October 2004 Progress report
article by: John McMillan
For a lot of the time this quarter we have been working on parts
that won't be seen once they're fitted to the locomotive. This is a
little frustrating, but we have consistently applied the same
standards of quality to the 'unseen' parts as we have to the 'big
shiny bits'.
The latest large project to be undertaken in the machine shop is
completing the manufacture of the water sump for the tender. The
shut-off valve had been finished in the last 'Progress' report, and
now it was the turn of the main sump casting. This is one of the
largest castings we have had to machine, and it was fortunate that
we had the versatile Huron milling machine available for us to
undertake the work. The two water outlet pipe faces for the tender
tank and trap door have all been machined, but this revealed a
problem. Although the casting looked very good on the surface, a
large blow-hole in the casting was revealed during the machining
process. However, as the casting is steel (rather than the original
cast iron), our friends in the 8F Group were able to weld up the
hole for us, a gesture much appreciated. We now have some work to
do on the seat for the shut-off valve to ensure a watertight fit
when the valve is closed.
On the locomotive itself, the major work this quarter has
centred on the cladding being fitted to and around the cylinders.
Unfortunately, this has involved the removal of some sections of
running board and pipe-work to gain access to the cylinders, and
this gives an impression (only temporary) of backwards progress!
All three of the steam pipe covers have been completed, together
with the Snifting valve cover. We are pleased with the finish on
these large parts, although on the finished loco the smoke
deflectors will cover up most of the work, leaving only a small
part visible to the outside world.
The purpose of the cylinder cladding isn't to make them look
smart (although it does that), but to hold the cylinder lagging in
place. Without the lagging there would be considerable cooling of
the cylinders, especially at speed. Making up the cladding is a job
that has started and stopped many times during the restoration, but
at last it has been completed! This is no small achievement as
there are 26 separate pieces to be made up for the outside
cylinders.
Elsewhere we have been able to salvage a large part of the
original steam dome cover that sits on top of the boiler, and with
the addition of some new metal plus a reasonable amount of filler
paste the final painted result has proved acceptable, and much
cheaper than having a replacement dome made up. It just needs the
rim drilling to match the securing holes on our new boiler
crinoline rings.
A start has been made on the firebox cladding with the rolling
to shape of the two top sheets that meet on the centre line of the
firebox. These sheets are of substantial thickness, as in service
they will occasionally have to take the weight of a beefy loco
fitter without distorting! The sheets will also have to be provided
with holes so that fitters can gain access to the washout plugs on
the firebox sides.
Finally, away from the cladding, the injector cones have been
fettled up and the upper cones fitted to the injectors. We can now
complete the two rods that connect the steam valves on the
injectors to the cab control wheels, and investigate why one water
control wheel works smoothly whilst the other one is very stiff. In
B.R. days, firemen were known to use metal bars to gain extra
leverage on the injector valve wheels, but we want to make sure
that as far as 35006 is concerned, that is one tradition that can
definitely die out!