August 2011 Progress report
article by: John McMillan
We've spent a lot of effort this
quarter tidying up more of the loose ends, finishing off tasks that
for one reason or another were never quite finished. Perhaps
we didn't have the right length of bolt to hand, or a part needed
more work to finish it. So it's been a period of
'consolidation', which means an awful lot of work has been done
without much to show for it, but it's better to be doing this work
now at our leisure, rather than desperately trying to fit all the
tasks in with the loco needed in service, and thus risking a
failure.
However, those who want to see 'big
shiny bits' need look no further than the boiler which now has all
its insulation fitted (including behind the back head, which
footplate crews should appreciate!), and most of the cladding
fitted as well. The cladding sheets for the fire box were
painted up to top coat and fitted first. Although all the
sheets had previously been fitted on the loco, those on top of the
fire box now had to fit round the Combine Pipe where the clearances
were very small indeed.
We'd received many comments that the
sheets would never go back in exactly the same places, but with
time, patience and judicious use of luggage straps with tensioners,
everything could be made to fit properly.
The Regulator Stuffing Box has now been
fitted. This is the box that fits at the top of the back head and
contains the mechanism to operate the regulator control rod where
it passes into the boiler. The control mechanism was
assembled, including the driver's regulator handle, and aligned so
there was no binding of the shaft where it feeds through the
bearings on the boiler back head. Where the shaft passes into
the stuffing box, packing was fitted to make the shaft steam
tight. None of the mechanism inside the boiler can be
lubricated, and at present operation of the regulator is as stiff
as you might expect. A combination of heat from the boiler
and regular use will ease the mechanism in time, and meanwhile
people have been trying their hand at opening and closing the
regulator.
The Combine Pipe connects between the
steam manifold in the cab and a control valve on the fire box
shoulder, allowing steam to be cut off externally in the event of a
serious steam leak on the footplate. The pipe is a complex
shape and was fabricated by Chatham Steam in one piece. It carries
steam at full boiler pressure and has been hydraulically tested to
prove the pipe and its flanges are up to the job. The pipe
was tested up to 400lbs.p.s.i. to give a considerable margin over
normal working pressure, and it passed with flying colours, which
was what we expected. Some scaffolding and a chain hoist were
used to lift this heavy piece into place on top of the fire box,
and the steam manifold, a very heavy casting, was fitted up by the
same means.
When we came to reassemble the fire
hole doors on their frame, it was noticed that one of the doors
didn't fit very well. Closer examination revealed that one of
the pivot pins was badly bent. This has been machined back
true, and a collar made to bring the pin back to correct
size. The door then fitted very well in the new frame.
The rear of the frame has been adjusted to get a better fit to the
boiler, and the whole assembly has now been lifted up and bolted in
position on the back head.
The very skilled and time consuming job of preparing all eight
faces on the Injectors has been completed, with all the faces
dressed and blued up to get them perfectly flat. The water
feed pipes have been similarly treated. The Injectors were
assembled as a pair on the ground, then hoisted into position on
the loco for, hopefully, the last time.
Work has continued on the outstanding copper pipework around the
cylinders. The last of the lubrication pipes have been completed
and good progress made on assembling the drainage pipes.
These pipes drain condensate off the steam supply pipes to such
equipment as the lubricators, vacuum exhaust pipe, and drain cock
actuators. The drain valves are held shut by steam pressure
when the pipe is in use, then open when the pressure drops.
These pipes can often be seen dribbling when a loco is left
standing for any length of time.
Although the boiler hasn't been used, we've recently had our
first annual boiler inspection carried out. Before the
Inspector arrived, we decided to give the boiler a washout, just in
case, and were amazed at the amount of muck and scale that came
out. We can only assume it was dislodged by the steam test at
Detling.
The inspection was passed satisfactorily, which is what we
expected, but it is good to know that the Inspector is happy with
the way we are looking after the boiler before use. His next
visit should be to start the 'ten-year ticket' and there's plenty
of work to do in the meantime!
Finally, it hasn't all been good news and forward progress; as
you may have seen in the railway press Toddington was the target of
metal thieves on July 18/19th, and we were among the
victims. By far the most serious loss was the brake ejector,
a very complicated casting which will take a lot of work to
replace, and set us back in completing the project unless we can
borrow an identical piece pending the casting and machining of a
replacement. We've had the generous offer of a brake ejector
from the Mid-Hants Railway, but unfortunately it wasn't compatible
with our model so the search goes on.