As I'm getting many questions, I thought I'd convey what little we know so far. One guy died, one in hospital. When the latter gets better, we'll know more. Fred Hopengarten, Esq. K1VR Six Willarch Road Lincoln, MA 01773 781.259.0088, k1vr@arrl.org New England Director cid:a4a12f0b-0468-4a39-b953-31b2a3da8564 Serving ME, NH, VT, MA, RI and CT -----Original Message----- From: yccc@groups.io [mailto:yccc@groups.io] On Behalf Of Mpridesti via Groups.Io Sent: Tuesday, July 30, 2019 1:18 PM To: Ed Sawyer Cc: yccc@groups.io Subject: Re: [yccc] Stepping up in the wake of tragedy [was: Sad news] Ed
From what I have learned, yes the base was a tilt over but was bolted to prevent tilting while the tower was being taken down. Assuming the plan was to get it taken down to 20 ft, then tiltover. Perhaps a 20 ft mast was inside the tower at that point? Probably felt tilting over 40 ft was too much. Nothing wrong with that approach. Commonly done with tiltover Rohn towers where at the hinge, a bolt is placed to prevent tilting while taking down the upper half of the tower.
Also the tower was higher than 40 ft to begin with, so guys were present. I am guessing there was an expectation of it being self supporting as it was when the tower first went up. With these failures due to aging or improper water drainage, or other unknowns, it compels all of us to use that extra set of safety guys with any tower take down. I have seen plenty of poorly engineered sites or damaged towers where the owner thinks it is still safe to climb. NOT. And like Jack, I cut those down when I can! Got lazy at my last QTH and dropped a 100 ft tower with a yagis on top. A site behold but oh so much easier! Regards, Mark, K1RX 603-231-8965
On Jul 30, 2019, at 9:46 AM, Ed Sawyer <sawyered@earthlink.net> wrote:
I actually do failure analysis as part of my work at our company here in Vermont. I agree with Jim, that these tragedies are an opportunity to train and publicize for the good of overall community safety. However, broad brush training is rarely effective. Actual failure analysis, think NTSB after an airplane accident, and addressing fixes and training that would have prevented the actual event is VERY effective.
It seems from what I have gathered so far from the pieces of information:
- They were taking down a tilt over tower. What didn't they tilt it over to disassemble?
- They were harnessed in and went down with the tower
- The movement of the tower after they removed the last set of guys initiated the failure. This implies there were no temporary safety guys installed as they disassembled the last set of permanent guys. And why were guys even attached on a tilt over tower? I personally always install safety guys on the top of the section directly under the section with the guys before removing the guys. And the guys should be loosened from the ground, not from the tower. You can then safely climb the tower and lift and drop the previously guyed section with the guys still attached if desired. Never being on that section in this part of the process.
Rust at the base weakened the legs. Possibly the tiltover plate was part of the problem.
I am not sure if the above fully captures the questions. But as is normal in an fatal accident, its a combination of things that cause the event. Sibgle event fatalities occur, and are tragic, but the typical story reads like above.
We would do well as a community to have the equivalent of an informal NTSB on tower injuries and fatalities. The community gets safer by understanding, learning, and preventing.
Ed N1UR
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