Plate thicknessand other scantlings for aluminium construction

[Willallison]

I am trying to find some web based information on recommended plate thickness and other scantlings for aluminium boat constructions.
Can anyone help?

[Jeff]

If you're just starting to think about metal boat construction, Michael Kasten has some interesting articles on his site:

Metal Boats for Blue Water - Why choose metal for a boat's structure?
Any discussion of metal boats inevitably encounters the question of whether a boat should be aluminum or steel. Not often realized is that there are other metals that may be effectively used. "Metal Boats for Blue Water" is intended to provide an overview of the possibilities, and to discuss why one might choose metal for a boat's structure.

Aluminum for Boats - Is there good reason to consider aluminum over other hull materials?
This article first appeared in the September 1997 issue of Cruising World magazine. It includes several good images showing different hull forms suited to metal construction, the relative advantages of each, and what factors one should have in mind when considering the use of aluminum as a hull construction material.

Aluminum vs. Steel - A comparison of their relative strengths, and the advantages of each...
The choice of hull materials is the most fundamental of choices when considering a new vessel design, or even when considering the purchase of an existing boat. If you intend to make use of metal as a hull material this article will be of some value in that choice. It will shed some light on the various ways to compare steel versus aluminum for a boat's structure.

And the Marine Metals Reference PDF

And although I certainly don't want to steer you away from our forums, you might also find the Metal Boat Society forums to be useful http://www.metalboatsociety.com/phpBB/index.php

[Scott]

You might also find Bret Swain and his "origami" folded method interesting. I think the first time I saw this was on the Confidence Custom Boatbuilding site: http://www.boatbuilding.ws/

Brent Swain boats use the so-called frameless construction method, where the hull is pulled together and stiffeners and bulkheads are installed where needed afterwards. This method results in a short hard chine in the midsection ( not visible, as it is below the waterline ), with compound curvatures in the forward and aft portions of the hull, which results in great strength. Without all the unnecessary framing, we can use thicker plating without increasing the weight. The steel thickness is 3/16 inch for the entire hull and this, combined with the compound curvatures, makes for a very strong hull. 3/16 inch plate has nearly 3½ times the resistance to holing as 1/8 inch plate, and also 3½ times the resistance to distortion.

On our aluminum Brent Swain boat hulls we use the same construction method and 1/4 inch plating

but my interest wasn't really peaked until I read this thread: http://boatdesign.net/forums/showthr...p?threadid=249

[Scott]

I'm sorry - that was supposed to be http://boatdesign.net/forums/showthr...p?threadid=248

Thanks to all who replied! I've seen and read a number of the articles / sites referred to. I'll have a look at the others and see if I can find the info I'm after.

[Polarity]

Trevor Bolt refers to the ABS scantlings in his article here

Cheers

Paul

[Stephen Ditmore]

Bolt appears to be responding to a story of some sort at the beginning of his article. It may be
http://www.komotv.com/news/story.asp?id=16797
that he's talking about.

Any of the classification societies, including ABS, Lloyds, and DNV should be able to provide aluminum scantling information. The most up-to-date thinking is likely to be in their "High Speed Craft" guides, and DNV is the one used most among modern fast ferries.

Paul, are you a member of the Origami discussion group now? They discuss a number of issues that might be of interest to you, whether your Brewer is built origami or otherwise.

[Polarity]

Stephen

That story went up since I posted the above!

Thanks for the origami tip, I will grit my teeth and try and join the origami group I seem to remember I tried for about half an hour and understandably gave up - I still want to see how they waterproof the paper ...

Cheers

Paul

You might also try "The Elements of Boat Strength" by Dave Gerr, International Marine ISBN 0-07-023159-1

[Tim_Hastie]

Have you looking into the "shrink wrap" method of construction. ? Makes for a fair set of lines on thinner metal boats.
TIM

[CDBarry]

Look for NVIC 11-80 on the US Coast Guard website. You can download it for free.

Originally Posted by Tim_Hastie

Have you looking into the "shrink wrap" method of construction. ? Makes for a fair set of lines on thinner metal boats.
TIM

Where can I find information on this? A web search did not bring up anything of interest.
Thanks

[Tim_Hastie]

The web site I originally found it on no longer has it posted....go figure ! if you email me your fax number I will fax you the copy I printed.
TIM

Tim:
Thank you for the offer of the fax. I am not a member so I cannot E-mail you. This will do just as well, fax to 845-369-3940 in the United States.
Thanks:
Robert Gainer

[Tim_Hastie]

I'll fax it today...Good luck

TIM