Abstract: A gantry system has at least one crane assembly, at least one support post, and at least one hoist. The crane assembly has a stationary base, a rotating base, and a crane arm. The rotating base is attached to both the stationary base and the crane arm in such a ways as to allow the rotating base and the crane arm to rotate while the stationary base remains stationary. The crane arm is supported on its far end by a support post. The crane assembly is configured such that the support post rests on an in-place girder. A hoist is attached and can move along the crane arm to position a railway component, such as a replacement girder and/or a precast panel.