Built in 2004, by Washburn and Doughty Associates of East Boothbay Harbor, Maine (hull #82) as the Rainbow for the Providence Steamboat Company of Providence, Rhode Island.
In 2006, the Providence Steamboat Company was acquired by the McAllister Towing and Transportation Company of New York, New York. Where the tug retained her name.
Powered by two, Caterpillar 3516 HD diesel engines. Driving two, Rolls Royce, Aquamaster US 205 z-drives. Outfitted with two, NiBrAl 90.5(in), fixed pitch propellers. She is a twin screw tractor tug, rated at 5,000 horsepower.
Her electrical service is provided by two, 99 kW, John Deere, Tier II compliant, non paralleling generator sets. The tug was designed with sufficient space, and structure to accommodate future installation of Fire Fighting One (FiFi 1) equipment and systems.
The tug is outfitted with a Timberland model A180-1-60-EVC electric hawser winch. With level wind and line rendering features, mounted on the bow. Equipped with 500(ft) of 2 5/8(in) plasma line. An Almon Johnson 18(in) diameter Series 351E capstan, driven by a 208/3/60 motor, is located on the stern.