Concrete ships?

[seadude]

Concrete ships
https://en.wikipedia.org/wiki/Concrete_ship

Can they still serve in various functions and be built like they once were during the early to mid 20th century? Would concrete ships still have any usefulness or function in today's world?

One recent idea I had was what if a modern Habakkuk ship were built, but not with wood pulp and water, but instead with concrete? Would it work? What would be the advantages/disadvantages?

[rickshaw]

Concrete has problems with mass versus strength.  They tend to be appreciably larger than metal or fibreglass hulled vessels, drawing extra depth.   They also, because of their strength problems are appreciably heavier.    They would be valuable if a massive number of ships were required, although I suspect the use of plastics/fibreglass would surpass them for building speed.

[jcf]

With the advances made in concrete technology in the last few decades - fully customizable formulations
and additives for strength, durability, weight etc., you probably could design a new type of concrete ship
that would address the issues Brian mentions, the question is: why?

[rickshaw]

With the advances made in concrete technology in the last few decades - fully customizable formulations
and additives for strength, durability, weight etc., you probably could design a new type of concrete ship
that would address the issues Brian mentions, the question is: why?

Cost?  Not really.  Ship steel is now the cheapest item when building ships.   Speed?  Not really.  Concrete requires significant time both for manufacture of the moulds and to dry the substance to withstand water.   Fibreglass/Plastics offer greater advantages.

[PR19_Kit]

I hired a concrete cruiser on the Norfolk Broads back in the late 60s once. It was built by Windboats out there and they had a whole fleet of them for hire at the time. It didn't look too different from traditional Broads cruisers, but was quite a bit noisier when it was running, I guess they didn't insulate the engine from the hull all that well.

I'm not sure I'd like to have been aboard if it had hit something substantial though, there's precious little give in the hull!

[sandiego89]

Regarding the original musing about huge concrete ship like a Habbakuk size, I would wonder if concrete would not scale up well due to being so rigid? I would think such a massive ship would need flexibility to deal with swells. Large ships bend much more than many realize.  Did the habbakuk flex or have expansion joints?

[jcf]

Moulds? One of the main points of concrete ship/boat construction is that
it doesn't require moulds. The concrete used is not the same as your shed
pad, curing is not really an issue. The composite fibre, glass fibre etc.
additives add strength with little weight, some produce a stronger and
lighter weight concrete. As I said "concrete" has changed a lot.