It is also by far the largest and most powerful newbuilding for both owner and shipyard.

In keeping with the majority of vessels in the Holyhead fleet the new tug has a shallow draft and is designed to support dredging, coastal improvement schemes, marine civil engineering projects and a wide variety of other offshore projects such as wind farm construction.

Afon Alaw was designed by Hepworth Shipyard, working in close collaboration with Holyhead Towing's technical staff, and is almost identical in configuration to the Afon Cefni delivered by the yard two years ago. The latter has proved to be a highly successful and popular vessel. In keeping with the earlier tug, Afon Alaw is equipped to carry out coastal towing operations, dredging with a towed plough, anchor-handling, lifting, and other supporting services on site.

The new vessel will have greater scope to carry out seagoing towage operations and is classed by Lloyds +100 Tug, has a full load-line certificate and also complies with the UK MCA Code of Practice - Category 1 for operation 150 miles from a safe haven.

The tug is of all steel, welded, construction with an overall length of 25.5m, a beam of 9.0m and depth of 3.6m. An important factor in the design of this type of vessel is the shallow working draft of 2.4m. As with its predecessors a single chine hull design was chosen in order to achieve a shallow draft, the required buoyancy for lifting and good sea-keeping characteristics.

The hull is heavily constructed with transverse framing and 10mm and 12mm shell plating.

Steel for the project was supplied by Dent Steel Ltd and approved to Lloyds Grade A. A semi-raised foredeck affords some protection when at sea and the bulwarks are 'stepped in' significantly to prevent damage when working alongside and provide safer access for personnel. Openings in the bulwarks amidships enable dredge-hoses and similar components to be brought aboard to allow work to be carried out on deck and are closed when not in use by wooden 'slot-in shutters'.

Afon Alaw is heavily fendered, with rectangular, moulded rubber, sections encircling the hull and forming robust rubbing strakes under the forward shoulders of the hull.

The bow incorporates a single 'push-knee' incorporating a single, cylindrical, rubber fender.

Sovereign Rubber Ltd supplied all of the moulded rubber fendering. The open-stern is cleverly shaped to prevent fouling while anchor-handling and towing and is fitted with a 3.5m wide stern roller manufactured by ACB Ltd.

Afon Alaw has a fuel capacity of 100 cu/metres in tanks located forward of the engineroom, more than double that of her predecessor. Domestic fresh water tanks have a capacity of 12m 3and additional tanks for ballast and transfer to other vessels have a total capacity of 60m 3. Electrically operated high capacity Desmi pumps, and a purpose designed manifold system, enable fuel and water to be transferred to other vessels and plant at high flow rates.

The spacious engineroom houses main engines and auxiliaries, electrical switchboards, and all other related systems. Two Cummins KTA 38M2 main engines run at 1800rev/min to produce a total of 2,600 brake horsepower. The engines are provided with a Weka 'box cooling' system incorporating copper/ nickel heat-exchange elements.

Power is transmitted through a pair of ZF-Masson reverse reduction gearboxes with a 4.96:1 ratio to fixed pitch propellers, rotating within Kort nozzles. The fixed nozzles are carefully positioned to achieve good water flow to the propellers and meet the shallow draft requirement. Twin rudders, of Hepworth's own semi-balanced, high lift, 'fishtail' design are fitted and controlled by Servi electro-hydraulic steering gear from 'jog levers' in the wheelhouse.

Afon Alaw has a bollard pull of approximately 35 tonnes towing ahead and a free running speed of over 11 knots.

Widely spaced propellers ensure a high degree of agility that is enhanced further by the installation of a Kort KT-150 bow thruster powered by a 150bhp hydraulic motor powered by the diesel driven deck hydraulic system and producing 1600kg of thrust. Kort Propulsion Ltd supplied the Weka coolers, propellers, nozzles and the transverse thruster for this new vessel.

All three of the tug's diesel driven auxiliaries are located in the space between the main engines. Electrical power is supplied by two Cummins powered 50kvA generator sets, one with closed circuit radiator cooling to ensure that power is available under any circumstances. A third Cummins diesel drives the necessary hydraulic pumps for the deck machinery and bow thruster systems.

Afon Alaw 's afterdeck is impressive, with a very large clear work-space protected by hardwood cladding and well sited deck machinery.

Located immediately aft of the superstructure is the towing and anchor-handling winch supplied by North Sea Winches. The hydraulically powered winch has a single 'split' drum capable of accommodating 500m of 44mm diameter steel wire towline, in addition to a shorter wire for dredging with a towed plough or anchor work. A maximum brake load of 112.5 tonnes is specified and line pull of 45 tonnes is possible at a speed of up to 9m per minute. Hydraulically actuated spooling gear serves the main drum. North Sea winches also supplied a hydraulically powered rope storage drum designed to carry one complete spare towline. The drum is bulkhead mounted in a rope and equipment store immediately aft of the engineroom. A neat system of fairleads enables the spare wire to be fed, in or out, through a small watertight access cover in the afterdeck. The same manufacturer was responsible for a small single-drum, 14 tonne, tugger winch strategically located on the port side immediately adjacent to the main winch.

A quick release towing hook of the rotating disc type by Van der Graaf, with a 35 tonnes safe working load, supplied by Britannia, is mounted on a 'Dutch style' towing bollard and fairlead. Two hydraulically operated towing pins are fitted in the deck forward of the stern roller and a recessed lug on the centreline can be used to secure a gob eye. Two further, hinged, 'stop pins' are located on either side of the aft bulwarks. Fittings on deck allow the use of a demountable 45 tonne 'A frame' for plough dredging and similar operations, utilising the same towing and anchor-handling winch. The tug's two, high holding power, anchors are handled by a small hydraulic windlass, incorporating a drum-head on each side.

The after deck is dominated by a powerful 90 tonnes/metre Heila HLRM 90/55 'knuckle-boom' crane supplied by MET. The hydraulically powered long reach crane is capable of lifting 29,700 kg at 2.89m reach and 5,100kg at 14.47m. A lifting winch, wire and hook is also incorporated.

The superstructure and wheelhouse aboard Afon Alaw isspacious and configured to allow maximum flexibility of use, as befits a truly multi-purpose work vessel. In the wheelhouse a full width console at the forward end incorporates three control positions, each with a full set of propulsion, steering and bow thruster controls. The navigational and communications package, supplied and installed by Boat Electronics Ltd includes magnetic and GPS compasses, an auto-pilot, two daylight viewing radars, a Navtex receiver, GPS navigator and chart display. The central control position, equipped with a fully adjustable 'skippers chair' gives the tug-master access to a series of large integrated visual display units. A high degree of integration allows multiple display options on a single screen, such as the overlaying of charts, radar and GPS information.

Likewise, the two radar plots, each set to a different range, can be displayed side by side on one screen. Images from a closed circuit television system, used to monitor the engineroom and winch, can also be shown on the display units. Communications equipment installed includes two VHF radios, one with DSC, a medium frequency DSC radio, and GSM telephone and fax.

A fourth control station is located at the rear of the wheelhouse with an exceptional view of the afterdeck and winch.

A small but useful feature is the fitting of a wiper on the low-level window immediately above the winch. The towing and anchor-handling winch is also controlled remotely from this station.

Both wheelhouse and accommodation can be air-conditioned and are fitted out to a very high standard.

The tug will normally be operated by a crew of three but accommodation has been made available for a maximum complement of 12, including contractors staff and passengers.

This enables the vessel to support offshore projects and carry the necessary staff for distances of up to 60 miles from the coast. Six cabins, each with an additional 'Pullman' style berth, enables any additional personnel to be housed in comfort. A very large combined mess room and galley is provided, capable of seating for all twelve personnel, along with the usual washing, drying and storage facilities.

When Afon Alaw completes trials and commissioning on Humberside towards the end of February she will sail immediately to relieve smaller sister Afon Cefni working for GE Wind on the massive Arklow Bank wind farm project. From there the tug will move on to provide towage and on-site services to two separate wind farm construction contracts on the Scroby Sands near Great Yarmouth. This is exactly the type of work for which the vessel was built and where a shallow draft, good bollard pull and comprehensive onboard lifting and transportation facilities are paramount.