Wooden Yacht - Integral Strength over Time

Gents, I have a question but please bear in mind I have no design skills or formal yottie education.

Scenario: A skilled boat builder chooses seasoned wood and builds a 40´ yacht to the design of a respected architect. At this point, the strength of the individual planks and wood component parts can be considered to be '100'.

That was in 1960. In the next 48 years the yacht has been based in Italy (where it was built) with the effects of the sun, wind and dryness offset by average use (which I expect to be surprisingly little as read in other posts on this forum). The yacht has not been in a collision, ignored and has received basic family-affordable maintenance and loved by successive owners over the years.

Fortyeight years later, how strong is the nett some of the parts, the hull, deck and fittings? I imagine the boat would have dried over time becoming to some extent brittle and then regained moisture many times over the years, been used less in some seasons than others, maybe left out of the water for a season or two as well (thats normal at some stage of a yachts life isnt it).

What got me thinking was seeing such a 1960 yacht looking lovely after a cosmetic refit, and describing to my long-suffering wife how nice it would be to cruise Patagonia, through the Magellan Straight, up Chile and onwards to alaska. Then I imagined the inevitable pounding and I found myself asking the above question.

If on launch day she scored an integral strength, sound structure, safety and a competence for use score of 100, what would she most likely score today? 65?

Grazie,
Richard

 

Richard I bought an old yacht to restore infact I have resorted to a re build approach. At first glance all misty eyed and full of plans for a quick lick of paint and a spot of epoxy. Ha! iron sicknes wet and dry rot only reveal themselves when a plank is lifted or some paint is scraped off. Afordable maintenance is a myth.Old boats are rotten to some degree or the other. They dont gain or maintain strength through maturity. Fasteners corrode iron to rust and brass to green powder and a flake of copper. A expired fastner will still hold a plank in place untill the right amount of persuasion is applyed,usually a tap or a slight tap.

All that aside I love my old rotten rebuild boat.There is nothing like sailing on an all wood boat. There is nothing more satisfying as replacing the rotten timbers and seeing the boat emerge from the pile of old planks. I am not planing to sail the world with her just a bit of coastal cruising. When I get to the point of long distance sailing it will be in steel.

 

The scantlings used for wooden boats (60's) were so strong compared to brand new cruiser/racer it can still be (if in modest condition) stronger even if having 50 of it's original strength left. But so much variety in boats that age.

 

Used boats and motorcycles - always assume the worst if buying a secondhand unknown. I know surveyers who won't survey wooden boats over 5 years old. I would guess the only reason you are interested is because "the price is right" ? They will probably take 25% less than that.

be prepared for a world of pain ... especially in the wallet!

 

Assuming proper maintenance and repairs were preformed during it's life, then 90% of it's original "strength" could be realized. Strength is a very relative term, one that in itself doesn't mean anything in particular.

Commonly a well cared for yacht will have systems and equipment upgraded or replaced as time marched on. This "renewal" schedule will retain all or damn near all of the integrity of the structure and systems.

The current condition can be accessed with a comprehensive survey, by one familiar with the type. This is the only true way to evaluate the present state of affairs, within the yacht.