What went wrong?

[stock]

http://www.youtube.com/watch?v=xz71eVreMDc

I have my own opinions but it a very expensive bridge now....

 

[fast_st]

Looks like at 17 seconds the camera operator and pals spots cracks and abort the set, shortly followed by the backfilled slope giving way. Did the counterweight overcome the rotational motor? It was probably a rental crane, hopefully they paid the damage waiver.

 

[S.R.E.]

The crane pad failed. They should of dropped that load when they noticed the cracks. Next time they should use a bigger crane and stay away from the edge of the bank.

 

[muzy]

Foolish, looked like he had a chance to set load down. One end in the water other on the pier. Would have bought him some time. Think I wached that over twenty times. After seeing the crack, down, set down was all I could think.
That operator, man if he was not hurt I'd be suprised.
Side note. Looks like we start to see vide after she has already slide a foot or more. muzy ointhead

Also did not see any extra footing/padding on far side of crane.

 

[DirtHauler]

Yeah there is no shame in dropping a load. In this case there were no people under the load to have nightmares about later if you did drop the load. BAD SITUATION all the way around, it is easy to 20/20 hindsite. I hope no one was injured.

 

[shipman]

So you think he was trying to get the load back to the shore before setting it down?

 

[muzy]

So you think he was trying to get the load back to the shore before setting it down?

Yup, what do you think shipman?
And futher more I'm wondering why both cranes were placing loads at the same time? muzy
Or thats what it looks like

 

[shipman]

Looks like the far outrigger was even closer to the edge due to the angle of the bank, once the load came off, and the upper swinging around like that, and the boom up, it sure went pear shaped fast, bad day in middle earth. Do you think if he could have stopped the upper from swinging it might have stuck?

 

[stock]

Now for a little more info..................



We have received more details and photos from the crane accident in Auckland this week from an eye witness in a bid to help others learn from any mistakes.

It seems that the crane, a 200 tonne Terex All Terrain was lifting the second beam of the new Huruhuru Cycleway bridge into place, when the embankment, built for the cranes and trucks on each side of the creek, gave way.


Heavy rains helped cause the subsidence

The crane slews the beam

The outriggers were set on a decent set of mats

The crane, owned by Auckland and Waikato cranes, was set up on some decent outrigger mats, but as the full weight of the beam came over the outriggers on the bank side of the crane the temporary embankment simply gave way. It is possible that heavy rains overnight might have undermined the integrity of the embankment.


The embankment gives way

 

[cranetools]

This is a good example of the value of job site cameras as a protection against liability for many parties concerned on the job.
Just shows you can never be too sure of the recommended distance from the edge of an embankment - daily observation of ground condition and crane set up is vital!
Think First - Be Safe!

 

[willie59]

It's good to see you're able to post here once again Stock.

Me and Stock were discussing this event a few days ago via email. I always preface these type of accidents by saying the best we can do is speculate because we weren't there to experience it. However, the You Tube video is rather compelling in this incident, with the operation and outcome of the crane. Given the visual evidence presented in the vid, I told Stock what so many others here have said, the operator should have dropped the load in the creek at first sight of problem. Then hope that machine would somewhat stablize and then regroup. To continue the operation by trying to bring the load closer was nothing less than foolish. It was a concrete beam for crying out loud, drop it in the creek, it ain't gonna drown!

The fill base is questionable, it's hard to tell, but it looks like simply loose stone. Might be sufficient if it was placed and compacted properly, information we're not privy to. The last pic that Stock posted is interesting to me. The deep cracking and heaving of the creek mud bank indicates it slid out from under the stone work base. Most likely a combination of being wet (it is a river bank after all), possibly help from the rain, and the weight of the equipment bearing on it. Looks like a precarious work set up, but again, we can only speculate about that. But to continue to manuver the load? Foolish.

 

[Buckethead]

I hope no one was injured. It goes to show how quickly things can go bad. This should be mandatory viewing for anyone who works anywhere near a rig, especially foremen and superintendents.

 

[Tiny]

I'm not sure about the Terex machines but the Demags ,Groves and Krupps we have DO NOT have a free fall like the old conventional's did .No way to "Dump" the load.

The thing I was looking at was after the beam was down, The machine never slowed down any what so ever.So dumping the load may not have helped a bit

Also it looked to me that the ground gave way in a straight line .

 

[willie59]

When one says "dump the load" Tiny, doesn't necessarily mean via free fall, just means set it down promptly. No, there's no way this would guarantee the rig would stablilize, but in my experience, when things are going bad, it's more likely getting rid of the load will help more than continuing to manuever the load. Get rid of it and re-group.

 

[muzy]

Yes Atcoequip and I'll quote if you don't mind " Looks like a precarious work set up," I agree 100 percent starting with the outrigger mats, outrigger is not in the middle. That can be seen clearly 12 sec in. As my understanding of crane placement and set up is not formaly taught. But learnt on site. Basic common sense told me the out rigger always gose in the center of the mat or pad. And if there is an edge with a radius on your pad that gose down.
The pad was good, at least where that second axle comes down and squishes the tire right down to the rim. Yea don't watch wakie-talky guy run around, look at the wheel.
Any ways thanks for posting that stock. It's been a while since my hair has stood strait up. muzy

 

[classictruckman]

The thing I was looking at was after the beam was down, The machine never slowed down any what so ever.So dumping the load may not have helped a bit

One thing I noticed is that as soon as he did drop the load the ground gaveway on the counterweight side, maybe if he had dropped it right away while he was still over the rear he might have had a chance.

 

[qball]

gimme a friction rig over a squirt boom any day. i wanna be able to get rid of trouble in a hurry.

 

[2stickbill]

Wakie Talkie man looked straight at the big crack by the rear tire.He should have shut down this operation or at least told the crane operator.

 

[Hoister]

This whole situation is just bad. Bottom line, the material this rig is sitting on is garbage. And they are too close to the edge of this fill, junk material or otherwise. Best thing for one to do here is not be set up on junk fill, the boss can go to h#ll if he tells you to, because the man in the white hat is going to blame you for this. Now as was mentioned this operator should have touched that beam down in a hurry, after all the ground is giving away under the loaded outrigger, not under the counter weight as I see is written above. Now youll never find me in a situation like this, I usually take a 550 toner out and on occasion when that rig isnt needed Ill go out with the RTs. And if you have to build a pad for us to setup on like this one, your doing compaction testing, PERIOD.

 

[cranetools]

I can say this to all of the operators reading this as my experience and observation of newer cranes and the progress of cranes over the years.
Newer type hydraulic cranes have changed in ways many operators and owners have not thought about.
Because of weight laws and the longer higher capacity cranes the crane chassis is lighter than ever - this now means that there are in some cases much higher outrigger loadings in ways you may not think about - the counterweight of these new cranes is much higher than earlier machines - the frame flexes more, the boom has more deflection, many factors that have changed the loading of the crane across the chassis and on to the ground.
It is clear that the operator and job site had taken the proper precautions to cribbing the crane up however when the weather changed so should have the game plan at that point - but I suspect somewhere money and time got in the middle and we then know what happens after that!!! Bye Bye Safety

Think First - Be Safe