Turkey’s Med Marine Shipyards recently delivered Vittoriosa, the first RAstar 3000-W Class LNG terminal escort tug to Tug Malta, a wholly owned subsidiary of the Rimorchiatori Riuniti Group, Genoa, Italy.
The Vittoriosa will soon commence operations for Tug Malta at Malta’s Delimara LNG terminal.
Med Marine, a long-time builder of Robert Allan Ltd. designs, has recently begun expanded its portfolio of tugs and the RAstar 3000-W is the latest addition to its product line to be delivered.
The RAstar series is a unique class of very high-performance ASD tugs, designed with a sponsoned hull form proven to provide significantly enhanced escort towing and seakeeping performance. Roll motions and accelerations are less than half those of comparable sized “standard” tug hulls.
These tugs are high-powered and well suited for escort operations in weather and the exposed areas encountered at many new LNG terminals where a high standard of seakeeping is required.
Beyond the high-performance hull form, the RAstar 3000-W design for Tug Malta has numerous other features for LNG terminal support. The bow fendering system is designed for a low contact pressure requirement of 20 t/ sq.m. A gas detection system is fitted to warn the crew of a potential hazardous atmosphere. Ventilation dampers can be remotely closed. All essential electrical equipment on deck is certified safe and type suitable for use in a Zone 2 LNG environment and all non-essential electrical equipment can be electrically isolated. Fi-Fi 1 capability with water spray is provided along with a large capacity of fire-fighting foam.
The RAstar 3000-W is designed with a low profile for operation under the flare of assisted ships. The wheelhouse provides excellent 360-degree visibility from the operator’s position and superb sight lines to the fore and aft working decks. The fore and after decks can be fitted with various deck machinery options. Tug Malta elected to use a double drum winch with dual aperture escort staple on the fore deck and a towing hook on the aft deck with the option for future installation of an aft towing winch.
The Vittoriosa was designed and constructed to RINA rules with the following notation:
RINA C ✠ HULL ✠ MACH; ESCORT TUG; FIRE FIGHTING SHIP 1; WATER SPRAYING; UNRESTRICTED NAVIGATION; AUT-UMS; AUT-PORT; COMF- NOISE C; COMF-VIB C; INWATERSURVEY
Particulars of the RAstar 3000-W tugs are:
Length overall: 29.70 m
Beam, molded, extreme: 13.30 m
Depth, molded (hull): 5.45 m
Operating Draft (100 DWT): 5.42 m
Load Line draft (250 DWT): 5.95 m
Gross Tonnage: 481
Tank capacities are:
Fuel oil: 203 cu.m
Potable water: 18 cu.m
Foam: 10 cu.m
Sewage tank: 5 cu.m
Grey water: 5 cu.m
The vessel’s accommodations are outfitted to MLC compliant standards for a crew of up to eight personnel. The Master and Chief Engineer cabins with private ensuite washrooms are located on the main deck with three double crew cabins all with private ensuite washrooms, are located in the lower accommodations.
Main propulsion for the tug comprises a pair of box cooled MTU 16V4000M65L diesel engines, each rated at 2,560 kW at 1800 rpm, driving through a carbon fibre floating shaft system a Rolls Royce, US 255 P30 FP fixed pitch Z-drive unit with HD slipping clutches on the drive units.
The double drum escort rated bow winch, Rolls Royce model ETWH 2500/1000 is driven by two high pressure hydraulic PTO pump units off the front of the main engines. First layer pull on low speed is 102 tonnes at 9 m/min and high speed pull is 12 tonnes at 57 m/min. Rendering is 145 tonnes at 14 m/min. low speed and 24 tonnes at 51 m/min high speed.
Two (2) identical diesel gensets each with a power output of 99 ekW provide electrical power to the vessel.
Ship handling fenders at the bow consists of an 800 x 500 cylindrical fender with 600 x 300 mm “M” block fendering below. A 300 x 300 hollow “D” fender provides protection at the main deck sheer line and along the knuckle, and 600 x 300 mm “M” block fendering is used at the stern.
On trials, the Vittoriosa demonstrated nearly equal ahead and astern performance:
Bollard pull: 81.5 tonnes ahead, 81 tonnes astern
Free running speed: 13.8 knots ahead, 13.7 knots astern