Foss Tug Conversions Boost Power and Maneuverability

Friday, September 24, 1999
Two Foss Maritime conventional twin-screw harbor service tugs have been repowered and converted into azimuthal stern drive (ASD) vessels. The projects, involving 96 ft. sister ships, increase horsepower by 46 percent, and bollard pull by 63 percent. Vessel manueverability and pilot visibility are also dramatically enhanced. Work on Seattle-based Daniel Foss is complete with the Los Angeles-based Peter Foss scheduled to return to service in March 1999. Foss uses both vessels to provide harbor services, including ship assist, tanker escort and barge transportation. The vessels were originally designed by The Glosten Associates, Seattle, and built in the late 1970s at Main Iron Works, Houma, La. Conversion and repowering are being done at Marine Industries Northwest, Inc., (MINI) Seattle. With the repower, two electronically controlled CAT 3512B engines, each rated 1,650 bhp (1,230 bkW) at 1,600 rpm, drive two Ulstein azimuthal stern drives with skewed propellers inside Nautican high performance nozzles. The new propulsion system produces more than 90,000 lbs. of bollard pull and provides high thrust over a complete 360-degree range. To improve pilots' sight lines in all directions, the traditional pilothouse forward was removed and a new high-visibility pilothouse was placed amidships. The ASD conversions were conceived by Foss' in-house design team, with engineering support provided by Glosten and MINI. According to Ulsteain President Ewan Moir, these are some of the first Ulstein installations involving former conventional tugs. "These tugs were good candidates for conversion because they are very robust, well-built, have the correct proportions and have many years of productive service life remaining," says Don Hogue, Foss engineering manager. "Also, the existing deckhouse, stack geometry lent itself well to the installation of the new high-visibility pilothouse." Hull modifications included changes to the keel profile to provide increased lateral hull resistance and additional ballast for improved stability. Aft hull lines were re-contoured to accept the stern drive units, add buoyancy and improve performance while going astern.
Maritime Reporter March 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Legal

U.S. DoI Upholds 2008 Shell Arctic Lease

The U.S. Interior Department on Tuesday upheld a 2008 lease sale in the Chukchi Sea off Alaska, moving Royal Dutch Shell a step closer to returning to oil and gas

Japan, U.S. Look to Expand Naval Cooperation

Japanese Prime Minister Shinzo Abe's push to allow Tokyo to come to the aid of an ally under attack will pave the way for closer cooperation between U.S. and Japanese forces across Asia, a top U.

India Halts Iran oil Imports Under U.S. Pressure

Oil imports from Iran at 220,000 bpd in year to March 31. U.S. pressured India not to raise annual Iran oil imports. India halted oil imports from Iran for the

Bulk Carrier Trends

Shipping Confidence Hits 2.5 Year Low

Overall confidence levels in the shipping industry fell to their lowest level for two-and-a-half years in February 2015, according to the latest Shipping Confidence

Baltic Sea Freight Index Up on Higher Capesize Rates

The Baltic Exchange's main sea freight index, which tracks rates for ships carrying dry bulk commodities, rose on Tuesday, mostly on higher capesize rates.   The index,

Shipbuilding: Mitsui Delivers Bulk Carrier

Mitsui Engineering & Shipbuilding Co., Ltd. (MES) completed and delivered a 56,000 dwt type bulk carrier M.V. Desert Osprey (MES Hull No. 1862) at its Chiba Works

 
 
Maritime Careers / Shipboard Positions Maritime Contracts Maritime Security Maritime Standards Navigation Pipelines Pod Propulsion Port Authority Shipbuilding / Vessel Construction Sonar
rss | archive | history | articles | privacy | terms and conditions | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1623 sec (6 req/sec)