July 2006 Progress report
article by: John McMillan

Brake hangers and brake shoe holders (Pete Mason)

Inside cylinder cover (Pete Mason)
With the improved weather we have turned our attention to the
outstanding work required to complete the tender. The major task
still remaining is the manufacture of the brake gear. We reported
last time that we had taken delivery of the castings for the brake
hanger arms, and much of our machinist's time has been spent
working on them. There are three pivot points per arm, each of
which requires a steel bush to be made and pressed into place. Case
hardened steel pins will be inserted through these bushes so that,
when in use, the bushes will wear faster than the pins. Eventually,
the bushes will require replacement and can be pressed out, and a
new set made. This task might be needed after about 200,000 miles,
so we're not anticipating any trouble in this area for a very long
time. A set of brake block tensioners is being made; these hold the
brake block so that it doesn't droop and rub against the lower part
of the wheel, wearing the block on the lower edge.
We have a complete set of brake shoe holders in store that were
acquired years ago from a scrap Southern EMU, and we're currently
in the process of trying them for fit to see if they will be
suitable. We won't know for sure until we have assembled the
completed hangers on the tender chassis and checked the alignment
of the brake blocks with the wheels. However, an initial
investigation suggests we may have to have some different brake
shoe holders cast. Our tender has a set of wheels originally fitted
to a "Peak" Class diesel, and one of these locos is being restored
in Toddington yard . So far we've resisted the temptation to make a
night time visit with tools to its brake block assembly!
Meanwhile, on the locomotive we are taking the opportunity
whilst the boiler is raised, to complete as many as possible of the
jobs we thought would have to wait until the boiler lift for the
steam test. The main activity over the quarter has been
needle-gunning and painting the inside cylinder block, smoke box
saddle, and the chamber between the frames immediately in front of
the inside cylinder. The front dragbox and frame plates have
received the same attention, repeating some restoration work
undertaken many years ago, which has since deteriorated. We are
using the anticorrosive galvanising paint in all areas that will be
inaccessible once the loco is in one piece.
This has been covered with conventional undercoat and topcoat of
"signal red" between the frames. This area is now so shiny that our
painting volunteer thought he'd left a light on between the
frames!
Having this area so well restored will make the job of fitting
the Snifting valves easier. These valves are fitted to the inside
face of the outside cylinders, and prevent vacuum being created in
the main steam pipe when the regulator is closed and the engine is
still moving. The vacuum would otherwise suck smoke box ash back
down the exhaust pipes, which wouldn't do much for the lubrication.
When the regulator is closed, the Snifting valves drop open and
allow air to enter the cylinders instead of steam.
Unfortunately we haven't been able to progress with the boiler
cladding this quarter as our contractor has been called away on
other commitments, but we're hoping to see him return soon.
On the boiler back-head we have started work on the faces of the
various fittings. The faces need to be perfectly flat to achieve a
steam-tight joint, and we are following original Eastleigh practice
by not fitting gaskets to boiler fittings for good safety reasons.
Gaskets are permitted, but if one blows there is no way to control
the leak. Bulleid locomotives never had gaskets originally and
we're doing our best to emulate that practice. The first faces to
be tackled were the water gauges. The faces were heavily pitted, so
the first task was to clean up what was left and build up the
surface to its original thickness with weld. Then followed the
tedious job of grinding and hand dressing the faces to achieve the
required perfectly flat surfaces. One set has been done, and the
second set is well on the way to completion.
On top of the firebox, there is a fifteen-foot length of
four-inch diameter pipe, which connects the steam shut-off valve to
the steam manifold in the cab. The original pipe is badly corroded
and heavily damaged, but it has been useful to us as a pattern for
the cladding covers fitted on top of the firebox. We are trying to
have a new pipe made in a single length to avoid corrosion problems
from pipe joints, and research has been undertaken to identify the
correct specification. A couple of promising suppliers have been
identified and we have begun assessing these for their willingness
and ability to make the pipe.
Finally, to make room in the yard for Toddington MPD during the
spectacular Steam Gala in late May, the tender was 'tripped' over
Stanway Viaduct, the first steam loco tender to pass over in more
than 30 years. Let us hope that its next run over the viaduct finds
it travelling to Broadway attached to the locomotive!