Built in 2012, by Sneed Shipbuilding Incorporated of Channelview, Texas (hull #358) as the Olivia Grace Settoon for Settoon Towing Incorporated of Pierre Part, Louisiana.
In 2017, the tug was acquired by Savage Marine Services Incorporated of Salt Lake City, Utah. Where she was renamed as the Savage Spirit.
In 2020, Savage Marine Services Incorporated was acquired by the Kirby Corporation of Channelview, Texas. Where the tug was renamed as the Ralph Renfro.
Powered by two, Mitsubishi S12R II diesel engines. With Reintjes reduction gears, at a ratio of 5.7:1. Turning two, stainless steel, fixed pitch propellers. She is a twin screw towboat, rated at 2,400 horsepower.