Built in 1978, by Main Iron Works Incorporated of Houma, Louisiana (hull #327) as the Itco XVI for the Independent Towing Company of Harvey, Louisiana.
In 1978, the tug was acquired by Lihue Plantation Company Limted of Lihue Kauai, Hawaii. A division of American Factors Limited of Honolulu, Hawaii. Where she was renamed as the H.A. Walker.
The tug was named for Henry Alexander Walker, Sr. Who served as president of the American Factors Limited from 1933-1950.
In 1994, she was acquired by Weeks Marine Incorporated of Cranford, New Jersey. Where she was renamed as the Trevor.
In 2021, the tug was sold and renamed as the David R. Schanock.
Powered by two, Tier II compliant, Caterpillar C32 diesel engines. With Twin Disc MG- 5225DC reduction gears, at a ratio of 5.04:1. Turning two, 66(in) by 46(in), four bladed, fixed pitch propellers. She is a twin screw tug, rated at 1,500 horsepower.
Her electrical service is provided by two, Tier II compliant, 44kW generator sets. Driven by two, Caterpillar C4.4 diesel engines. The tug's capacities are 29,500 gallons of fuel, 300 gallons of lube oil, and 7,600 gallons of water.
The towing equipment consists of a single drum, Smatco 34-DPS-75 towing winch. Outfitted with 1,700(ft) of 1.25(in) towing wire. And, a "suitcase" drum outfitted with 300(ft) of 1.25(in) towing wire.