Engineers on site began work to reduce the load placed on these cables, in part by trying to loosen a series of “backstay” cables that helped the tower itself stay upright. Other options, Zauderer said, involved using a crew strapped to a helicopter to take the weight off the support tower, but safety concerns ultimately founded the idea. Either way, it soon became too clear that the Arecibo complex was living on borrowed time.
“After the cable failure of November 6, the [remaining] the cables could have failed at any time, “said Gaume.” We weren’t able to predict when this would happen, [but] we knew it would happen. “Gaume later noted that no matter what the Arecibo ground crew tried, they” could never have relieved enough of the load to get the cables back together before November 6. “
The team’s worst fears came to fruition on December 1, when – after watching for individual wires breaking under tension – the second trunk cable running from Tower 4 to the receiving platform failed. The receiver’s weight was then supported at one end by just two cables, both of which failed fractions of a second after the first, sending the platform sinking into the massive reflector plate. During this time, Tower 4 was suddenly free of any weight to bear, but was still pulled by seven backstay cables – this pressure tipped the top 65 feet of the tower back. And through the dish, the same thing happened at tower 12; its upper part was sent down a hill near the Arecibo operations building. Fortunately, no one got hurt.
Now all that remains is to pick up the pieces – literally. Gaume said the NSF expects to have a “full assessment” of the damage from the collapse and its environmental impact by the end of this week. And while the NSF has not ruled out the possibility of restoring or rebuilding the facility, this cannot happen without significant input from other parties.
“NSF has a very well defined process for building large research equipment and facilities,” he said. “This implies that Congress owns the funding, as well as the assessment and contribution of the scientific community, including research and other stakeholders. This process should take place. “