Aireside Railway - Steve Smith shows how to build a viaduct
The track baseboards were formed with 12mm ply, 150mm wide at a radius to match the post alignment. Each board was supported by simple 2x1 cross pieces. Both sides were faced with 6mm ply to form a "H" section; the joints in manufacture being screwed and glued. There are three lengths of around 8ft each and these are joined, at the post supports, with brass plates on either side to clamp the lengths together.
The return loop at Lakeside station was set out to 5ft radius with 2 x 75mm sq fence posts set to a level with 4ft spacing.
The timber is protected with exterior paint, both sides and underneath, with a bitumastic for the track to sit on.
and April 2010 the new bridge: high enough for the largest traction!!
photos ©Steve Smith