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And thus the work proceeds;
the two tackles hoisting and lowering simultaneously;
both whale and windlass heaving, the heavers singing,
the blubber-room gentlemen coiling, the mates scarfing,
the ship straining, and all hands swearing occasionally,
by way of assuaging the general friction. —Herman Melville

Ahoy,

It's hot. In a day or two the temperature should reach 120 F. The early morning hours from 5:00 am to 9:00 do allow some outside work. During those hours, the boat is somewhat in the shade.

A dorade box has been on my mind lately. That would be a small project I might do in the later morning or even early afternoon. I checked the Internet for ideas and prices. It seems I could buy a teak box for the bargain price of $200.00. That's a deal I would like to pass up.

So, this evening I scrounged around, looking for scraps of teak, and I found some. Elated, I laid my treasure out on the table saw. Maybe tomorrow I will have a chance to begin milling the stock. It doesn't look like much now, but in a few days, we should have a dorade box.




A dorade seems easy enough to build. I would like to have a decorative joint or two. Apparently, the size is a little critical. According to Matē's book, there is even a mathematical formula so that the airflow can be just right. I would have never thought a dorade would have had such precise parameters, but seemingly that is the case. My biggest problem now is trying to figure out that mathematical formula. Maybe I'll just take a good guess and hope for the best.

One thing Matē does stress is that you need a screen over the opening to keep out mosquitoes. That sounds prudent to me. You also need baffles, he said. Baffles are good in keeping out unwanted sea water from some rogue wave breaking across your deck.

Since the ventilation is for the anchor locker, I wonder if I could not just have a second hole for the forepeak locker as well? That may not be a good idea. The mud in the anchor locker can become smelly. On the other hand, maybe a single cowl vent cannot feed two openings anyway. I just don't know. I suppose I could always add the second hole later.

I need to ponder this for awhile. After all, you just can't go around building dorade boxes without some thought. If you did something like that, people would laugh your dorade to scorn. No, this project must at least look important, even if it is not. It's all a matter of the ecstasy and agony I suppose.

I almost forgot. I don't know how I could have overlooked something like that, but I did. You're probably sitting there right now with bated breath, wondering what the mathematical formula might be. We don't want any cats out there dying because of curiosity, so here's the formula, outlining what you are suppose to do—

Throat diameter of cowl vent multiplied by pi radius squared.

(For some reason, I can't get the mathematical notation to print on the screen. Writing the formula out, though, at least makes everything readable.) Maybe, though, a verbatim quote from Matē will clear everything up for you—

Quote:Commonly thrown about formulas, such as box height must be twice the diameter of the throat, are näive. . . To make a box with greater area capacity than the throat would be damaging to the system, for it would provide an expansion space where the air can eddy and disrupt the flow into the cabin.

You need to figure in the size of the baffles inside the box as well. Well, that leaves me baffled, very baffled. Maybe someone like Charles Goodall will read this posting, and immediately work the formula out on paper.

For what it's worth Jim, tests have been conducted on the baffles inside a Dorade and their size and placement can increase the flow by 2:1 if done properly. I'm sure you know the story behind the Dorade vent, so I will not bore you with it, but Dorade is a proper noun.

There are a number of sources to get the formula for "venting" which is necessary for many different things, like engine intakes inside enclosed engine spaces, fume venting, bilge venting, engine space hot air exhausting, enclosed space venting, cabin air circulation, etc. Some can be trying, such as air cooled engine intake and exhaust, which can require considerable and sizable venting arrangements.

Your forepeak shouldn't prove difficult, though I do think the vent is vulnerable to boarding seas, in it's current location, plus could have the nasty habit of snagging sheets and other lines on the foredeck. It's often seen with a cage over it, to shed lines that attempt to foul on it. Stylish yachts have these of bronze tubing or solid bar stock, modern craft use stainless or even plastic.

Make sure the scuppers, along the lower edge of the box, are big enough to drain the box very quickly. In the event of a boarding sea flooding the box, green water can get below in an alarming fashion, unless healthy sized scuppers are incorporated into the lower edge of the box named after the mighty yacht, who's name it bears.

Ahoy Paul,

Thanks for the kind comments.
No, I know nothing about the Dorade narrative.
Yes, I would like to hear the story.

I thought the dorade was just a fish, but there is a story behind the name.

Ahoy,

We set our course on the open seas. checked our charts, and sighted stars through our sexton. We were determined to find the famous yacht, Dorade. Keeping up with her, though, was beyond what we could do. Paul Riccelli was the first to sight her. "Dorade, ho!" he yelled from the crow's nest.

Before we knew it, we had come upon several short historical narratives, such as the one below

Quote:Dorade is considered the very first modern yacht. It appeared in Europe in 1931 at the Fastnet, sailed by the two Stephens brothers Rod and Olin.
At first sight Dorade seemed to be too thin and delicate even though it won the Transatlantic Regata doubling Fastned first, all alone. In 1932 it won the Bermuda regata and in 1933 it defeated all participants the Fastnet. At that time the "Times" entitled it as "the smallest amazing yacht of the Ocean regata ever built."

The Wall Street Journal of November 5, 2006 featured an article of the Dorade's accomplishments. Maybe Paul will provide us some insight as well? After all, he was the first to sight her on the open water. In the meantime, here are a few photos of the Dorade, along with the famous Dorade ventilator.

Undoubtedly, one of the first features you may notice are her spoon bow and stern overhang. Designed for looks; built for speed, astonishing speed.



Here is a glimpse from her deck. The cowl vent are mounted on the famous Dorade ventilator box. The skylight does not look too scruffy either.



"What about the interior?" you ask. Well, here too, the shipwright's skill is evident and abundant. If the Dorade pulls up next to you at the dock, you may want to move your boat. That would be prudent, very prudent.




Hanging knees! These have got to be hanging knees. I had read about them, but never had seen them. Yes, I plan to build some for our small boat as well. I mean you don't want someone to look into the cabin and ask about hanging knees. Without hanging knees aboard your boat, you may have to hang your head in shame. A boat without hanging knees could be an embarrassment indeed!

Quote:Mr. Stephens was the skipper and navigator during the race, which set out for England from Newport, R.I., on July 4, 1931. His seven-man crew, which included his younger brother Rod, who had overseen the yacht's construction and would become a partner in Sparkman & Stephens, was young: Even with the inclusion of the Mr. Stephens's 46-year-old father, the average age was just 22.


Olin Stephens was at the helm when Dorade crossed the finish line on July 31. Longer sailboats generally go faster than shorter ones, but Dorade, the third smallest of the 10-yacht fleet, reached the line more than two days before the second-place boat. When the times were handicapped, or "corrected," to reflect the differences among the yachts, Dorade's time was almost four days better than its closest rival. Dorade went on to win the Fastnet Race by a wide margin. When the crew returned to New York City, where Sparkman & Stephens had its office, they were rewarded with a ticker-tape parade, a first for sailors.

For the full article, read the Scuttblebutt Newsletter—

http://www.sailingscuttlebutt.com/news/06/1106/

Olin Stevens was the first real engineering yacht designer, Capt. Nat Herreshoff not withstanding of course, but Olin's work refined yacht design a fair degree and is considered one of the greats.

The era was changing rapidly. Racing rules were being modified and designers stretched the envelope of performance, some generating "freaks" only a mother could love (but beating the rule it was designed around). Formerly, ocean racing yachts were full keeled, high D/L ratio vessels that could take a whipping and come out all standing with some luck and a capable crew. It was becoming clear that reduced wetted surface, cut away forefoot, tucked under, keel hung rudders and lofty sail plans were the things that made boats faster. Weight reduction, while maintaining strength, fully equipped, raised panel interiors, cleverly arranged and engineered rigging hardware, with underwater shapes that met the rule requirements, but produced good flow were carefully studied, then crafted.

Nat Herreshoff really took this to heart and invented most of what is now regarded as standard equipment on modern yachts. His engineering background paved the way for more innovative efforts on the next generation of designers, such as Rod and Olin Stevens, who were two young designers, trying to cut their teeth in a difficult field.

In 1929 Dorade was developed and build (for less then $30,000). She was not particularly highly thought of at first sight. She had fine ends and was narrow in beam (reduced weight and decreased wetted surface). Her forefoot well cut back, her deadwood aft was also. A yawl rig (again using the rules to advantage) was selected and she looked like the skinny, underfed sister compared the other yachts of her era.



She was full of innovation, which included a clever little box under her cowl vents. These boxes cured a consistent difficulty in off shore sailing, which is boarding water and spray can easy flow down the mouth of a vent and douse whatever is directly under. This yacht quickly began a very enviable racing record, that has held her name and designers to high esteem ever since. Several successive yacht designs including her slightly larger sister Stormy Weather, concreted their position as place holders in the big book of notable yacht designs.

Even though she was "lightly" built by comparative standard, the yacht was stout as a tank. Substantial framing, strapping and considerable thought in the distribution of loading, have helped her survive may years of service with grace. This can be seen in the (sorry it's so small) construction drawing above.

All designers eventually adopt a "style" of some sort. L. F. Herreshoff was noted for the slight knuckle found near the LWL on his stem profiles, Olin Stevens his spoon bows and sweet sheers, a Phil Rhodes sheer can be recognized a few miles away, my bows often have an "Indianhead" shape to them. I don't think we intentional set out to develop this style thing, it just works out that we like some shapes better then others and this becomes reflected in what we draw. An example would be, all my kickup rudders are the same, just sized to the particular design they're employed on. It's a design I've found works very well and I'm not changing it, until I invent (or plagiarize) something better.

Jim, skip the hanging knees. They are a common source for issues, rot, racking, weight, etc. We have better methods now, though a big old knee sure looks good, but you'll soon learn to cuss them after you've banged your hat holder on it a few times. You'll note those used on Dorade are naturally grown crooks, likely a Hackmatack root, which is what they look like. Common, modern interpretations are laminated from smaller stock, but more effectively engineered as a gusset, metal strap or flange and struts, all of which are lighter, stronger and less prone to the difficulties of installing grown knees, though not nearly as pretty.

Ahoy Paul,

What's this aversion to hanging knees, Paul?
Did you happen to bump your head on one of those once?
Is there a story here?

Ahoy,

Here's the latest update on the dorade ventilator. Apparently, there are several commercial varieties, all expensive and all boasting of biscuit joints. We wanted neither the expense nor the biscuit joinery.

We ran across a nice sketch in Matē's Finely Fitted Yacht. Even though the sketch had no dimensions, we were able to estimate the proportion of width to height and length.



After we milled our stock, we laid out the dimensions for a 3/8 finger joint. Every cut would need to be absolutely precise. We began making our cuts, carefully checking our measurements with each set change. Gradually, the stock began to look more finished. Our last cut left a paper thin strip on the stock. Any closer tolerance would have made fitting our joints difficult, if not impossible.



We could have set up a jig, but Kenny Mann thought building a jig not worth the time and effort. "Besides," he said, "I want to see if you can work from a tape and by sight. That's where the skill is."

Now, I must tell you that I have a lot of confidence in Kenny's level of skill, but not so much in mine own. Even so, when he asked me to make the cuts with precision, I was pleased that he had asked. Craftsmen don't come any better than Kenny.

Our next step, of course, was to cut the top. We did not want the box to look heavy, so we cut a rabbet on each edge. That way the top would fit inside the box.



We glued our joints and placed the lid on the top. Sheba Girl closely inspected the finger joints, and barked out her approval.



We set our dorade ventilator on a table and carefully placed the cowl vent on top, just to see how everything might look. Not too bad. Not too bad. We still need to round edges and cut the scuppers. After that, our dorade ventilator should be ready for sanding, and finishing.



Yes, you are right. That is Kenny Mann's tablesaw, not mine. I had gone to Kenny's so that the cuts would be a little more precise. Kenny is a good teacher, and I have a lot to learn. Kenny also has a good feel for proportion.

They look fantastic Jim. I'll send you my address so you can ship them to me asap. They will look great on my boat! Very nice work, but your grizzly would have cut them just as well as that Delta saw you used. Now get them on and launch that sucker!

Keith

Hanging and quartering knees have been a source of trouble for many repair and restoration folks for centuries. Small craft don't need them and larger vessels can use a different approach, in the engineering of the load distribution, which is their sole reason for use. If you don't need it and it's a problem prone piece, then it's wise not install it.

Ahoy Keith,

Thanks for the encouraging words. Looking over some photos, I ran across a picture of your interior. A true blue sea dog was lying on the berth! What a great photo. Of course, I immediately had to show the photo to Sheba Girl. She thought the berth was a pretty nice spot for a good nap.