Cost Of Traditional Wood Build Vs Various Modern Techniques

Thats right, in this case my argument does not bite.

 

Nope, you don't want the glass fibers going bow to stern. You want them on the diagonal.

You might, perhaps, use bow-to-stern orientation in those places where the fibers are at maximum distance from the structural null axis: generally the centerline bottom and at the gunwales. However, even there one generally wants the fibers on the bias, because you want to transfer the load across the structure, especially at the structural extremes.

So consider the diagonals in the bridge truss the diagonal laminations of the panels between the structural extremes: the deck and hull.

The longitudinals of a bridge correlate to the gunwale and centerline of the hull. While, again, it may seem appropriate to put longitudinal fibers in these locations, you still need to ensure that the energy being absorbed by the structure is transferred throughout the structure in order to absorb peak loads without failure.

If one layer of longitudinal fibers provide a local strength of S in the fore-and-aft axis, two layers at 45 degrees provides 1.417 times S at 2x the weight. Sounds like fore-n-aft is lighter, right?

However, that load must somehow be transferred to the panels between the extremes -- the deck and hull sides near the gunwales, and both sides of the bottom of the hull near centerline. So you need some fibers off-axis. If those fibers are at 90 degrees, they still double the weight, but they add nothing to fore-and-aft strength, so you still get 1.0 S, but at 2x weight. So it turns out its weaker at the same weight.

If those fibers are at 45 degrees, they of course transfer best to the panels. So you need to go across those extremes anyway with 45 degree laminations. These simply can also provide the longitudinal structure.

 

not to reopen an old wound but I once asked which was cheaper to motor or sail
which provided the best bang for the buck across the board from build to demolition
what I found was that it is dependent on what area you are primarily voyaging in and in my case that was the pacific northwest.

now just for the sake of fun what about some other areas of interest
how about the east coast of north America, Hudson bay to the Bahamas and out to Bermuda
build would still favor the motor yacht but operation is what I'm curious about. Several posters mentioned a low tec approach would yield favorable results in sail over power but several others were not so sure.

If this issue is so highly dependent on area of choice then it might be interesting to discuss some other areas or interest

 

Yeah, here in the Pacific NW there are overwhelmingly powerboats, due to the long fiord runs upwind, strong currents etc. The Caribbean Islands on the other hand where you're usually on a reach and the wind is reliable would make sail attractive. Low tech sail works very well when one stays close to the truth of the original design. Low tech=cheap usually. Cheapest bang for the buck (and an East coast US type) is a Presto-derived Sharpie, of which several variations have come out in the past years. Long, shallow, easily driven by sail or power, very cheap shape to build out of wood. Easily driven means less sail area needed in light conditions and smaller engine and smaller tankage needed etc. Shallow draft means you can go many more places and opens your options wonderfully. Lighter rig is much much cheaper and the kids can handle the sheets while you sip a mint julep.

 

See Ruell Parker's marine designs for excellent build/use/demolish ratios

 

In general one can say, the larger the boat and the longer the passages the more you have a advantage for the motoryacht.

In windy regions like the Aegean Sea or the Baltic, and according to the relatively short distances we have to sail there, the sailing boat shines.

Regards
Richard

 

I have a set of prints for the Atkins Tern which although an older design has many of the feature you are describing. I would think if fitted with a top mast it could fly a bit more canvas and do ok in light airs. I also like Brewers Friendship sloop. and one by Daniel Crocker JR called the sea dawn. All are within about the same size and cost range and each has its advantages and drawbacks. One thing I liked about all of them is that they are fairly primitive in there simplicity.

not changing my mind again but the issue of which is cheaper seemed to be so dependent on a number of things that it almost seemed to demand we revisit the issue

cheers
B

must have both posted at the same time Richard

ya the super yachts which to me are things over about 50'~65' and up are pricey on rigging and sail that and they have lots of auxiliary systems
I suppose I should have specified a boat to boat comparison but I tried to keep it as general as possible and merely specify primitive

 

My observation from the Stockholm Archipelago is that sailing boats go by motor 80% of the time when they have to get from point A to point B. Sails are used for the joy of sailing when on open water and the wind is fine.

Because the sails are not used very much anyway, I find it difficult to believe that there is any money to save by choosing a sailing boat instead of a displacement type motor boat of the same size. To save money with sails you need to use them a lot, which could be the case if you're mostly sailing on open waters with good wind and don't have a schedule to follow.

Erik

 

I guess it depends how low – low teach is one prepared to go. Really basic boat can be bult incredibly cheap.

For example, couple of years ago during the winter some friends of mine banged together boat shown in the attachements from the home depot wood and under layment, cut tree for the mast, rope for the rigging, got some second hand sails and recut it... Spring arrived, boat was declared finished and of they sailed to the Caribian and over the Atlantic. They didn’t have any engine, electricity, nothing. Interior was empty, “comfort” very much 18th century seamen “style”.

Still, they enjoyed the voyage, arrived to the Canaries in the good health, with a taste for more…

That couldn’t be done so cheaply with an motor boat.

Conventional modern sail boat is different mater. Sails and rigging are not cheap, and most modern sailors can’t imagine sailing without powerful diesel engine that is used half of the time. In that case, simple motor boat with efficient, low resistance hull, could be cheaper to run.

We had very long discussion about that couple of years ago, there is a huge thread somewhere on the forum, I’ll try to find it.

 

Not soo long ago Milan:

http://www.boatdesign.net/forums/po...powerboat-cheaper-run-than-beowulf-25549.html

and Bostons own thread:

http://www.boatdesign.net/forums/boat-design/cheaper-motor-sail-31976.html

 

dam your good I was looking for that last in the search and it didn't come up at all.
oh well

 

Not as good as it seems Mate..............

I just subscribed (and contributed) to these, because the question comes up again and again.

 

Ah, yes, thanks. It seems that sail versus engine economy resurfaces periodically. Unfortunately, I don’t have a time to regularly follow all the threads that I find interesting.

I searched this thread:

http://www.boatdesign.net/forums/bo...oats-versus-motorboats-11479-6.html#post87621

 

It all comes back to budget. If you can afford fuel and want short, predictable passages, then of course a power boat or a fully powered auxiliary sailing vessel. But that means you pay for a full sailing rig and full power in your boat. If you have no money but have time and willingness, sailing is free, once the rig is built. Some traditional rigs can be built very very cheaply and still work fine with all that nice free wind that BP hasn't figured out how to sell us yet.
Here in the Pacific NW most vessels are power and I see them charging along leaving (and paying for) the big wakes from their inefficient hulls. Moving all that water costs fuel you're paying for. The boat's supposed to move, not the water. For the right way to do a power vessel, see late ww2 German "Schnell-boats", commonly called E-boats. These long lean torpedo boats could do 40 knots in big sea conditions that kept the equivalent US and UK PT boats down to a crawl because they would pound apart. Not the schnell boats. They were one of the more perfect boat designs of the 20th century and make a good place to look if you want to see a good motorboat.

 

Milan,

Schonker is an amazing boat. A simple dory hull and without any rocker in her bottom. Do you know how long Schonker is? Where is she located at present time? More information would be greatly appreciated.

Looked at your post mentioned and agree with your ideas for efficiency: narrow, lightweight, and low with steadying rig.