Deliverable ISSIA 1.2 RITMARE

This work describes the design of a new propulsion unit for an Unmanned Surface Vehicle developed by CNR-INSEAN and CNR-ISSIA. U-SWATH is a big dimensions autonomous surface vehicle belonging to the category of Small Waterplane Area Twin Hull, better known by the acronym SWATH. A twin-hull ship design that minimizes hull cross section area at the sea's surface. The vehicle will be modular and its dimensions are reported in Figure 1. The weight of the vehicle will be around 1500 kg, of which 400/500 of payload. Figure 1: USWATH dimensions The SWATH shape is chosen although the small variation of restoring hydrodynamic contribution could not guarantee a perfect seakeeping for vertical motions, it ensures excellent transversal stability, it allows in an excellent manner satisfy the need for modularity. Since the vehicle will be modulare, INSEAN and ISSIA have identified 6 modules for each hull. Every module will be waterproof and can be easily modified and/or changed, if needed, to contain different types of instrumentations. Each of the two submerged hulls will be connected to the deck via two vertical struts, one forward and the other aft. The bridge is constituted by a rectangular box almost 20 cm high with an exposed area of approximately 15 square meters with solar panels and possibly host a solar sail. It will also evaluate the possibility of hosting other mechanisms for the extraction of energy from wind and waves and currents. On the deck it is provided a winch necessary to recover objects present in the water (if necessary UUV and AUV). The typical duration of the missions carried out by USWATH will be of 7-8 hours and the maximum speed will be of 3 m/s for transfers, while it will be of 1 m/s or even less for the steps of monitoring and measurement. The possible applications of the vehicle are: oCoastal monitoring oFirst emergency monitoring for oil-spill oLoading on board the vessel Urania and the new research vessel oDocking of AUV (aircraft) and UUV (underwater) oForming a bridge of communication between various vehicles and the mother ship oLaboratory for bio-chemical type measures oHydrodynamic noise measurement oTesting of new materials oTesting of new engines oTesting of new propellers oTesting of new stabilizers oTesting of new control surfaces oTesting of new optical and electromagnetic oTesting of new sensors.