Jaager

What PietFriet said, but it should probably be bookbinders pH neutral version of PVA.  It is white, dries clear, and does not potentially degrade natural fibers that are vulnerable to acid.  

What PietFriet said, but it should probably be bookbinders pH neutral version of PVA.  It is white, dries clear, and does not potentially degrade natural fibers that are vulnerable to acid.  

Terry,
 
I suspect that when discussing 1650-1860 warship construction, there are details and practices that are very different from 1900 +/- 50 merchant.   The strength and physics of wood would be the same, so necessary scantlings in proportion to vessel size would be reasonably close.  I also have ASA 1870, 1885, 1903 and I use them for 19th century vessels when Meade is mute on the part in question. (My interest ends at 1860.)  The camber vs sheer vs round-up is a point of confusion.   I have slowly come around to realizing that academically generated scientists and engineers with professional discipline,  standards, and vocabulary is a late 19th century creature at best.  The earlier data sources are generally the work of enthusiastic amateurs or individually trained professionals.  There was no board of grey-beards and silver-backs who edited their work for errors or inconsistencies in nomenclature.   I feel  that being dogmatic, rigid, and self-sure about much of this is neither wise or supported by reality.   I go by, does it match what existing plans and information is available? For the gaps, does it match known contemporary  practice within reason and does it seem it fit its time? 
 
As far as deck beams,  in order to fit what I see on plans,  I will shape the curvature of each beam as an individual.  To use the same curve for all and still match the plans as far as the crown would require that I shim the land at the clamp.  By doing this, I would not be following the plan for where-is the underside of the deck at the side.  My plans are 1732 not ~1900.  I am going to have to soak a while about how I will deal with there being a bevel on the top where the slope of the profile line becomes significant.
Batch production of deck beams is an idea that I will file in the specious folder.
 
Dean

Terry,
 
I suspect that when discussing 1650-1860 warship construction, there are details and practices that are very different from 1900 +/- 50 merchant.   The strength and physics of wood would be the same, so necessary scantlings in proportion to vessel size would be reasonably close.  I also have ASA 1870, 1885, 1903 and I use them for 19th century vessels when Meade is mute on the part in question. (My interest ends at 1860.)  The camber vs sheer vs round-up is a point of confusion.   I have slowly come around to realizing that academically generated scientists and engineers with professional discipline,  standards, and vocabulary is a late 19th century creature at best.  The earlier data sources are generally the work of enthusiastic amateurs or individually trained professionals.  There was no board of grey-beards and silver-backs who edited their work for errors or inconsistencies in nomenclature.   I feel  that being dogmatic, rigid, and self-sure about much of this is neither wise or supported by reality.   I go by, does it match what existing plans and information is available? For the gaps, does it match known contemporary  practice within reason and does it seem it fit its time? 
 
As far as deck beams,  in order to fit what I see on plans,  I will shape the curvature of each beam as an individual.  To use the same curve for all and still match the plans as far as the crown would require that I shim the land at the clamp.  By doing this, I would not be following the plan for where-is the underside of the deck at the side.  My plans are 1732 not ~1900.  I am going to have to soak a while about how I will deal with there being a bevel on the top where the slope of the profile line becomes significant.
Batch production of deck beams is an idea that I will file in the specious folder.
 
Dean

Terry,
Being sort of tongue in cheek,  given the situation involving your subject,  I would probably pretend that my customer was rich and valued form over substance.
I would do the ideal version of the vessel - how it would have looked if the designer and builder had possessed superior skills.

Terry,
 
I suspect that when discussing 1650-1860 warship construction, there are details and practices that are very different from 1900 +/- 50 merchant.   The strength and physics of wood would be the same, so necessary scantlings in proportion to vessel size would be reasonably close.  I also have ASA 1870, 1885, 1903 and I use them for 19th century vessels when Meade is mute on the part in question. (My interest ends at 1860.)  The camber vs sheer vs round-up is a point of confusion.   I have slowly come around to realizing that academically generated scientists and engineers with professional discipline,  standards, and vocabulary is a late 19th century creature at best.  The earlier data sources are generally the work of enthusiastic amateurs or individually trained professionals.  There was no board of grey-beards and silver-backs who edited their work for errors or inconsistencies in nomenclature.   I feel  that being dogmatic, rigid, and self-sure about much of this is neither wise or supported by reality.   I go by, does it match what existing plans and information is available? For the gaps, does it match known contemporary  practice within reason and does it seem it fit its time? 
 
As far as deck beams,  in order to fit what I see on plans,  I will shape the curvature of each beam as an individual.  To use the same curve for all and still match the plans as far as the crown would require that I shim the land at the clamp.  By doing this, I would not be following the plan for where-is the underside of the deck at the side.  My plans are 1732 not ~1900.  I am going to have to soak a while about how I will deal with there being a bevel on the top where the slope of the profile line becomes significant.
Batch production of deck beams is an idea that I will file in the specious folder.
 
Dean

If
If tooter has some serious tools, I can see that getting a 220 V. line into a unit could be expensive.
If he does not feel physically up to the task, a helper with some wood shop skills could be hired prn.
Or, skip the physical ownership of the tools work a deal.  Trade the whole kit to someone who would use it and get them to do the major tasks for him.
 
He does not say where he resides,  but if he is lucky, there may be other ship modelers that live close enough to to work a cooperative deal.
There is a woodworker guild here - with commercial cabinet makers involved ( I think) - another source for a possible deal. 
I suspect that the amount of money from a tool liquidation would be marginal when compared to the acquisition amount.

I recalled an article in Wooden Boat magazine that addressed this topic.  It has taken me this long to find it - "Deckbeam Moldes - Ye Olde Mythe of Boatbuilding" by Andy Davis, Wooden Boat, #165, April, 2002, pp., 40 - 45. 
 
The answer is, in order for the height of each beam's crown - at center-line - to match its height - as seen on the shear draught - each beam must be made to its own arc.  The "constant camber" approach will only work on vessels shaped like barges, with parallel sides and no shear.  Davis outlines several "tried and true" methods for establishing a uniform arc for all of a vessel's beams and shows how they all fail to produce a fair deck.  Davis describes how a fair deck will only result from these methods after shaving and shimming to make up for each methods inaccuracies.  Davis also describes a sliding-batten method for establishing each beam's curve, that will result in a fair deck. 
 
On a vessel with deck shear and tapering ends, the inaccuracies of a constant camber show up as a dip in the stern and bow areas of the deck.  At model scale, you might be able to live with it.  It all depends on the model's scale, the degree of bow and stern taper and the amount of deck shear.  

Hi Terry,
I have always looked at stanchions as being a push fit or wedge fit element.  Not as something already resisting really serious downward force.
In a model, I tend to see them as optional because with my style, they would never be seen. 
 
Random thoughts:
 
This would probably never work in a model.  It would be like planking the hull without pre-bending the curve in the plank.  But the forces involved would be much much more.
 
In a multi-deck warship, doing beams thus way would make the decks a tightly tensioned spring.  The effects of a projectile eliminating  a stanchion: ...  The beam alone would exert downward force, wanting to go horizontal.  Adding on the weight of the guns,  I do not think I have seen illustrations of stanchions large enough for this.
 
Jacking up the middle would pull ends of a beam in.  The joinery during the build would be interesting. If it is a tight fit before being jacked, placing wedges at the ends would fill the gap and help the stanchion, but there would be serious outward force on the frame it is mated with.
 
If I am reading this correctly,  some beams  had bottom edges that were chords of the round up and not parallel to it.  a lot easier to model.   No jacking up with this.  Smaller vessels only.  For a large vessel, the timber thickness would possibly require a Redwood tree sized balk.  I would think economy built merchantmen only.
 
The trimming to sit on the clamp -  it would need to be from the inner corner up.  The outer corner up would affect the height of the crown. 
 
In the vessels with jacked up beams,  the cross sectional curve is an arc.  But each beam would have an arc for a different circle.
 
OK.  Someone here ( I think Bob Cleek) pointed out that camber is the curve of the deck seen in profile - i.e. from bow to stern.  It is not the curve along the top of a beam as seen in a Body plan ( cross section ).  To do this, each beam must have its own individual curve as seen in cross section. ?
 
Dean

If
If tooter has some serious tools, I can see that getting a 220 V. line into a unit could be expensive.
If he does not feel physically up to the task, a helper with some wood shop skills could be hired prn.
Or, skip the physical ownership of the tools work a deal.  Trade the whole kit to someone who would use it and get them to do the major tasks for him.
 
He does not say where he resides,  but if he is lucky, there may be other ship modelers that live close enough to to work a cooperative deal.
There is a woodworker guild here - with commercial cabinet makers involved ( I think) - another source for a possible deal. 
I suspect that the amount of money from a tool liquidation would be marginal when compared to the acquisition amount.

Mark,
 
I do not know the practical difference between an ellipse and a parabola when it is a small segment of the curve that we are interested in.
 
An arc has a constant slope.  The slope between any two points on the curve is the same. 
For an actual deck, I think the slope increases as the end is approached.
The middle section is sort of flat,  but the rate of water runoff out increases as the waterway is approached. 
Chapelle has the curve as a parabola.  (If you do not own Boatbuilding by Howad I. Chapelle, you may find it valuable if you did.)
His method  for drawing the curve is different from what I tried to describe above.
Maybe the difference between an ellipse for a deck curve and a parabola is that the middle stays flat(er) farther out and drops off more sharply with an ellipse.
 
By being in these weeds,  I see that no matter which curve is chosen, the same pattern cannot be used for every beam - unless you wish the difference in height between the crown and the end to decrease as the stern and bow are approached.
I just checked HMS Centurion's draught.  The lines defining the difference in height for the crown and at the deck clamp are parallel all the way aft and in the fore up to the last station. The lines converge from there to the FP (rabbet at  the stem.

That is indeed the major question. i.e. is a different curve drawn for each beam? 
If a master pattern is used for a whole deck,  The beams would still be the same thickness along their length.  As each beam gets shorter, the height of the crown above the chord is less.  The ends of a beam would be up to spec, but a curve connecting the crowns would be flatter than spec.
 
As for model scale effects, at 1:48 and smaller the difference in a deck curve that is an ellipse/parabola vs the arc of a circle is beyond our ability to discern   this is my take home of the  published consensus for 50 years. 
I bought a plastic drafting tool long ago that forms an arc along the top edge.  The radius of the arc decreases as I turn a dial.  If I accept an arc as my curvature, it makes drawing the proper curve for beams of different lengths pretty easy to do.  I just turn the dial until the arc connects the two end points with the crown.
 
I have long seen that the gun-ports go from rectangle to parallelogram as the ends are approached.  I just never noticed that the deck beams also do this.

Greetings Mark,
 
I believe it was in the NRJ,  maybe  in the 1970's.  Or possibly Shop notes v.1.
When I was a lab rat, I kept a card file of references to my pack of journal article photo copies.  The cards had relevant quotes about the key points.
For ship modeling, the best I did was just the basic title etc. in a database -
 
A quarter circle with a radius that is the difference in height between center and end of the beam.
The radius along the base-line is divided into 4 equal spaces and a perpendicular drawn at each of the 3 points.
The distance between the center of the beam and the end is divided into 4 equal spaces.
The three perpendiculars moved out to the three points along the beam half length.
A curve connecting these 5 points is an arc of a circle.
or
The quarter circle has a fan of three lines that each define 4 equal segments of the quarter circle arc.
The perpendicular height at each of those 3 points is instead along the same equal distant segments of the beam half length.
A curve connecting those 5 points is an ellipse ( or part of one).
 
The point being that an article showing these two geometry exercises =  a little semicircle with perpendicular lines inside and a big arc above it  and another with a fan inside the little semicircle and a different shaped arc above it,  the article in question has been found.
 
Maybe I have confused an ellipse with a parabola.  I checked HIC's Boat Building  and he shows a different way with different sort of fan.
I also seem to remember a perpendicular at the end of the half beam with a fan drawn from the mid-point. The intersection of the 3 section perpendiculars with their fan line:  connecting those 5 points is another sort of curve - but maybe that is another way to get an arc?
 
From a fast scan of HIC, I think he is saying that the curve for each beam is drawn to compensate for the difference in length.  
I also recall seeing Bob Brucksaw (I think) using a disc sander to shape the beam curve.  The beam was clamped at the end of a long stick.  The stick had a pivot at the distant end. Swinging the stick would allow the disc sander to produce a smooth and reproducible arc on the beam.  I have always been stumped. How do you get a fixed pivot point that is level with the sander table and be so far away?  The length of the stick will also need fine-tuning.
 
I did a database search, perhaps of of these has the answer:
 

A JIG FOR CUTTING DECK BEAMS   WEBB,WM G   MODEL SHIPWRIGHT , 1987, 60, 52-55

DECK BEAM CONSTRUCTION   BRUCKSHAW,ROBERT V   NAUTICAL RESEARCH JOURNAL, 1977, 23,42-43

DECK BEAMS - ADDITIONAL NOTES   FLEMING,EDWARD S   NAUTICAL RESEARCH JOURNAL, 1977, 23, 99-100  

DECK BEAMS AND CAMBER   HOBBS,KEITH M   NAUTICAL RESEARCH JOURNAL, 1978, 24, 43-44

PLANKING VISE, CONSTRUCTING DECK BEAMS, TURN SQ STOCK IN 3 JAW   COLE,N R   NAUTICAL RESEARCH JOURNAL, 1978, 24, 100  

DECK BEAMS MATHEMATICS OF CAMBER   BRUCKSHAW,ROBERT V   NAUTICAL RESEARCH JOURNAL, 1978, 24 , 152-153  

DECK BEAMS  AN EARLY SURVEY OF THE WORD CAMBER   SEARLS,DELMAR E   NAUTICAL RESEARCH JOURNAL,  1979, 25 , 98-99   
 
Dean
 
 

If
If tooter has some serious tools, I can see that getting a 220 V. line into a unit could be expensive.
If he does not feel physically up to the task, a helper with some wood shop skills could be hired prn.
Or, skip the physical ownership of the tools work a deal.  Trade the whole kit to someone who would use it and get them to do the major tasks for him.
 
He does not say where he resides,  but if he is lucky, there may be other ship modelers that live close enough to to work a cooperative deal.
There is a woodworker guild here - with commercial cabinet makers involved ( I think) - another source for a possible deal. 
I suspect that the amount of money from a tool liquidation would be marginal when compared to the acquisition amount.

Personally I put glue on every surface the plank touches.
 

If
If tooter has some serious tools, I can see that getting a 220 V. line into a unit could be expensive.
If he does not feel physically up to the task, a helper with some wood shop skills could be hired prn.
Or, skip the physical ownership of the tools work a deal.  Trade the whole kit to someone who would use it and get them to do the major tasks for him.
 
He does not say where he resides,  but if he is lucky, there may be other ship modelers that live close enough to to work a cooperative deal.
There is a woodworker guild here - with commercial cabinet makers involved ( I think) - another source for a possible deal. 
I suspect that the amount of money from a tool liquidation would be marginal when compared to the acquisition amount.

You posted while I was typing.  You might consider a storage unit rental.  Reconstitute your shop there.

I have a 9" generic Asian bench-top band-saw.  I use it almost exclusively for its scroll cutting function.  It uses the more common 59.5" blades.  I have a Carter Stabilizer on it to make the curved tracking necessary for the scroll cutting to be even possible.  My journey with this has taken me from using 1/16" wide blades at first - these seem to no longer exist.  For years I have been using 1/8" blades.  At first, Bosch blades did OK, but there has been evidence of major corporate changes.  Vermont American is now Bosch in a different package and the sharpness of the recent blades was such that they would have cut better if I flipped the blades 180 degrees and used the back edge.  The Power? blades I tried had poor steel and were brittle.  I then tried Olson blades,  They are more expensive, but are sharper, stay sharper longer, and break less often.  In gearing up for my current HMS Centurion build, I decided to visit Olson and stock-up.  I found a deal on thin kerf blades,  about 1/2 price.  The stock I would cut is 1/4" Maple and anyone's blades break more often than I wish.  I bought 10.  Turns out  that my aging eyes missed the small print - the blades were 1/4". not 1/8".  I thought that I had screwed the pooch, but when I started cutting and the mounted 1/8" blade broke, I tried a 1/4" blade.  Turns out that it will cut almost as tight a curve as a 1/8" blade - just a bit more backing and filling in tight places.  The 1/4" also last a whole lot longer. I think my case will outlast me.  There are fewer TPI but the set is slight. So the surface scaring is about the same as a 1/8th blade.
 
If imy 9" dies on me, I will probably get a 10" Rikon with the larger motor.  But still only use it for scroll cutting.
 
I would not use the 9" for any sort of resawing.  Certainly not 2" Pear, which is harder than Hard Maple.  The motors are not up to the load.  The available blades =  serious surface scarring, so a slice needs to be thicker for a thickness sander to get it to a smooth surface.  The blade will likely wander as the guides are not up to the task.  The wedge shaped slices may be usable but they will be either thinner, or a slice to get what you want needs to be ridiculously thick.  The same result occurs if the wander is serpentine.
 
I have a 14" floor model  with a 3HP motor, 220 volt  excellent guides.  It tracks without wandering.  If you are doing resawing, a machine engineered for this function is the reasonable way to go.  Anything less will cost you time, wasted blades, and a lot of wasted wood.  Trying to make do will lead to a mountain of frustration.
 
Unless you are only doing a few passes, no steel blade will be worth buying.  The economy blades leave a really ugly surface -  really deep scarring.  The thin kerf steel resaw dull really quickly and a dull blade soon breaks.  These are false economy.  The carbide resaw blades last a long time,  but they are really expensive - I would not factor in the resharpening they advertise - they will break.  I have found that Lennox Diemaster bimetal blades are in the sweet spot. They last 80-90% as long as a carbide blade and the cost is about 1/4 as much. 

My mental vision missed the effect of the slope as the ends are approached.  Thank you for pointing out the additional factor to add to this equation.
Since the deck clamp follows a curve, if the beam sits directly on it as is, the beam top surface has the necessary bevel. No longer vertical are they.  If the decks are completely planked, who is to know?  I suppose the beams at the hatches at the ends would need a bevel to fake it.  That would be a lot less work.
Yet another reason to stick to modeling the actual surface and forego showing  the underlying structure.

A for real horror movie.
 
Were I writing the laws for the planet, machines like those would be limited to use on tree farms.  If there are any original growth forests or old secondary growth even left, it would be human handled cutting machines and draft horses or oxen  and only senile trees would be harvested.   The efficiency of these machines is horrifying.  They are the equivalent of strip mining the surface of a forest.
The one machine missing is a giant chipper shredder for the tops, branches, and parts of the stumps that are not harvested for exotic and specialty grain.

My mental vision missed the effect of the slope as the ends are approached.  Thank you for pointing out the additional factor to add to this equation.
Since the deck clamp follows a curve, if the beam sits directly on it as is, the beam top surface has the necessary bevel. No longer vertical are they.  If the decks are completely planked, who is to know?  I suppose the beams at the hatches at the ends would need a bevel to fake it.  That would be a lot less work.
Yet another reason to stick to modeling the actual surface and forego showing  the underlying structure.

As I understand it.  The actual curve is an ellipse and not an arc of a circle.  I see the advantage for this.  It would have a more flat middle section and accelerating run off as it approaches the side.  I also suspect that variations in shaping the beams would probably be greater than any perceived difference between an arc and an ellipse at model scales.
My question is about how the curve is determined for each deck beam.
 
If the mid-ship beam is used to determine the curve for all beams for a particular deck.  If a parallel curve if used to shape the underside of the beams and the thickness is constant along a beam, I see the following:
All of the beams can be shaped as a batch.  
Either a block is shaped and each beam if sliced off -  much loss of shaped material.
Layers the width of each beam can be temporarily glued into a block, shaped, and each beam released by reversing the glue bond.
Or the same curve pattern can be used to shape each beam individually.
 
If a deck clamp is used to site the beams:
With constant thickness. The crown has a down camber as the width decreases.  As the width decreases the height of the crown above the line of the bottom plane decreases.  The rate of change in slope of an ellipse is lost.  But that is mitigated by the water running down hill to the mid-ship as well as to the sides.
If the spirketting is used: butting the top edge up instead of the bottom edge down, I see the result being the same.
 
If each beam has its own curve - a curve determined by the beam's actual width, the camber of the crown will parallel the slope of the deck clamp.
Each beam is a one off.  A lot more work and the possibility of error is much greater.
At model scales,  the difference in effect would probably be nearly impossible to notice.  If  one goes old school and lays  deck planking, would not there be an effect in how the planks lay?
I am wondering what the big boys did full size?

A for real horror movie.
 
Were I writing the laws for the planet, machines like those would be limited to use on tree farms.  If there are any original growth forests or old secondary growth even left, it would be human handled cutting machines and draft horses or oxen  and only senile trees would be harvested.   The efficiency of these machines is horrifying.  They are the equivalent of strip mining the surface of a forest.
The one machine missing is a giant chipper shredder for the tops, branches, and parts of the stumps that are not harvested for exotic and specialty grain.

You posted while I was typing.  You might consider a storage unit rental.  Reconstitute your shop there.

I have a 9" generic Asian bench-top band-saw.  I use it almost exclusively for its scroll cutting function.  It uses the more common 59.5" blades.  I have a Carter Stabilizer on it to make the curved tracking necessary for the scroll cutting to be even possible.  My journey with this has taken me from using 1/16" wide blades at first - these seem to no longer exist.  For years I have been using 1/8" blades.  At first, Bosch blades did OK, but there has been evidence of major corporate changes.  Vermont American is now Bosch in a different package and the sharpness of the recent blades was such that they would have cut better if I flipped the blades 180 degrees and used the back edge.  The Power? blades I tried had poor steel and were brittle.  I then tried Olson blades,  They are more expensive, but are sharper, stay sharper longer, and break less often.  In gearing up for my current HMS Centurion build, I decided to visit Olson and stock-up.  I found a deal on thin kerf blades,  about 1/2 price.  The stock I would cut is 1/4" Maple and anyone's blades break more often than I wish.  I bought 10.  Turns out  that my aging eyes missed the small print - the blades were 1/4". not 1/8".  I thought that I had screwed the pooch, but when I started cutting and the mounted 1/8" blade broke, I tried a 1/4" blade.  Turns out that it will cut almost as tight a curve as a 1/8" blade - just a bit more backing and filling in tight places.  The 1/4" also last a whole lot longer. I think my case will outlast me.  There are fewer TPI but the set is slight. So the surface scaring is about the same as a 1/8th blade.
 
If imy 9" dies on me, I will probably get a 10" Rikon with the larger motor.  But still only use it for scroll cutting.
 
I would not use the 9" for any sort of resawing.  Certainly not 2" Pear, which is harder than Hard Maple.  The motors are not up to the load.  The available blades =  serious surface scarring, so a slice needs to be thicker for a thickness sander to get it to a smooth surface.  The blade will likely wander as the guides are not up to the task.  The wedge shaped slices may be usable but they will be either thinner, or a slice to get what you want needs to be ridiculously thick.  The same result occurs if the wander is serpentine.
 
I have a 14" floor model  with a 3HP motor, 220 volt  excellent guides.  It tracks without wandering.  If you are doing resawing, a machine engineered for this function is the reasonable way to go.  Anything less will cost you time, wasted blades, and a lot of wasted wood.  Trying to make do will lead to a mountain of frustration.
 
Unless you are only doing a few passes, no steel blade will be worth buying.  The economy blades leave a really ugly surface -  really deep scarring.  The thin kerf steel resaw dull really quickly and a dull blade soon breaks.  These are false economy.  The carbide resaw blades last a long time,  but they are really expensive - I would not factor in the resharpening they advertise - they will break.  I have found that Lennox Diemaster bimetal blades are in the sweet spot. They last 80-90% as long as a carbide blade and the cost is about 1/4 as much.