35006 Progress Report, December 2004
by John McMillan, 15th December 2004

We have concentrated on just a few projects over the past three months or so, but have seen a lot of effort and considerable progress achieved on each.

The most obvious progress has been made on the fire-box cladding. Of all the “big shiny bits” on the locomotive, these are certainly among the largest, and the whole of the fire-box has been clad in sheet steel. Combined with the almost-finished cab, the back end of the loco is really beginning to look complete, and is a definite indication to the world that we mean to see this long-running restoration project through to a successful conclusion.

Getting to this point, however, has involved a good deal of painstaking work. On the driver’s side, some final adjustment had to be made to the steel crinoline strips that support the cladding, and an old vacuum exhaust pipe (the original, retained as a pattern for a new one), plus the reverser shaft were temporarily fitted in place to check the alignment. Once we were happy, the cladding sheets could be fitted.

The sheets on the fireman’s side are of fairly straightforward design, but those on the driver’s side are far more complex, having tapering indents to accommodate the vacuum exhaust pipe and the reverser shaft. Both the sides and the crown sheets also required holes to be cut for access to the boiler wash-out plugs.Ensuring that the sheets were being cut in the right places to locate the plugs behind them, required the development of a special technique which has worked well (so far!).

The next interesting piece will be the tapering cover for the manifold main steam pipe, which runs along the centre line of the fire-box crown. After that it gets even more interesting; the pieces covering the fire box throat, where it joins the boiler barrel, can best be described as fiendish, and the barrel is clad with a series of sheets, each twenty one feet long! Fortunately, our sheet metal worker has done similar work on Bulleid Pacifics before, so he is aware of the problems, and in addition, we have received welcome co-operation from the Group overhauling 35028, “Clan Line”. They are replacing much of the time-expired B.R. cladding on their loco, and we have visited them for advice and to see examples of the parts we are trying to make.

Elsewhere on the locomotive, final adjustments have been made to the injector control rods, and the universal joints have been permanently pinned in place. End-stops on the travel of the control wheels have been set to restrict the opening of the steam and water valves to prescribed settings. The troublesome water valve, which was very stiff, has been reworked but is still too stiff for our liking, and will require revisiting in the future, to try and free up the movement a little.

We have been able to complete various machining jobs at Toddington this quarter, thanks to the large number of machine tools available. These belong to various other restoration groups as well as ourselves, but the good level of co-operation among the groups gives access to a wide range of tools that would otherwise be beyond the resources of any individual group. The well-equipped workshop benefits everybody in saving a great deal of money through having to have parts machined commercially, and enabling quality control to be maintained ‘in-house’.

Parts receiving machine shop attention have included the pair of clack valves. These non-return valves supply cold water to the boiler from the injectors, and will require steam-tight mating faces where they attach to the boiler. Machining these involved the making of a “female” nut, which in turn required the making of a “male” spanner. Well, it would, wouldn’t it?

Another major item now completed is the main steam manifold shut-off valve, whose hand-wheel is located on the front of the firebox on the left hand side of a Bulleid Pacific. The valve supplies steam to all the auxiliary system controls in the cab, and is an important safety feature of the locomotive. If a serious steam leak develops in the cab, possibly causing the crew to evacuate, the steam supply can be shut off safely from outside. Our valve is original, and required a full overhaul. Machining is complete, but the faces still need to be scraped flat to achieve steam-tight joints. As the complete assembly weighs about three hundredweight (160kg), lifting it up and down between trial-fits is going to be a lot of fun!