Page 52: of Maritime Reporter Magazine (May 2020)

In the Yard

New Ship & Boat designs, contracts & deliveries

BMT

Pentamaran: Next-gen Hull for Autonomous Ops

MT released details of its ‘Pentamaran’ platform for possible results.” autonomous applications, vessels that can be custom A key consideration when a vessel is operating autono-

Bconfgured for military, patrol, intelligence surveillance mously for long periods is the reliability of the propulsion and reconnaissance (ISR), anti-submarine warfare (ASW) and setup. “When looking at autonomous operations, removing hydrographic survey work. The current designs go from 40 to the human operator requirements into the design fundamen- 80m, but it can be scaled up or down to suit particular require- tally changes the design philosophy that impacts not just the ments. “As for the hull construction, we have used aluminium confguration of the power systems but also the entire below to keep the weight down,” said Martin bissuel, Business decks arrangement,” said Bissuel. “The propulsion design

Sector Lead for Specialized Ship Design at BMT. “For the could therefore move away from conventional setups. Mul- smaller units, composites could also be considered.” The tiple diesel-electric generators provide power for electric pro- design features a narrow central hull and two smaller hulls pulsors. The generators are positioned in different locations or on each side, for a total of fve hulls. The two small hulls, or compartments, increasing survivability and resilience because sponsons, are set one behind the other. BMT tests have report- if one of the generators has an issue, power can still be provid- edly established that the Pentamaran design reduces drag in ed by the other units. Maintenance is made easier because of comparison to monohulls, catamarans and trimarans. the smaller generators, but more importantly, operationally it “In calm conditions, the forward small hulls or sponsons provides what we describe as graceful degradation of perfor- on each side are not submerged in the water, and therefore mance if units should fail, but providing high confdence that do not generate any drag. These forward sponsons serve to the unit can be returned.” supply roll stability when waves develop,” said Bissuel. “As With variables in propulsion system, speedand fuel, it’s not a result, the Pentamaran has less hull volume permanently possible to pinpoint duration, but Bissuel said that “When it immersed in the sea than a trimaran would have, resulting in comes to endurance the Pentamaran has been designed to push reduced resistance through the water. Also, the positioning of the boundaries. The profle varies depending on the customer the outer hulls, length-wise, is absolutely key to obtaining the requirements. We have run models when the 40m vessel will best results. Through extensive tank testing we have been able be able to do 40 days deployments, while 60 days can be to optimize the overall arrangement of the hulls for the best achieved with the 62m version.” 52 Maritime Reporter & Engineering News • May 2020