The present disclosure provides a boom structure including an elongated body having a first end and a second end, the first end configured to couple to a dipper and the second end configured to couple to a support structure. The boom structure further includes a top member, a bottom member, and a pair of sides members of the body coupled to the top member and bottom member. Each side member includes a first portion extending between the first end and second end of the body and forming an outer frame structure. Each side member also includes a second portion coupled to an inner surface of the first portion and being substantially enclosed by the first portion.