Since the last entry on this blog in March, I've not been too idle! Two entries in the 2012 Challenge, 'Weavers Yard' in the Upton Dene blog and a pacemaker fitted have effectively taken care of the (?)summer... Retirement's wonderful! However its time to get down to some modelling where there is a danger that something might actually RUN soon!

The first issue was finding a way to connect the boxfiles together. Their lightweight construction rules out my usual method of 'engineers dowels' but any method had to be rigid and allow accurate mating bearing in mind the fine tolerances in 2mm. A little 'blue sky' thinking was required.

During the '2010 Challenge (what a long time ago!) I'd succesfully mated a 'dropped baseboard' (representing a river/canal & viaduct scene) with standard boards either side. I used bolts passing through the boards mating with fanged nuts which, as the bolt was tightened initially, located themselves in the baseboard frame -

They are known by various names but my hardware supplier refers to them as 'prawn tees'... However, as with the 'patternmakers dowel' system they could not be mounted in the end walls (too thin & flimsy). The process I decided on was to insert wooden 'tongues' through slots in the box ends. One end is permanently secured to a box, and is located in the next box by the aforementioned 'prawn tee'.

First, prepare the box ends -

I used 3mm ply for the tongues, so cut the relevant slots to fit -

At this point the fragility of the boxfiles became apparent, with some re-assembly required -

The tongues are 4" long and 1" wide. Two are used at each location -

and are secured in place by PVA & self-tapping screws.

As the spine and front of the boxes are made from materials of different thicknesses, a certain amount of packing was required -

which also helped brace the tongues -

and stop them wagging.....

Pilot holes were then drilled through the box & tongue and then opened out to the relevant diameter (5mm through the box for the bolt & 6.5mm through the tongue for the retaining bolt -

The bolts were carefully tightened down to ensure that the bolts did not pierce fully through the tongues as they would then foul the end slots....

At last I could contemplate a complete run of boxes -

The various openings will have to be modified somewhat - a beautiful image in Vaughans 'GW Architecture' taken from a similar viewpoint shows a shallow curve in the trackbed approaching 'Potley Lane Bridge' (the other end of the visual scene). I am also saved the effort of making a point as (contrary to the sketch plan in Magg's book) there was no access to the quarry in the modelled section (no comments about a 'pointless exercise' please!).

So just for a change I was able to proceed to some 'civil engineering' today -

Having initially started in 6mm 'Depron' I then made the decision to face it with scribed .030' plastikard as I need to be able to inlay some 'engineering brick' into Brunel's original (understated) masterpiece -

So thats the progress thus far this week. Today I intend to finish the main tunnel portal and that of the quarry tunnel, then set out the running lines down toward the bridge. Electrics (now there's no point) should be even easier - particularly as I intend to use 'DCC'.

TTFN

Regs

Ian