Recently delivered to her Owners Bay-Houston Towing Co. of Galveston, Texas is the latest Z-Tech 7500 Class tugTristan K. This powerful new ship-handling/escort tug began her maiden voyage on June 9, 2011 for the destination of the recently commissioned LNG terminal in Cameron, Louisiana, where it will be operated by G & H Towing on behalf of the Owners. Tristan K was designed by Naval Architects Robert Allan Ltd. of Vancouver, B.C., with significant input from Mike Nigro, Vice President of Engineering at G & H Towing and his team and is the 8th of this class of handsome tugs for the same Owner. The Z-Tech 7500 design builds on the international success of its smaller cousins, the now well-known and well-proven Z-Tech 4500, Z-Tech 6000 and Z-Tech 6500 Classes. Since their introduction to the world market only a few years ago there are now a total of 50 Z-Tech tugs operating throughout South-East Asia, Australia, the Middle-East, in the Panama Canal and at US Navy bases in Japan and the United States. Tristan K and its recently delivered sister tugHercules are classed for both harbour and coastal towing and for tanker escort duty, and were built to ABS Class notation " A1 Towing Service, AMS, Escort, Fi-Fi 1".
Particulars of these Z-Tech 7500 Class tugs are as follows:
Length Overall - 98'-8" (30.00 metres)
Beam, Moulded - 39'-4" (12.00 metres)
Depth, Moulded - 16'-5" ( 5.00 metres)
Draft, Maximum - 17' ( 5.18 metres)
Fuel Capacity - 169 cubic metres
Potable Water Capacity - 24 cubic metres
Compared to the previous six Z-Tech 7500 tugs for the same operator, Tristan K and Hercules are equipped with a different propulsion system and hawser winch. Propulsion comprises a pair of MTU 16V4000-M70 diesel engines; each rated 2,240 kW at 2,000 rpm, driving a Rolls-Royce US 255 Z-drive with a 2,800 mm diameter propeller through a hollow, in-line shafting system. This combination delivers a Bollard Pull of 73 tonnes ahead, and provides a free running speed in excess of 13 knots, thereby fully satisfying the Owner's performance objectives.
The configuration of the Tristan K is shown on the accompanying general arrangement drawing and photographs. The tug is outfitted for a crew of six persons, in modern and well-equipped facilities.
The unique docking skeg fitted forward of each z-drive unit will considerably reduce dry docking time and costs for the operator during the tugs service lifetime.
The main hawser winch is an electrically driven single drum Model DESF-48 200HP winch supplied by Markey Machinery of Seattle, WA. The winch has a line capacity of 700 feet (213 metres) of 9" circumference (72 mm dia.) synthetic line and a line pull of 456,275 lbs. (207,000 Kg) at a speed of 13 fpm (4 metres/minute) or 2,850 lbs. (1290 Kg) at 671 fpm (204 metres/minute).
Electrical power is provided by a pair of John Deere 6081-AMGK75 gen-sets, each rated 185 kW.
The tug has a full Fi-Fi 1 rating in accordance with Class notation requirements. The two fire pumps are each driven by independent fire pump engines.
