After assembly and performance tests at the 2900 m elevation Operations Support Facility (visible in the background of the picture), a Japanese 7 m antenna is being transported to the Array Operations Site located at 5000 m altitude. Like this one, all of the ALMA antennas were transported slowly and carefully, each taking roughly 6 hours to travel the 30 kilometer road to the Array Operations Site where they were then installed. The white of the antenna and the yellow of the transporter stand out in the Atacama Desert with its sparse high-altitude vegetation and giant cacti.

The antenna transporter was specially designed and built for ALMA. Currently, there are 2 in operation. These unique vehicles (20 m long, 10 m wide, 130 ton weight) can be used to move the antennas between the Operations Support Facility and the Array Operations Site. They are also used to rearrange the antennas in the Array Operations Site. With two 700 horsepower diesel engines and 14 pairs of 28 independently driven tires, they safely transport and precisely install the 100 ton antennas. Before transport, a road preparation team levels the road surface, and the transporter operator team uses a dummy antenna to conduct a test drive. As a result of the antennas being repositioned countless times, ALMA can achieve high precision radio images.

Author: Masaaki Hiramatsu