On Battens

[Dave Fleming]

Posted this to another forum some time back.

Jes' like a broken record I keep going 'round and 'round and 'round.

:wink:

Caveat: this based upon my own personal, emperical knowledge and experience!

Wood for Battens: Eastern White Pine, True Mahogony, Alaska Yellow Cedar, Port Orford Cedar, Douglas Fir ( old growth if possible) , are to be preferred. Rarely hardwoods for battens of length. Ash is fine for short ones say 6 to 8 feet. Shorter lengths of most any wood can be used for say diagonals or places where there is no curve.

Lengths:

Sheer= 1/2 x 2 inch and longer by several feet over both perpendiculars.

Waterlines= 1/2 x 1 1/4 inches with a TAPER on both ends. Taper allows the batten to tuck up a bit at the forward and aft sweeps.

Body Plan= 1/2 x 1/2 inch with if possible a thinner center to flex around the lines.

Long lengths are spliced with about a 12 inch splice. The glued up splice is made proud and planed or scraped down to final dimension.

No rivets or nails through the splice. You want it to be as flexible and fair as the rest of the batten. Weldwood Plastic Resin glue was favoured but later on we did use the yellow stuff even though there were rumours that it creeps under load. Cannot recall ever seeing that myself.

Nails are driven along side the batten NEVER through the batten. Initially blocks of steel, edges smoothed off with felt or neoprene glued to the bottom would be used to nudge the batten into fair. After lots of squinting and bending over and looking at the line, it would be nailed( alongside!)to the loft floor. Sometimes a pail of awls would be used to set the batten in place but usually it was the nails alongside the batten. Blue Plaster nails were mostly used for this work. Thinner shank and being dark blue or black did not cast another distraction to the eye. Lines were drawn with drafting pencils and artists colour pencils NEVER pens or marking pens.

Reason? Those inks would bleed through the paint when the floor was prepped for the next job. Oil based paint in palest grey or white tinted with black was used. Natural light or flourescent light was preferred over incandescent. Incandescent casts shadows don'cha know.

As mentioned before, I have used battens 1 x 3 inch x 40 FEET long out in the field. Took most all the layout crew to 'conga line' that batten out to the hull. Approximate measurements were taken, soapstone marks were made on the steel plate, clips were tacked on, batten set in clips, wood wedges used between batten and clip to raise batten to line marked. Leadman would stand back, waaay back, look at the line and with hand signals indicate which wedges needed to be snugged up or slacked off to bring batten into a fair line. After much squinting and after everyone had a chance to look at the line and add their approval, a soapstone line was drawn on the plate.

The batten removed and 'conga lined' back to the loft and the layout people assigned to that section would then punch dimples in the plate along the line at about 3 or 4 foot intervals. Then the section became the domain of the ship fitters and burners under the watchful eye of the layout person.

Right handed people it is best to look at long lines on the loft floor through your legs backwards...Picture the cartoon with the fellow kissing his arse goodbye, folla?

Left handed people don't need to look at the line this way. Something about Right brain vs Left brain. Believe me it does make a difference

When in 'white hat' mode, I would use my left handed people for layout and special fitting jobs. Rightys, unless old pharts like me, didn't have the training or experience to over come that brain thing. Recall that 'Ability to See' essay?

[Guest Commander Zero]

for another version see my post in my hello forum thread

[Simon]

My thanks to you both. 8)

I'm a mathematician by vocation (and nature I guess), so I'm interested in ways to fair curves (which we call "interpolating points"). As an interesting aside (to me ), a mathematical curve which smoothly joins a set of known points is called a spline ... now why would that be :roll: :wink:

[Dave Fleming]

:wink:

With absolutely no authority but my emperical experience.

A spline is what a draftsman would use at his drawing board with 'ducks' to draw lines for a design.

A batten is what we in the loft would use to connect the points developed by the designer in the Table of Offsets.

OR

Splines is light battens

Battens is heavy battens.

???? Does that make any sense? :? :? :?

[Simon]

Sure it does Dave!

The real question is one of scales - suppose you are drafting a boat at, say, 1:16 scale one uses a spline made of wood, of the appropriate dimensions for its flexibiltiy, to draw the sheer. When you come to loft the boat, you'd really like a piece of wood which has the same scaled properties as the original spline, but 16 times the length. That would give you the best chance of reproducing the original curve based on your calculated offsets.

In practice, as yourself and the good Commander have pointed out, its really just a matter of eyeballing the curve - upsidedown if dextoroially challenged - and seeing if it "looks right."

If not, one has the choice of selectiong another batten from one's collection, or adjusting the original measurments to make the new curve look fair.

[Dave Fleming]

Nah, most draftsmen would be using the ACETATE splines from the likes of K&E on the board.

Fine Basswood/Mahogony/ splines disappeared long ago.

The ACETATE aka Plastic ones are more stable and put up with abuse better than the wood ones did.

[Simon]

I guess those plastic ones would be more consistent too, so that if you gave two different draftsman the same offsets they would draw the same curve.

I don't think you'd find many contempory pro-draftsmen using splines at all these days anyway, unless they are totally anachronistic and/or catering to an anachronistic client, since CAD is faster, more accurate and more convenient. Will the art die? I think not, because it will always be practiced by amateurs with a masochistic bent (pun intended).

The tools on autocad for fairing lines are called splines, after the mathematical objects, which are in turn named after the oriiginal splines ... now that's funny!

One also has a choice of splines on CAD, which may or may not reflect different choices of material for the spline one is hopnig to simulate.

[Dave Fleming]

:?:

since CAD is faster, more accurate and more convenient

Not wishing to get in a pissing contest with you Laddy Buck but, says who about the above.

NO Argument that for many contemporary designs CAD is clearly the weapon of choice.

But just for the hell of it, take one of LFH's or Capt Nats or William Hand or Bill Garden's designs and reproduce that in CAD WITHOUT the Table of Offsets that is.

That tell tale line, to my eye the most important line in a design...

THE SHEER is better done in CAD or by the eye of the designer??????????

[Simon]

Hehe, you won't get a pissing contest from me. You can give a genius any tool that will get the job done and they will do the job with flair and distiinction. On the other hand if you give a dolt the finest tool available, your just as likely to end up with a load of crap.

If you gave me a copy of a classic design and told me to work up some offsets using CAD, my path would be to scan the drawing into the computer and work from there. Of course I'd have to learn how to use CAD first!

As you imply, you won't find a modern boat design place that doesn't use CAD, but as to whether an old master would have used CAD, were it available, well its very hypothetical isn't it? I feel they probably would have, as it surely would have been the industry standard, and I see no particular reason why that would have affected their work in a negative way.

I have a great deal of appreciation for old ways of doing things, but this world we live in is in constant evolution. Just because its easier for a less talented person to produce a result using technology, does not mean that a talented persoon is less likely to produce a work of genius using the same.

The issue as I see it is that "adequate" results can be produced by a dolt, with the possible effect of dissuading a true talent from the field. But is this the fault of technology, or a more profound problem with society?

[Dave Fleming]

, but as to whether an old master would have used CAD, were it available, well its very hypothetical isn't it? I feel they probably would have, as it surely would have been the industry

This type of argument has been used for donkeys years about almost every new device/invention that has come along.

I won't go there, Laddy.

What I did say simply put is this, the ART the FEEL the SENSE of what will work is NOT based on any software or machine. It is based on intellect in that bit of the brain that SEES the difference between what is Workable and what is ART and has the ability to combine the two.

A Nelson Mareck design suits its purpose at THIS TIME quite well but in 50 or 100 years what will catch your eye in a parade of sailing vessels?

The reverse sheer of the NM design or the sweet flowing lines of Herreshoff, father or son.

Capt Nat was on the cutting edge of technology of his time, he revolutionized many aspects of yacht design and construction. He did this all out of his head. William Hand did his best with paper and emperically. Build a design, use it for a season, learn how it works and what does not work and next winter improve upon it all with the the enormous assistance of his draftsman. The collection at MIT is called the Hand-Davis collection in recognition of Davis's contribution to the Hand collection.

NM do sail on their designs also, learning again what works and what is less than efficient.

Unfortunately these days RULES are the defining factor in much design work.

[Guest Commander Zero]

..... most marine draftsmen I know would use a ships curve.......

[Simon]

What I did say simply put' date=' is this the ART the FEEL the SENSE of what will work is NOT based on any software or machine. [/quote']

I'm in total agreement, the tool is just the medium for the artists expression. Its almost irrelevent, but for the fact that modern technology allows an amateur some leeway in the field. Of course, this leeway may be ill-founded, and lead to a monumental cock-up.

A computer does not design boats, any more than a drafting board does, they are just different ways of accomplishing a result - a boat if you please - whose quality will depend upon the designers ART, FEEL and SENSE ... and of course their skill in the medium. A skilled CAD operator is no less an artists than a skilled splinographer.

Not contradicting or aguing, I have a great deal of respect for you ... I think we're saying the same thing.

[Dave Fleming]

most marine draftsmen I know would use a ships curve.......

Are you referring to Copenhagen Ship Curves?

[Guest]

This is what seperates the men from the BOY TOYS in many cases.

What I did say simply put, is this the ART the FEEL the SENSE of what will work is NOT based on any software or machine. It is based on intellect on that bit of the brain that SEES the difference between what is Workable and what is ART and the ability to combine the two.

[Dave Fleming]

'eyster' in the cold light of day, I edited my comments that contain your quote.

I had the emphasis in the wrong place, or so it seems to me.

[Guest]

Well there Brother Dave, with my little pea brain of thoughts, we use to build creatures that had to work under seaway, first time everytime, upon launch day, built by banjo string, batten and eye, even in those sheds that had the hanging dropcord light bulbs. Dig?? 8) We knew who could do this over and over, and who was going to create a "Spruce Goose" We seem to have a lot more of Spruce Goose dock barges in these days, created by those fancy wangledangle mouses, that are done by climate controlled goose egg heads, IMHO!! Howsboutdat, for an opinon???? :wink:

Signed :

Yours truely,

Oyster- of- old

[Dave Fleming]

Loud and Clear 'eyster', Loud and Clear.

One place I worked put new hire 'green pea' engineers out in the yard for a full year before letting them put on a tie and pocket protector.

Yard has seen better days BUT, some of the people I recall seeing and conversing with in their year of 'OTJT' are now principals in Design Houses in Seattle, Washington State, Chile, Taiwan etc.. Others are doing well in engineering depts and software development.

And not a few found easier places to work without putting on overalls and workboots.

Wonder what they missed and now what I consider the lack, is showing up in their work??

Since we are a bit off topic with this line of thought, let me repeat something I have posted in other places.

There is a book out there, The Wheelwrights Shop by a fellow named Sturt. He lived at the turn of the 19th-20th century. His family had been country wagon builders in rural England for centuries. He initially chose to be a teacher but, when his father took ill he returned to run the family business out of a sense of obligation to both his father AND the craftsmen employed. Briefly, he relates how he tried at approx. age 30 or so to step into the shoes of a lowly apprentice in the shop to help when things got too busy for the regular crew. He laments upon not having what he refers to as 'trained hands and eye'. He states that the true apprentices could do things with more ease and skill than he could because of the eye to hand development.

As I see it, CAD is fine BUT it is just a tool. The skill is in the eye and hand of the person operating the device.

Fine craftsman made chisels are a joy to use but if not well sharpened and maintained will give no better performance than the cheapest dime store tool. The cheap dime store tool can be made function reasonably well by the skill and experience of the worker holding the tool.

Now, put the fine chisel in the hands of that same workman and it is a true melding of the best of both and the work will show it.

Another one for thought..

John Guzzwell was crewing with Miles and Beryl Smeeton when they had their first 'pitchpoling' incident in the far South Pacific off of Chile.

He had taken time off from his circumnavigation aboard his own built boat to help the Smeetons.

Guzzwell had his kit of shipwrights tools on board. Out at sea, demasted, deckhouse swept away, Beryl's collar bone shattered,he Guzzwell, was able to rework the masts, step the jury rig, rig covers over the gaping hole where the deckhouse had been make repairs down below and, help Miles and Beryl sail into port in Chile.

Thumping good read: Once Is Enough by Smeeton.

Been to the boat shop John had in the San Juan Islands of Washington State years ago. Fine craftman, or so says I.

Point is he is a craftman and he was able to use his learned skills in a most difficult situation to save not only his own life but two others as well.

In fact some of the work he did below to the interior joinerwork the Smeetons left when the boat was repaired in Chile. He had improved some features and his work was above what they thought they might get in the Naval Yard in Chile! All this in those cold heavy Southern Ocean seas!