The Jet normally operates for two hours daily between 2.00pm and 4.00pm sending water to a maximum height of 147 metres.
Note: The Captain Cook Memorial Jet has unfortunately had another setback in its operations, as a possible result of the unexpected failure of its pumping system earlier this year.
The Captain Cook Memorial Jet was constructed on behalf of the Commonwealth Government by the National Capital Development Commission to commemorate the bicentenary of Captain James Cook's discovery of the East coast of Australia. It was officially inaugurated on 25 April 1970 by Her Majesty Queen Elizabeth II.
Water is drawn from the lake through a 50-metre intake tunnel to the underground pump house. There are two 4 stage vertical spindle centrifugal pumps capable of pumping 250 litres per second against a head of 183 meters. Each of the pumps is driven by a 560 kilowatt water-cooled 3.3 kilovolt electric motor. Operation of the jet can be carried out both remotely using programmable logic controls and also locally using switchgear.
The water is then pumped through a 450mm diameter steel pipeline which extends approximately 205m from the pump house, through the tunnel and along the lake bed to the concrete nozzle housing structure. The nozzle housing is located 150 metres from the lake wall in the central basin of Lake Burley Griffin . The nozzle housing accommodates 2 discharge nozzles - a main nozzle which operates with both pumps operating simultaneously and a resulting jet of water 147m tall, plus an auxiliary nozzle which operates with a single pump operating and a resulting jet of water 110m tall. Remote controlled nozzle selector valves, located in the nozzle housing, direct the flow to either the main or auxiliary nozzle. The exit velocity of water leaving the nozzles is 260kph and the mass of water in the air at any time is 3 tonnes on single pump operation and 6 tonnes on dual pump operation.