Similar to a single girder crane, but as the name would indicate, is comprised of two parallel girders connecting the end trucks. Like single girder cranes, these can be top or under-running, though a large majority are of the top running variety. The major difference between single and double girder cranes is that the double girder allows the hoist to ride on top, in between, or below the actual girders. In tight headroom applications, this can create better hook height than the single girder alternative.