Built in 2009, by Marine Builders Incorporated of Utica, Indiana (hull #258) as the Helen Merrill for for SCF Waxler Transportation Incorporated of St. Rose, Louisiana.
In 2016, the tug was acquired by the Kirby Corporation of Channelview, Texas. Where she was renamed as the Mark Shell.
Powered by two, Cummins KTA50-M2 diesel engines. With Haley reduction gears at a ratio of 6.864:1. She is a twin screw towboat, rated at 3,200 horsepower.