by Simon Bamford4 May 2022
Scope
Rolls-Royce Energy Systems were constantly striving to reduce costs associated with the transport and installation of their large offshore gas turbine generator packages. Factory assembly, including connecting the compressor and turbine elements, significantly reduces transport and site assembly times and costs but leads to a heavier package and precision lifting requirements that do not put any compression loads on the stillages or any bending loads on the drive shaft. The total load to be lifted increased to 415 tonnes and the tolerance on the level of the lift in both planes was set at 1 degree from horizontal.
Rossendale Group was asked to offer a design for the lifting equipment, backed up by calculations, detailed drawings, manufacture, testing, certification, QA documentation and operating manuals
Solution
Rossendale Group has an in-house spreader beam design system which uses SolidWorks 3D CAD and DriveWorks software, linked to FEA output. This system can produce a verifiable design output within minutes for any configuration of package lifting/spreader beams up to 500-tonne SWL.
Result
Rolls-Royce ordered a spreader beam system, using 2 tiers of beams and 3 tiers of wire ropes.
The design, which had a 3:1 factor of safety on all steel load-bearing components and a factor of 5:1 on all shackles and wires, conformed to:
- BS EN 13155:2003, Cranes – Safety – Non-fixed load lifting attachments
- ANSI/AISC 360-05, ‘Specification for Structural Steel Buildings’
- Det Norske Veritas (DNV) ‘Rules for planning and execution of Marine Operations’
- Det Norske Veritas (DNV) ‘Rules for Certification of Lifting Appliances’
- Machinery Directive 2006/42/EC – 2nd Edition
- Supply of Machinery (Safety) Regulations SI 2008/1597
- LEEA 055, The Verification of Spreader Beams, Lifting Beams and Lifting Frames
The manufacture was carried out in-house at Rossendale Group’s facility in Lincoln. Manufacture was supported by a quality plan which included approved welding procedures, qualified welders and MPI and ultrasonic examination of welds.
The spreader beams were tested at Rossendale Group’s facility in Ellesmere Port, which applies calibrated hydraulic loads to the beams in an arrangement which accurately simulates the modes of use. The tests were third party witnessed and approved by Lloyds Register.
The finished product, which included the spreader beams, wires and shackles were packed for shipment and sent to Houston, USA, from where they were used for several successful onshore, inshore and offshore lifts.
The lifting of our gas turbine compressor packages is a vital part of our product offering that we have to outsource. A reliable, competent supplier who can offer the correct equipment for the job, with all necessary design calculations, quality control, testing and certification is essential to us. Rossendale Group is a rare find in this respect. We can rely on them.”
Dan Bidlac | Engineer, Rolls-Royce Energy Systems
