Jensen Maritime designs new tractor tug meeting Tier IV emissions standards
Jensen Maritime, Crowley Maritime Corp.’s Seattle-based naval architecture and engineering firm, has designed a new high performance tractor tug for Vessel Chartering LLC that features some of the first Tier IV engines meeting higher federal air emissions standards among U.S. tugboats.
The multipurpose tractor tug, which is being built by JT Marine of Vancouver, Wash., was jointly developed by Vessel Chartering LLC and Jensen. The 110-foot long vessel will feature the ship assist and escort capabilities of smaller harbor tugs, while delivering the improved towing performance and increased range of larger ocean-going tugs. The escort capability was enhanced to provide support for assisting large, 18,000 TEU containerships due to an increased future demand in West Coast ports of call. The design offers the flexibility to support ship escorts, assists and towing.
The engines are designed to meet the federal Tier IV standard, which incorporate the emissions-reducing performance requirements by the U.S. Environmental Protection Agency (EPA). To meet the requirements, the two engines on this vessel use systems that clean exhaust gases after they have left the engines. This is the third tugboat designed by Jensen Maritime with engines meeting the Tier IV requirement.
With new ballast water treatment requirements on the horizon from the EPA and U.S. Coast Guard, the tug was designed without any ballast tanks, thereby eliminating the need for ballast water discharge and the potential transfer of invasive species. In lieu of ballast tanks, the tug will transfer fuel, as necessary, in order to maintain proper trim.
The vessel, which will be 40-feet wide, will be powered by a pair of 3,385-horsepower Caterpillar 3516 Tier IV engines. With an electrically powered, double drum tow winch aft by Rapp USA and an electrically powered hawser winch forward by Markey Machinery as deck machinery, the vessel will be capable of a 93-to-95 short-ton bollard pull. Both winches’ electrical power will remove any chance of a hydraulic oil spill on deck.
The tug is designed to carry up to 123,000 gallons of fuel, 4,300 gallons of fresh water, and up to 4,500 gallons of urea, which is used for treatment of the main engine exhausts in order to meet Tier IV emissions requirements. A water maker is being installed for potable water when out at sea. A large pilot house will provide all-around visibility, and the deckhouse has an open feel with a large mess and lounge area along with accommodations for a 10-person crew.
Seattle-based Jensen Maritime Consultants Inc. is a naval architecture and marine engineering firm owned by Crowley Maritime Corporation. The company offers a diverse range of consulting, design and engineering services developed from more than 50 years of experience working around the world. Jensen is a recognized leader in the design of all types of vessels and has built a favorable reputation on a long history of successful designs and conversions with close attention to engineering basics. The company's services include detail and conceptual design and engineering, vessel modifications, lofting, regulatory and shipyard liaison as well as on-site consulting services and on-location assistance anywhere in the world.
About JT Marine Inc.
JT Marine Inc. has more than 80 years of combined shipbuilding and repair experience and offers an ideal, complete service location for major retrofits and vessel repair. With covered fabrications bays outfitted with overhead cranes, and assembly locations alongside 1,200-ton dry dock, JT Marine is equipped to handle whatever job you need, big or small. In addition to traditional steel work, skilled workforce is capable of meeting specialty services including paint, aluminum, electrical, carpentry, and pipe work.