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The investigation into why a cable mysteriously broke on the Arecibo Observatory has begun 9

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WKTaylor

WKTaylor

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I have seen flight control cable failures under high tensile load... especially during crashes... but nothing like this failure...

Failure obviously occurred under high tensile load... wire strands unwinding/splaying about... but the break appears almost straight across all the wires at one discrete location. This is going to be an interesting failure analysis...

The investigation into why a cable mysteriously broke on the Arecibo Observatory has begun
Officials at the Arecibo Observatory in Puerto Rico still don't know what caused a cable failure that severely damaged the facility's iconic radio telescope this week, forcing it to shut down temporarily.

On Monday (Aug. 10), an auxiliary cable supporting a platform that is suspended above the 1,000-foot-wide (300 meters) radio dish broke and crashed into the telescope's reflector panels, creating a gash in the dish measuring about 100 feet (30 m) long.
… …
From the article... A photo of the support cable that broke on Aug. 10, 2020. (Image credit: University of Central Florida)


Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
 
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The observatory was built in 1960-1963. It received a major upgrade in 1973 that extended it's frequency range from 500MHz to 5,000MHz (5GHz). The Gregorian reflector system (the big dome in the middle) which allowed full capability to maximize use from 1 to 10 GHZ and track a point in space was installed 1997. Many other incremental improvements have been made over the years. In the James Bond film (1995) you don't see the Gregorian dome.

Arecibo can only be steered a few degrees by moving the receiving focal point. Because of Earth's rotation Arecibo can stay fixed on a point in space for a few minutes. For radar work (imagining asteroids) the time from transmit to reflection off the object to receive must be within this time period.

The National Science Foundation (NSF), frankly, has been trying to dump Arecibo for years by cutting funding, (big time between 2007 and 2011), transferring management from Cornell 2011 to other institutions, and more recently moving oversight to secondary institutions (UCF). Secondary funding sources and donated money have somewhat filled the gap. The NSF wants to fund only New glamorous science which comes with big money funding and prestige, and is not interested in maintaining established scientific tools. It's the same kind of minimum investment management theory that has resulted in other modern management successes like the 737 Max.
 
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Another video on the current state of Arecibo. The recent cable that snapped was an original cable from the 60's. The focus structure of Arecibo was built first, hoisted into place, and then the dish was built underneath. When the additional loads of the Gregorian reflector were added in 1997, two more support cables were added to each supporting tower. It was one of these 1997 cables that pulled from it's fitting in the initial event back in August.
 
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I think you have personal attachment to this installation Comco.... I really do feel for you and the political situation that made it happen. Its not an engineering failure its pure lack of maint and cash for political reasons
 
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Wait...

comcokid said:
The National Science Foundation (NSF), frankly, has been trying to dump Arecibo for years by cutting funding, (big time between 2007 and 2011), transferring management from Cornell 2011 to other institutions, and more recently moving oversight to secondary institutions (UCF).
Click to expand...

Is that the same UCF responsible for the pedestrian bridge design that collapsed?
 
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UCF had nothing to do with the pedestrian bridge collapse. The university that commissioned the bridge is FIU, and saying that they are responsible for the collapse is also a big stretch.
 
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News out of Arecibo this morning is that the instrument platform fully collapsed at some point over night. Towers are still in place, no injuries or damage to the outlying buildings, but the telescope is completely destroyed.
 
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Arecibo wire supported antenna structure completely collapsed 'last night'.

Scott Manley, YouTube, 'Arecibo Radio Telescope Collapses!'




Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
 
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Video of the gigantic Failure...
Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
 
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I sincerely hope there will be some phenomenal 'Lessons Learned' from the engineering failure analysis.

Hate-to-say-it, but sometimes failure like this allow a clean-sheet-of paper redesign that is vastly superior to the first generation. The Arecibo location is certainly unique in this world.

I wonder if the Atacama desert might be a 'better' location for something like this.

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
 
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I don't think the location was a problem... this is, after all, a structure that survived almost 60 years.

Based on the ownership turnover of the facility in the last 5 years or so, and even during the previous era of control by the NSF, Arecibo has had continuous funding problems. I suspect that this structure could have remained in service indefinitely, or at least for several more decades, with sufficient maintenance.
 
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I don't believe poor maintenance can be implied. The initial cable failure was completely unexpected so it's unlikely that there would have been any addition maintenance or inspection activity on those.

Brad Waybright

The more you know, the more you know you don't know.
 
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Amazing that the drone was right there when the cable pulled out. I came in to post the very same video but I see a few people already beat me to it!
 
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The cable might have failed prematurely, but it seems to me that there would be enough redundancy to get through a single bad cable. That cable failure resulting in the collapse strongly points to lack of maintenance, or at least proper inspections.
 
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thebard said:
The initial cable failure was completely unexpected
Click to expand...

An unexpected cable failure in a structure like this IS an indicator of poor maintenance. 'Maintenance' doesn't just mean that you fix things when they're broken- it also means that you're continuously and rigorously inspecting safety critical parts of a structure. It's impossible to say for sure that a lack of maintenance is a primary factor here, but all the information we currently have certainly appears to point that direction. Which also fits into the story of a facility that has struggled with continuous budget cuts, management changes, and funding shortfalls over the last 10-20 years.
 
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