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Michel Selig II

The Construction of The Classic Six Metre Model Yacht Michel Selig II

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Construction of the classic Six Metre<br />

model yacht <strong>Michel</strong> <strong>Selig</strong> <strong>II</strong><br />

By Basil Carmody (basil@sfr.fr)<br />

Table of contents<br />

[xxx] = illustration<br />

P<br />

a<br />

g<br />

e<br />

I. <strong>Michel</strong> <strong>Selig</strong><br />

A. Six Metre yachts 1<br />

[comparison of 6mR hulls]<br />

[Third Rule equation]<br />

B. The birth of Sixes 2<br />

[Architects]<br />

[Onkel Adolph]<br />

[Louis Dyèvre]<br />

C. Falling in love with Sixes 4<br />

[Caprice]<br />

[<strong>Michel</strong> <strong>Selig</strong> in Cornwall]<br />

D. <strong>Michel</strong> <strong>Selig</strong><br />

1. History 5<br />

[Launching]<br />

[Steering wheel]<br />

[Hebrides n = 3]<br />

[Chris White & nail rot]<br />

2. Restoration becomes reconstruction 9<br />

[Unloading at Villa Manou]<br />

[Temporarily propped]<br />

[Movable props]<br />

[Cabin & cockpit removed]<br />

a. Taking off the lines of <strong>Michel</strong> <strong>Selig</strong> 11


[JMM & masking tape]<br />

[Chevalet]<br />

- Offsets 12<br />

[Stations]<br />

[Stations & waterlines]<br />

- Two fundamental errors 15<br />

b. Condition<br />

- Lack of stiffness 16<br />

- Floors 16<br />

[Ring floor]<br />

- Nail rot 17<br />

[Nail rot from inside]<br />

[Ring floor]<br />

c. A complete re-build or a component by component<br />

replacement?<br />

19<br />

[Nirvana moulds]<br />

[Nirvana ribbands]<br />

[Nirvana frames]<br />

d. Lofting 20<br />

[Half shell]<br />

[Lofting platform]<br />

e. Abandon 22<br />

<strong>II</strong>.<br />

<strong>Michel</strong> <strong>Selig</strong> <strong>II</strong> (MS <strong>II</strong>)<br />

A. Intention 22<br />

B. Bread n' butter contruction method 23<br />

[Cardinal <strong>II</strong>]<br />

C. Lofting again<br />

1. Profile 24<br />

[Station sections]<br />

2. Stations and waterlines 25<br />

D. Calculation of the ballast 25<br />

E. Wood 26<br />

F. Fabricating the rough hull<br />

1. Transfer of waterlines to the planks


a. Slaloming through the knots 26<br />

b. Drawing the waterlines on the planks 26<br />

[Top and bottom of plans with red and green lines]<br />

2. Half lifts<br />

a. Cutting the half lifts 27<br />

b. Preview of the finished hull 27<br />

[Cumulative build up of lifts]<br />

c. Drawing stations on the sides the "half" lifts 30<br />

[Drawing the station lines on the sides of a half lift]<br />

[Stacking the lifts]<br />

[Alignment of the station lines]<br />

3. Knots 31<br />

[Two bits]<br />

[Keyhole guide]<br />

[Nail points]<br />

[Bungs in place]<br />

4. Gluing the half lifts together 33<br />

[Close up of gluing the forward part]<br />

[Close up of gluing the aft part]<br />

[Overall view from the bow]<br />

[Overall view from the stern]<br />

5. Upper part of the hull 36<br />

[Gluing the two lowest lifts together]<br />

[Gluing the two top lifts together]<br />

[Exterior bridges]<br />

[Upper hull]<br />

[Interior bridges]<br />

[Bottom of the studs]<br />

[Stud supports]<br />

[Complete rough hull]<br />

6. Plugs and sternpost 38<br />

7. Full rough hull 39<br />

I. <strong>Michel</strong> <strong>Selig</strong> I


A. Six Metre yachts<br />

Six Metre yachts are built according to the International Rule<br />

which was first drafted in 1907. They are among the most<br />

beautiful yachts in existence, with long forward and aft<br />

overhangs. They are referred to as "Sixes" or "6mR's".<br />

A comparison of 6mR hulls. The top boat is the 1985<br />

"Capriccio". The 2nd the 1930 Totem and the bottom<br />

one the 1938 Goose, perhaps the most successful Six of<br />

all times.<br />

A rule is different from a class. The hulls of boats of the same<br />

class are all identical (more or less).<br />

A rule is an equation which specifies the relationship between<br />

various parameters of a boat, with a number as the solution of<br />

the equation. The current equation for the International Rule is:<br />

where:<br />

L = the overall length


d = a measurement of how much the hull has a<br />

"wine glass" shape<br />

F = the freeboard<br />

S = the sail area<br />

The International Rule also includes Eights, Twelves and even<br />

higher. The numbers of their names correspond to the solution<br />

of the equation. If the equation gives a result less than 6, it will<br />

qualify as a Six . Ditto for the other names.<br />

B. The birth of Sixes<br />

1907 was at the highpoint of the first worldwide globalisation<br />

period. It ended with WW I.<br />

This globalisation also extended to yachtsmen of various<br />

European countries who wanted to race against each other with<br />

equivalent boats. The Rule permitted naval architects of these<br />

countries to come up with their best designs for boats whose<br />

parameters conformed to the Rule. In each country, yachtsman<br />

commissioned boats from these architects and then raced them<br />

in international competitions. The best architects were:<br />

William Fife (UK)<br />

Johan Anker<br />

(Norway)<br />

Torre Holm<br />

(Sweden)<br />

Gustav Estlander<br />

(Finland)<br />

Olin Stephens (USA)<br />

The first international race of Sixes was sailed in 1907 on the<br />

Seine River in France at Meulan, organised by the Cercle de<br />

Voile de Paris. When the current was too strong, the boats<br />

anchored. They also ran aground on the mud flats. It was won<br />

by the German entry, Onkel Adolph, pictured below:


The class (the word is applied to Sixes) prospered. 1000 boats<br />

were built before WW<strong>II</strong>. It became an Olympic class and it was<br />

"the" development class. New ideas were first tried out on<br />

Sixes.<br />

An anomaly of the Rule is that the boats are twice as long as<br />

their numbers. A Six is about 12 m. long.<br />

This goes back to a humourous story at the London conference<br />

that created the Rule in 1907. In fact the conference was fixed.<br />

The northern countries and the U.K. had already decided the<br />

form of the equation.<br />

The monolingual French representative, Louis Dyèvre, wasn't in<br />

on the "fix".<br />

He huffed and puffed in French at the blackboard advocating a<br />

variant of the American Universal Rule which has a parameter<br />

in the denominator.


As a sop, the conference included a useless denominator to the<br />

equation with a value of about 2 (see above). As a result, this<br />

has the effect of dividing the overall length of a Six by 2,which<br />

is why a boat which is about12 m. long is called a Six.<br />

C. Falling in love with Sixes<br />

We have a summer house at Saint-Tropez, France. It's over a<br />

century old and it was tiny when we bought it (less that 500 sq.<br />

ft.)<br />

After the general contractor walked off the job after a year, I<br />

took over. During this time, I came to love Saint-Tropez during<br />

the winter.<br />

When the house was finally finished, I wondered what I could<br />

do to justify coming to Saint-Tropez during the winter instead of<br />

staying in Paris.<br />

By chance I saw a Six, GBR 48 Caprice<br />

The 1946 Six "Caprice" designed and built by<br />

McGruer & Son of Clynder, Scotland


and fell in love with the class. I then decided to look for a<br />

wreck of a Six, which I soon found in Cornwall, which I could<br />

restore in our garden in Saint-Tropez. She was K 75 Joanna, ex-<br />

G 24 <strong>Michel</strong> <strong>Selig</strong> and Avalun V<strong>II</strong>I.<br />

D. <strong>Michel</strong> <strong>Selig</strong><br />

1. History<br />

<strong>Michel</strong> <strong>Selig</strong> at the Ocean Yacht Co. boatyard in<br />

Cornwall at the time of purchase<br />

First her name: G 24 <strong>Michel</strong> <strong>Selig</strong>, G 24 being her sail<br />

number.. It remains an unknown. Literally, it means<br />

Michael the Blessed. No German speaker I've met has<br />

come up with an explanation.<br />

She was commissioned by Hans Collignon, a prosperous<br />

printer and active yachtsman who sailed on the Wannsee, a<br />

lake on the outskirts of Berlin. He intended to enter her in<br />

the June 1936 German elimination trials for the upcoming<br />

Olympic Games, whose sailing activities were located at<br />

Kiel, just to the east of Denmark.<br />

For some unknown reason, he commissioned Reinhard<br />

Drewitz, probably the world's best designer of sailing<br />

dinghies of the period, as architect. Drewitz must have told<br />

Colllignon that he was no match for successful 6mR<br />

architects like Anker, etc. (see above). He may have<br />

convinced Collignon to make a bet on the weather.<br />

The Berlin boatyard of Wilhelm Buchholz built her. She is<br />

the only Berlin built Six.<br />

In June, the weather in Kiel is usually quite windy. There is<br />

a 10% chance that the Scandinavian high will descend to<br />

Kiel bringing calm breezes. Drewitz may have said that he<br />

could design a Six optimized for low wind speeds and thus<br />

perhaps faster than the other Sixes with their general<br />

purpose all weather design.<br />

His design was a Six that resembled a centreboard sailing<br />

dinghy. In the formula of the International Rule above, the<br />

variable "d" corresponds to a penalty for having a wineglass<br />

shaped cross section, rather than a rounded one. Drewitz's<br />

centreboard shape resulted in a severe penalty. To<br />

compensate for it, he designed the boat to float bow down,


almost exposing the rudder, to lower the waterline length<br />

which compensated the "d" penalty.<br />

Two key opposing concepts in sailboat design are wetted<br />

surface and hull speed In light winds, one wants a<br />

minimum of wetted surface. For stronger winds, when the<br />

boat reaches full speed, it reaches a limit based on its<br />

waterline length (its hull speed). The longer the waterline<br />

length, the faster the hull speed.<br />

Drewitz designed such a light boat that, if the crew moved<br />

forward, the boat tilted forward and its wetted surface was<br />

reduced and, if it moved aft, the boat tilted aft, extending its<br />

waterline length. It was a remarkable concept for the<br />

period. It is now common practice for certain modern<br />

racing yachts.<br />

Apparently, Collignon rejected the concept after the boat<br />

was built. To make her float "normally, he had 120 kg. of<br />

the forward part of the ballast moved aft in the form of forty<br />

3 kg. lead ingots, thereby also rendering her rating so that<br />

she was no longer a Six.<br />

Photo of <strong>Michel</strong> <strong>Selig</strong> before launching. The caption in<br />

German explains Drewitz's concept of shifting the<br />

crew's weight forward and aft, but the boat had<br />

already been "adjusted" by Collignon to give it a


"normal" waterline. (Note the "wine glass" cross<br />

section.)<br />

He sold her, bought a second hand Six for the Olympic<br />

trials and was eliminated. Her new owner, Dr Tubiak,<br />

named her G 24 Avalun V<strong>II</strong>I, sailing her at Collignon's<br />

yacht club, the Verein Seglerhaus am Wannsee<br />

The Scandinavian high didn't descend on Kiel in June. It<br />

also turned out that no one was able to get <strong>Michel</strong> <strong>Selig</strong> to<br />

sail fast. (Previously, a dinghy owner had complained to<br />

Drewitz that his Drewitz designed boat was too slow.<br />

Drewitz took it over and raced it for the rest of the season,<br />

winning almost every race.)<br />

By 1939, she was in England, renamed K 75 Joanna. In the<br />

1960's she was modified as a cruiser with a steering wheel!<br />

Joanna at Tobermory equiped with a steering wheel<br />

and a two cycle Sea Gull outboard<br />

For the period 1970 - 1984, she sailed in the Hebrides.


<strong>Michel</strong> <strong>Selig</strong>, then named K 75 Joanna, in the Hebrides<br />

Her owners, a syndicate of young yachtsmen, loved her.<br />

By the 1990's, she was in need of a restoration. She had<br />

several owners, each intending to restore her and then<br />

giving up<br />

Chris White, one of the syndicate members, and his<br />

son with Joanna at the start of her restoration period.<br />

Note the black spots on the hull. More about them<br />

below.<br />

An interesting sidelight of her history is what became of her<br />

plans. Drewitz bequeathed his practice to Helmut<br />

Ruhrdanz. After the Soviet occupation, Ruhrdanz was in


East Berlin. His son needing medicine only available in<br />

West Berlin, he was allowed to go back and forth.<br />

One evening as he was entertaining three young East<br />

Berliners, they told him of their plans to cross over to the<br />

West via a tunnel. They were caught and mentioned their<br />

conversation with Ruhrdanz to the Stasi secret police. The<br />

The Stasi arrested and imprisoned Ruhrdanz and, in the<br />

process, confiscated all of Drewitz plans, presumably<br />

including the only copy of those of <strong>Michel</strong> <strong>Selig</strong>.<br />

2. Restoration becomes reconstruction<br />

As mentioned above, friends found <strong>Michel</strong> <strong>Selig</strong> for me in<br />

Cornwall. I had her shipped to Saint-Tropez sight unseen.<br />

<strong>Michel</strong> <strong>Selig</strong> arriving at our house in Saint-Tropez<br />

Propped up preliminarily. Note the prevalence of the<br />

black spots


Shored up with movable props<br />

After removal of the cabin and self bailing cockpit<br />

added when converted to cruising


2. Restoration becomes reconstruction<br />

a. Taking off the lines<br />

One of the first tasks in restoration of <strong>Michel</strong> <strong>Selig</strong> was<br />

to create a set of plans for her. I knew that the hull was<br />

sufficiently twisted that the distance from the port and<br />

starboard sides of the hull to the centreline would not<br />

be the same because of this<br />

The first step in doing this was to "take off her lines",<br />

i.e. measure enough points on the surface of the hull to<br />

be able to produce a three dimensional model, of the<br />

hull.<br />

With my gardener, we measured 800 points on the hull<br />

along the waterlines, the stations and the buttocks<br />

(longitudinal sections) - both port and starboard.<br />

My gardener establishing the reference design<br />

waterline on the hull


Establishing reference verticals at a station. An offset<br />

was the distance between a vertical and the hull.<br />

Despite the appearance of the photo, the verticals were<br />

truly vertical.<br />

- Offsets<br />

In preparing the design of a boat, a naval architect<br />

first defines a side view of a boat (its "profile").


A drawing of the profile of <strong>Michel</strong> <strong>Selig</strong> with detail of<br />

the components of the backbone, which is thus more<br />

properly called a construction plan.<br />

He then draws a number of equally spaced vertical<br />

lines on the profile (the"stations") which represent<br />

vertical sections of the hull.<br />

Similarly, he does the same thing horizontally (the<br />

"waterlines") which represent horizontal sections of<br />

the hull.<br />

Three views of <strong>Michel</strong> <strong>Selig</strong>: 1.) upper left - the station<br />

profiles, viewed from the stern, are superposed, 2.)<br />

upper right - ditto, but viewed from the bow, 3.) the<br />

waterlines of the starboard half of the boat, viewed<br />

from the bottom, are superposed.<br />

The results remain a two dimensional representation<br />

of the hull. One can combine the stations and


waterlines on a profile view, thus creating<br />

intersections of the stations and waterlines.<br />

To add a third dimension of the hull, the architect<br />

defines a plane which cuts the hull longitudinally<br />

(the "centre plane"). (The waterlines shown above<br />

are drawn reative to the centre plane.) He then<br />

defines the distance between the centre plane and<br />

each intersection of a waterline and a station. This<br />

distance is called an "offset". Once he has done this<br />

for each intersection, he has in effect defined the<br />

hull in three dimensions. The set of these offsets is<br />

called a "table of offsets".<br />

Our 800 points were in effect a table of offsets for<br />

both the port and starboard sides.<br />

- Two fundamental errors<br />

My architect should have told me to immediately<br />

convert the take off data into a set of plans and a<br />

table of offsets. This would have led to the<br />

discovery of the inevitable errors in our<br />

measurements which could then have been corrected<br />

by re-measuring the erroneous data.<br />

He didn't and I merely set the take off data aside.<br />

I also didn't record rigourously precise data defining<br />

the profile of the boat. This would haunt me later<br />

b. Condition<br />

- Lack of stiffness<br />

The condition of the hull was abdominal. I could<br />

move the transom 20 cm. to the left and right. The<br />

ballast keel had been removed. Planks were<br />

missing. The wooden keel and the deadwood below<br />

all seemed rotten.<br />

- Floors<br />

When a boat heels, the ballast keel would like to stay<br />

in a vertical position, thus separating itself from the<br />

hull.<br />

"Floors" are used to counteract this force. They are<br />

metallic. They are firmly attached to the ballast keel<br />

and then they extend upward alongside the inside of<br />

the hull distributing the force of the ballast keel on<br />

the hull.<br />

Between the wooden keel and the ballast keel, there<br />

were a number of shims which adjusted for the<br />

difference in the angles of the two. These are called<br />

"deadwoods".


As was customary for the period, and especially for<br />

fresh water sailing, Wilhelm Buchholz had used soft<br />

steel for the floors and also for all the bolts attaching<br />

the floors and deadwoods to the hull..<br />

In saltwater, the "through hull" steel bolts attaching<br />

the floors to the hull had begun to electrolise.<br />

Similarly, many parts of the floors in the bilge had<br />

rusted away.<br />

"Ring"floor completely rusted at the bottom where it<br />

was in the bilge<br />

- Nail rot<br />

Two photos above showed the black spots on the<br />

exterior of the planking.<br />

All the black spots corresponded to "through hull"<br />

steel bolts attaching the floors to the hull. Seen from<br />

the inside of the hull, the wood around the bolt was<br />

completely rotten. The floor could be removed by<br />

simply pulling it away.


Holes of rotten wood where the floors were attached to<br />

the hull (between 17 & 18 and between 19 & 20<br />

This is a fairly unusual phenomenon called "nail rot"<br />

where the electrolysis of the bolt causes the<br />

surrounding wood to rot. It occurs on some Sixes,<br />

but never to this extent.<br />

In <strong>Michel</strong> <strong>Selig</strong>'s case, the nail rot had attacked<br />

every plank and also the wooden keel and the<br />

deadwoods.<br />

I don't know why this occurred to this extent.<br />

Perhaps the steel used by Wilhelm Buchholz<br />

favoured nail rot.<br />

I also don't understand why my own architect and<br />

other architects who examined <strong>Michel</strong> <strong>Selig</strong>, never<br />

explained the nail rot situation to me. I wonder if<br />

the seller of <strong>Michel</strong> <strong>Selig</strong>, a professional yacht<br />

restorer with whom I even developed a friendship,<br />

knew, but decided to take advantage of me.


I could only conclude that almost every components<br />

of <strong>Michel</strong> <strong>Selig</strong> was rotten. The task I faced was not<br />

to restore, but to re-build completely.<br />

- A complete re-build or a component by component<br />

replacement?<br />

Given my age and my health, I knew that I would<br />

never be able to constru20ct a new <strong>Michel</strong> <strong>Selig</strong>.<br />

The approach of replacing individual components of<br />

a deformed hull seemed unwise and extremely time<br />

consuming for a mediocre finished product. I<br />

therefore chose a complete re-build, hoping that I<br />

would advance sufficiently to motivate a successor<br />

to finish the re-build.<br />

In building a Six, one usually works on the hull<br />

upside down.<br />

The planking is the fourth layer of the construction<br />

process. The layers are:<br />

-a set of vertical "moulds" which establish the shape<br />

of the hull:<br />

Moulds of the 2011 replica of the Six "Nirvana" (or<br />

"Seasta") designed by Olin Stephaens and built by<br />

Yachtwerft Robbe & Berking Classics GmbH &<br />

Co.KG of Germany<br />

- a set of horizontal "ribbands" which create the form<br />

of the boat:


Ribbands of Nirvana<br />

- the vertical "frames or "timbers which are steamed to<br />

the point of being pliable and then attached to the<br />

ribbands:<br />

Frames cooled and hardened after being attached to<br />

the ribbands<br />

- and finally the planks which are usually attached<br />

to the frames by rivets.<br />

I hoped toget to the point of creating the moulds which<br />

would have permitted my successor to set them up and<br />

proceed to the following stages.<br />

d. Lofting<br />

The sequences of steps for producing the moulds<br />

are:<br />

- taking off the lines of the hull (discussed above)<br />

- drawing the plans of the hull<br />

- lofting or laying off: drawing the plans on a 1:1<br />

scale,


- cutting the moulds from the full size plan.<br />

When I started the reconstruction phase of <strong>Michel</strong><br />

<strong>Selig</strong>, the first step was to lay off her plans full size<br />

so as to be able to fabricate the "moulds" over which<br />

the hull would be built. I had decided to sidestep,<br />

the drawing the plans.<br />

This included the construction of a "drawing board"<br />

slightly bigger than the size of <strong>Michel</strong> <strong>Selig</strong>.<br />

Because of a lack of space and because I was setting<br />

off to re-construct <strong>Michel</strong> <strong>Selig</strong>, I dismantled her,<br />

saving every component.<br />

<strong>Michel</strong> <strong>Selig</strong> partially dismantled<br />

Next, I built the full size "drawing board" or lofting<br />

platform.


Lofting platform for laying off the lines of <strong>Michel</strong> <strong>Selig</strong><br />

at a 1:1 scale<br />

e. Abandon<br />

As I started lofting , I encountered the errors introduced<br />

at the time of taking off her lines. The major problem<br />

was that I was unable to fit the wooden keel within the<br />

profile.<br />

To analyse the problem, I entered my data into<br />

AutoCAD. There was no solution, I would have to<br />

shorten the wooden keel.<br />

It was at this point that my age and health caught up<br />

with me. The lofting process probably required<br />

kneeling down and then getting up again over a<br />

thousand times. My knees weren't up to it, so I had no<br />

choice but to totally abandon the project.<br />

It was one of the saddest events of my life. Not that I<br />

had spent so much time arriving at that point, but that<br />

wouldn't leave a usable trace of <strong>Michel</strong> <strong>Selig</strong> for<br />

posterity.<br />

<strong>II</strong>.<br />

<strong>Michel</strong> <strong>Selig</strong> <strong>II</strong> (MS <strong>II</strong>)<br />

A. Intention<br />

Since I was unable to finish a full sized version of <strong>Michel</strong> <strong>Selig</strong>,<br />

I wanted to leave a physical model (<strong>Michel</strong> <strong>Selig</strong> <strong>II</strong>, referred to<br />

as MS <strong>II</strong> hereafter) of her for posterity.<br />

With luck, I discovered the Six Metre Class - Model Yacht<br />

Association in England which counts over 80 yachts (referred to


as R6M's), most of which are "moderns" as opposed to<br />

"classics". <strong>Michel</strong> <strong>Selig</strong> is a "classic", so MS <strong>II</strong> will be also.<br />

The association has its own Rule which is virtually identical to<br />

the International Rule and ten times more readable.<br />

The scale of the model yachts is 2/3" for each foot of a Six or a<br />

multiplier of 0.139.<br />

The yachts are radio controlled.<br />

Three of its members were extremely helpful:<br />

- Mike Ewart, president of the class, who encouraged me<br />

every bit of the way and who guided me to the two key<br />

counselors, without whom I could not have built the<br />

model.<br />

- Henry Farley, the official measurer of the class, who<br />

has measured over 80 model yachts. He was extremely<br />

helpful for all the quantitative aspects of planning and<br />

building the model.<br />

- Cliff Grove, one of the top builders of model yachts in<br />

the world. Our ample e-mail correspondence led to a<br />

genuine friendship. He helped me with all the details<br />

of actually constructing the model.<br />

When finished, I hope to donate the model and its plans and<br />

offsets to a maritime museum so that Michael <strong>Selig</strong> can continue<br />

to live after I'm gone. (I'm now 79.)<br />

The finished boat would measure 1415 mm overall with a mast<br />

of 1806 mm.<br />

B. Bread n' butter construction method<br />

There are two principal ways to build a model boat:<br />

- the "planking" method which approximates that of<br />

building a full size boat with frames and planking<br />

- the "dugout" method which resembles the construction<br />

of a dugout canoe, starting with a single piece of wood<br />

and then emptying the inside and carving the outside<br />

At age 12, as a summer camp project, I had already used the<br />

dugout method, starting from a single piece of redwood.


Cardinal <strong>II</strong>, built by the author at age 12 as a summer<br />

camp project (restored by his son, Nathaniel)<br />

A variant of the dugout method is the Bread 'n Butter method. It<br />

consists of slicing the boat horizontally into a stack of planks cut<br />

to the waterlines. Each slice (a "lift") can be cut to the outline of<br />

the waterline at the eventual thickness of the hull. This enables<br />

the use of a band saw to cut away all the excess wood both<br />

outside and inside the intended hull thickness.<br />

It was this method used for <strong>Michel</strong> Seling <strong>II</strong>.<br />

C. Lofting again<br />

1. Profile<br />

The profile was the first priority. It permitted the<br />

calculation of the position of the beginning and end of each<br />

waterline. Similarly, it provided the values for the bottom<br />

ends of the stations.<br />

The profile plan permitted me to draw the bottom ends of<br />

the stations on each cross-section of the sections plan


2. Stations and waterlines<br />

Station profiles for stations 15 - 20<br />

First, each station and waterline was drawn separately to<br />

ensure a smooth line. Next they were drawn together, as<br />

per the finished product of a naval architect, to make sure<br />

that they were correctly separated, one from the other.<br />

A table of offsets was prepared from these drawings<br />

D. Calculation of the ballast<br />

I wanted MS <strong>II</strong> to float on the same lines as <strong>Michel</strong> <strong>Selig</strong>. In<br />

fact, this was necessary for MS <strong>II</strong> to conform to the Rule.<br />

Henry Farley said that the only way to determine the weight and<br />

position of the lead ballast would be through trial and error. He<br />

advised me to build the lower portion of the hull (the "plug")<br />

detached from the upper portion - and also to build several<br />

copies of it for the trial and error process. The plug would be<br />

connected to the upper portion of the hull by two lengths of<br />

threaded stock which would also connect the ballast keel to the<br />

hull.<br />

In fact, the plug didn't run fully aft. I fabricated a fixed<br />

sternpost for the after portion. This would permit me to build<br />

the rudder and its radio control independently of the task of<br />

fabricating the plug..<br />

E. Wood


I wanted a light wood which would be relatively easy to carve.<br />

Western red cedar was my preference, but its price at the saw<br />

mill near Saint-Tropez was prohibitive. I settled for a spruce<br />

(Picea abies) which has an average of one or two big knots for<br />

every 1.5 metres.<br />

The saw mill didn't want to plane the planks to the spacing of<br />

the waterlines (13.9 mm. or about half an inch). I settled for the<br />

thickness of two waterlines (27.8 mm. or about 1-1/8").<br />

Separate planks were used for the starboard and port halves of<br />

lift. This allowed cutting the inside portion of the lifts with a<br />

band saw.<br />

F. Fabricating the rough hull<br />

1. Transfer of the waterlines to the planks<br />

Whereas the margin of error in drawing the plans was ± 1<br />

mm., that for working on the wood was of at least ± 2 mm.<br />

a<br />

Slaloming through the knots<br />

The first task was to find a path on each plank which<br />

avoided knots. To say the least, it was tedious.<br />

For a given plank, the upper and lower waterlines lines<br />

of the lift form a pair, which can be named by the upper<br />

waterline. There are four possible positions of the<br />

upper waterline relative to the two faces of the plank:<br />

- on the topside of the plank, the centreline of the<br />

upper waterline can be on the right or left edges<br />

of the planks<br />

- ditto for the underside of the plank.<br />

For each position, one can slide the waterline from one<br />

end to the other of the plank looking for a point where<br />

the upper waterline doesn't pass through a knot.<br />

One must next verify that the lower waterline also<br />

avoids knots.<br />

To do this, I produced lengths of cardboard with the<br />

upper and lower waterlines drawn on them. I cut it<br />

along the upper waterline and then slid both cardboard<br />

halves from one end to the other of the plank to find the<br />

best position<br />

I cut then cut the cardboard along the lower waterline<br />

and verified that the position chosen for the upper<br />

waterline also proved a knot free path for the lower<br />

one.<br />

b. Drawing the waterlines on the planks.<br />

I then drew stations on both sides of the plank<br />

corresponding to the correct position of the waterlines.


On the upper side of the plank, I drew a "safety margin"<br />

line 3 mm. outside the waterline. This was the line<br />

used for cutting.<br />

On the lower side of the plank I did essentially the<br />

same thing: 6 mm. for the thickness of the hull, plus 3<br />

mm. as the safety margin.<br />

The top side of the lift that goes from waterline 11 to<br />

13. One can see the waterline (green) and the 3 mm.<br />

safety margin. The extreme width of the plank<br />

indicates that the hull is almost flat between these<br />

waterline.<br />

The bottom side of the same lift that goes from<br />

waterline 11 to 13. The distance between the green and<br />

red lines on the bottom of a lift is 9 mm. : 6 mm. for the<br />

thickness of the hull and a 3 mm. safety margin.<br />

2. Half lifts<br />

a. Cutting the half lifts<br />

Since I can't use electric cutting tools because of the<br />

anti-coagulants I take, I subcontracted the cutting of the<br />

lifts to my old friend and ship's carpenter, Manu<br />

Allibert of Saint Tropez. He found the planks well<br />

prepared and cut the lifts with his band saw, working<br />

for a total of five hours.<br />

b. Preview of the finished rough hull


The photos below show the cumulative stacking of the<br />

seven pairs of half lifts, starting from the highest lift to<br />

the full boat. In the next to last photo, one sees the four<br />

lifts of the plug and sternpost stacked on the lowest lift.


The two half lifts of lift no. 1 The four half lifts of lifts nos. 1 & 2<br />

The six half lifts of lifts nos. 1, 2 & 3<br />

The eight half lifts of lifts nos. 1, 2, 3<br />

& 4<br />

The ten half lifts of lifts nos. 1, 2, 3, 4<br />

& 5<br />

The four lifts of the plug and the<br />

sternpost<br />

The complete hull consisting of<br />

fourteen half lifts of lifts nos. 1 - 7,<br />

plus the four lifts of the plug and of


the sternpost<br />

c. Drawing station lines on the sides of the "half" lifts<br />

In preparing the plans for cutting, station lines had been<br />

drawn on the top and bottom of the lifts. During the<br />

carving phase, station lines are needed on the outer and<br />

inner sides of the boat.<br />

This meant connecting the station lines on the top of a<br />

half lift with those on the bottom. Disappointingly, the<br />

lines rarely lined up completely. There was usually a<br />

discrepancy of 1 - 2 mm. - and sometimes much more.<br />

This led to drawing lines of three colours:<br />

- blue: for the initial linking of the top and bottom<br />

lines, i.e. one half lift at a time,<br />

- green: for resolving discrepancies between the blue<br />

lines on both the inner and outer sides of the two<br />

halves of the lift, i.e. two half lifts at a time,<br />

- red: for defining a definitive station line on the<br />

outside of the hull over all the lifts (after gluing the<br />

lifts together).<br />

Drawing the station lines on the sides of a half lift.<br />

They should correspond to the station lines on the top<br />

and bottom of the lifts. One can see that they don't.<br />

The square ensures that the lines will be<br />

perpendicular.<br />

The next step was to verify that the station lines of the<br />

two half lifts are in alignment.


3. Knots<br />

The alignment of the station lines on the sides of the<br />

four lifts of the plug are being verified. Thrre are<br />

discrepancies.<br />

Despite slaloming among the knots in drawing the<br />

waterlines, some half lifts ended up with knots. For these, it<br />

was necessary to drill out the knots and fill them with<br />

bungs.<br />

I found that a 19 mm keyhole saw could cut out a bung to<br />

fit into a knot drilled with a 16 mm. drill.<br />

The two bits used to drill through knots and then<br />

fabricate a bung. The 16 mm. drill removes the knot.<br />

The 19 mm. keyhole saw produces a bung which will fit<br />

tightly in the hole drilled.<br />

A keyhole saw bit has a drill in the centre to guide it. The<br />

bungs needed to be solid throughout, so it was necessary to


emove the drill from the bit. Normally, this results in the<br />

bit skidding on the wood before it starts cutting.<br />

To avoid the skidding, I used a guide - and I also drove nails<br />

through the guide with the points sticking out to avoid<br />

skidding<br />

The keyhole saw bit guide (centre). The other holes were<br />

drilled in attempts to find the right combination of keyhole<br />

bit and drill bit.<br />

The nail points sticking out of the keyhole guide to<br />

avoid skidding<br />

It was important to line of the grain of the bungs with that<br />

of the half lift.


The bungs and the rest of the hull were glued with<br />

polyurethane glue. In France, it is considered carcinogenic.<br />

It is no longer available to non professionals. Accordingly,<br />

I had to buy 5 litres at an exorbitant cost.<br />

The bungs glued in place and lined up with the grain of<br />

the half lift.<br />

4. Gluing the half lifts together<br />

In gluing to half lifts together, I lined up the station lines<br />

and held the half lifts snugly one against the other and in the<br />

same plane, securing them with clamps.<br />

The first point to remember is that polyurethane sticks to<br />

everything except polyethylene. I covered my work board<br />

with a sheet of polyethylene and I wrapped the parts being<br />

glued in what is called in the U.S. "Saran Wrap", a light<br />

polyethylene film for the kitchen used to cover food<br />

It was necessary to insert nails just forward and just aft of<br />

the wedges to prevent them sliding along the hull as I<br />

tightened the clamps.


Gluing the forward part of two half lifts together. One<br />

can see the Saran wrap around the part being glued.<br />

Its purpose is to avoid adhesion to the wedges. One<br />

can also see two nails which prevent the wedges from<br />

sliding forward under the pressure of the clamp.<br />

Gluing the aft part of two half lifts together. One can<br />

see two nails at the aft end of the lift. Their purpose is<br />

to avoid the entire lift sliding aft under the pressure of<br />

the clamp and wedges at the forward end.


Forward view of two pairs of half lifts being glued<br />

together. One can see the nails blocking the wedges.<br />

Note the use of a mason's clamp for the wide part of<br />

the lift


Aft view of two pairs of half lifts being glued together.<br />

One can see the nails blocking the wedges.<br />

5. Upper part of the hull<br />

The upper part of hull consists of the seven lifts glued<br />

together.<br />

Gluing the two lowest lifts together<br />

My collection of wood clamps was insufficient for gluing<br />

together the upper lifts, which are the longest, using them<br />

alone. I had recourse to 3 kg. lead ingots and masons'<br />

clamps.<br />

For the ingots to squeeze correctly, it was necessary to place<br />

a support under the lifts where the ingots were placed.<br />

Before clamping, I placed the ingots in place. Their weight<br />

stabilised the structure, preventing it from shifting as I<br />

placed the clamps.<br />

The centre of gravity of the masons' clamps is not in line<br />

with where the pressure is being applied to the lifts. This<br />

gives them the tendency rotate out of the vertical, thus<br />

placing a twisting force on the lifts. To avoid this, they<br />

were placed next to the lead ingots which helped the lifts<br />

resist the twisting force<br />

Gluing the two top lifts together. Note<br />

the lead ingots and the masons' clamps.<br />

As the upper part of the hull narrowed, it was no longer<br />

possible to place the clamps directly on the lifts. Bridges


were necessary. According to the need, some were placed<br />

outside the hull and others inside the hull.<br />

The narrower width of the top lift, with respect to the two<br />

below, makes it impossible to place the clamps directly on it.<br />

The solution is to use a "bridge" which spans the top lift and<br />

then to put the clamps on the bridge.<br />

Fulll upper hull being glued. The bottom ends of the clamps<br />

are shown in the following photo


The use of bridges on the inside of the hull where one sees<br />

the bottom ends of the clamps of the previous icture<br />

6. Plugs and sternpost<br />

The plugs, the sternpost and the lowest lift were drilled<br />

vertically for four pieces of threaded stock (studs).<br />

Holes were drilled in the aft part of lift 1 of the plug to<br />

lighten it. Given the uncertainty as to the eventual position<br />

of the ballast, no other holes were drilled in the lower lifts.<br />

The lifts of the sternpost and one of the three plug were<br />

glued together.<br />

Four temporary "bridges" were placed in the upper hull to<br />

anchor the studs, thus allowing the plug and the sternpost to<br />

be attached to the upper hull.<br />

The bottom of the four studs permitting the removal of<br />

the plug from the upper hull<br />

7. The full rough hull


Temporary supports on the inside of the upper hull<br />

permitting the attachment of the plug studs<br />

Complete hull with the upper hull, the plug and the<br />

sternpost, the latter two attached to the upper hull by<br />

the studs

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