The pumping station has four horizontal tandem compound-type steam engines. In this type of engine the steam from one cylinder – a high-pressure cylinder – is sent to a second, low-pressure cylinder on the same piston rod. The four steam engines (which still operate today) are fitted with large flywheels and horizontal cylinders and piston rods. They run on superheated steam of 3100 C , at an overpressure of 10 atmosphere.

The engines operate in parallel in opposite directions. Up until 1955 the required steam was provided by six coal-fired boilers. The boilers formed, two by two, a ‘combined system’ with ‘flame pipe boilers’ above and Lancashire boilers below. In 1955 these combined boilers were replaced by four boilers built by Werkspoor, which were converted in 1967 into oil-burning boilers. Each steam engine drives two centrifugal pumps. These ‘Jaffa pumps’ (named after the manufacturer) are constructed of flat and curved sheet-iron segments. They are positioned in line with the four flywheels, thus emanating enormous power. Together they are able to pump and discharge 4,000 m3 (4,000,000 litres) of water per minute.