With single elements weighing up to hundreds of tonnes and lifted to heights of 100 meters, offshore wind turbines can pose risks to personnel, assets, and the environment during installation and maintenance interventions. To increase safety during offshore lifts, this study focuses on solutions for human-free lifting operations. Ideas in the categories of logistics, connections, as well as guidance and control, were discussed and ranked by means of a multi-criteria decision analysis. Based upon 38 survey responses weighting 21 predefined decision criteria, the most promising concepts were selected. Logistically, pre-assembled systems would reduce the number of lifts and thus reduce the risk. A MATLAB-based code has been developed to optimise installation time, lifted weight, and number of lifts. Automated bolting and seafastening solutions have high potential to increase safety during the transport of the wind turbine elements and, additionally, speed up the process. Finally, the wind turbine should be lifted on top of the support structure without having personnel being under the load. A multi-directional mechanical guiding element has been designed and tested successfully in combination with visual guidance by cameras in a small-scale experiment

Balaam, T.

Brennan, Feargal

Causon, Paul Douglas

Cevasco, Debora

Kolios, Athanasios

Leimeister, Mareike

Richmond, M.

Journal of Physics Conference Series

English

Cranfield CERES

Human-free offshore lifting solutions

Leimeister, M.

Causon, P.

Cevasco, D.

Kolios, A.

Brennan, F.

Fraunhofer-ePrints

Current offshore wind turbine lifting procedure: -single elements weighing up to hundreds of tonnes and lifted to heights of 100 meters; Current offshore wind turbine lifting procedure: -risks to personnel, assets, and the environment during installation and maintenance interventions. Objectives: -increase safety during offshore lifts; Objectives: -solutions for human-free lifting operations. Methodology: -ranking and selection of most promising concepts based on a multi-criteria decision analysis with 38 survey responses weighting 21 decision criteria; Methodology: -logistics: development of a MATLAB-based code for choosing pre-assembly method to optimise installation time, lifted weight, and number of lifts; Methodology: - connections: high potential of automated bolting and sea fastening solutions to increase safety during transport and speed up the process; Methodology: -guidance and control: design and small-scale test of a multidirectional mechanical guiding element in combination with visual guidance by cameras

Balaam, Toby

Causon, Paul

Richmond, Mark

University of Strathclyde Institutional Repository

Download  the poster  windeurope.org/summit2018 #GlobalWind2018 Travel offshore(after jack-down)Pre-assembly of components (port)Loading on vessel/bargeJack-down and travel to next turbineJack-up and turbine installationReturn to port “empty” and jack-upFarm fully installed? Vesselempty?STOPYESYESNONOSTARTFITTING CODE(no. turbine on deck)Human-Free Offshore Lifting Solutions Mareike Leimeister1,3,4, Toby Balaam2, Paul Causon1, Debora Cevasco1,3,  Mark Richmond1,3, Athanasios Kolios3, Feargal Brennan3 1 Cranfield University, 2 University of Oxford, 3 University of Strathclyde, 4 Fraunhofer IWES Replace with QR code Existing pre-assembly methods: • bunny-ear (BE) method (figure 1a); • rotor star (RS) method (figure 1b); • single piece (SP) installation (figure 1c); • tower installation as one piece (1T) or two sections (2T).      Figure 1. Pre-assembly methods: (a) Bunny-ear [1,2], (b) Rotor star [1,3], (c) Single pieces [1,2]. Pre-assembled wind turbines: + require fewer lifts; + reduce number of hazardous offshore lifts; - heavy load with large wind exposed areas; - increased lifting hazard; - feasibility constrained by lifting capacities, vessel requirements, and stability limitations for transportation and installation. Developed MATLAB code (figure 2) and GUI: • find optimal compromise between number of lifts and lifted weights; • maintain or even decrease installation time.          Figure 2. Installation pre-assembly MATLAB code flow chart. PO.201 Logistics Connections Guidance and Control Global hoisting procedure: • mostly vertical lift to height; • use of taglines and remote control. Final positioning of load on counterpart: • use of guide pins/rods and socket sections, cones or funnels, and manual guidance; • proposed solution: combination of visual and mechanical guiding systems. Visual guidance: • test of different camera configurations; • best camera setup (figure 4a): 3 circumferential standard cameras + 1 central 360°-camera.          Figure 4. (a) Cameras for visual guidance, (b) Experiment setup with visual and mechanical guiding systems. Holistic mechanical guiding system (figure 5): • for centralisation and rotational alignment; • guide rod (on lifted part) + socket section within conical extension (on fixed section); • removable  and reusable.    Figure 5. Holistic mechanical guiding system design. Small-scale experiments with visual (figure 4a) and mechanical guiding systems (figure 4b): • fast lifts with exact positioning; • cheap auxiliaries will pay for themselves and may even enhance economic gains. Commonly used ring-flange connections: • more than 120 high-strength, pre-stressed bolts of large size (M64 or M72 [4]); • accurate tightening of pre-assembled bolts. New connection and seafastening methods: • friction-based connection solutions [5]; • BLUE Wedge [6] (connection and seafastening); • hydraulic or internal jack seafastening [7]; • automated bolting systems [8,9]. Enhanced seafastening methods: • hydraulic seafastening is safer and quicker; • robot arm employment for automated bolting (figure 3), retaining reliability, reducing risk, and increasing speed.           Figure 3. Automated bolted seafastening, concept illustration [10]. Current offshore wind turbine lifting procedure: - single elements weighing up to hundreds of tonnes and lifted to heights of 100 meters; Current offshore wind turbine lifting procedure: - risks to personnel, assets, and the environment during installation and maintenance interventions.  Objectives: - increase safety during offshore lifts; Objectives: - solutions for human-free lifting operations.  Methodology: - ranking and selection of most promising concepts based on a multi-criteria decision analysis with 38 survey responses weighting 21 decision criteria; Methodology: - logistics: development of a MATLAB-based code for choosing pre-assembly method to optimise installation time, lifted weight, and number of lifts; Methodology: - connections: high potential of automated bolting and seafastening solutions to increase safety during transport and speed up the process; Methodology: - guidance and control: design and small-scale test of a multidirectional mechanical guiding element in combination with visual guidance by cameras. Abstract  a) b) Feasible solutions for human-free offshore lifting operations: • optimised planning of logistics and turbine installation (MATLAB program); • novel automated bolted seafastening concept; • holistic guiding auxiliaries (visual and mechanical) allow human-free lifts. → Increased safety with additional economic benefit. Conclusions References 1. Uraz: Offshore Wind Turbine Transportation & Installation Analyses, Gotland University Sweden (2011). 2. US Wind Energy Industry Develops around Block Islands Turbines, https://www.aiche.org/ (2015). 3. Royal HaskoningDHV Team Studies OW Financing Side, https://www.offshorewind.biz/ (2015). 4. Ring flange connections, SKI (2018).  5. Heistermann, et al.: Flange connection vs. friction connection in towers for wind turbines, NSCC (2009). 6. Fistuca BLUE Wedge Connection, http://www.heavyliftnews.com/ (2018). 7. Hoeksema: Innovative Solution for Seafastening Offshore Wind Turbine Transition Pieces During Transport, Delft University of Technology (2014).  8. Sydenham: Robotic Installation of OSI-Bolts, SAE (2015).  9. Müller, et al.: Robot guided bolt tensioning tool with adaptive process control for the automated assembly of wind turbine rotor blade bearings, Prod. Eng. Res. Devel. 8 755-764 (2014).  10.Richmond, et al.: Multi-Criteria Decision Analysis for benchmarking Human-Free Lifting Solutions in the Offshore Wind Energy Environment, Energies 11 1175 (2018).   

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Human-free offshore lifting solutions

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