A series of free-running models of fast wind-farm support vessel designs have recently been tested by Seaspeed Marine Consulting for South Boats in order to develop the most appropriate hull forms for their next generation of vessels.
Models of different hull designs, instrumented for performance measurement, were outfitted for self propulsion and run at sea and in a test tank in a range of situations likely to be encountered during wind-farm support activities.
Seaspeed’s Managing Director, Stephen Phillips, said “The results have provided surprising insights into the relative performance of different designs and have lead to a far better understanding of small fast workboat performance. These tests have been particularly useful for the study of limiting motions such as slamming, bow wetness, lateral and vertical motions, directional stability, loss of speed in a seaway, manoeuvrability and handling when thrusting-up against a wind-turbine tower for personnel transfer in rough weather.”
“This free-running test technique provides the most cost effective and realistic performance characterisation available for fast vessels, covering important issues which cannot be successfully investigated using either conventional tank testing or Computational Fluid Dynamics techniques, or even full scale trials, where risk and safety issues limit the actual trials that can be undertaken.”
“The models were fitted with appropriately scaled propulsion systems, instrumented to measure the parameters of interest and run at sea in measured sea-states over a wide range of speeds and headings. The long run times available in open water allowed for reliable statistical data analysis and edited videos of the tests taken from the chase boat provided good visual appreciation of performance, particularly when two different models were run side by side.”
“Wind farm support vessels present an unusual mix of rough weather operational requirements covering transit at high speed, loitering at low speed, transfer of personnel and heavy gear to fixed structures and the flexibility to tackle a range of routes and varying workboat tasks. These open water tests have proven to be an excellent method for providing a realistic and rapid assessment of the performance of a range of designs for this demanding application.”
Seaspeed also recently used this test technique for development of the RNLI’s new Shannon Class all weather lifeboat hull form and, in past years, for the development of fast ferries, patrol craft and luxury yachts.
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Source: Seaspeed Marine Consulting, March 8, 2012