by Hans | October 4th, 2009
The Port of Milford Haven, Britain’s sixth largest port, has experienced a surge of activity over the past few months with not only the usual tanker and other commercial traffic, but also the start of operations at both of the new Liquid Natural Gas (LNG) terminals.
Significantly, that additional activity coincided with a report showing that 2008 was the busiest 12 months in the 50 year history of the port – a record 52.8 million tons of shipping. A predicted gradual increase in LNG traffic can only enhance the figures for the present period.
Provision of efficient towage, escort and marine services, capable of serving the new LNG terminals operated by South Hook LNG at Milford and Dragon LNG upriver at Waterston, in addition to the existing oil berths, was an important feature of the planning process. After a lengthy and complex tendering process the multinational towage operator Svitzer was contracted to put together a tug fleet to serve all of the oil and gas traffic frequenting the port. That fleet is now virtually complete and is one of the largest and most modern tug fleets in the world.
Nine brand new tugs and six line handling boats were ordered specifically for the new fleet which is now based at new facilities at Pembroke Dock. Six of the tugs are high performance terminal/escort tugs of the unique Robert Allan Ltd RAstar Class built by Freire Construcciones Navales of Vigo, Spain. The order placed with Freire comprised six vessels built to two distinct RAstar designs, five 34m RAstar 3400 Class and one 39m RAstar 3900. Of the RAstar 3400, three have General Electric main engines, Schottel propulsion units, and a minimum bollard pull of 92 tonnes and the remaining pair have Niigata engines, Z-Peller propulsion units, and a minimum bollard pull of 80 tonnes. The most powerful vessel is the 39m tug Svitzer Kilroom which has the same basic General Electric/Schottel machinery but rated to achieve a bollard pull of at least 112 tonnes.
An account of the first vessels delivered, the two 92 tonnes bollard pull vessels Svitzer Lindway and Svitzer Waterston, was included in the January issue of Maritime Journal. During the intervening period the remaining RAstars have been delivered. A recent visit to the fleet provided an interesting insight into the remainder of the six tug batch and current operations at the new LNG terminals.
To briefly recap on the major features embodied in the sextuplets; all five RAstar 3400 tugs have an overall length of 34m, a moulded beam of 14.50m and a maximum operating draft of 6.55m. The tugs have a raised foredeck and a very large, clear, afterdeck and excellent fendering, particularly on the bow and forward shoulders where protection is required during push-pull operations.
All six vessels are equipped for fire-fighting to FiFi 1 standard. A pair of main-engine driven pumps, each rated at 1,400 cu/m/hr, supply a pair of Kvaerner monitors and a self-protection waterspray system.
A Rolls Royce Marine towing winch, combined with an anchor windlass is located on the fore deck, with a capacity for 250m of 76mm diameter high performance fibre towline. The three-speed winch incorporates the render-and-recover facilities required for escort work and can be controlled from the deck or in the wheelhouse. A touch-screen display enables line tension and length to be preset by the tugmaster. Towing bits and a quick release tow hook are fitted on the afterdeck but no winch.
Svitzer Lindsway, Svitzer Waterston and Svitzer Haven have a pair of General Electric GE 7FDM 16 diesel generating a total of 7,880 bhp (2 x 2,900kW) at 1,000 rev/min (MCR). Power is transmitted to Schottel SRP 3030 CP fully steerable propulsion units incorporating controllable pitch propellers. This installation gives the tugs a bollard pull of well over 100 tonnes pulling ahead and an almost identical figure pulling astern (exceeding the contractual 92 tonnes by about 10%), with a maximum free running speed of 13.7 knots at 85% MCR.
Svitzer Caldey and Svitzer Ramsey each have a Niigata propulsion package, including main engines developing a total of 5,978 bhp (2 x 2,200kW) driving a pair of Z-Peller propulsion units with fixed pitch propellers, via ‘Omega’ slipping clutches. The result is a bollard pull of 82 tonnes and a free running speed of approximately 13.5 knots. The largest tug of the entire fleet, the Svitzer Kilroom, was the third vessel to be delivered, arriving at Milford Haven in mid December. Svitzer Kilroom measures 39.10m in length overall, with a moulded beam of 14.70m and a maximum operating draft of 6.55m.
This RAstar 3900 variant is also powered by two General Electric GE 7FDM 16 diesels but each rated at the higher figure of 3,050 kW at 1,050 rpm at 100% MCR (total approximately 8,288 bhp). The tug has the same Schottel SRP 3030 CP propulsion units as the Svitzer Lindsway and Svitzer Waterston. During trials in Spain Svitzer Kilroom delivered a performance beyond all expectations achieving a maximum bollard pull ahead of 117 tonnes and113 tonnes continuous and a maximum bollard pull astern of 113 and 107 continuous. Speed trials revealed a maximum performance ahead of 15.7 knots.
A similar Rolls Royce model single-drum towing winch is installed on the fore deck, with a capacity for 250 metres of 76mm diameter high performance towline. Strangely and contrary to the account given in the January issue of MJ, the extremely powerful Svitzer Kilroom has no towing winch aft. The deck has however been strengthened to enable a winch to be retrofitted if required.
To complete the nine tug fleet, a trio of Svitzer designed ‘Stretched M’ or ‘Wick’ class tugs were ordered form the Qingdao Qianin Shipyard in China. All three tugs, named Svitzer Gelliswick, Svitzer Musselwick and Svitzer Watwick, were delivered to the UK under their own power and suffered badly during an arduous delivery voyage, made longer by the need to choose a route avoiding piracy problems in the Gulf of Aden. As a result all three have been undergoing protracted voyage repairs and modifications at a shipyard in Vigo, Spain.
The ‘Wick’ class are 33.4m in length, with a moulded breadth of 11.60m and a design draft of 4.50m. They closely resemble the familiar Svitzer ‘M’ class vessels but have a 3.3m increase in length and one additional deck in the superstructure. Winches are fitted fore and aft and a Niigata propulsion system, comprising engines and azimuthing units, is employed to give the tugs a bollard pull of 80 tonnes. From this fleet of nine tugs Svitzer Kilroom and Svitzer Lindsway and all three ‘Wick’ class vessels are deployed at the South Hook LNG terminal. The five are identified by, a red top band added to the funnel markings.
Svitzer Waterston is the dedicated escort tug at the Dragon LNG terminal, supported by Svitzer Caldey, Svitzer Ramsey and Svitzer Haven. The latter trio will also be deployed to provide towage services at the Milford Haven oil berths when require. Due to the upriver location of the Dragon terminal there is little likelihood of conflicting vessel movement schedules.
The Dragon LNG terminal received its initial commissioning cargo on the 14 July when the LNG carrier Methane Lydon Volney arrived alongside, after a trouble free berthing operation. Its cargo of 145,000 cubic metres of LNG from Atlantic LNG in Trinidad was used to start the process of commissioning the new terminal and its equipment.
Ships arriving at both LNG terminals are escorted from sea via the approach channels to their respective berths by one of the escort tugs, made fast to the stern of the ship. Once the ship is safely moored, assisted by mooring boats from the Svitzer fleet, the escort tug takes up a predetermined station and stands by the ship throughout its time alongside. In this way the tug can provide immediate fire fighting cover and enforce an exclusion zone around the terminal. All passing ships receive a passive escort past the moored ship.
As if to reinforce the continuing importance of oil to the port, June saw the largest ship to visit Milford Haven for almost 20 years, when the 300,000dwt Ocana berthed at the Murco jetty with a part-cargo of crude oil from Angola. With oil reserves in the North Sea depleting, UK ports are likely to see increasing numbers of VLCC’s in coming years, carrying cargoes from Russia, West Africa and the Middle East. Milford Haven Port Authority Harbourmaster Mark Andrews said the arrival of the Ocana was a further reminder of the port’s significant UK role.