HMS Queen Elizabeth, which had her maiden voyage in June 2017 and is now joining flight trials with stealth fighter jets off the east coast of the United States, and HMS Prince of Wales, due for service in 2020, are the largest warships ever built for the Royal Navy, capable of carrying up to 40 aircraft each.
Each ship carries five cranes from SCX Special Projects: three overhead cranes for the ship’s hangar, one of which is a ‘high-hat’ crane; an overhead crane for the workshop; and a 360° knuckle boom crane for loading duties. All have been engineered with at-sea operation firmly in mind, and safety for both crane operators and crew is a primary design objective. All the cranes are Lloyds compliant and are deigned to operate safely in very rough conditions and waves up to 20 feet in height.
Running bow to stern, the gantry cranes span up to 8.1m. The ‘high-hat’ cranes – designed to maximise the lifting area – span 2.8m running port to starboard. Rack and pinion drive systems remove any potential for movement normally found in rail-based crane systems, and anti-uplift brackets ensure vertical stability on rocky seas.
SCX Special Projects has designed the cranes to withstand shock loadings and has included reinforced areas where the crane hoists can be stowed away safely. Monitoring sensors and slow-down switches ensure minimise any unwanted movements of the load and the hoist, while inverter controls guarantee smooth movement in all directions.
All cranes are operated via an infra-red remote control – radio controls could have caused interference – with a plug-in cable pendant as a backup.
Andy Whitworth, director of SCX Special Projects commented: “We bring together decades of experience in safe load lifting with outstanding engineering talent across mechanical and electrical engineering.
“Our solution includes a vast number of carefully engineered enhancements to proven crane designs, each tailored to meet the demanding ocean-going conditions that HMS Queen Elizabeth will encounter.”
SCX Special Projects www.scxspecialprojects.co.uk
Photo credit: © Crown copyright