John Connett, Steam Team Volunteer
Cambridge Museum of Technology
The best time to see this boiler is during the New Year Steaming. The cold outside contrasts with the warmth of the boiler room and the glow from the furnaces. Most visitors see the impressive pair of Hathorn Davey steam pumping engines with their bright paintwork and polished brass in their beautifully tiled engine room before visiting the boiler room. It’s a big contrast with simple lime wash brick walls, coke dust and cobwebs. When not in steam, many walk quickly past not realising that this boiler and its three older relatives were the heart of the pumping station. Without them none of the steam equipment would operate.
On a cold winter’s day the boiler is harder to ignore, especially when one of the furnace doors is opened to receive several large shovelfuls of coke releasing a burst of heat and light. When I grew up domestic coke fires were common and coke was a cheap byproduct of the gasworks where they made town gas from coal. The boiler is lit in the same way, starting with paper, then wood, then coke. Many of our younger visitors have no experience with domestic fires. We burn around 1.5 tonnes of coke over a steaming weekend. Five steamings a year, a total of 7.5 tonnes. I think that makes the boiler’s carbon footprint slightly bigger than twice the average for a person in the UK.
Visitors at a steaming weekend only see a fraction of the work needed to demonstrate the operation of this boiler. A lot of volunteer effort is required to cut up wood needed to light the boiler and warm it up. The boiler has 80 water tubes, 37 of which have been replaced after they have developed a leak. Finding which tube is leaking can be a real challenge! We have a team that have become experts in tube replacement. Unfortunately, there is only so much that can be achieved by volunteer effort. The boiler will soon need major work to keep it operating.
The next few years could be very interesting if the boiler is rebuilt.