August 2021

As in the previous month, August witnessed an all-out assault by our Engineers to complete the Boiler Re-tube project. Following the preliminary hydraulic test when the applied pressure of 230 psi revealed a number of small, and totally expected weeps, further expansion of the offending tubes was carried out. Also some further attention to the boiler top door ensured that on 19 August hydraulic pressure reached the ‘magic’ figure of 270 psi. Four days later this was witnessed by the Boiler Inspector, and passed. This enabled attention to be switched to the myriad of pipes, valves and gauges that now require refitting for the all-important live steam test. The most important of these fittings are the safety valves that ensure the maximum working pressure of 180 psi is not exceeded. The background to the origin of these valves is interesting. When we acquired the vessel in 1971, the boiler was fitted with a pair of sprung valves. As these did not appear to be marked, it was assumed that these came off the original 1913 boiler, and refitted to the 1935 Admiralty boiler installed in 1936. Whilst these initially performed perfectly adequately, lifting as set at 180 psi, by the mid 1980’s they were beginning to ‘fizz’ a bit early and would leak a little when shut. As luck would have it, the steam machinery in the Wallasey Dock Pumping House, was being removed, and this included a large pair of high-lift ‘Pop’ valves, which we acquired for scrap price. These were professionally overhauled, re-set to 180 psi, and fitted to Kerne’s boiler. Pop valves derive their name from their mode of operation; when the design pressure is reached, the valves lift with a tremendous roar, sending a large column of steam into the air thus quickly lowering the boiler pressure, and when this has dropped they suddenly shut with an audible ‘pop’ and silence is restored. Work has also continued on the smoke box bottoms, plating and welding is underway to replace the sections of cut-away bunkers but it is all hands to the pumps as we push ahead with our goal to be at the Leigh Arms Steam Gathering on the first week of October. Keep an eye on our Facebook page for updates.