The Crosby Group, a leading manufacturer of rigging, lifting, and material handling hardware and equipment, has received a significant order for custom 115-tonne safe working load(SWL) sheaves to overhaul the drilling towers on a fleet of vessels.
These hulking drilling towers reach 65m above the deck of vessels that have been modified to drill oil and gas wells. Such drill ships are equipped with a drilling derrick; the sheaves handle the guiding of the wire to lift the drilling equipment up and down the tower(or derrick).
For this latest project, the sheaves each weigh 1.5 tons and meet EN 1563, DNV, and other relevant standards. With an outer diameter of 2,273mm, the sheaves will be used with 70mm-diameter wire rope to raise and lower drilling equipment.
The in-service vessels each have a drilling depth of nearly 12,200m(approx. 40,000 ft.) and typically work in 3,650m(approx. 12,000 ft.) water depth. They required a strategic overhaul, due to shortcomings with a previous solution, that had to be completed over a period. The scale of the order represents The Crosby Group’s continued ability to meet the offshore industry’s biggest challenges—from drilling to heavy lifting.
Øvstetun belongs to  the Engineered Solutions department at The Crosby Group and  is based in Bergen, Norway, but serves the global operation. The company boasts an extensive catalog of Crosby-branded and other rigging, lifting, and material handling hardware, but it is also a specialist manufacturer of heavy-duty, high-capacity custom solutions, which goes through Øvstetun’s team. He pointed to recent standout projects, including a 1,000-tonne capacity quad hook, which leveraged Crosby Feubo equipment; an 800-tonne capacity hook block; and sheaves that were over 16 ft. in outer diameter.