While I am still pondering on the best way to set about finishing the ballasting, as a diversion it occurred to me that I should protect the last unprotected side of the layout, where the track hovers over a precipice and, fortunately, in nine years only one locomotive has fallen to the floor.

For a time, I had a programming track fixed along the edge but I decided to remove this and set up a portable programming track so I could work on the dining room or kitchen table when it was cold in the garage. A first idea was to acquire a strip of plywood or hardboard and nail it on to the edge of the baseboard, then I thought it was more scenic to build a brick wall and fix it all along the curve. So, I set about making a wall from a cardboard shoe box, using two thicknesses and overlapping 24 cm long strips half by half to make one 140-odd cm strip as per the photograph.

I then prepared a brick pattern downloaded some time ago on glossy photographic paper but it didn't look right, so I acquired some matte paper. Although the pattern was to scale, the bricks looked too small against other brick papers I had bought locally in the past, so I increased the size by 70% with Photoshop. However, when I printed it out I made the mistake of using Windows Live Photographic Gallery and the bricks came out even larger, about twice the scale size. When I realized, this I had already printed the three sheets I needed, so I let it be. Here is a photo of the brick paper.

I then covered the whole strip on both sides with this paper and added columns every 12 cms using Metcalfe paving slabs.
I started attaching this wall to the edge of the track when I had done about half, I felt I should have tested first to see whether the rolling stock could pass freely. Out came my Lima HO scale wagon lits coach and it did pass, but at a distance leaving room for only a fag paper. I tried with a DMU, a steam loco and a passenger coach, all OO scale. They also passed but I felt that the space represented only 2 or 3 scale inches and that more space was need to make it more realistic, so I unglued half of what was already done and widened the space and it now represents slightly more than one scale foot.
I then finished off fixing the wall in place, installed the capping using the Metcalfe material and filled in the gap caused between the base of the wall and the edge of the track board by widening the curve. And here is the final result.