Professional Skipper Magazine from VIP Publications

#84 Nov/Dec 2011 with NZ Aquaculture Magazine

The only specialised marine publication in Oceania that focuses on the maritime industry, from super yachts to small craft to large commercial ships, including coastal shipping, tugs, tow boats, barges, ferries, tourist, sport-fishing craft

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ABOVE: Tug master Chace Rodda at the controls LEFT: The electronic machinery monitoring panel RIGHT: Preparing to be transported for launching their length, turning ability, speed, wind conditions and the pilot's judgement. What makes Napier probably unique is that tug operations commence in unprotected waters outside the breakwater in what is essentially open coastal waters, and generally on the side of an approaching vessel exposed to the prevailing open seas and swells. For the port's management team, a Voith water tractor tug had the lowest risk and highest operating ability from a ship-handling perspective within their environs. After the arrival of the Ahuriri with her 70 tonne bollard pull, the port was able to determine this massive grunt was only rarely required, as for the majority of the time she worked at less than 100 percent power. This was taken into consideration when scoping the need for the replacement tug. Paul says tugs have an effective working life of 20 years in a port environment, as service and through-life costs start to escalate from that point on, to the stage where service costs rise and efficiency drops. The demands on the port continue to grow, as does the size of the ships, and it is now not uncommon to have to turn and berth ships up to 294m in a 360m gap. Now that's getting a bit tight! Especially if there is already a ship on one of the basin berths and the distance is reduced to say, 328m. It is only because the pilots can use the MARIMATECH electronic positioning system for precision pilotage monitoring, coupled to an OMC dynamic under-keel clearance system accurate to within centimetres, which gives the tug masters and pilots the confidence to demonstrate to the ships' masters that all is well. They can watch the ship's profile within the port on the pilot's lap top computer as the bow or stern passes within metres of other ships or wharves. With this in mind, given the proven ability of Voith tugs as a stable platform at sea and their excellent reputation for indirect towing and manoeuvring ships within tight confines, the decision to remain with a Voith water tractor tug was logical. The new tug had to be under 24m long, similar to the Ahuriri, to ensure crews maintain familiarity of size when operating either vessel. As we watched her master, Chace Rodda, operate the Te Mata, it was easy to see how quickly man became a part of machine as the two became one. Lowering the bollard pull requirement to 60 tonnes meant smaller engines could be used, thus two cylinders were dropped. A pair of Wartsila 6L26s producing 2049kW, coupled to two Voith 28/R5/234 AE45 propulsion units, was selected. Te Mata was built by Strategic Marine of Western Australia in their yard in Vietnam. The decision not to choose a turnkey build from a known yard and go offshore instead was based on build quality, price and flexibility in design and construction. The design combines a lot of ideas from existing and past vessels and the pilots, tug masters and engineers all provided constructive input. Some of the traditional bluffness has been removed and she has a slightly more refined bow shape than usual. The deck structure and wheelhouse is also a combination of international and Port of Napier ideas. Essentially the design and plans are owned by the Napier Port Company, in what is now affectionately known as the Te Mata class, Voith water tractor tug. An agreement of intent was signed once the yard was identified as being in Asia and, given the nature of the project, that its build would be a joint venture between Strategic Marine and the Port of Napier, as it was important to have the principles clear from start to finish. Paul Hines was appointed project manager, with responsibility to ensure the project went smoothly and delivered what the client wanted and had specified to a required standard. The project began in December 2008 when the steel was purchased while it was still relatively cheap. This was cut in November/December 2011 Professional Skipper 21

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