Once again the Crane Service company is in the news, and another death due to a fail machine of theirs in Big D Dallas. Nothing yet as to cause other than high winds: https://www.cbsnews.com/news/dallas...midst-severe-weather-storms-today-2019-06-10/
The news report that I saw said That they had experienced hurricane force winds. The article that you linked doesn't seem to say anything nearly that significant. Is there really a way to make a tower Crane safe in those conditions
Two other tower cranes same area of the city survived none to minimal damage.
In that one camera video, that shows it actually falling, you can see the jib is sideways to the direction that it gets blown over. Tells me they didn't leave it weathervaning, or that the weather vane somehow locked or wasn't working correctly. It was pointed a different direction from the other crane you see in the video, and it blows over in the direction that the other crane is pointed towards. For those that don't know, on big towers you want to leave them to weather vane or "freeswing" overnight and in wind storms, if the wind catches the side of the jib, it will take them over.
Well , I guess there's my answer.
I am located just north of Dallas, and this crane collapse has been all over the news. The winds are reported to have been in the 70-80 MPH range. These were straightline winds. The early indications/speculation is that the crane did not "weathervane" during the storm. If so, it is going to take a while to determine if the operator had anything to do with this, or if it was a crane malfunction in the swing brake system.
Agreed, have watched Tower units weathervane in worse, even to tornado winds and tolerate it, had to have some failure to lock it as a sail in the wind, but my point is still made, Bigge takes it on the chin AGAIN.
I feel it’s fairly obvious that the crane wasn’t in weathervane. My question is one step further. It shouldn’t have mattered. The swing brakes on those cranes should not hold in those winds. They’re designed to slip at certain wind speeds. For this very reason. There should be some hard looks at the service records of that crane. No way should that have happened. I should add that tower cranes should safely withstand 130-140 mph winds.
The last Potain tower cranes we used had a warning buzzer that came on in the cab when the wind speed approached the cranes safe operating wind limit. That was well below any damaging wind speed. Usually about 18 MPH. If the near maximum wind speed was recorded a loud horn would sound and the book stated that the crane would go into weather vane automatically in 5 minutes if not put in weathervane manually in that time frame. It was designed to warn everyone to unhook the load and get the block sucked in as recommended in a strong wind. I'm sure this one had the same safety requirements. We just got back to civilization and I have not seen the video yet. I would hope they did not have it tied off to something. As Knepptune stated even if they had not or could not put it in weathervane it should still have slipped the brakes.