Developed in 1976, the Crandall system for mooring floating dry docks is a fully-articulating, two-point, three-arm type which can provide essentially unlimited flexibility of movement, sufficient to handle all drydocking situations. Each of the three assemblies consists of a linkage arm and gripper connected with a spherical bearing. The grippers slide along the guides which form an integral part of the dock’s wing wall structure. The support brackets for the linkage arms are bolted to a pier or dolphin at two locations.
The normal configuration has two mooring arms at 90 degrees to the wing wall and the third at 45 degrees. Other configurations can also be used. Each Crandall mooring system is designed to meet the requirements of MIL-STD-1625B “Drydocking Facilities Safety Certification Criteria for Docking U.S. Navy Ships.” It is available in sizes to suit virtually any combination of floating dock and mooring conditions and is presently operating successfully in over twelve major shipyards throughout the US and Canada.