The WOT has three different water rams on site. The oldest water ram, the ‘Billabong’ from Australia, has become a ‘collector’s item’ because the manufacturer no longer produces this type. It is recognizable by the blue colour and convex shape. The Billabong is made out of cast iron and is very solid. The costs of comparable ready-made water rams vary from €1000,- to €2000,-.
A number of tests with the Billabong were carried out at the WOT. To perform the test, a galvanized pipe was fixed to the Billabong and linked to a ferro-cement tank on the WOT site. From the Billabong, the water can be pumped 12 meters up to the top of the pump test rig. The water that is not pumped upwards flows into the reservoir at the bottom of the pump test rig.
The billabong uses the energy from the flowing column of water inside the tube coming from the ferro-cement tank to push the water up to the top of the test rig when a flap closes. The flap switches from dispensing the water in a “waste” reservoir to the tube connected to the top of the rig when the water has built up enough speed to push it upwards.
The result of the test was that if 1000 litres of water from 2.25 meters high is supplied in twenty minutes, more than 60 litres of water can be pumped to the height of 12 meters. This is an efficiency of 32%. It is known that if systems are properly dimensioned, with the correct length of the supply pipe, an efficiency of 80% can be achieved.