We designed 100t and 300t portal crane structures for design-build contractor National Oilwell Varco. Each structure includes gantry equalizer beams, gantry frame, supporting cone design, machinery deck, and boom. 3D beam elements, shell elements, and solid elements were used in the FEA analysis. The unique leg/cylinder and cylinder/cone  structural details reduce both the stress concentrations and the fabrication costs. Complete calculation packages and detail engineering design drawings were provided to our client.