Cost Of Traditional Wood Build Vs Various Modern Techniques

everything is right

This photo above shows how you can build a narrow boat with a big boxy cabin and have it look totally perfect (crown, proportion, sheer, tumblehome), as well as efficient. Others can build a narrow boat with a big boxy cabin and make a hideous box with the same volume and efficiency. (shakes head in wonder). The Renaissance and Age of Enlightenment (think Thomas Jefferson) taught study of Greek classics of Architecture with its gently swelling lines as the ultimate discipline, subtle and refined. Yacht designers and the skilled craftsmen of the late 19th and early 20th century took it to heart and produced beautiful things like this.

 

Generally they got it rather close to right....classic proportion was "in".

http://www.classicyacht.org/gallery/thumbnails.php?album=11


The real freaks did not survive...thankfully.

 

Tad
cool and yes the plan is for the aft deck area ( cock pit ? ) to have a sole well above water line
sorry I did not make that clear in my drawings

Peter
thanks for the link, the vessel you pictured is precisely the look I am after however, I was hoping to use a few tricks to produce a vessel of half that weight, a bit narrower and with way less draft yet stronger than the typical commuter so that I might in good weather make the run across to the sandwich islands or down the south american coast to the canal and on to the virgins and the Bahamas
I wont know till I really start in on the weight budget and that I cant do until I do these elevations and sections

not sure how this will go over but I have worked with laminated glue ups and making my own beams for a long time
mostly by clamping veneers up between steal beams ( comes out perfectly straight every time )
I keep thinking I should be able to thick veneer black walnut over a cedar core using resorcenol and end up with a nice looking light weight beam that can be used say as the cabin ceiling beams. and the deck house beam posts bla bla bla
my thinking is that I can get the sense of bulk and most of the strength but loos a significant portion of the weight

the drawings presented are a first draft although the initial elevation showing the complete vessel is pretty close to the look Im after

I am very open to suggestion so please feel free
tonight I think I will forgo drawing and research tumblehome in these type vessels
my intention is to mimic the past but with modern techniques and hopefully produce a sleek efficient commuter style yacht that even an experienced eye might find hard to identify as a modern construction

thanks for all the input folks
I am humbled by the generosity of your many suggestions

best wishes
B

 

Tad I look at those picts and I just dont see any tumblehome
looks slab sided to me

am I really just not seeing it ?

I dont mind putting some in the plan since the head room at the extremes is limited
say 6'6" at best
that and it allows for my to keep my cabin roof overhang

specifically
look at the corsair 11 and tell me she has a 1/4" to 1' slope inwards on the deck houses
I want to understand that you are suggesting but Im just not seeeing an inward slope to these deck structures in most cases

Elmisico also does not appear to have a slope to the deck house walls

oh
I had originally incorperated an aft cabin that norrowed with the hull but it just didn't work out to well in the sections
so I nixed it for a simple rectangle form

 

"I was hoping to use a few tricks to produce a vessel of half that weight, a bit narrower and with way less draft yet stronger than the typical commuter so that I might in good weather make the run across to the sandwich islands..."

Boston,
All optimized around a cast off motor with a finished dispacement of 25,000#, for 1/2 the cost. So the design spiral starts there. Your tankage is how much?

How much sea time do you have?

 

cast off
no
used
yes
also the more I learn about this engine the more it seems to be respected in marine applications
so Im feeling pretty comfortable with my decision to use that particular power plant

I say stronger because by extending the cabin sides down to the hull and including some diagonal webbing I am basically making a pair of truss girders that run the majority of the length of the boat. Should provide some serious stiffening and strength to the whole thing. Support those in roughly mid span by the decks and I can lighten the webbing considerably. The traditional deck house that live loads onto the deck is a far weaker arrangement requiring heavier deck beams and placing concentrated loads on the hull framing. I can spread out the weight of the structure better by including these trusses and thus lighten the structural members to a point were there is a net saving in weight

I hope

I need to get detailed before I really know what my weight totals are
which is what Im doing by making the preliminary sketches of the interior so I know what the girder trusses will look like and where the stringers need to be in order to optimize there being supported off the main girders

I should probably not have presented the drawings yet but after two years of study on the subject folks seemed to be getting impatient, ah the peer pressure. Anyway the exterior elevations are more like conceptual drawings at the moment and the interior elevations are synonymous with flipping coins to see what comes up. The one plan view so far is also a flip of the proverbial coin as its all about possibilities and options at the moment

not sure how much building and design work you have done but I've been designing structures for quite a while. Laminating beams of different materials is another trick that has worked well in the past. Sorta like engineered lumber. You can glue a few stuctural pieces with some lighter stuff between and they provide lateral support allowing the structural members to be thinner. thinner = lighter. I was also thinking of webbing to the stringers from the girders thus making the stringers more like web trusses than solid stringers.

not sure if any of that plan will work but its ideas that are tried and true in other realms of construction
might work in the boating world
might not
wont really know till I draw it all up and present it for scrutiny/abuse

I was planning on presenting these ideas much later in the process but since the subject came up what the hell

my roof beams deck beams stringers and even bulkheads can be made of laminated materials using the method described above. Plywood is heavy, really heavy. Doesn't need to be, in a bulk head what it needs to do is provide stiffening for the longitudinal members and in case of emergency keep water from penetrating to the next section

that means that the ideal bulk head would have a structural outer edge only with something impermeable to water in the center that also resists compression. I can build this kinda like an interior door, with two thin outer skins, a edging of structural wood and an interior of something extremely light like polystyrene or something similar. Should turn out significantly lighter than the basic plywood bulkhead and with similar strength characteristics
I have seen this done in yacht construction before so I know that technique at least is tried and true however, my panel work can also be incorporated to assist in the structural integrity of the bulkheads

speaking of which the panel work might end up being flat panel rather than raised as it would be lighter that way. I can still do something nice with the inside edging and make it look good but the central panel would end up being 1/4 ply veneer rather than 1/4 solid wood
once again I would need complete drawings including all room elevations to do a proper estimate of these considerations

stringers are the same way
they need to be able to hold a fastener from the planking but beyond that they can also be made of dual material lamination's ( at least the ones above the water line ) and thus end up lighter than typical solid stringers

the stringers bellow the water line can be webbed to the girders and end up lighter because they are no longer point loaded on the bulkheads which in turn allows the bulk heads to be lighter as well.

there is a plan

its an evil plan but there is one

might work
might not

wont know till I bang out some drawings and show what I've got to the more experienced in the crew for some critique

cheers and best to all
B

 

Tad
Compadre is pretty much what Im building with a few minor modifications to its general design

http://www.classicyacht.org/gallery/displayimage.php?album=11&pos=18

thing looks completely slab sided to me although I might be just missing it
are you sure this style typically had much tumblehome cause Im just not seeing it
that deck house looks about a square as it gets

now I can see that adding some angles and by following the deck curvature you add a lot of character to the vessels deck housing but it looks to me like this style did not typically incorporate that design feature

if they did it was in years far later than the 20s look I am after

I will do up some drawings that include some tumblehome as you suggest and see what they look like
pencils are cheaper than building and at this stage you never know what just might end up incorporated into the plan

cheers
B

 

Just a note on "COST".

The real cost is the "Round Trip" , the coat of obtaining the boat , compared to the resale value.

This is the big problem with many wood or high maint boats , or even GRP BOATS WITH GARBAGE FOR CORE MATERIAL..

The best resale seems to be GRP with Airex core , and all downhill from there.

FF

 

You missed the point and basically ducked the questions. Your design challenge doesn't really revolve around personally reinventing the wheel. Starting with some fixed parameters, in this case a particular powerplant, a roughly designated displacement, endurance requirements that now include hitting Hawaii, and live aboard as opposed to voyaging accommodations the engineering questions poised at this point aren't really centered around ultimate structure strength and mininum weight.

Certainly weight plays a role. It affects the performance and power requirements among other things. With your powerplant an arbitrarily fixed point, for your specified endurance some primary questions need to be resolved.

What is the volume of fuel required and where to place those tanks?

How much water will I need and where to place those tanks?

How many cubic feet of stores does the crew need to outlast the fuel requirements of the arbitrarily chosen powerplant for the specified endurance and where do I place them?

All of this constrained by your minimalist budget. Not as fun and sexy as designing trim details or furniture for your "master suite" but far more critical.

Do you have any actual seatime?

 

I do not know about Boston, but I still think that for a personal boat built by the owner, design by the owner, the resale value should not enter in the equation. It is already mute due to the pedigree.
Why bother about something so elusive, difficult and anyway so far away from the dream of owning your own boat built and design by yourself.
Look at boat magazine, thousand boat are for sale, for years and years without no interest from nobody.
The dream, and the finality is far more important than a uncertain sale.

Daniel

 

I grew up on Cape Cod working in my grand fathers boat house I had more sea time than land time at least before I hit the age of about 18 when I went off to WHOI to study marine biology. From there I spent less and less time actually on the water and eventually transferred to CU Boulder Co.

Wally you seem to have a chip on your shoulder all of a sudden

this thing was always going to be a live aboard, not sure how long you have been following the various threads Ive started seeking the various answers needed to get this show on the road but most if not all of the questions you are inquiring about have already been asked, the answers considered and the basics are there

for instance my sea experience has been stated numerous times
as has my background as a woodwright
style of construction
place of construction
fuel type and quantity
stowage
etc etc etc

I appreciate the interest and input but I simply cant recall everywhere these questions have been addressed and haven't time to dig up everything and present it is haphazard form

I should not have presented anything until I had things farther along but folks seemed anxious to see what I was working on so I threw out a few of the drawings I was working on at a the time

the elevations are the fun part and given that I need design some things according to the finish it seemed reasonable that I draw a few interior elevations

didnt mean to upset you

am not ignoring the more critical of the engineering considerations

25000 is the weight of Wigeon a Chesapeake bay commuter I sorta modeled this thing after



I'm considering some extensive alterations in the basic engineering of her frame, namely changing her to a stringer over bulkhead configuration with double diagonal planking and the use of cored lamination's and some truss like components. Seems like I should be able to make a stronger boat in the same weight range.

I wont know the weight until I add everything up and I cant add everything up until I know what Im putting in

I thought I'd start my knowing the weight and balance of the basic hull and its furnishings and then place tanks engine and stowage were needed to get her level and keep her there as things like fuel get burned off and the beer stock dwindles

cheers
B

ps
Daniel hit the nail on the head

for me hands down wood construction is the way to go and resale is not a primary consideration although its always on the list

 

If you do not value your own labor, resale value is of little consequence. To me, resale value is of great importance.

 

I am not quite sure what the correlation between between valuing ones time and resale value is

to me anything I build should have a high value, once upon a time its how I made a living.

although things have picked up in just the last week and now it seems like I have more work than I know what to do with

 

Boats seem to be one of the few places where passion throws logic out the window. Maybe resale value is the wrong word. It should be sale value at the time you finish the boat. Once you own it for a while the price drops due to wear and tear.

Its quite simple. The price of the materials and overhead subtracted from the value at the time of finish divided by the number of hours equals the labor rate. If you have $70k into the boat plus $10k in overhead have 6,500 hours in labor and the value when done is $100k then the labor rate is $3.08 per hour after tax for skilled labor. Its nice to have a positive number instead of a negative one. I try to shoot for at least $10 per hour after tax for my own skilled labor.

 

My dream becoming a reality is not for sale.
I am very shelfish, I want to enjoy my dreams.
And when I am dead, I don't care, I will ask in my will to burn my dream.
I spend my life building and selling boats. When it's for me, it is an other ballgame.
I don't mix pleasure with business.
Daniel