It's a Marine unit, not a lot of info online. Here is what I have. Wayne
The Crane, High Speed, High Mobility is a diesel-powered, rubber-tired crane with a hydraulic boom and the capability to mount/operate the Pile Driver. It is capable of all general crane operations, clamshell, container handling, and general lifting up to 50,000 lbs. It is capable of operating over rough terrain and in 60 inches of water. The Heavy Crane attachments include: Pile Driver, Self-Powered, Diesel: Bucket, Concrete; and Bucket, Clamshell.
Manufacturer: Harnischfeger Corp.
Weight: 69,825 lb
Width: 102 in
Length: 499.8 in
Height: 138.9 in