left - a cross-sectional view thru' a typical weight loaded hydraulic accumulator illustrated within the Kemp's Engineers Year-Book for 1969. [065] The diameter of the ram chosen for the Penarth Dock installation was 22 inches. The area of the ram is therefore approx. 380 square inches and the working pressure is specified as 750 pounds per square inch.

Since the cylinder force generated, excluding losses for friction etc., in pounds is the product of the pressure and the effective area worked upon, it follows that the mass of ballast, the ram and other attached steelwork, necessary to generate this working system pressure would be approx. 130 tons.

The stroke was specified at 26 feet, so the quantity of water held under pressure in the accumulator would be approx. 425 imperial gallons (c.1,944 litres).