QUOTE (Richard Johnson @ 27 Oct 2008, 03:57)
<{POST_SNAPBACK}>*** That kind of specific wear pattern is nothing to do with lubrication or weathering powder at all...
I should have mentioned that there are three screws with almost identical wear; both back wheels and the centre left, which is the one that I photographed. Why not the centre right is a puzzle; perhaps something to do with the lubricator crank that makes for a different arrangement on the left side. Presumably a quartering error should be near impossible.
The engine has always run very well with no sign of binding or waddle, so if it wasn't for the oddity of the centre wheel that didn't wear, the wear pattern would be symmetrical and as expected. The one-sided wear of the screws is of course normal, because if the engine goes mostly in one direction it is always the same side of the crank under stress. There was a trace of oil on the con rods so I don't suspect lubrication failure.
The Q1 regularly pulls trains that lesser 0-6-0's won't, so this is perhaps just normal wear of a hard-working engine, possibly exacerbated by the weathering. In any case, I am going to keep an eye on it and get another spare set of rods.
David
