Root Cause Analysis of Versalift Incident - Part 1

[dogsnake12]

I was there when it happened...It fell on the scaffiold builders lunch tent. I was in the fluid unit though, kind of close to the Coker.

[justchillian]

i just compleyed a job with this craneafter rebuild it went great the men on that rig were very perfecinal and dame good you go boys HILLBILLY you the man

[canucksteel]

it was my understanding the operator wasn't in the cab at the time and forgot to take crane out of an boom up "inching mode" which causes crane to boom up very slowly and almost imperceptibly .

[malaycobra]

@canucksteel

There is no such manufacturer-approved setting on any crane. How safe would it be to leave a crane "inching up" and wander off.

Unthinkable.

[canucksteel]

@malaycobra not safe at all, that is why it could occur because its not noticable. if you have any experience you would know that levers can stick allowing movement of crane. "how safe would it be", does this mean people always do things safely or cranes don't have the capacity to be operated in an unsafe manner?

[malaycobra]

@canucksteel

Sorry, didn't mean to sound harsh. If there is an inching mode it is only to make sure that there are no sudden or large movements of the crane. I'm pretty sure it doesn't allow the crane to be left moving unattended.

If the operator jerry-rigged the controls to move with out direct input then that's a different story. Hence my comment about "manufacturer approved" settings.

Anyway, while you are right about an inching mode, that wasn't the cause here.

[canucksteel]

@malaycobra this is just what i'd heard. i was told maintenance was being done on the crane at the time and not under a load.

[malaycobra]

@canucksteel

The crane wasn't under load, it was still being assembled. They were pulling the derrick mast back to pin the super-lift counterweight. The operator forgot to lower the boom as he did it and pulled it over backwards.

[canucksteel]

@malaycobra i see. i did work around this crane once at a turnaround . thanks for the info.

[canucksteel]

@malaycobra one last question. if they were pinning the cwt at the time why was the crane booming up so slowly, over a long period of time?

[malaycobra]

@canucksteel

The main boom may have been at the high point before they started pulling the derrick mast back. I have no idea how far the mast had to come, but t was obviously far enough to pull the main boom through the point of no return.

[canucksteel]

@malaycobra i forgot to mention that the new link-belt 250t crane does have an "inching mode" for crane operation at near capacity, or for extremely delicate situations.

[malaycobra]

@canucksteel

I'm sure it does. Not without the operator there though! ;-)

[cputb1]

Very interesting.