Elevated Tank in Belfast

Abstract

An outstanding feature of the buildings which constitute the modern Ulster Hospital, at Dundonald, Belfast, is the elevated tank which supplies the hospital with water. The shape of this tank is pleasant and it provides a charming and smooth outline against the sky: it is reminiscent of a large sized drinking cup. The structure, made of reinforced concrete, is of straighforward design. The central support is used as the chimney stack for the boiler room. The water tank has an overall height of 32.5 m and will hold 450 cubic metres of water. The tank itself is 15.5 m high and has a maximum diameter of 10 m. The walls vary in thickness between 0.32 and 0.15 m. The hoop reinforcement is provided by 19 mm bars, whilst the radial reinforcement consists of 9 mm wires. The central column, or stack, has a wall thickness of 0.15 m, and is of circular cross section. Vertical 35 mm rods provide the metal reinforcement. Externally, this central column has eight ribs, 20 cm wide and 30 cm deep. The whole structure rests on an octogonal slab, with a maximum horizontal dimension of 9 m and is 2 m thick. The maximum tensile strength allowed for the concrete, when working in the most unsatisfactory conditions, is 12 kg/cm².