Tank testing results: >
In first phase; the BB GREEN team developed two ASV designs; one ASV Catamaran and one ASV Monohull. Benchmark was State of the Art (SOA) planing monohull with a design speed of 30 – 35 knots (@ 20 m LOA and with a beam of 6 m). Design displacement / load 25 m3 / tons. Two ASV tank-testing models were built, fully instrumented and tested at SSPA Sweden in Gothenburg; in calm waters (hull resistance etc) and in waves (onboard motions, passenger comfort aspects etc). Testing an ASV is much more demanding than testing a conventional “wet” hull concept. There are several more parameters to investigate and adjust; including but not limited to lift fan set up, ducting, volume flow, pressure; air cushion enclosure flap arrangement and more. All test runs were fully documented; including full data acquisition of all key parameters, still photos (over and under water), videos (also inside the air cushion) etc.The results were then analyzed and scaled to ship values; then compared with SOA conventional “wet” monohull results.
The hull resistance values (kN) vs.speed (knots) are presented in below graph (Source SSPA Sweden) and Tank testing for BB GREEN type of ASVs for more demaning sea states.:
The blue line shows State of the art planing vessel while the green line shows the selected BB GREEN ASV Mono hull. The red line shows the values of the BB GREEN catamaran version.
The hull resistance for the selected BB GREEN monohull shows significant reductions not only at design speed, but over the full speed range – from 10 knots all the way up to 60 knots.