another crane accident

[Jeffksf]

sorry if this a repost, I didn't see it posted though.
http://gazetteonline.com/local-news/2009/11/10/crane-falls-at-federal-courthouse-construction-site

[heavylift]

Lucky group of workers....

[willie59]

News Reporters are so lame at taking construction accident pics! He took a pile of pics of...crane boom on the pickup trucks, ok, we see that, la de da, and only one decent pic of the crane, pic #13. We can only speculate what happened. There was a good bit of lattice boom on that crane, and it looks to have been about a 45 degree angle, and crane over the front, at least it is now. The one detail I noticed, not a single outrigger out or down. He had to erect that boom over the rear, you can't do it over the front. After erecting, did he attempt to slew around front with no outriggers deployed? Or, did he have the erected boom over the front, and was walking crane, then on slight side grade, the boom took it over sideways. Lucky no one got hurt.

[liebherr1160]

That may be a Grove GMK 7550...looks as though they were walking it with jib or a short luffer...

There are provision's in the chart for this..but it dosent include the unit laying on her side ..:(

[Crane Op]

That may be a Grove GMK 7550...looks as though they were walking it with jib or a short luffer...

There are provision's in the chart for this..but it dosent include the unit laying on her side ..:(


You are correct! It is a GMK-7550 owned by Dawes Crane & Rigging out of Milwaukee Wisconsin.

Some more information on what happened

http://www.vertikal.net/en/stories.php?id=9103

[crane operator]

I would guess that the suspension would be the main culprit here. The Mega track suspension, if travelling slowly, unlocked and in "active" mode, can set up a type of oscillation effect. Traveling on uneven ground, it will adjust, making the whole crane tilt just a little, with that huge boom in the air, a little movement on the axles, makes a lot of movement up there. Then the suspension gets pushed on the opposite side and pushes back. Back and forth, side to side it can set up a rocking motion, and then "dink". I'm sure the book says travel this way only on a "smooth, level surface, at only creep speed, suspension locked". Real world conditions seldom are that way. Typically you manually level the crane, lock the suspension, drive slowly till the slope gets too much, unlock the suspension, relevel, relock, and continue. Leaving the outriggers out and "skimming" the ground is a great security measure. If it started to go, they would catch it, and if even hit hard enough to bend those, they are just quick detach on them, and much cheaper/easier to replace than a boom and damaged carrier. Keep it safe everyone.

[willie59]

I would guess that the suspension would be the main culprit here. The Mega track suspension, if travelling slowly, unlocked and in "active" mode, can set up a type of oscillation effect. Traveling on uneven ground, it will adjust, making the whole crane tilt just a little, with that huge boom in the air, a little movement on the axles, makes a lot of movement up there. Then the suspension gets pushed on the opposite side and pushes back. Back and forth, side to side it can set up a rocking motion, and then "dink". I'm sure the book says travel this way only on a "smooth, level surface, at only creep speed, suspension locked". Real world conditions seldom are that way. Typically you manually level the crane, lock the suspension, drive slowly till the slope gets too much, unlock the suspension, relevel, relock, and continue. Leaving the outriggers out and "skimming" the ground is a great security measure. If it started to go, they would catch it, and if even hit hard enough to bend those, they are just quick detach on them, and much cheaper/easier to replace than a boom and damaged carrier. Keep it safe everyone.


I think your on to something crane op. I know I'm not on the site to see the variables, and there's not enough views in the pic to form a correct opinion, but, the question I have is; why walk the crane at appx a 45 degree angle on what looks like an open jobsite? Seems to me, boom lowered would have prevented this "could have got somebody killed" incident.

[heavylift]

The outriggers may have saved it. He could have done it hundreds of times. It may have been really windy also...

TEXTING....heck they blame everything else on it....


I've always disliked moving cranes around with manuals and jibs..out and on...

There were several refineries around the area that had absolutely the worse areas to set up cranes... drive in with 80' of boom at 0 degrees while trying to negotiate a 90 degree corner.... severe pucker power even with outriggers dragging

[TSK415]

It was a suspension failure, the crane was not moving when it went over. Moving from first tower to set up for second tower, stopped before moving to final setup spot. Fixed jib, site was graded, little wind, suspension locked. Boomed up is how it is supposed to be moved, in that configuration, to distribute the weight over the suspension.

[crane operator]

tsk415 is right in the boom having to be up to spread the weight. Grove dictates in the manual proper moving conditions. Just sitting there and then falling over I find hard to believe. The operator bumping the switch from locked to unlock suspension causes a instant movement in all the suspension, (they can really rock), or the electronics messing up and making it switch are possible. All the suspension on that side failing (the suspension is really just hyd cylinders on beefed up a-arms) I find hard to fathom. I can most easily see the operator unlocking the suspension to relevel a little and not realizing how much it was out of level and the suspension rocking it over. With the boom up and all that jib on there is a lot of weight out there. This is a 500 ton crane though, and I'm sure the operator has to be a experienced guy, but we all get careless and in a hurry, sometimes the bad gremlins reach out and get us, on something we may have done hundreds of times and gotten away with. Still glad no one was hurt, they make machines every day. Hopefully we all learn a little.

[liebherr1160]

crane operator...Its not your first day at the rodeo is it!!! :drinkup

[insleyboy]

Every time one goes over, no matter how it happened. Every safety gain we have achieved seems to go for naught. OSHA will be all over this one and will have some new bulletin that will effect all of us in some way!

[liebherr1160]

Every time one goes over, no matter how it happened. Every safety gain we have achieved seems to go for naught. OSHA will be all over this one and will have some new bulletin that will effect all of us in some way!
Actually no ..they wont ..

As crane operator was saying ....the procedure is written in the manual ..which ..may include the outriggers half out and pinned ..just clear of the ground ..
If anything here i think it well be ruled operator error through missing a step in the "moving while rigged" section of the manual

[james-laws]

Thousands of construction workers are hurt or killed in construction site injury accidents every year. It is a disturbing fact that 3.9 per 100,000 construction workers die annually according to the Bureau of Labor Statistics and countless thousands suffer non-fatal but debilitating injuries

[frenchriverland]

Those guys sure are lucky!!

[MichaelM]

Miracle escape for the workers...Great!!