At one time it was said the largest crane the Navy had was the one in the Phila Navy Yard.
Trying to find a pic of it and all I find so far is this one...
U.S. Crane Ship Kearsarge
Test of the ship's 250-ton revolving crane, while she was undergoing conversion at the Philadelphia Navy Yard, Pennsylvania, 30 October 1922. Kearsarge is seen here lifting a 312-ton load on the right and left main hoist with equalizer at 101-foot reach on an even keel. Jib fore and aft at an angle of 38 degrees 46 minutes.
Photo #: NH 43453
Philadelphia Navy Yard, Pennsylvania
View of the Yard's Delaware River waterfront, with the hammerhead crane in center, 31 May 1923. Among the ships visible are:
USS Lamson (DD-328), in left center;
USS Sandpiper (AM-51) and USS Teal (AM-23), at right, with the crane ship Kearsarge beyond;
Destroyers Preston (DD-327), Coghlan (DD-326) and Sharkey (DD-281), partially visible at left.
USS Dobbin (AD-3) is fitting out on the opposite side of the pier, at left.
Although these are large, I believe there is or was at one time in the late 60's and 70's a larger one that looked like the one above at the yard. We could see it plain as day when crossing the Walt Whitman Bridge over the Delaware River.