Wednesday, August 17, 2022

Study of Arecibo Telescope Collapse Focuses on Cables and Sockets

The Arecibo radiotelescope in better days
(CQ Newsroom archives)
A forensic analysis of the collapse of the Arecibo radiotelescope in 2021 has concluded that problems in both the suspension cables and the sockets that held them led to the failures that precipitated the collapse. The detailed study, by the engineering firm of Thornton Tomasetti, reported that a combination of five major factors was responsible: “(1) the manual and inconsistent splay of the wires during cable socketing, (2) the design of the cable system with relatively low safety factors, (3) the occurrence of extreme environmental events such as hurricanes and earthquakes, (4) the non-replacement, repair or bypass of the sockets where large cable slips were observed, and (5) the addition of auxiliary cables as isolated cables.”

The report concluded that, while further study is needed to determine the service life of cable-socket assemblies, “the risk of socket failure can be mitigated by … (1) controlling the number and geometry of splayed-out wires during cable socketing, (2 and 3) designing cable systems with larger safety factors under gravity and transient loads, (4) monitoring the cable slip and slip rate after cable installation, and (5) designing cable systems with multiple adjacent cables on each span.” (Tnx WP3R)