Svitzer tug master James Clarke works on board the high-performance LNG-escort tug Svitzer Kilroom, based at the Port of Milford Haven
Svitzer tug master James Clarke works on board the high-performance LNG-escort tug Svitzer Kilroom, based at the Port of Milford Haven. Here, he describes working at the helm of the world’s most powerful RAstar 3900 tug as it guides large LNG carriers in and out of the South Wales port’s two LNG-import terminals.
How long have you worked at sea on board tugs? What changes have you seen in tug technology and working practices during that time?
I have been working at sea since I was 19. I spent 20 years working on aggregate dredgers around Europe and the last nine years on tugs.
Some of the biggest changes have been from wire tows to all soft rope. The advances in marine electronics include automatic identity system (AIS), digital selective calling (dsc) radios, having mobile internet on board and the changeover from a paper-based management system to an electronic one.
How does operating tugs at Milford Haven compare with other ports you’ve worked in?
The biggest difference is the five miles we go out of the pilot station to escort vessels in, and the constant sea swell off the entrance to Milford Haven. In many other ports the tugs meet the vessels within the shelter of the port.
What shifts do you work and how busy is a typical working day?
I work two weeks on, two weeks off. During our two weeks on, we live on board the tug as we can be called to assist a vessel at any time. Working hour’s laws only allow us to work 14 hours in any 24-hour period and we have to balance towage with drills and maintenance, while remaining abreast of changes in regulations. Kilroom is a big tug so there’s always plenty for the five of us to do.
What were your impressions when you took the helm on Svitzer Kilroom for the first time?
The first thing is the size of the vessel compared to other tugs I’ve worked on. Kilroom is not as nimble as some smaller tugs but is designed as an escort tug to operate in the sea swell we get in Milford.
It is a similar difference between driving a sports car and a lorry; the size when you come to berthing being 20 feet longer than other Milford tugs. Kilroom also responds more slowly due to her size.
What kinds of vessels does Svitzer Kilroom escort? What particular challenges do you associate with each?
Kilroom escorts mainly South Hook LNG vessels. The LNG vessels tend to be twin-screw, twin-rudder ships. The rudders are mounted very close to the transom of the vessels and can affect our movements when making fast.
The VLCCs we escort tend to be single-screw with a single rudder mounted deeper down. When making fast the tow line in big swells there is a danger of the tug surfing on the swell into the stern of the LNG vessel.
What are Svitzer Kilroom’s fire-fighting capabilities?
We have two fire-fighting, FI-FI, monitors that can spray water at 1,500 m³ or tonnes an hour, each at a pressure of 12 bar/175 psi. We can also act as a floating pumping station to the jetties by connecting into their fire main.
Can you describe a typical operation, escorting an LNG carrier in and out of Milford Haven?
With an incoming LNG carrier, we normally leave our berth an hour and a half before the pilot is due on board. We meet the LNGC at the pilot station, five miles from the entrance, at the same time that the pilot boards the vessel.
We make fast our tow line to a strong point on the aft end of the vessel at a speed of around eight knots and pay out about 100 m of tow line. We then have an escort mode on the towing winch that keeps a constant tension on the tow line to prevent it snatching in the swell. We then follow the ship into the port.
The other tugs make fast to the side of the LNG ship as it sails up the west channel. Usually, the pilot will start to slow the ship after rounding the angle buoy and the bow tug will make fast. About a mile from the berth the pilot will ask us to start giving weight astern to slow the LNG vessel.
As we approach, we stop applying astern pull and move to a position to stop the stern of the LNG vessel coming into the berth too fast; a check position. When the LNG vessel is alongside the berth the two tugs alongside the LNG vessel push with full force to hold it alongside until the ropes are made fast.
When the spring lines and breast lines are secure, the pilot releases us so the stern lines can be run. The sailing is reverse but we may assist with a swing of the LNG vessel if it did not swing on berthing.
How do you expect tug designs and operations to evolve?
I expect changes in tug propulsion, away from diesel engines to gas or even electric. Svitzer has already has trialled a hybrid-powered tug in Southampton. The energy market is continually evolving but ships are always going to need tugs.
Kilroom: technical spec
Svitzer Kilroom was built by Freire Construcciones Navales at Vigo in northwest Spain.
Delivered at year-end 2008 and entering service when Dragon LNG received its first cargoes in 2009, Svitzer Kilroom is the largest, most powerful RAstar tug built for the terminal. Vancouver-based naval architect Robert Allan designs the RAstar series.
The vessel was the third of six high-performance RAstar escort tugs that Svitzer ordered to support LNG carriers delivering cargoes to Milford Haven, South Wales-based Dragon LNG terminal. Dragon LNG is jointly owned by Shell and Petronas.
Svitzer Kilroom is designed and equipped for ship-handling and escort duties. It features a Rolls-Royce model TW 3000/1000H single drum hawser winch on the fore deck that has capacity for 250 m of 76 mm diameter, high-strength towline.
The escort-rated winch is driven by a twin-pump electro-hydraulic pump set. It features a three-speed drive system that can deliver line recovery at 100-tonne line pull at 5.2 m/min or of rendering at 150 tonnes at 8 m/min in the first speed range, or of recovering at 24 tonnes at 18 m/min and rendering at 50-tonnes line pull at 28 m/min in the third speed range.
The aft deck is strengthened for an aft towing winch that is not presently fitted.
Robert Allan designed Svitzer Kilroom to minimise the impact on vessel and crew of noise and vibration. This included essential resilient mounting of the main engines and isolating all the exhaust-system components. The tug is also fitted throughout with visco-elastic flooring.
“The shipyard executed all these requirements exceptionally well,” Svitzer says. “The reward was an extremely quiet ship throughout.”
Svitzer Kilroom has accommodation for up to ten crew. It has two officer’s cabins on the main deck, each with private en suite bathrooms and four double cabins below deck, two with private en suite bathrooms.
The galley serves a large common lounge/mess area, equipped with video and audio entertainment systems.
Svitzer Kilroom is Milford Haven’s largest, most powerful tug (credit: Owen Howells)
Ship spec: Svitzer Kilroom
Built: CNP Freire, Vigo, Spain
Keel laid: 2007
Length: 39.71 m
Beam: 14.71 m
Draught: 4.81 m
Depth: 6.1 m
Gross registered tonnage: 819
Bollard pull (tonnes): 115 ahead; 107 astern
Propellors: Twin Schottel SRP 3030 CP
Main propulsion system: Twin General Electric 7FDM16D10