Mesh Fence Minutiae

Mesh fence on the Hayes to West Wickham railway path. March 2011.

This is the same mesh fence I wrote about here.

I walk along this path quite often and I wonder about this fence. Why is every other row fading to silver? The rows are apparently identical otherwise.

Well, first, the wires are not fading. Looking more closely shows that the strands are painted, and the paint is coming off in places. Then you can see that the fence is constructed of vertical strands which are woven together and fixed at the top and bottom by simple crimped loops.

The alternate rows you can see in the first photo are from alternate vertical strands. So the paint seems to have come off differentially on every alternate vertical strand.

How has this come about? It's not that the fence is being rubbed by passers-by, because the parts set back have lost at least as much paint as those at the front. Is it that during assembly, alternate vertical strands came from different rolls of wire, which were either rubbed differently or were made differently?

Detail of mesh fence showing paint coming off the strands

Perhaps the paint starts to flake off as the strands expand and contract when heated by the sun and then cooled in the shade. I don't see the same effect on lengths of the fence that are always out of the sun. This would still require alternate strands to react differently to the same effect.

This still seems odd to me.

There is another thing about this fence. I didn't see the process of erection, and it looks continuous. It's too long to have arrived in one piece, so how was this seamlessness achieved? Suppose it came in rolls. The strands at the ends of each length must have been woven together by the installers, and if so, then there would be some of the connecting loops which look hand done. And indeed, there they are.

I feel quite pleased with myself, having worked out a hypothesis and found confirming evidence; even though this must be already quite obvious to some, and completely trivial to others. At least I am not totally clueless about the fence.

Detail of the top of the mesh fence, showing one hand-crimped junction and three machine-crimped junctions