Interesting topic. One thing that I've always found remarkable is how long the United States Navy keeps some of its ships in service. Their oldest front line warship, the aircraft carrier USS Kitty Hawk, is 45 years old. They were still using the Iowa-class battleships in the 1990s, albeit after intermittent periods in lay-up and modifications.
The same went for their merchant ships. I spent 4th July 1976 ( the bicentennial ) aboard the
Sealand Paraguay off Curacao. Like their military vessels, US merchantmen are dry, so we brought over the beer in a lifeboat while they got the steaks going. Anyway, it looked a fairly modern ship, judging by her size and superstructure, but once we were aboard and having the guided tour, we found out the hull, boilers and machinery went back to 1945. It had been extended and a new 'modern' looking funnel and superstructure fitted, but it was very much mutton dressed as lamb.
Must have been a good party though, because to this day I can't remember coming back to our ship or climbing the pilot ladder! The next morning we were flying the Stars and Stripes, and they were flying the Red Duster. What a great bunch they were.
