Crane collapse in Seattle

[Old]

I feel so sorry for the workers and their families involved in this headline: Crane collapse in Seattle, 4 killed. 

This really puts a damper on my day. I had a crane collapse in in Seattle killing 2, a terrible, very long ordeal for both the victims families and our company's management. A great amount finger pointing and shifting of blame. The lawyers  directed us to have zero contact  with the families of the deceased, not even writen condolences,  it might be construed as an admission of guilt. Litigation from that project went on for 2.5 years. The years of stress aggravated  a heart condition  causing my early retirement.

Retirement good, stress bad.

Please “Let Him speed up his work; Let it come.." amen,  amen, amen.
 

[Lee49]

Well, anyone working up high, especially in construction,  is always at a risk, but the innocent below, unbeknown to them with no warning, terrible! Shouldn't the street, the whole area, have been closed down, at least rerouting the traffic away from said danger area?

[tekmantwo]

2 hours ago, Lee49 said:

Shouldn't the street, the whole area, have been closed down, at least rerouting the traffic away from said danger area?

Cranes, such as this one, do not regularly come crashing out of the sky. They have a fairly good safety record, thousands of them are used every day.

 

If the road should have been closed, while the crane was being taken down, may have been considered but not implemented. In retrospect, it would have been better.. hindsight is usually 20/20...

 

Whoever decided not to close the road will have some rough nights ahead..

[Old]

2 hours ago, Lee49 said:

Well, anyone working up high, especially in construction,  is always at a risk, but the innocent below, unbeknown to them with no warning, terrible! Shouldn't the street, the whole area, have been closed down, at least rerouting the traffic away from said danger area?

Totally clearing the area could involve emptying several blocks of High rise office buildings, closing down Mercer Avenue, the busiest street in Seattle. Shutting down light rail and rerouting public transit in every form. Such action would severly impact a several of hundreds thousand of people. Knowing Seattle I could see closing down the area could back up traffic for thiry miles in each direction. The procedures for operating a crane of this sort is dictated by the building department.

The purpose of a tower crane is to move materials over structures to where they are needed for construction. Except for hoisting material off trucks parked in the street they do not swing loads over pedestrian or vehical traffic. 

The crane was being taken down, which is why you see so many iron workers in the photos. Dissasembly of large cranes is done by iron workers and only iron workers, they are extremely cautious and safety minded. They follow a bolt by bolt, pin by pin procedure. During dissasembly the crane is not stable  as various bolts and pins are removed even in a carefully engineered sequence. During dissasembly no one is allowed under the rig except those doing the work. This is a very critical period and it is a good possibility that the failure happened when a strong gust of wind struck at a  precarios moment, time and circumstance befall all. . Human error well be a factor, look at the 737MAX. The fact that there were two iron workers in the cab at the time indicates great care was being taken to insure safety.

Also note the crane did not directly fall into the street, but collapsed onto the builtding breaking up and then a porions fell onto traffic.

[Lee49]

To Old, "During disassembly no one is allowed under the rig except those doing the work" am I missing something here, traffic/ people were allowed to travel  under the crane "during disassembly " "this is a very critical period " so how long would it take to close off the area during this "critical period"? 😕

[Old]

1 hour ago, Lee49 said:

To Old, "During disassembly no one is allowed under the rig except those doing the work" am I missing something here, traffic/ people were allowed to travel  under the crane "during disassembly " "this is a very critical period " so how long would it take to close off the area during this "critical period"? 😕

The crane or cranes were not operating over the street. The way I see it from the pictures. It appears to be a topslewing crane in the process of disasembly. A video shows the tower crane being disassembled by a very tall jib boom crane. The boom and counter weights have been removed from the tower. The tower is free standing but hooked up to the Jib crane. High winds are depicted by both the leaning of the tower and the difficulty the jib crane is having trying to stay with it. Shortly thereafter the tower unit came crashing down onto the east lanes of Mercer Avenue. The tower  actually snapped into several peices with one short section lying on top of the cars. What I thought was the boom appears to be the majority of the rest of the tower structure. (Sorry I can't relocate the video)

One observer stated: "I looked up. The wind was blowing really strong," she told the newspaper, adding that the crane appeared to be eight or nine stories tall and broke in half, with one part falling down the side of the building and the other onto the street."

We are gettinga a few more pictures at this time. 

 The crane was not swinging over the street even though  the tower and cab twisted and fell onto the street.  What caused the tower to start leaning could possible be a problem with the foundation connection as when a crane fell over in Bellevue a few years back.  In this case they were not swinging anything over the publics head. If there had been any anicipated danger the street would have been cleared. You never hoist anything over the publics head, be it with a crane or a helicopter, it just isn't done.

A reported 23 MPH wind gust should not have caused any problem, frequently winds exceed 60 or 70 mph in that region and the only effect is no hoisting in those conditions. Notice that the piece of the tower laying in the street is just a short section, what caused it to break off in that manner will a matter of thorough investigation.

This is justmy opinion and I could be mistaken, but I have erected and and dissasembled several tower cranes and one 300 ton ringer crane all in congested areas and am somewhat familir with the procedure. I had to sign-off on the safety procedure before they began erection or dissasembly. (That is why I was in litigation for 2.5 years when a crane went down on my project.)

We will probably never find out what triggered the accident, though a thorough report will be made but it will no longer be a news item.

[Old]

The following video covers the whole collapse. The vehicle that recoreded the scene was driving east on Mercer Avenue. They were not swinging any thing over the public. You might want to turn your volume down as the language is all swearing.

 

https://youtu.be/Sk29sqZ9_VQ

 

[Lee49]

Wow, so it fell from one side of the structure across  to the other side with the top section of the crane (the heaviest  part) dropping down below! Wind and gravity do not mix.Time and unforseen  occurrence! 😢Thanks for posting, I understand that there are some 49 other cranes in that area.

[Old]

Some cities are recognized by their association with a bird. Seattle regional bird is the crane, the tower crane.

 

Actually the crane is almost centered in the building. The foundation block for this crane would be immense, probably close to 30' square by 8 , maybe 10 feet thick.This base is usually placed underneath the bottom of the elevator shaft and the crane is secured to the base with huge specifically engineered anchors imbedded in the concrete block. It is the first major construction after site excavation. This huge weight at the bottom has the same effect as one of those inflatable toys that alway bounce upright. If this huge anchor block was sitting in a parking lot the crane would still function. The reason for burying it under the building is it can be left in place after the building is erected.

 

From the pictures it appears someone started cutting the crane free from th foundation much too soon. The tower can be seen leaning against the side of the shaft. The crane used for this disassembly can be seen swinging in an unsuccessful effort to take the two iron workes of the top.

Washington state has a law to the effect that the final and sole responsibility for project safety rests on the shoulders of the project superintendent. Been there a couple of times, I wouldn't want to be in his shoes tonight.

[Lee49]

USA Today is reporting the crane fell because of worker error, stating that " the reason this tower fell over is ironworkers and the people working on it did not follow the manufacturer's instructions for disassembling the crane" said South Carolina crane accident investigator Tom Barth. "If the pins had been in, that crane would have never fallen over." Crews shouldn't have taken out the bolts holding together  one section  below  it, Barth said, until they secured  line from another crane to the top of the section getting  removed. " What I'm seeing is a crane that looks as though the pins were popped all the way down to the pedestal section" , said Dave Kwass, a trial attorney  who handles crane accident lawsuits.

[Old]

Typical view from I-5 in Seattle. Howmany of these Seattle birds do you see?

[Lee49]

Warning - Find Alternate Route! 😉

[tekmantwo]

8 hours ago, Old said:

Typical view from I-5 in Seattle. Howmany of these Seattle birds do you see?

Jerry, look on youtube for this guy,  AvE.

He's a bit rough around the edges, drops the occasional F bomb at times but only because he gets a little emotional about this event.

 

He has a pretty good video that looks at possible causes behind this crane falling.

 

(I dont want to link it here because I dont want any of the members here to be offended by his language. Its ez to clik a link, a little more effort is required to find it...)

[➕👇 ꓤꓱꓷꓠꓵ🎵Tone]

Side note.

In China a noticed scores of cranes all over the place. This was just 1 example of many, in just one 'outer' housing precinct.
Perhaps one thing I would suspect, if one collapsed in USA, it will make the news. If one collapsed over there, it wouldn't rate a mention....

Just Older