Benoit Duflos' Moth-Pop, Construction Plans, Part 2

Plans de dériveur classique Moth

• Detailed dimensions of the Moth-Pop Moth Classique are in Part 1 of this series.
• A computer rendering of the Moth-Pop can be found in Part 3 of this series.

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Here is a short PDF showing the construction details of building the Moth-Pop upside down over the flat deck. Use the pop-out icon on the top-right corner to put the PDF file into another tab on your browser. From there you can print or download.

Benoit Duflos' Moth-Pop, Moth Classique Plans, Part 1

Plans de dériveur classique Moth

• Construction details for the Moth-Pop can be found in Part 2 of this series.
• A computer rendering of the Moth-Pop can be found in Part 3 of this series.

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Benoit Duflos was the designer who, in the 1960's, introduced the narrow waterline, very V'eed Moth design that would prove to be the fastest Moth design of that decade, the Duflos ruled the roost until the class merged with the Antipodean scow fleet and adopted wings. Until George A, the USA Classic Moth plan librarian handed me these plans, I hadn't realized that Benoit also designed a more stable design, specifically for home-builders. Benoit's design, the Moth-Pop (no idea where he came up with the name) is a flat-bottom design, in the tradition of French dinghy designs, Staempfli's Sharpie 9m² and, Herbulot's very popular Vaurien dinghy. It is designed to be built upside down on a flat deck using three bulkheads, a small bow transom and the normal transom. Starting at the front of the cockpit the flat bottom transitions into a arc'd V toward the transom to reduce wetted surface. There are probably a couple of Moth-Pop's still sailing in France but I have yet to come across a photo of one

I have taken a couple of JPEG's of the plans which can be viewed or downloaded. Use the pop-out icon on the top-right corner to put the image into another tab on your browser. From there you can print or download the file.

In this first side view image we can see that:

1. Stations b, c, d and bow transom (1a) and regular transom (8e) are the bulkheads that Moth-Pop is built around and stay with the hull after completion.
2. The bulkheads are set up on the flat deck with a backwards angle (angled towards the transom) as shown by the arc Benoit has drawn at section 1a. This is to keep the bulkheads perpendicular to the design waterline.
3. All dimensions are in cm. (mm are indicated as a superscript to the cm dimension) unless it is a single digit, which is mm.

Below is an iso view of the underside of the Moth-Pop deck. Benoit has the builder plot the sheer and cockpit dimensions on the flat piece of plywood deck before placing the bulkheads upside down.



The section plans. Note how the bottom becomes an arc as it transitions toward the transom. Benoit has written the metric dimensions on the plans which can be viewed when zoomed in.




A closeup of the angle of bulkheads when placed on the flat deck.

Header Photo: Mariposa Again!

As far as I know this is the first sailboat to be featured twice in a header photo. This is Bertrand Warion's Mariposa, a French design Classic Moth with the sauciest sheer (hence the most photogenic) of all current Classic Moths. (Plus I'm partial to lime green as a hull color.) This is the second iteration of Mariposa. Bertrand Warion decided to change the interior of the original Mariposa over to a double bottom (an idea he has since back-tracked on since he is a tall fellow and he felt somewhat cramped when he took away some of the room for his legs).

No matter. This still shows the room for experimentation in the Classic Moth class with probably the most roomiest interior going in the Classic Moth. The trade-off? The tiny gunwhales are definitely not a comfortable hiking platform.

Mariposa line drawings.

House Chores

I was vacuuming one of the side bedrooms in our house and came across two small pieces of paper on the floor. In picking them up, I discovered they weren't scrap paper but thumbnail prints (most likely cut out from a contact sheet) of the blogmeister sailing his Laser out of SSA (Annapolis) back in the 1970's. They must have fallen from some book I had re-shelved. I don't know who took the photos. (Warning! Blogmeister with hair and beard)

It looks like it was a gusty northwester as I was sailing upwind towards the U.S. Naval Academy.

Nobody had invented flat leg hiking yet!

From the Earwigoagin archives; a few of the Laser posts featuring the blogmeister.

• Of the Laser Borg
• Blogmeister Returns to a Weekend Laser Race - Part 1
• Blogmeister Returns to a Weekend Laser Race - Part 2
• Speed Bump

Header Photo: Shannon One-Design Start

The previous photo is a start of the Shannon One Design, an Irish, 18 foot, clinker, cat-rigged traditional dinghy that is raced primarily out of Lough Derg on the River Shannon. The class came about when, in 1920, sailors on the River Shannon decided to ditch their motley assortment of 18 foot sailing/rowing open boats and settle on a design by Morgan Giles.

These Shannon One Design's are very quick in a breeze.

Photo from Technology and Culture - Boats

In looking up the Shannon One Design, I came across the BBC show, "Three Men in a Boat", which seems to be a watery takeoff of the hit BBC car show, "Top Gear"; both shows featuring three guys swimming in back-and-forth witty banter . "Three Men in a Boat" did a show on cruising the Shannon and featured the Shannon One Design (seen at about 19 minutes in on the following YouTube).

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The Wikipedia page for the Shannon One Design can be found here.

Music Whenever: Heifervescent "Billy Comes Home"

A boppy rock tune - it's got a little of the late 60's Monkeys vibe to it (and to tell you the truth, I liked the Monkeys). I guess this band isn't into putting up a produced music video but it's the music that counts.



The lyrics:

Billy comes home
I've been waiting for so many years to find a reason to ride back home

It's been a long time
and these houses and haircuts and horrorbags I hardly would have recognised

I call up my friend
and he tells me his wondrous adventures in financial investment went wrong

but I'm all right Jack I hate to say
I've got no money but I'm happy this way so hey hey!
so hey hey!

Oh dear what have I done?
I had an idea and took the money and ran...
...into a brick wall

These goofs are bigger than me
yeah
These goofs are better than me
yeah
These goofs have friends in high places

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I wondered how often I used the adjective "boppy" to describe a tune. It turns out not that often. Click here to see the tunes I described as boppy.

George Steer's 1856 design "Laura"

In 1856, the last year of his life, George Steers, the designer of America, designed a small 24' racer for Harry Latrobe Roosevelt of Skaneateles N.Y. Named Laura, this Steer's racer would spend her entire career on Skaneateles Lake. On Christmas Day, 1936, after being hauled for the last time, Osgood R. Smith, John Barnes, and Art Emerick would measure Laura on the beach. Eight years later, Osgood R. Smith wrote an article on Laura in the August 1944 issue of Yachting magazine and included the lines they had assembled.

Laura provides a glimpse of how the New York designers were moving the lines of the New York oystering workboat into a recreational racer. (See also Chris Thompson's article on the 1853 Una design by Bob Fish). We see the basis of form that would be tweaked, some fifteen years later, into the all-out Sandbaggers of the 1870's. Compared to Sandbaggers,  the George Steer's Laura is a wholesome hull of moderate proportions though we can see the fine bow and the tucked-up aft rocker of the Sandbaggers. There is no record of Laura needing sandbags to be raced.

Laura's sections show a fair bit of tumblehome.

The beam is not excessive.

This side view has the stern lopped off because the copier distorted the stern as the page made it's way down into the binding of the book.

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My night of Sandbagger sailing.