Analysis of Causes of Failure and Collapse of the 305-Meter Telescope at the Arecibo Observatory in Puerto Rico

The National Academies of Sciences, Engineering, and Medicine (NASEM), Board on Infrastructure and the Constructed Environment (BICE), will convene an ad hoc study committee to conduct an independent assessment of the December 2020 failure and collapse of the 305-Meter Telescope at the NSF-supported Arecibo Observatory in Barrio Esperanza, Arecibo, Puerto Rico. On December 1, 2020 the 305-meter telescope at the Arecibo Observatory suffered a catastrophic failure, which resulted in the collapse and destruction of the 900-ton platform and supporting tower structures.

This followed the loss of an auxiliary cable which pulled away from its connector at Tower 4 on August 10,2020, and a main cable failure on same tower on November 6, 2020. The auxiliary cables were added in the 1990's to support the added weight of the Gregorian dome. Details and video of the December 2020 event, as well as an engineering summary prepared before the collapse, can be found at the following web site: https://www.nsf.gov/news/special_reports/arecibo/.

The NASEM study committee will issue a report explaining the contributing factors and probable cause(s) of the failure and recommendations for measures to prevent similar damage to other scientific research facilities in the future. At the end of the twelve-month study, the committee will issue a single NASEM report, which will be available on the NASEM web site, that will present the committee's analysis, findings, and recommendations.

The eight-member NASEM study committee will assess the environmental, physical, and design considerations for the Arecibo facility as well as administrative or management practices that may have been contributing factors to the December 2020 failure. The committee's report will provide insight on the performance of tensioned-cable structures under multi-hazard environmental and loading conditions, such as corrosion, creep, and the recent hurricane and earthquake events in Puerto Rico.

The study will also identify actions and best practices for consideration to limit or prevent other large facility damage or failure. It will also assess oversight and management policies and practices that may have been contributing factors to the failure, including contractor selection and procurement during construction and repair, maintenance planning and oversight, inspection, and structural review.

Drawing from this analysis, the committee's study report may have implications for establishing best practices for oversight and response actions for the physical condition, integrity, and function, including end of design life considerations, for NSF-supported scientific research facilities and may provide insight into decision processes for major recapitalization of older, or beyond design-life, research infrastructure still serving scientific purpose.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.