![Half Term Hydraulic Pump Demonstrations](https://underfallyard.co.uk/wp-content/uploads/2016/09/PumpDetail800x800-300x300.jpg)
Saturday 22 October to Sunday 30 October – join us throughout half term to see the 1907 hydraulic pumps in action.
The three electric hydraulic pumps were installed in 1907. The pumps pressurise water to 750psi (52 bar) and powered an entire network through underground pipes running around the harbour to lock gates, swing bridges, cranes, capstans and more. Over the years many parts of the network ceased to operate – cranes were dismantled, bridges stopped swinging – and by 2010 the Power House was only operating Cumberland Basin lock gates and providing back-up for Prince Street Bridge (which has always had its own pump and accumulator).
The pumps were decommissioned in 2010 and are no longer connected to the network of pipes. Our new Workshop Manager, Rachel, has been working out how to run the pumps for demonstration purposes now that the pressurised water isn’t being used. On a few occasions we used the pressure relief valves on the pumps. This was problematic on two counts: it is an emergency feature so forcing the valve too frequently risks causing damage and it dumps all the water into the Pump Room basement! The other option was to do nothing but this would mean waiting hours, if not days, for the pressurise to gradually reduce through small leaks in the system. But, with the support of Bristol City Council’s Docks Engineer’s team, Rachel has identified our current solution: we are currently using a hose to return the dock water to the harbour, and de-pressurise the pumps.
Supported by the AIM Biffa Award National Heritage Landmark Partnership Scheme.