• Monday, October 22, 2018

Fast patrol craft reaching for better boat handling

By BCShippingNews 21 March 2018
Fast patrol craft reaching for better boat handling
Aluminum davit performance goes beyond standards set for SOLAS...

The lightweight aluminum davits chosen as the boat handling solution best suited for fast patrol craft are rapidly extending their appeal among navies and other border forces, according to Vestdavit.

The leading supplier has recently been advising classification societies on upgraded guidelines on davit performance that go far beyond the standards set by the Safety of Life at Sea Convention. The soon-to-be published guidance is expected to coincide with longstanding recommendations from Vestdavit that boat lifting and lowering speeds should take account of sea states, and acknowledging the safety benefits of dynamic shock absorbers, boat guiding arms and self-tensioning wires.   

Davits used on fast craft merit special attention, according to Rolf Andreas Wigand, Managing Director, Vestdavit. The company recently saw two 26-knot Cape-class vessels enter service with the Australian Border Force, each equipped with a pair of lightweight PLAR-6500 units to lift 6,500 kg rigid hull inflatable boats (RHIBs). Vestdavit has already installed 16 units on eight earlier ABF Cape-class vessels. The all-aluminum davit system is 30 per cent lighter than its steel counterpart.

“Davits must be optimized for safety and efficiency, but fast patrol craft pose challenges for marine equipment,” says Wigand. “Weight is a specific variable; every kilo saved is an opportunity to enhance vessel stability or add payload, or both. Resilience and reliability are performance prerequisites, but so are stability and rapid deployment. Lighter davits enhance maneuverability, fuel consumption, speed responsiveness, in turn expanding a vessel’s operational window.” 

The all-aluminum option from Vestdavit is also preferred for fast patrol boats by the Royal New Zealand Navy, the Danish Navy, the Swedish Navy, and the US Coast Guard, says Wigand. The US Coast Guard is currently installing aluminum PLA-2000 rescue boat davits on their nine (9) Bay-class 140 foot icebreaking tugs. Security forces in the Middle East and South Asia are now considering the solution for fast patrol vessels.

Safe working loads for all-aluminum davits from Vestdavit range between 850kg and 7,000kg, and the equipment type is easy to retrofit, Wigand says. The self-tensioned PLAR-6500 davits are fully SOLAS-compliant but, in line with Vestdavit’s recommendations to Class, also feature shock absorbers, guiding rails, wire haulers, hydraulic end stops and independent HPUs. These attributes combine to help launch and retrieve boats safely at up to 10kts in heavy seas which, in the case of the ABF, stretch from the tropics to the Antarctic.

“A-frame aluminum davits have been designed for use where weight is a high priority, but they are also corrosion-proof and proving themselves day-in-day-out as hard-wearing, high performance assets that navies and coastguards rely on for rapid boat launch and recovery.”

PLAR Type davits are hydraulically operated with power stored via accumulators in compliance with latest SOLAS requirements. They can be installed with optional Wave Compensation System on winch, Hydraulic Wire Puller, Hydraulic Limit Switch and Remote-Control unit.