Towards the end of WW1 and with steel in short supply, orders were placed at 17 British shipyards by the Admiralty for a total of 154 ferro-cement tugs and barges, intended to carry iron-ore from Spain across the English Channel, though only 12 tugs and 54 barges were actually built.

ChasB46, thank you for your comment, I've completely forgotten the concrete caissons of Mulberry harbours - and I saw the remains of one of them off Omaha Beach in Normandy...

Cheers

Vlad

All the caissons for the Normandy landings 1944 to build the two Mulberry harbours were made of concrete, towed across the English Channel and then sunk into place. Steel was too valuable/in short supply so concrete was used. Ad they still sit off the French coast.

Thank you all for your comments. I remember being a young boy, hearing about "concrete ships" and not quite believing that such things were possible... (A stone does not float! But neither does steel, and I somehow didn't think it was the same... :) )

Back in the day when ships made of concrete were more common, they were the product of steel shortage; their limitations were acceptable during war times, but they could not compete with the "regular" cargo ships once the war was over...

Cheers

Vlad

Was built as a concrete hull coated tanker. In 1924 converted into a sardine cannery in Alaska. After years of disuse Macmillan Bloedel purchased hull in 1958 and moored as part of a giant floating breakwater in Powell River to protect the company's log storage pond.
Largest US concrete ship still afloat.

Looks coated in concrete??

Nice shot
Cheers
Dennis