Ferrocement ship revival?

That picture of the helsall build mentions POST tensioned steel framing.

What the F is POST tensioning ?

 

Pre stressed concrete is where the concrete is put in compression by a tensioning cable. Post tensioning is where the pre stressing is applied after the concrete has set. There are various reasons for this, one being that it's easier to tension on large spans if you don't have to worry about propping up the tensioned cable. You lay tubes through the concrete, then fish cable through the tubes afterwards and apply tension. Then you pump grout inside the tubes.

 

After seeing the first below picture, it came to my mind post-tensioning could be tensioning with a post . . ? ?​

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Creators of super powerful structures ---> Evolution ---> History ---> Peter Ellen - (the pics and the quote are all from the last link)

‘‘ Peter received many international awards and titles for his skills and accomplishments with post-tensioned steel and concrete composite structures. One particular highlight was his radical post-tensioned steel and concrete yacht design (Helsal I) that went on to take line honours in the 1973 Sydney to Hobart race. ’’

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