21 Wolseley Parade 
Kensington, Vic 3031
21-10-96
Brian Hampson
Esperance Power Station
Esperance, WA

Dear Brian,
		Thanks for the informative fax a few weeks ago. In the end
I decided to stick with a conventional brake pad material. Fibrous, woven
stuff with strands of bronze in it. The cagey brake expert would neither
confirm or deny the presence of asbestos, so it almost certainly has it!
Are you using the sintered metal pads and what are the performance stats?
We are getting stopping times of 5-6 seconds from high speed with the new
pads, and we did take the shine off the disc with an oilstone, on the
recommendation of the local brake expert. Any quicker than this and we will
be shearing teeth in the gearbox, or snapping a blade root. By the way our
caliper is a Westwind, not a Voith.

I am primarily writing to let you know that we have developed a successful
technique to remove all 3 blade tips (air brakes) from one machine
simultaneously without the use of a cherry picker. Our method required 4
persons for 4 hours (approx.), but time will reduce with practice. If you
would like to know the details, I am more than happy to share them with you.
Maybe you have already worked out a method, with the lifting cradle? We are
using a cargo net, but it is fiddly.

We found the air brakes in poor condition. One spring badly rusted (the bung
was the only one with no drain hole drilled in it). Missing washers. Two
air brakes had missing spacers! (the spacers go between the shaft and the
spring, and are vital in getting the right compression on the spring.) The
only spacer we found was buckled from over-tensioning of the nut (probably
by our volunteers). The air brake which would not reset had a badly chewed
guide pin, a missing bushing, and the one bushing present looked like a bit
of mild steel water pipe which had been hastily hacksawed and pressed into
service! That bushing had obviously been deformed by the extreme force of
the air brake deploying.  It also looks like one of the mounting shafts has
a slight bend in the thin outer (threaded) section.

Luckily one of our volunteers is a fitter & turner, and is making a new
guide pin/bushings set. I have been busy with the angle grinder and  epoxy
resin today, repairing extensive cracking in one air brake. (it looked like
a previous repairer had used auto body filler on a section subject to
considerable mechanical loading). We are using an epoxy paste Ciba-Geigy K330
on the advice of Ciba-Geigy Polymers (Melbourne Office). It is quite buttery,
and will not flow out of even large cracks. Quite tricky to mix thoroughly,
though.

I hope some of the above information will be of use to you. Please let us
know of any relevant tips and tricks from your end, especially in relation to
the air brakes.