The Philadelphia Naval Shipyard occupied two different locations. The second site at League Island was the larger of the two sites and saw the greatest amount of shipbuilding activity. The Dravo Wellman Company was a pioneer manufacturer of steel plant equipment with an international reputation for engineering some of the largest material-handling projects ever built. Photographs show tests of a revolving crane ship (perhaps manufactured by Wellman-Seaver-Morgan Company) in the Philadelphia Navy Yard.