Cable Socket Failure on the Arecibo Radio Telescope

At the time of its opening in 1963, the radar–radio telescope at the Arecibo Observatory was the world’s largest, with a primary reflector having a horizontal aperture of 1,000 ft. On August 10, 2020, one of twelve auxiliary main cables installed in 1992 failed during normal observatory operations. The cable was a critical component of the structural system that suspended the steel-framed platform supporting the telescope above the primary reflector. The failure damaged portions of the facility and forced suspension of observatory operations.

On November 6, 2020, while preparations were underway to reduce loading on structural elements affected by the first failure, one of the original main cables failed. The telescope ultimately collapsed on December 1, 2020, following failure of a second original main cable.

This presentation describes the failure analysis of the auxiliary main cable that initiated the sequence of events leading to the catastrophic collapse of the telescope. The investigation included detailed examination of the failed cable components and evaluation of the conditions that contributed to the loss of load-carrying capacity.