Steel is scarce. Wood is not an option. And you need a boat now. These wartime circumstances drove innovation in all kinds of crazy directions, and one somewhat less crazy direction — concrete boats. As [Peter Sripol] demonstrates in the video below the break, making an RC concrete boat isn’t hard. Making a fast one on the other hand is. But that didn’t stop him from trying, and we think the effort deserves a look.
Starting with a basic displacement style hull, [Peter] and his cohorts experimented with a simple RC boat that worked, but could only move at slow speeds. They turned things up a notch or two and instead modeled their concrete boat after an RC speedboat hull that they had on hand.
The construction methods left a lot to be desired though, and they even tried various wire meshes as rebar, but they proved too heavy. Eventually though, they got a working hull, and had some fun with it. Rather than try to make the hull watertight with a rudder and propeller, they opted for a ducted fan and an airboat style rudder to make what they call the “world’s fastest concrete boat”.
Whether it’s the fastest or not is unconfirmed, but it is fast and actually gets on step fairly nicely. We applaud the exploration of alternative materials and the experimentation with different build methods. If building things with concrete floats your boat, then be sure to check out this concrete pinhole camera.
Real engineers race concrete canoes.
I’m a little behind on this one, but came here for this comment. And that they could have used a light weight mix.
A bloke my Dad used to work with, built a concrete yacht. He took me down to see it afloat, when I was too young to understand that things heavier than water could do that. I thought he was putting me on.
OT: Good riddance Mr Pi. I’m going used Celeron, and with awesome graphics too.
They need to collaborate with a material scientist. And power it with a pulse jet. 🚀
Nodehi, M. Epoxy, polyester and vinyl ester based polymer concrete: a review. Innov. Infrastruct. Solut. 7, 64 (2022).
Looks like Peter laid the groundwork, poured everything into it to the mix just right, and is now all set to pave the way forward.
He has truly cemented his hacker fame.
Indeed. His boat now floats on the water in much the same way that bricks don’t.
bitumen paint should work to waterproof the leaky hull.
You know what else that floats? Very small rocks.
A number of concrete ships were built by the USA in WWII. Several still exist as a breakwater at Kiptopeke State Park in VA.
In WWII the US and Canada tried aircraft carriers out of ice – was a special ice mix – I don’t think they made anything large and didn’t get past the prototype stage – but was interesting – Seems to me the Myth Busters might have tried an ice boat also
It was called Pikecrete if memory serves? –My spelling probably doesn’t though.–