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The Boiler Overhaul The boiler overhaul workscope took a lot longer to finalise than was originally anticipated. Several boilermakers were approached and asked to tender for the overhaul work. Although there was general agreement that replacement of the boiler barrel was required there were a number of different proposals that had to be evaluated. The final decision taken was to accept a quotation for a workscope that included the manufacture of a welded steel barrel of 4' 91/4" diameter (as per the original) with a welded steel tubeplate. The new barrel will be riveted to the existing firebox. The boiler tube arrangement will be unchanged from the original although it is possible that the lowest row of tubes will be blanked off to eliminate problems with poor water circulation in the lower levels of the water space. Work on the firebox will include renewal of corroded steel rivets in the lap seams of the copper inner firebox. Since we are not removing the inner firebox during this overhaul the corroded rivets will be renewed using screw rivets. The copper platework appears to be in good condition and it is felt that screw rivets will provide a successful method of repair for the next ten years of service. On completion of the overhaul the boiler will be fully tested (hydraulically and under steam) before being returned to Aviemore for assembly onto the locomotive. The timescale originally agreed for the overhaul in 2005 was 6 - 12 months. The boiler overhaul has taken far longer than anyone estimated when the work was awarded to the Bury company of Ian Riley and Sons. There have also been substantial increases in workscope and also in price inflation - particularly affecting copper and steel. The result is that it is only in January 2009 that we can see a final completion date for the overhaul. We hope that the boiler will be hydraulically tested during January 2009 with a steam test following as quickly as possible. Assuming that all is well the boiler will be returned to Aviemore for initial testing out of the frames. This will ensure that any remedial work required to tighten seams or rivets can be done with everything fully accessible. The attached photographs (courtesy Mr WP McCarthy, Kingussie) show the progress of the boiler through Mr Riley's works from late 2005 - 2008.
Firebox detached from Barrel This shows the firebox section of the boiler following separation from the life-expired barrel. The firebox throtplate can be clearly seen. Protruding from the upper part of the firebox are the remains of several longitudinal stays which had to be cut. The palmstays which attached the throatplate to the boiler barrel are lying in the lower part of the firebox. We had hoped to use them again but on close inspection they were beyond recvery and had to be renewed completely.
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.JPG "Dome reinforcing ring cracks.")
