Stumbled upon this...

Click title for link to Wikipedia article on the S.S United States. This ship was the longest and fastest while serving a dual purpose - serving as a luxury passenger liner in peacetime and as a potential troop transporter in times of war. There were special "secret" elements designed into the ship for that, but was never used for military purposes. It was decommissioned in 1969 and has been in limbo ever since. It sits in a Philadelphia shipyard looking more and more forlorn with each passing year. Groups have formed to encourage its restoration. Interesting part of our nation's history which lacks the resources to be restored to its former grandeur.

Look for a PBS special that aired earlier this year called "A Lady in Waiting" - about the history of the ship and current status of restoration efforts.