Modern professional ferrocement boatbuilders?

Ferrocement barges and boats started being built in 1860. There is a long successful history of them. During WWII the technique was used fairly extensively: http://www.concreteships.org/
This is an interesting paper because its reference to Lloyd's willing to issue a 100 A1 rating to ferrocement ships: http://pdf.usaid.gov/pdf_docs/PNABJ040.pdf

 

Look through this opinion 2 or 3 times. It reads as good as any abstract from a doctorate level thesis. No small amount of effort goes into penning this type of quality response. I'm not sure if I just had a history lesson, or an economics lesson, or a engineering lesson.

Crasch,,,, I think you could explain what your ferro plans are. You might get a slight ribbing, but by and large some of these forum members have more knowledge and experience than I could achieve in two lifetimes.

 

These days about the closest you'll find might be these guys

http://promanconstruction.com/index.php

http://www.floatingstructures.com/

 

I agree they are far to expensive to build these days. But there are a lot of beautiful ferro boats still sailing around Australia. Khan walkers ferro boats have a great reputation and are sought after. I think a good pro built ferro is as good as any other boat but all the dodgy builds gave it a bad rap. I have seen several which I could not pick as ferro they were so well finished. The walker method of tensioning the armature over molds resulted in a much lighter hull.

 

Unless you can solve the labor costs ... know where to lay hands on some Oompa Loompas?

But kidding aside: if I were to try to summarize the criticism of FC hulls it is that far too many haven't lived up to the promises made, though a fair number have just as you mention.

But they don't look like anything but nicely made boats so if someone sees one of them floating next to some goblin-thing guess which one he'll associate with FC?

If I were to add anything to the criticisms given (and I actually would like to own a nice FC boat) it's that an eyesore of a wood, or even steel or aluminum, boat will go away all on its own if nothing is done to it (after enough time the bones of a wood boat can even be scenic) whereas a FC eyesore benefits from that one inescapable advantage of the material.

 

From what I have read and seen,FC seems to be best for barges nowadays,but sheet steel lately can be had for $700 a ton and one could weld up a barge in short order,and for little money.

Just for interest's sake,the maintenance over the last 65-70 years on these ships has been to pump the rain water out once a year..

http://www.concreteships.org/ships/powellriver/

http://powellriverbooks.blogspot.ca/2008/11/thats-my-world-hulks.html

 

The history of ferrocement is initiated by the French gardener Joseph Monier, who in 1847 incorporates steel mesh concrete used in the manufacture of large pots. His compatriot Josep Louis Lambot, the Universal Exhibition of 1855 in Paris, presents the world's first small boat built with mortar reinforced with steel rods and wire, patented in 1852 material, which he calls Fercimen. The rowboat, preserved in the Museum of Brignoles, is 3.66 meters long and 1.22 b readth with between 2.5 and 3.8 inches thick.
Using a similar technique, the Italian constructor C. Gabellini, built ferrocement small boats in 1887.
In the early twentieth century, was built in North America, for the government, a motorboat 5.5 meters long and 1.9 cm hull thick.
At the end of the First World War, to meet the shortage of steel, ferro was employed in building merchant.

 

My Father has owed a Samson designed 48 foot (LWL) ferro-cement ketch since 1984. The hull was commercially built in 1972 by Romack Marine in Long Beach (company no longer exists).

This boat sat on a mooring un-maintained for many years before being bought, fixed up and sold to my Dad.

We subsequently found several problems the seller glossed over, including soft spots in the hull, which we subsequently repaired after hauling the boat.

If properly built and maintained these can be good boats. However, as with any boat electrolysis and rust is an issue that must be dealt with. Further, the quality of the hull construction is not readily visible and hard to assess. If commercially made there is a good chance quality construction materials and practices were employed. The quality of DIY/home built hulls is highly variable. It could be superior quality or junk depending on the builder's choices of materials, attention to details and use of appropriate construction processes.

My Father and I have experience repairing the ferro-cement hull of his boat and from my first hand experience it can be done by a non-professional. However, it requires attention to the use of proper materials and procedures as well as an investment of time. Our hull repairs have held up for 10 years so far.

I am not aware of any commercial manufacturers of Ferro-cement boats at this time. I believe there is an active Ferro-Cement user group in Australuia/New Zealand (Colin Brooks - Hartley)

Regards,

Craig

 

don't forget all the hippies in Alviso, CA during the 1970s.

many were building craft that (thankfully) seemed to have little chance of making it to the water, except in a flood (which happens regularly there).

Some were down right bizarre, with designs that looked more like 1970s vintage sci-fi star-ships.

Some included large garden areas, for some sort of WaterWorld survival.

 

Just the other day I was dream gazing on Yachtworld and there was a listing for a FC yacht of good size that is near completion and not launched. They mentioned the builders and I presume that they were in California.

To find the boat select ferrocement as your hull material. I believe she was 58'-ish if that will help narrow the search.

 

Most larger engineering schools have teams that enter concrete canoe competitions, these modern and exotic designs look remarkable compared to the ferro-cement hulls of the past. They use special modern reinforcement, admixtures and other advanced methods to make it much more structurally efficient. Not sure about the labor involved, but all boat hull construction is labor intensive.

If you need to design a similar structure I would suggest find out who the top winning teams of this international contest are and see if you could hire them to design hull the OP had in mind.

a few pics of some amazing concrete canoes:



https://www.engr.wisc.edu/news/archive/2000/Jul17.html


http://knue.com/the-university-of-texas-at-tyler-wins-regional-concrete-canoe-competition-video/


http://www.clarkson.edu/news/2012/news-release_2012-04-13-4.html


https://www.rit.edu/cast/cetems/clubs-activities

 

Petros, these school competitions have not direct practical purpose but fun and mental exercise to get the max from the basic material.
You take an object and you have to make it with the least convenient material. We had the challenge to make a canoe with toilet paper, polyester rope and the paint or varnish of our choice (only "ordinary" mono-component paint or varnish, the epoxy and bi components paints were excluded). Any other material forbidden except gel silica and talc for thickening. That was great fun, we got floating ugly canoes, we raced with. But I wouldn't recommend toilet paper and paint as naval material.
If you make a search in Internet to get the characteristics of the canoes, none is really interesting and none approaches those of a wooden or composite canoe.
I would remark that all these canoes can be made far cheaper with far less work with other materials. A native birch canoe, which is beautiful engineering using simple forest materials and astounding craftmanship, is more interesting and is highly successful.

At least for working boats, with the low prices of steel, even the Corten, cheap welders, plasma cutters and sand blasters, you can make anywhere a fishing boat above 30 feet in hard chine steel. It's simple and straightforward. No molds, just a flat floor, you cut, you weld, you paint. Easy to modify later, easy to repair. Ferrocement can't match that.
For yachts , as the hull is about 25% of the total cost thus the eventual savings by the ferro cement are marginal, is better to use a more convenient material.
All the examples given in this thread are anecdotal, none proves that ferro is a convenient, widely used, and commercially successful material.

 

The Navy ferro cement manuals are up on this site. There was also a NAVY study of FC boats for local construction in Vietnam published as a SNAME paper a while ago - there may be other as well as plenty of student papers on the FC canoe contests. These are probably good resources to begin with.

FC has a place, but one "problem" with FC is that unlike metal, wood or composite (wood planking over mrtal), CNC still doesn't help FC much whereas it has revolutionized all of the other techniques, so FC is still largely stuck in the 70's at least as regards labor costs.

It is possible to make a "good" FC boat, but it will take a lot of labor.

 

So-called wire-plank seems to address some of the issues, however, even then the (if you'll pardon the expression) underlaying problem still exist.

Any unfairness in the armature cannot be easily, or lightly, addressed by plastering and I will also opine that as the higher strength, less permeable concretes may be used this effect may be all the more serious because these need less covering thickness (so people will try to use less) so there may be less to work with to fair.

Again, wire plank is still better, but care (= time) in making the armature remains necessary.

That said, the technique of using a female mold, applying concrete and pressing steel into that may be worthwhile ... but then the armature is discontinuous and you've already built a fair mold one might also use for glass....

 

Petros ... Golf ball dimples in a boat?

Does that actually work without the hull (improbably and unsafely) spinning?

BTW: found this great funny quote: "When I tried a similar principal, using barnacles, I found it did not have the desired effect." -- "Wingless" on The Hull Truth Boating Forum