Over She Blows.

Not what happened here, which looks like failure of the fibre glass, but in the early days there were problems with anchor bolts failing due to cyclic stress, by being installed with a nut below and above for each stud in the anchor ring.- the section between the nuts always in tension, not an issue, but the section below the lower nut oscillating between tension and compression rather than a uniform load share, failing after a few years. It is fair to say that the designers had quite a lot to learn at the outset, and are still learning as designs get ever bigger and push materials design into areas not perhaps as well bottomed out as more general engineering. However, designs are getting better all the time, and failures like this are mercifully rare - especially when you consider the number in service

Even so, I'd expect a man with an ultrasound probe to turn up and check the others for cracks in the same place, a failure after decade  or so is not at all desirable, even if just the one..

Mike

Not what happened here, which looks like failure of the fibre glass, but in the early days there were problems with anchor bolts failing due to cyclic stress, by being installed with a nut below and above for each stud in the anchor ring.- the section between the nuts always in tension, not an issue, but the section below the lower nut oscillating between tension and compression rather than a uniform load share, failing after a few years. It is fair to say that the designers had quite a lot to learn at the outset, and are still learning as designs get ever bigger and push materials design into areas not perhaps as well bottomed out as more general engineering. However, designs are getting better all the time, and failures like this are mercifully rare - especially when you consider the number in service

Even so, I'd expect a man with an ultrasound probe to turn up and check the others for cracks in the same place, a failure after decade  or so is not at all desirable, even if just the one..

Mike