The 64th and final foundation for the MeerKAT telescope antenna was poured on Tuesday at South Africa’s SKA site in the Karoo. Close to 5 000 m³ of concrete and more than 570 tons of steel were used in construction of the foundations over nine months.
MeerKAT is the South African precursor to the Square Kilometre Array (SKA) telescope, to be built in Africa and in Australia. The SKA Project is an international enterprise to build the largest radio telescope in the world.
“The completion of the foundations and the soon-to-be completed first antenna represents a major milestone on building of MeerKAT which will become an integral part of the SKA project. I am pleased with progress and the quality of the work our scientists and engineers are delivering on this challenging assignment and wish them well with the enormous task ahead in meeting the tight schedule in the next two years,” Science and Technology Minister Derek Hanekom said.
“The foundations were built to stringent specifications to ensure the antennas will be exceptionally stable. Even at wind gusts of up to 69 km/h scientists must be able to point the dishes at distant celestial objects in an exact manner and the antennas must be able to survive wind speeds of up to 144 km/h,” Tracy Cheetham, general manager for infrastructure and site operations at SKA South Africa, said.
To meet these stability requirements, each foundation consists of eight steel-reinforced concrete piles at depths of between five and 10 m, depending on local soil conditions. A square slab of concrete (5,2 m x 5.2 m, and 1,25 m thick) rests on top of the piles to add further stability. The 32 “holding down” bolts are pre-assembled in a circle to form a steel ring cage, or so-called “bird’s nest”, into which concrete is cast.
All other MeerKAT infrastructure should be complete by the end of March.
“We are on the last leg now,” Cheetham said adding finishing touches are underway in the Karoo Array Processing Building (KAPB) and the power facility. The KABP, a specialised underground bunker protected from radio frequency interference, will house all the data processing racks and the power and back-up equipment required for MeerKAT.
The primary focus for the next two months will be on verifying all infrastructure functions according to the required specifications. Testing involves cold and hot commissioning.
Cheetham explained: “During cold commissioning power is connected without switching on the equipment. During hot commissioning machines are turned on and tested for a period of time.”
Cheetham also said the ducting for the fibre optic cable has been completed, so all that is left now is for optic fibre contractor, Plessey, to pull through and connect the cable.