May 27, 2009
Washburn & Doughty to build Z-Tech LNG escort tugs
Washburn & Doughty Associates, Inc., East Boothbay, Maine, has signed contracts with Suderman & Young Towing and Bay-Houston Towing to build each company one Robert Allan Ltd designed Z-Tech 7500 Class Terminal/Escort Tug.
These tugs will be constructed in Washburn & Doughty's new shipyard, which is scheduled for completion in June 2009. The new building measures 225 ft x 155 ft and features two construction bays, each equipped with two, twenty-ton cranes. A central, two level mezzanine contains shop space and offices for production support. This 42,000 sq. ft. facility is designed for vessels up to 200 ft long by 50 ft wide. The new building provides Washburn & Doughty with increased capacity, which allows the shipyard to take on more projects and build larger boats than was possible in the previous building.
The Z-Tech 7500 is a high-performance twin screw ASD ship-handling/escort tug, designed for berthing and unberthing large ships and for providing escort, emergency response, and fire-fighting capabilities in the vicinity of oil and LNG terminals. The tugs will each measure 98 ft 6 in x 39 ft 4 in.
The tugs will be operated by the G&H Towing Company of Galveston, Texas. These tugs will be used primarily at Sempra LNG's Cameron LNG terminal.
The tugs will be constructed in accordance with American Bureau of Shipping requirements for the following notations: ABS Maltese Cross A1 Towing Service; ABS Maltese Cross AMS, Escort Service; and ABS Maltese Cross Fire Fighting Vessel Class 1.
The tugs will feature two MTU Detroit Diesel 16 cylinder series 4000 engines with M70 Rating. These EPA Tier II certified engines are each rated at 3,000 hp at 2,000 RPM. Lufkin Model MV1600S, with 2:1 ratio reduction gears, will be installed between the main engines and z-drive units. The z-drive units will be Rolls Royce model US 255 FP for a minimum thrust ahead of 80 tons at bollard condition.
Two John Deere JDFMG-6081A-185KW-ABS-T2 engines will drive Marathon Magna Plus 185 kW generators with PMG excitation. The generator sets are identical with the exception that one is electric start and one is air start. Generators will be set up for automatic paralleling and in the event of failure of the on-line generator; the standby generator will automatically start and go on-line. The generator with failure will automatically shutdown. Generators will automatically parallel when using the hawser winch.
A Markey DESF-48-200 electric hawser winch will be installed on the foredeck. The aft deck will be outfitted with an H-bitt fabricated from 16 in Schedule 120 steel pipe.