Other work has meant that progress has been slow on Queen Anne. The engine is running better (of which more later), but most work has concentrated on the cab.
The New Cab
The edges of the "doorways" into the cab are reinforced by what is known as "Half-round Feather Edging" which is riveted to the side platework. Because the edges are curved in places, the feather edging has to be bent to the same shape as the platework. To do this a jig was made from a 10mm flat metal plate and circular discs which had been turned to the radii of the curves on the cab sides. The discs were held in place by 10mm bolts and other 10mm bolts were used to hold the feather edging in place and guide the bending process.
By carefully heating the feather edge to orange heat using an oxy-propane torch, the feather edging was bent to the required profile. Care has to be taken in heating the metal. Too much heat and the edging will kink to a radius that is too small. Too little heat and the edging will not follow the circular arc. The heating and bending has to be done carefully and slowly. Some hammering is required to keep the edging flat.
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Feather Edge - Making the first bend |
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Feather Edge - Making the second bend |
The finished edging was offered up to the cab platework
and found to be a close match requiring very little fettling. A special
jig was made to help drill 6mm holes in the centre of the edging and
each piece (there are 8 in all) was drilled to take the rivets. The
edging was clamped to the platework and matching holes drilled through.
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All 8 shaped Feather Edge strips |
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Feather Edge being fixed to the cab side |
The edging on the upper sections of the cab has to be merged with the edging around the roof, so these panels had their edging bolted on as we are not yet ready to work on the roof. The edging for the lower panels was cold riveted in place using custom-made 6mm countersunk rivets. Before riveting, a thick layer of red oxide paint was applied to both surfaces, and some oil-based mastic was applied around the curved parts where the edging is not absolutely flat. The paint and mastic are used as an interfay compound to fill up any imperfections and prevent corrosion setting in between the two pieces of metal. The edging is riveted while the interfay compound is still soft.
Engine Progress
The engine is now running better without the grey smoke caused by unburnt diesel. One of the original injectors was not really serviceable and suffered from severe back leakage. Fortunately a local injection specialist happened to have a reconditioned VRH injector in stock that still worked, which has now replaced the bad injector.
Paint Colours
Someone (I believe he was working on an 88DS shunter) sent in a question about the proposed "Ruston Green" colour, but unfortunately it was accidentally deleted. The sender queried the original blog post that suggested using Lincoln Green (BS381C 276). The acknowledged expert on all things Ruston, Ray Hooley, states that Ruston Hornsby used Deep Bronze Green (BS381C 224) and we have one of his paint samples. Deep Bronze Green is very dark, and seems much darker than the green paint that has been exposed by rubbing down. Further tests on the old paintwork will be carried out, and comparisons made with a batch of shade 224 paint. The actual shade that will finally be used is subject to further study.