Alaska diver executed an ice dive in negative 15 degree weather with an ice thickness of 5 feet to recover an offshore drilling tool that fell from a chopper sling load. The replacement tool value was $500,000.
Used two Rolagon’s to transport dive crew and support personnel to offshore location. 20″ hydraulic auger bits were used to create entry hole into dive location on the arctic ocean.
We performed emergency repairs to a leaking hydraulic system. The repairs were completed at a depth of 175 feet at an elevation of 5,400 feet. With altitude corrections,diving depths were equivalent to 200 feet. To accomplish this task,we mobilized all aspects of a mixed-gas diving spread to French Meadows Reservoir in December,2006.
Together with PG&E personnel,we replaced the existing 14″ hydraulic cylinder and portions of the existing lines. After the replacement of the cylinder,the new cylinder and hydraulic required less than 1/3 of the original hydraulic pressure to operate the gate.
The project was conducted over a three-week time frame involving 25 dives without incident. We were responsible for providing cranes,barges,and environmental controls for the operation. The operational considerations included -30 below zero temperatures and extreme snow accumulations. A major concern of all parties was the potential release of hydraulic fluids into the lake.
All diving and operations were conducted safely and without incident in the extremely harsh deep-diving environment. Environmentally,the project was conducted without incident.