Built in 2001, by Thoma-Sea Boatbuilders Incorporated of Houma, Louisiana (hull #111) as the Dumar III for Dolphin Marine Incorporated of Golden Meadow, Louisiana.
In 2002, the Dolphin Marine Company was recognized into the Dolphin Marine International Company of Golden Meadow, Louisiana. Where the tug was renamed as the Dolphin III.
In 2010, the Dolphin Marine International Company was acquired by Harvey Gulf International Marine of New Orleans, Louisiana. Where she was renamed as the Harvey War Horse III.
In 2014, Harvey Gulf International Marine Incorporated's towing division was acquired by the Signet Maritime Corporation of Houston, Texas. Where the tug was renamed as the Signet War Horse III.
Powered by two, EMD-20-710G7B, turbo diesel engines. With Lufkin 500 HC-1640-10 reduction gears, at a ratio of 6:1. Turning two, 149(in) by 154(in), four bladed, stainless steel, fixed pitch propellers, mounted in kort nozzles, with a 500 horsepower, Schottel bow thruster. She is a twin screw tug rated at 12,500 horsepower.
Her electrical service is provided by two, Tier III compliant, 200kW generator sets. Driven by two, John Deere 6185AFM85 diesel engines. And one, Tier III compliant, 75kW generator set. Driven by a John Deere 4045AFM85 diesel engine. The tug's capacities are 268,060 gallons of fuel oil, 2,300 gallons of lube oil, 1,000 of hydraulic oil, 65,400 gallons of ballast water, and 25,200 gallons of potable water.
The towing equipment consists of an INTERcon DW 250, double drum, towing winch. Outfitted with 3,000(ft) of 3(in) towing wire on the primary drum. And, 2,500(ft) of 3(in) towing wire on the secondary drum. With two, 20 ton "deck tuggers", a set of 350 ton, Triplex H-350 "shark jaws," with a hydraulic towing pin system, a 5(ft) by 14(ft), deck level roller, and Alaskan pedestal crane.