that could be placed to cover most of the joins. But this left little cross section left for 'purchase' at the top for joining, so we are currently planning to make the joins between the arches and have detachable piers between the upper and lower joiners. Joining below the scenery will be straightforward with dowels, bolts and pronged-Ts, but joining at the top is a bit trickier because of accessibility to attach bolts (assuming both sides are potentially on show). At the moment we are thinking along the lines of dowels and high-strength magnets to do the job.

In theory construction now could be quite rapid, although there is no particular hurry and we certainly don't want to rush it. Apart from the main construction there is then also a lot of laminating of parts to do (to make 2mm thick laser cut details into the 4mm thickness we want). So that will undoubtedly mean more jigs to make sure the parts all register properly, and lots of PVAing.

Most of the basic brickwork will use Slaters English bond, but the arch sections (top and bottom of the pier apertures as well) are being etched in brass. Then there's the bracket supports for the refuges - not essential for the structure, but important nonetheless, and probably a casting job, either resin or whitemetal.

There is also a bit of detailed brickwork - 'beading' for want of a better term - which is still causing a bit of head-scratching. I'd like to think there would be something suitable from the world of dolls houses but we haven't found anything yet. Could be down to plastruct angle section filled in with Miliput or similar.