Manned Submersible Handling – Stern A-Frames

The Caley A-frame is recognised as the handling system of choice for operators of ocean research submersibles around the world. With a track record that includes several systems in continuous service for over 30 years, and many thousands of successful deployments, the company’s submersible handling systems continue to prove their worth time and again.

Woods Hole Oceanographic Institution

The Woods Hole Oceanographic Institution has used a Caley A-frame Launch and Recovery system since 1983 to launch and recover the Institution’s submersible ‘Alvin’ from the RV Atlantis II. The original Alvin submersible weighed 35,000 lbs (15,909 kg), later upgraded to 40,000 lbs (18,182 kg) at which point the A-frame was overhauled and moved to RV Atlantis in 1996.

The latest mechanical, hydraulic and electrical upgrade of the Caley A-frame enables the launch and recovery of the latest ‘Alvin’ submersible weighing 50,000 lbs (22,727 kg). Part of the project also involved the installation of a larger winch, high performance synthetic ropes and light tension control system, to provide accurate handling control of Alvin.

Photo by Dutch Wegman, Woods Hole Oceanographic Institution

Testing Times

To demonstrate the capability of the upgraded Caley A-frame, WHOI tested it with a lift of 100,000 pounds (45,360 kg) – twice the weight of the new ‘Alvin’ submersible. It passed with flying colours!