Turkish shipyard Sanmar has clocked up a first in its 40th anniversary year with the launch of is first Robert Allan Ltd (RAL) designed Voith tractor tug for Italian owner Tripmare S.p.A.

Voith Schneider Propeller (VSP) tractor tug Ares carries the design name VectRA 3000, developed exclusively for Sanmar and will shortly join the fleet of Trieste-based Tripmare after being transferred from Sanmar’s production hall to the floating dock at its Altinova facility on the shipyard’s modular transport system.

It was the intention of Sanmar along with RAL to produce a design including innovations aimed at developing a cost-effective Voith tractor suitable for the global market. The requirement was for a tug under 500grt incorporating high-speed engines, a clutch between thruster and engine, electronic controls and fully MLC 2006 compliant for the accommodation. The challenges were therefore concentrated on machinery design and overall layout. Basic dimensions of the Ares include a length of 30.25m, moulded beam 13m and draught 6m.

The interesting aspect with Ares is the arrangement in the machinery space. Main propulsion is from two Caterpillar 3516C high-speed diesels each developing 2,525kW at 1,800rpm. Instead of the more traditional Voith Turbo coupling however, the engines are connected to the Voith 32R5EC/265-2 units via a pair of Reintjes WAF 843 clutch and reduction gearboxes and Vulkan composite shafts. This arrangement reduces transmission losses, increasing overall propulsion efficiency while also enabling the drives to be de-clutched at idle with a significant reduction of fuel consumption. Electrical power is supplied by two 86ekW Caterpillar C4.4 gensets.

Space required by the drive machinery is significantly reduced through use of high-speed engines with much lower weight allowing a finer more efficient hull form for the same deadweight figure. Installed cost is reported as being ‘significantly reduced’ and performance figures are expected to be a bollard pull of up to 70 tonnes with RAL predicting an escort steering force in excess of 100 tonnes being achievable. Expected speed is not less than 12.5 knots.

Ares also incorporates the new electronic Voith Remote Control System, set up to work in 'combinator' mode whereby both engine speed and propeller pitch increase together at a pre-defined ‘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. Sanmar point out the arrangement is similar to that of ASD tugs where the thrusters can be de-clutched when operating at idle with consequential fuel efficiencies.

Traditional tractor configuration means the stern is the normal working deck and Ares is provided with a DMT TW-H 800kN hydraulically driven double-drum escort winch with hydraulic friction clutches and tension indicators. The two drums have a capacity for 710m of 54mm steel wire (10 layers) and 150m of 94mm nylon rope (six layers) respectively. Both drums have a brake capacity of 200 tons. The towing capability on Ares is enhanced with radial type tow hooks on the main deck forward and aft.

Being the working end as such, the stern features heavy duty cylindrical fendering with a ‘W’ fender below. Hollow ‘D’ fenders protect the sheer lines and tie into the ‘W’ fenders at the bow. The tug is built to ABS class requirements and carries the notation: *A1, *AMS, Towage Vessel ABCU, Unrestricted Service, FiFi1, HAB(W8), UWILD. It also complies with Italian flag regulations and carries oil recovery notation.

Maritime Labour Convention 2006 compliance requires all accommodation to be on or above main deck level resulting in a traditional flush deck layout. Crew facilities consist of four single and one double crew cabins, each with en-suite bathrooms. A lounge/mess area and galley are also located in the main deck deckhouse adjacent to a central area and wet lobby with galley stores and laundry room located below main deck forward. Ares meets ABS Habitability Workboat notation with specific attention to vibration and sound levels with the cabins achieving a 60dB noise level.

By Peter Barker