A big push to get the engine progressed, as well as a shortage of available navvies has meant that track laying has been somewhat delayed. Autumn seems to have crept up on us, prompting some slightly panicky action at last.
One major hurdle, and yet another cause for the pause, has been the problematic prospect of bending flat bottomed rail. All the usual issues I'm afraid, including lack of adequate funding, appropriate materials and especially specialist tools !!
I have maintained a rather forlorn belief that it must surely be possible to rig something up - that particularly
doesn't involve making three, very accurately turned, rail profiled rollers! This afternoon, I finally reached a point of utter desperation, where all the peculiar ideas and doubts that had been rumbling around in my head, had to be consciously consigned to the sin bin, and then go down to the workbench and commit myself to just one!!
In amongst the collection was a handy old cross-vice, with jaws that bolted on from the outside, which could be useful.
My thinking was along the lines of making a more aluminium friendly press, using the principals of a traditional "Jim crow", but with hopefully less tendency to produce "thrupenny bit" curves ?!
First, out with yet more of those fabulous Oak offcuts...
I planed two short pieces, one concave and the other convex to match. The curve was cautiously marked out and cut to be notably - but not too much - more than any radius that we might require. The idea was (again hopefully) to allow sufficient room for "spring-back", but not so as to cause a possible crimping effect ?
The two pieces did come snugly together before the next step was undertaken. A flat file slid between the partially closed jaws soon sorted out some awkward high spots !
Next, I cut some narrow strips of firm, but flexible 1.5mm Birch ply to laminate up into two, negative rail profiles...
The wider strips stand out from the base (which itself should grip the foot) by the difference between the rail head and foot, while the second layer on top is the same depth and width of the central web section. Contact over the entire profile would be maintained when pressure is applied.
Would it work...??
With heart very much in mouth - that rail is jolly precious stuff for us - it was time to put the theory to test...
It is difficult to see in the photograph, but it was indeed, slowly, steadily, starting to come round...
No nasty dinks or kinks apparent so far... and to my utter amazement, the foot was staying nice and flat, along the full length too !
In my excitement, I completely forgot to switch off Mr. O's "pondcam", so he will see me later, skedaddling down to the end of the line in order to try the successfully sinuous rail in situ...
I was concerned not to overdo the experimental exercise down in the remote workshop rather than on location, but I need not have worried:
Just a few more passes will be required, mainly at the furthest end, as I had allowed for a degree of transition in the curve when setting out the formation.
Pete.