First a correction, I said last week that the date of the new boiler house at the dairy was 1976, it should have been 1968. Sorry about that!
Back to Len and his boiler. The problem about cleaning a fire is that while the firebox door is open and allowing cold air into the flue, steam raising is drastically cut back. In addition you are destroying one half of the fire which further worsens the situation. The trick was to do the cleaning at a time when you knew demand was at a low point. Twenty minutes before cleaning Len turned up the stroke on the Weir steam feed pump and made sure he had his water level as high as was safe, this increased the reserve of steam in the boiler itself. When he had achieved this he shut the pump off so no more relatively cold water was being forced in, opened his firebox door and as quickly as possible, turned one side of live coals onto the other side, raked out his clinker, turned live coals onto the clean bars, sprinkled a couple of shovels of coal on and shut the door. He waited until this fresh charge was burning brightly and then repeated the operation on the other side. All this done almost quicker than it takes to tell. The result was that there was very little drop in steam pressure and everything could go back to normal until the next cleaning, steady feed from the Weir pump and light, frequent firing until he had his fire built up again. This was top class work, production was not interrupted and nobody noticed what he had achieved.
However, it wasn't always like this.... Once a week Len had a day off and Jack Brown, the dairy plumber and pipe-fitter ran the boiler. Unfortunately Jack was nowhere near as skilled as Len and this was obvious from the way steam pressure fluctuated during the day. I have seen the dairy stopped waiting for the steam pressure to rise again. One day I popped my head into the boiler house while Jack was on duty and found him staring intently at the pressure gauge which was falling rapidly. As soon as I came in he said “Open the door Stanley and see if the fire is going again.” I should have known better! I trod on the foot pedal, the door opened, there was a dull thud and a flame burst out fifteen feet into the yard! What had happened was that Jack, knowing his limitations, always made sure he had some wood and oily rags handy for fire lighting if he got into trouble. He'd stuffed the firebox full of this and only when I opened the door was there enough air to allow it to kindle. “I thought it might do that!” said Jack and I thanked my lucky stars I had been stood to one side. Everyone who tried to do this job had the same problem and that was why Len was so highly thought of.
John Plummer with a clear bright fire at Bancroft.
