Ferro-Cement Multihull Scantlings

...hereabouts we have a very apt phrase about these sort on endeavours which would translate into "re-inventing the wheel"...

 

Concrete boatbuilding is still alife and matter of scientific research. Look for concrete canoe: https://en.wikipedia.org/wiki/Concrete_canoe and https://www.youtube.com/watch?v=TTPnjIKqsEA , http://concretecanoe.engin.umich.edu/ ......

Is concrete used for traditional canal narrow boats? Weight doesn't seem too much of a problem since they've got to be low in the water to get internal headroom.

 

Yes I think so: http://www.canalworld.net/forums/index.php?showtopic=36910 and http://www.gloucesterdocks.me.uk/vessels/nwmnarrowboats.htm .

 

Ever heard of "Concrete Cancer". :?:

 

Let's see, we build a boat from one of the heaviest and least desirable of hull shell material choices and incorporate this into a hull form, that typically require lighter methods. What could go wrong . . .

A concrete airplane is possible, probably even built, though it still isn't the wisest option for the same reasons. If you're married to the idea, contact Jay Benford and get a real set of plans for ferro, or someone else with the appropriate experience in this material. Self designing just isn't an option without serious engineering skills and if you are an engineer, you already know the value of the research necessary when working in materials/processes you're unfamiliar with. You can go through this headache or pay to have it done by someone, where it's not so much of a brain stretch.

 

For all the badmouthing ferro gets, usually from those who have not actually built or owned one but somehow feel qualified to comment, there have been many very nice, long lived ones that have gone places and performed exactly the way they were meant to. I'm currently working on a Hans Cristian 38 that is heavier than the Hartley RORC 39 that I built 45 years ago as are many glass boats of the era when ferro building was popular. It would be possible to build a better one today, say, with basalt rebar and better mixes but I do agree that there are much better methods available today just like it has been pointless to build a carvel planked hull today (or for the past 50 years), There are simply better methods.

 

...only a typical thing with not-so-heavily pointloaded ferro hulls (thrown towards piers, touching a reef, etc.) would be the collaps of a goodsized piece of hull...
& their advantage remains to be demonstrated to not-only-my satisfaction...