Built in 1968, by St. Louis Ship of St. Louis, Missouri (hull #2535) as the Marjorie McAllister for the McAllister Brothers Towing Company of New York, New York.
On November 2nd, 1969 the tug sank with all six hands off the coast of North Carolina. However in 1972, her wreck was discovered, salvaged, and refurbished by the DonJon Marine Company of Hillside, New Jersey.
In 1980, the tug was acquired by the DonJon Marine Company Incorporated of Hillside, New Jersey. Where she was renamed as the Tracy Anne Witte.
In 1983, she was acquired by the Eklof Marine Corporation of Staten Island, New York. Where she was renamed as the Thor.
In 1999, the tug was acquired by the McAllister Towing and Transportation Company of New York, New York. Where she was renamed as the Mary L. McAllister.
Powered by a single, EMD 20-645-E3A turbo, diesel engine. With a Falk reduction gear, at a ratio of 6.552:1. Turning a single, fixed pitch, propeller mounted in a kort nozzle, with a flanking rudder. For a rated 4,000 horsepower.
The tug's capacities are 97,550 gallons of fuel oil, 950 gallons of lube oil, and 3,000 gallons of potable water.
Her towing gear consists of a single drum equipped 2,000(ft) of 2(in) towing wire.
The tug is an ABS Classed +A-1 Towing, A.M.S. tug. She is outfitted with three fire stations, and an Aurora Fire Pump. Rated at 500 Gallons Per Minute.