hangar collapse

[Natman]

This sucks....., some garbled accounts say the crane caused it, collapsing first, others just say it was involved. Across the state from me, but still hits home.https://www.today.com/video/crane-collapse-at-boise-airport-hangar-kills-3-injures-several-203395653912

 

[Natman]

A better link:

 

[1693TA]

The "lawyers" are already circling.

 

[OzDozer]

Shades of the Big Blue collapse?

 

[skyking1]

It is not one big canopy like Big Blue. We'll see what comes out in the investigation.

 

[Natman]

It's a real big deal here, the biggest construction snafu in a long time, and the worst, right by a busy freeway also, if I'm not mistaken. I avoid that side of the state, way too busy nowadays.

 

[crane operator]

Its a horrible event. 3 guys will never get to go home and another 5 in the hospital with critical injuries and a couple more hurt.

Its a airport hangar, big open span. Here's a picture from a day earlier when they were getting going. Multiple crane lift, hanging a full bay at a time. We've done buildings this way, but not at this long of a span. I set one a few years ago that was 100' wide, but we did it a rafter at a time, so not as much weight, and full locked each rafter in as we were going.

Weather from yesterday- 20 mph winds.

So here's my early guess, bays stood, but not enough purlins put in between stood bays. They put in enough purlins to hold the bays apart- and then on to the next bay. Get the extra cranes off site and come back and fill in later.

Only one crane in the middle in the accident pictures, so (my guess) they were using it to fill in purlins between the bays that were set. He was holding a purlin when it went over, and it took the crane boom with it.

Wind at 20 mph gets the building to moving, no x braces/ cables holding it all together yet. Guys all up in the lifts installing purlins and locking it all together.

So when the wind got up on it and got it moving, down like a house of cards. Taking down the crane, the guys in the lifts, and the guys on the ground prepping everything were right in the bad zone too.

 

[skyking1]

That is as good a take as any. Always in a hurry, like the ironworkers taking down the tower that fell in Seattle.

 

[crane operator]

Time is money, its always been that way, and always will.

Its hard to be the one to say "we need to get some more bracing on this"......

 

[skyking1]

you do it, I do it.

 

[crane operator]

Unfortunately, no one there had the guts to.

 

[Welder Dave]

It wasn't tragic but being in a hurry and not putting enough braces is what caused several huge girders on a new bridge to buckle a few years ago up here. They had to bring in one of the largest rubber tired cranes to remove the damaged girders. I forget how big but there was only 1 local company that had a big enough crane and there's only a couple of them in Canada if I remember right. I think it was over 500 tons, 550 maybe??

 

[Welder Dave]

I'm way wrong. I just did a quick Google search. The crane had to be brought in by truck loads because it was so big... 1200 tonnes! The 3 buckled girders were 40 tonnes each but they needed to support the rest of the bridge so the girders could be removed. Miraculously they were able to repair the girders. Only 7 of cranes in N. America. It's nicknamed the Irish Rover and is a Liebherr LTM 11200-9.1.

 

[Acoals]

I don't know a thing about steel, but Crane Op's take is pretty similar to what happens with wooden trusses. We have had several episodes in my area with truss systems coming down in the wind because they weren't braced well enough.

 

[crane operator]

Looking at some more pictures this morning. Looks like first bay had all the purlins in and x braced. You can see the crane is sitting in the bay that's still having purlins added. So they set two rafters with purlins in them (one bay), skip to the next twin rafter set- and right down the building. Coming back later to finish in the purlins.

The only other thing that I have done, and I can't see if they had this done here - I've installed cables up and down the rafter (bay) section to concrete blocks or deadmen on the ground, to take the sway out of the center of the building.

Its a pain in the ass because the cables are in the way for the lifts and getting around inside the building. Plus you have to get the concrete guys to pour the deadmen in as they are putting in footers. It also takes time to put the cables up, while you could be putting in purlins. But at least it gives you something to tie off the bays to, while you are getting it all locked together.

 

[OzDozer]

That's just all one horribly expensive pile of scrap steel now. Bring in the scrap dealers, cut it all up and start all over again, at massive additional cost. All because someone failed to understand building construction basics.

 

[terex herder]

We got a schedule to meet boys. No time to stop for wind.

 

[1693TA]

I set all six of my steel main frames with my single "Fred" truck by myself. Once in place I anchored them with mobile home screw anchors into the dirt and rope pulleys until the sidewall girts and roof purlins were firmly in place. I started in the center and worked out toward the end walls. Mine is only 70' free span so nothing in comparison to this hanger but I learned a lot doing that.

 

[Natman]

I did two small commercial jobs in '23 for a construction company with the same name, but it must be a different branch or something as I didn't send the bill to Boise. But the name is the same, the guys I worked with were a step above average, I got a free lunch, no one rushed things, and I got paid quicker than usual. Inland Crane has been around for decades, FWIW. That building looked like, what, 150' span? A whole different can of worms from a "mere" 100' span, no engineer here just an old carpenter, but I bet the loading go up expotentially real quick. I've seen contractors here, home builders, get in trouble when they take on a 60' span 16' high warehouse type structure, in fact the house set crew I did yesterday lost a guy on just such a job about 5 years ago, min bracing was the reason, luckily I wasn't involved. It'd be interesting to know if the crew had worked on such a large span before.

 

[digger doug]

We got a schedule to meet boys. No time to stop for wind.

How fast do you think they will find qty (3) replacement workers ?
got to make up for lost time eh ?