The purpose of the project is to allow the flood defense barrier to be fully lowered under emergency conditions allowing passage of vessels up and down the river Orwell.
The available space for the installation of the Ipswich flood defense barrier was severely restricted at one side this made it necessary to position the large hydraulic cylinders that lift and lower the barrier vertically, rather than horizontally. In doing so it meant that the ‘Full-Bore’ operating end of each cylinder would be more than 10m above the height of the hydraulic reservoir.
During emergency lowering of the barrier under gravity, the atmospheric pressure in the reservoir would have been insufficient to overcome the ‘Head’ pressure in the full-bore end of the cylinder preventing fluid from being drawn out of the reservoir to fill the full-bore void. This would lead to the hydraulic cylinder suffering cavitation damage and eventual premature failure.
A unique hydraulic circuit was developed and tested, which used the potential-energy of the raised barrier to power a pumping system that is then used to pump hydraulic fluid from the reservoir into the full-bore end of each hydraulic cylinder, therefore maintaining a positive pressure in the cylinder at all times.
As a result of the design and development work carried out, we were able to successfully deploy the potential-energy pump to overcome the problem.