We were working a job recently. I was a general foreman and we had several crews installing piping. There was equipment and tanks that were to be set and we had crews working on that also.
On this project we did not move any of the equipment or tanks, we only supported the rigging and crane companies. These were two different companies that had a working relationship with each other and worked well together. The rigging company places the straps onto the equipment and coordinates the move. The crane company follows direction from the rigging company.
We had assisted several times before and had also built a rapport with them. Each time we had to move anything, several hours of planning were involved. Then on the day of any move we would meet with our safety professional and discuss the events prior to starting any work.
This particular day, we did the same as we always did. There were some minor changes in that one of the riggers, who we had previously worked with was now the lead. The team operating the crane were different than any team we had worked with before. We talked about the job and we all felt comfortable with the plan. Our only responsibilities were flagging the area and observing. If anything went wrong, we were authorized to immediately stop the job.
The plan was to use the crane to lift a twenty foot tall tank, and place it on a flat-bed semi truck. It would then be driven to the location where it was to be set (about fifty yards). The crane would drive to a new spot, maneuver into place, then pick the vessel again and set it in place.
The first part of the move went brilliantly. They placed the rigging and secured the shackles on the load and moved the tank into position. The rigging had to be removed from the tank so the crane could re-position and make the final ‘pick’. We were making good time. The lead rigger seemed to be hustling more than we had seen in the past. I watched along with two of the foremen and we remarked to each other how he seemed to be trying to make an impression on someone.
The crane operator had lowered his boom and secured the hook before driving to the new location. We watched him maneuver the rig into place and raise the boom up into the air. Maybe I am still a little boy, but I am always fascinated by watching a huge piece of equipment in action. The semi truck was backed into position and the operator drew the line in, raising the block to the top of the boom.
The rigger was scurrying around getting things in order on the ground and we heard something contact the tank. It was a hollow ‘clink’ that sounded like a bolt hit it. We immediately alerted the rigging lead and he dismissed us, saying it was the rigging hitting the tank. All three of us saw that the rigging was up and away from the tank, but he didn’t want to listen.
Our safety professional came by to check on the job, so we told him what happened. He took his phone out and directed the camera toward the top of the jib. The rigging crew along with the crane crew were standing on the opposite side of the tank from, us guiding the headache ball down into position. When it was about twelve feet above the ground, suddenly it released and went into a free-fall, landing inches from the Oiler’s feet. If he had been standing inches forward, he wouldn’t have gone home.
During the investigation the operator said that he didn’t engage the anti-two-block after he had laid the boom down. The ATB has to be turned off so that the block can be drawn in all the way or else it will drag while driving. It it supposed to be turned back on when the pick starts.
I will always believe that the hurried pace was a major contributing factor.