Tier 4 Final Tug Goes Into Operation
By Jack Burke01 March 2017
Harley Marine Services accepted delivery of its first EPA Tier 4 Final tractor tug, the Earl W. Redd.
The tug is equipped with twin Cat 3516E Tier 4 Final main engines that will each produce 2675 hp at 1600 rpm. Each of the engines is paired with a selective catalytic reduction (SCR) after treatment system. SCR uses a urea-based solution to reduce NOx contained in diesel exhaust down to nitrogen and water vapor.
The 3516E also offers a closed crankcase ventilation system option, which allows operators to send emissions back into the engine intake instead of venting them separately out of the vessel.
Several cooling options are available with the 3516E, including a keel cooled option or a plate heat exchanger, which is built with the water’s thermal expansion accounted for.
The main engines will be paired with Rolls Royce US 255-P30-FP azimuth thrusters delivering an expected bollard pull capability of 75 tons.
Harley Marine Services said it is an environmentally conscious leader within the maritime industry and consistently raises the bar in an effort to practice ever stronger “green” business practices. Built at Diversified Marine of Portland, Oregon, the tug measures 120 ft. by 35 ft., with a loaded draft of 19 ft. 3 in.
Auxiliary power comes from John Deere 125 kW generators.
Harley Marine Services is a leading provider of marine transportation services in the U.S., with operations along the West Coast (including Alaska), New York Harbor and the U.S. Gulf Coast. Services provided include the transportation and storage of petroleum products, ship assist and escort, the transportation of general cargo and rescue towing.