October 2006 Progress report
article by: John McMillan
Lots of work has been going on with the tender, and much
progress has been made over the summer with making parts for the
brake-gear. We had assembled hangers and brake block holders
recovered from scrap Bulleid electric stock, but a trial fit
revealed that the alignment wasn't quite compatible with the Class
40 diesel's wheels we had used. Not that we were far out, only a
quarter of an inch or so, but it was sufficient for us to have to
look for more suitable brake block holders and blocks.
The search brought good and bad news. The good news was that we
found a supplier of suitable brake blocks; these blocks are still
used by vehicles on the national network. The bad news was a
minimum order quantity of 100 blocks! We need twelve blocks
initially, and even after retaining a good supply of spares we will
still have sufficient to sell on several sets to other Merchant
Navy loco owners whose tender brakes will require the same
blocks.
We have made up the twelve tensioners which are spring-loaded
devices that adjust the angle of the brake block to the wheel and
avoid uneven wear at the top or bottom. Periodically the brake
blocks need visual inspection, and the tensioners are adjusted to
even out the wear. A start has been made on fitting the brake
hanger arms to the tender, and nine of the twelve are in
position.
Meanwhile on the locomotive we have finished making the lagging
for the left-hand cylinder. The cylinder casing has been fully
de-rusted and painted, and with the lagging fitted the covers
should be going on now for the last time. We have also made a start
on final dressing of the mating surfaces for all the fittings which
attach to the cylinders. Unfortunately some of these weren't
finished as thoroughly as we had thought earlier in the
restoration. Currently receiving attention are the faces for the
cylinder relief valves. These spring-loaded valves are intended to
provide a last-ditch attempt to clear water from the cylinder if
the driver has forgotten to open the drain cocks. There are two
relief valves, one Snifting valve, two atomised oil feeds and two
drain cocks per cylinder, all with mating surfaces to get perfectly
smooth and flat. That makes twenty one faces over the three
cylinders, but at least we've made a start.
On the boiler the long, highly-skilled job of getting the water
gauge faces perfectly flat and parallel to one another has been
completed, and we are now working on the gauge pedestals to achieve
a perfect steam-tight fit. Similar work has been started on the
face of the Regulator Stuffing Box, located between the two water
gauges, that carries the regulator actuating rod through the back
of the boiler.
After a gap of some months, work has re-commenced in earnest
on the boiler cladding. The boiler bands, along with their
tensioners, have been made up. These allow the cladding to be drawn
down tightly, and to cover the gaps between the cladding sheets.
The tensioners are located on the underside of the boiler, where
they are out of sight and difficult to reach.
With some ingenuity our contractor has made up the decorative
ring that fits over the cladding where it adjoins the smoke box.
The ring holds the lagging in place and gives a neat finish to an
otherwise awkward join.
In the Machine Shop work has continued with making the vacuum
reservoir tanks for the tender, the caps for the oil pots on the
three connecting rods have been made and trial-fitted, and two of
the large 3" diameter nuts have been machined for the vacuum brake
ejector.
Finally, the blazing summer weather showed up one of the
disadvantages of the enclosed weather-protected cab on the Merchant
Navy locomotives. Our visitor 35005, "Canadian Pacific", was
getting through a different fireman per 20-mile trip at one stage,
as dehydration took its toll on the gallant crews feeding the 50
sq.ft. fire grate. What price some air-conditioning?