B+V Project: Crane

Nautical Structures was contracted to design, engineer and build a series of very custom cranes for a recent 98-meter build in Germany. The most challenging of the cranes were two sets of two 4500-Kg / 10,000-Lb capacity overhead beam cranes providing a total hoisting capacity of 9000-Kgs / 20,000-Lbs per side. Due to the unique and spectacular naval architecture of this build, these large-capacity cranes are installed in the overhead of the vessel’s full-beam beach club, below the main deck. To enhance the utility of the beach club space, the large shell-doors are designed to fold-down to open, and are treated with the same teak surfaces as the primary sole in the Beach Club. Once open the tenders may be removed from this space and a very large and opulent lounging and entertainment area is made available to owner and guests. This naval architecture added significantly to the complexities of the cranes. Because the shell-doors open down instead of up, the tender has to be transported a total of 7.6-meters to pass over and clear the door when launching. The cranes stow in a space only 4.3-meters long and telescope outboard in three sections. Built entirely from stainless steel plate these massive crane structures weigh 8-tonnes each! These cranes are synchronized together to ensure that when launching the tender the two crane systems move together. The cranes are also built with Linear Winch Technology; a specialized non-fouling and load-limiting hydraulic winch system using composite fiber line developed and perfected by Nautical Structures. In the design of these cranes the stern beam is configured with two synchronized falls. This adds to the stability of the tender while being launched or retrieved as it is hoisted by three falls in total. All hooks and weights self-stow after use. The crane operator has control over the trim of the tender, and may hoist the tender with a slight bow-up configuration if desired. The crane is controlled by a wireless proportional control system. The wireless controller features an optional-use wanderlead that may be used in the event the wireless signal is compromised. A back-up manual control system is installed in the event the electronic system is inoperative for any reason.

These cranes are constructed from Lloyd’s Register certified 316-L stainless steel plate, and mirror-polished to a superyacht finish. Because these cranes are located in a highly finished accommodation area on the yacht, and not in a more typical engineering space, the final finish and detailing of these cranes had to be addressed in unique fashion; 50mm thick plate finished as a piece of jewelry. The cranes were built to class; LAME (Code for Lifting Appliances in the Marine Environment), built under LR survey and delivered with Cargo Gear certificates.

The fact that the tenders were to be removed to evolve the tender garage space to a Beach Club space meant that provisions needed to be made to moor the tenders while removed. Nautical Structures designed and engineered a pair of hydraulic boat-booms for this purpose. These boat booms were designed to support a 9-tonne tender in dynamic sea conditions. The boat booms telescope 3-meters off the side of the yacht from LR approved watertight housings. Into the final section of the boat boom Nautical Structures installed a specialized hydraulic Linear Winch system that provided a fairlead to the tender. The hydraulic circuit prevents the booms from being retracted into the yacht while the line is out of the boom. These booms are manufactured from 316-L stainless steel, and mirror-polished.