Built in 1971, by Halter Marine Services of New Orleans, Louisiana (hull #314) as the Mister Harold for the Jackson Marine Corporation of Houston, Texas.
Jackson Marine was owned by the Halliburton Corporation. They owned a total of ninety boats mostly offshore tugs, a few supply boats and some chemical transport and some well stimulation boats.
Jackson Marine later merged with Zapata Gulf, and Gulf Fleet merged and the company became the largest shipping company in the world with a total of four hundred fifteen boats. Tidewater at that time had about two hundred seventy five boats.
In the fall of 1986, Seahorse was merged into Zapata Gulf Marine adding an additional ninety vessels to the fleet. Seahorse was founded by the Arthur Levey family as Arthur Levey Boat Company after WWII. Later it was purchased by Petrolane Natural Gas and renamed Seahorse Marine. In 1985, Petrolane was bought out by Texas Eastern a larger natural gas company. Then in the fall of 1986, Texas Eastern traded the company to Zapata for an exchange of stock. It happened overnight with no warning whatsoever.
On January 15th of 1992 Zapata Gulf merged with Tidewater. She was then sold where she was renamed as the Harold.
The tug was then acquired by Portland Tug affiliate, Stamford Service, Incorporated of Belfast, Maine. Where she was renamed as the Escort performing assist and escort work in the Cape Cod Canal area.
The tug was then acquired by McAllister Towing and Transportation of New York, New York where she was renamed as the Michael J. McAllister.
She is powered by two Alco 12-251 F diesel engines with Lufkin reduction gears at a ratio of 5.6:1 for a rated 4,100 horsepower.
The tug is fitted with four fire stations. Her capacities are 134,5000 gallons of fuel oil, 2,000 gallons of lube oil, 23,300 gallons of potable water.
Her towing gear includes an Intercon double drum towing winch with a line pull of 290,000 lbs and is equipped with 2,400(ft) of 2(in) towing wire in addition to the New England Trawler X1510 capstan.