Sanmar’s first Voith Schneider Propeller (VSP) tug of VectRA 3000 series, M/T ARES, being constructed for Italian tug operator Tripmare S.p.a. of Trieste, has been launched to sea at Sanmar Shipyard, Altinova last week.
The vessel has been carried from the tugboat production hall to the floating dock by the shipyard’s modular transport system.
VectRA 3000 series has been designed by the Canadian naval architects Robert Allan Ltd. This design, developed exclusively for Sanmar, contains many innovative ideas from both the builder and designer aimed at developing a cost-effective VSP tug for the world market. Sanmar’s brief to Robert Allan Ltd
was to create a VSP tug which was under 500 GRT and which would incorporate high-speed engines, a clutch between thruster and engine, electronic controls and be fully MLC 2006 compliant for all crew accommodation. The challenges therefore focused on the machinery design and the overall layout.
The tug measures 30.25 meters in length with a molded beam of 13 meters and an overall draft of 6 meters.
The most unique aspect of the design is the propulsion arrangement. Driving the forward located Voith type 32-R5 250 cycloid propellers are a pair of Caterpillar 3516C high speed diesels, each developing 2,525 kilowatts at 1,800 revolutions per minute. Instead of the traditional Voith Turbo coupling, the engines are connected to the Voith propulsion through a pair of Reintjes model WAF 843 clutch and reduction gearboxes. This reduces transmission losses, thus increasing the overall propulsion efficiency, and also enables the drives to be de-clutched at idle, significantly reducing fuel burn. Using high-speed engines also significantly reduces the space occupied by drive machinery and of course results in much lower weight, allowing a finer more efficient hull form for the same deadweight.
The installed cost is also significantly reduced. This machinery combination will deliver a bollard pull of up to 70 metric tons and will drive the hull at a predicted speed of not less than 12.5 knots.
This tug also incorporates the new electronic Voith Remote Control system. This control is set up to work in a combinator mode whereby both rpm and pitch increase together at a predefined ‘ramp up’. It is believed that this is the first installation of high speed engines with VSP drives in conjunction with the Voith Electronic Control System. Just like The ASD tugs, this combination lets the captain to clutch-off the thrusters when the tug stays at idle hence saves fuel.
The flush deck layout is relatively conventional for a Voith Tractor, but in compliance with Maritime Labour Convention 2006, all accommodation is on the main deck, with two single cabins for officers, two single cabins for petty officers and a double cabin for crew, each with private en-suite facilities. The galley and mess area adjacent to a central entry and wet lobby area complete the outfit.
The vessel is equipped with a DMT TW-H 800kN hydraulic driven double drum winch with tension indication. The winch is also provided with hydraulic operated friction clutches. First drum has the capacity of 710m Ø 54mm steel cable at 10 layers whereas the second drum has the capacity of 150m Ø94mm nylon rope at 6 layers. Both drums have the brake capacity of 200 tons.
The electric power is delivered by two 86ekW Caterpillar C 4.4 generator sets.
The vessel is also designed according to ABS Habitability workboat (HAB(WB)) notation, which requires specific attention to decrease vibration and sound levels. This is the first vessel of Sanmar that is constructed in compliance with this notation.
M/T ARES is classed by the American Bureau
of Shipping, with the notation *A1, *AMS, Towage Vessel,ABCU, Unrestricted Service, Fi-Fi1, HAB(W8), UWILD. Fully compliant with Italian Flag and MLC 2006 regulations. The vessel has oil recovery notation as well.
She will be ready for her maiden voyage by the first week of April.