Hull Thickness

C

changeman

Well-Known Member
Joined
22 Mar 2005
Messages
254
Location
Looe, Cornwall
Visit site
I am going to buy a Dutch barge, approx 20 x 4 metres and am looking at a number of options built around 1900.
Can anyone tell me what is the minimum acceptable hull thickness for a reasonably long life?
I am checking some previous surveys to help me decide which barges to view and as an ex yachtie, am more used to fibreglass.

Thanks
CR
 
3-4mm perhaps? (Awaits to be proven wrong by experts...)

I suppose it also depends how far from land you plan to go /forums/images/graemlins/laugh.gif
 
need to be careful about this if you want insurance. I suspect that a 3mm hull thickness would not be insurable.
 
If it is anything like Narrow Boats, at the time of manufacture the bottom plate is usually 6mm, hull side 4mm and the top 2mm. Surveys later in life talk about replating when the thinknes becomes 3mm or less.
 
I've just asked my barge-owner mate and he says a figure banded about is 6.8mm but 6-8mm is the norm. Insurance companies require 4mm minimum although I would think that that would be where there has been loss of metal due to rust. He also says that the dutch, although excellent at building barges, are crap at overplating, so keep an eye out for bad welds and leaks. It would possibly be better getting something that needs replating and getting it done in UK where you can check the quality of work but all depends on your budget and requirements.
 
[ QUOTE ]
3-4mm perhaps? (Awaits to be proven wrong by experts...)


[/ QUOTE ] I'm no expert in such matters but I would have thought that 3-4mm would be unacceptably thin. The underwater sections on our modern 13metre Dutch mobo are 8mm.
 
Apologies for differing, but my narrowboat (when I had one) was 10/6/4mm and that was 58ft long. 10mm bottom was pretty standard for the big builders when the price of steel was lower! That's how a 58ft narrowboat weighed almost 20 tons.
 
I believe the main difference is that UK builders have thicker bottom plates to cope with frequent grounding whereas the dutch use the same thickness for the bottom and sides as grounding is less of a problem.
 
Also Dutch boats are built like ships with proper framing etc whereas narrowboats (at least the modern ones) are just steel boxes with minimum framing.
The minimum that insurance companies will accept is 4mm I would be looking for 6mm in a tradionally built boat.

Julian
 
Rather than a fixed arbitary figure, I would suggest no lower than 70% of the original plating thickness. When a steel vessel "works" in a seaway, all the stresses will concentrate on the weakest area (similar to when a wooden vessel has a couple of cracked ribs). Any less than this, I would suggest re-plating (NOT overplating).
 
You must log in or register to reply here.

Share this page

Top