raghuvaran chakkaravarthy
497

Sharing as Received:

Subject: Initial Notification: contractor Dropped Load (Window) Crane Mishap - no injuries

ALCON:

At approximately 0900 on 22 October 2012 a Link belt Model 8690 crane in use by a glass installation subcontractor to set window panels shut down in mid-pick. A 1000 lb. window panel being lifted was rigged with two 1100 lb capacity Powergrip vacuum cup system attachments, for a total capacity of 2200 lbs. A crane mechanic was called at approximately 0915. The on-site prime contractor staff evacuated the hospital building and ensured everyone was accounted for. The area under the window panel was barricaded for the crane pick and remained so while the window panel was suspended. There were concerns that the vacuum cup system would fail and release the window. Because the building had been evacuated no one had a visual or audio confirmation on the vacuum gages or alarms on the vacuum cup devices. At 11:42 the crane mechanic arrived and began his diagnostic work. The mechanic discovered a blown fuse which shut down the fuel supply to the crane engine. Without engine power all systems shut down on the Link belt 8690 including all controls over the hoist line. At 12:05 the prime contractor SSHO reached the penthouse roof with his zoom lens camera to visually check the vacuum system holding the windows. At 1206 he was able to clearly see the cups were holding, no alarms sounding, and the gages were in the green. At 12:06 the mechanic was able to replace the blown fuse and the crane operator started the engine.

The crane operator immediately began to swing left, rotating the superstructure and the load back in the original direction from where the window panel was picked up. He was operating in the blind without the ability to see the load and without a signal person in place on the roof or ground. At almost the same time a subcontractor foreman positioned himself between the crane and the building and ordered the crane operator to swing right. The crane operator obeyed and immediately swung right. The foreman directing/signaling the crane was also in the blind, without a visual on the load. The window panel that had been suspended for the past 3 hours was nearly even with the penthouse roof, about 20 feet away. As the window panel began to swing right, it struck the west penthouse roof line and as it was pulled over the top of the guard rail, the bottom vacuum cup became tangled in the posts. When persons observing from a distance began to yell that the window was hitting the building, the crane operator immediately swung back left ripping the bottom vacuum cup device from the window. The window panel then dropped on to the upper vacuum cup device which broke its seal and released the window panel. The falling window panel struck the steel frame work of the entry way canopy. There were no injuries. The window panel was a total loss with an estimated value of $5000. The vacuum cups were also damaged and will need to be serviced by the manufacturer with an estimated cost of $1000. Operator began operation without direction and without a signal person in place with eyes on load.

DIRECT CAUSE:

. The Operator began operation without visual observation of the load and without a signal person in place with eyes on load to give him direction.

. The glass subcontractor foreman directed the crane operator to swing the load in a direction that neither he nor the crane operator could see before the signal person was in place and had established communications with the operator.

ACTIONS:

. All glass installation crane operations are halted.

. All use of the vacuum cup lifting devices are halted.

. All work by subcontractor glass installation crews are halted for a Monday, October 22 crew-wide stand-down and then all workers sent home except those involved in the incident. Those involved will be part of the on-going investigation.

. The on-site leadership of the glass installation subcontractor are removed from the project.

. The glass installation company senior leadership must conduct a full investigation and a develop a revised plan to complete the remaining scope of work without incident.

. Complete resubmission of the critical lift plan.

From United States, Fpo
Attached Files (Download Requires Membership)
File Type: pptx Below the Hook Vacuum Device Dropped Window.pptx (1.80 MB, 106 views)

boss2966
1166

Thank you Mr. Raghu for sharing such useful and essential learnings with our members. Of sure, I will disseminate with my Safety Team members. Keep on educating.
From India, Kumbakonam
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