Free standing Jib Cranes is directly fixed on the floor without any support to keep it upright. To maintain its stability and not topple over it you fix it to a foundation of 3 to 5 feet deep and up to 4 to 10 feet square foundation base. The foundation depends on the load and reach.
Advantage of this type of crane is it doesn’t need a support wall or structure and provides optimal range of span and control compare to wall mounted cranes and other types of Jib cranes. The picture here shows a 2 ton free standing jib crane used in a yard