SHIPBUILDING    



You are standing now in the area that will show you the evolution in boats and shipbuilding through the use of different materials and techniques.

 

Wood

 

Sailing on rivers and estuary zones started in Northern Europe five thousand years before Christ .The first boats called “monoxyles” were first carved in pine trees , and later in oak trees in neolitic times. These oak pirogues were carved with what is known as the “fire technique”, then they were shaped with flint adzes.

In the Bronze age, the boats became flatter and were sewn, which allowed huger loads to be transported. Two main tree species are commonly used :

-         the oak tree ( or sometimes the beech tree) for the hull

-          and the pine tree for the masts.

The elm, the chestnut tree  and acacia are used for bent- shaped elements while the rudders are carved in walnut tree.

In Normandy , there are two traditional techniques for building wooden boats : clincher work and free board;

 

-         Clincher works was inherited from the Vikings and their drakkars and has been

used since the ninth century.

First the hull is made with the same technique as a roof , with boards nailed the ones over the  others ; once the hull is finished and turned upside down, it is reinforced with thin ribs.

This type of shipbuilding reached its peak at the end of the Middle Ages. However, this technique will be used in Normandy and in Sussex until the first half of the twentieth century for small boats such as  the doris ,the caique  and the English punt .

 

-         free board :

This modern shipbuilding technique is still used nowadays for traditional wooden boats . Less wood is needed, which is a good way of preventing the deforestation of the French forests .

After adjusting the keel, the stem and the sternpost which are master pieces, the skeleton of the hull is built up ,  boards are nailed on it the ones after the others .

This technique allowed bigger transport boats to be built and it developed the sternpost rudder.

Then the waterproof quality of the hull and the deck is achieved thanks to the caulking of the planks : the empty spaces between the boards are stuffed with stings of oakum and pitch (tar and mastic). Once the boat is at sea, the wood saturates and the water proof quality is now totally assured.

   

Steel

 

Building steel boats started in Dieppe in 1890 with the creation of a shipbuilding site called “Amblard” , which took the name of “Ateliers et Chantiers de la Manche” in 1912, and eventually became “ Channel maritime Industry” in 1988.

Until soldering is developed in Dieppe in 1935, steel boats are made with iron plates

Put together with rivets on  skeleton of ribs and steel girders.

More than our hundred workers are needed to build a thirty-two-meter -long trawler.

Nowadays, with computer-aided design and numerical controlled machines, shipbuilding has been modernized and consists in  four stages:

-         drawing and conception: models and plans are made in the mould loft;

-         machining : the iron plates are cut out with numerical controlled blowtorches , then shaped and put into place;

-         pre-building : nowadays, a twenty-five meter steel trawler is made of five or six part assembled on the landing- place. Some parts may come from other shipbuilding sites( Nantes , St Malo)

-         The last stage is the fitting out and the motorization of the boat. More than twenty different corporate bodies work on the trawler six or eight months before it can be launched  ( painters, woodworkers, plumbers, mechanics, computer scientists …)

 

Today, more than one hundred years after the steel shipbuilding started, more than three hundred boats have been made in Dieppe and eighty people work on the site.

 

Aluminium

 

Aluminium is an alloy invented in 1886 from bauxite.

It offers five advantages for shipbuilding/

-         it is much lighter than steel;

-         it is non-toxic for the fish stored in the hold;

-         it is non-magnetic for the controls;

-         it has a high mechanical resistance.

However, as aluminium is very expensive, it is mainly used for small fishing boats (doris and trawlers)

The “ Allais” shipbuilding site in Dieppe employs more than 20 workers specialized in aluminium shipbuilding.

 

Composite Materials

 

Composite materials or polyester allows boat making in series.

The economic crises which touched the fishing industry at the beginning of the 80’s obliged to lower the production cost. Composite materials ,which had been used up to then for pleasure boats only, began to be used for 12 to 22 meter fishing boats.

This type of in series construction is made from a mould in which layers of gel coat , textile glass, carbon and resin are superimposed .

Composite materials offer 4 advantages:

-         The cost and time for making the boat are reduced;

-         It is free from corrosion;

-         It is extremely light; it can be easily maintained and repaired.

 

 

Different propelling means

 

Oars and sails have been used since Ancient Times, as can be seen on many bas-reliefs.

Indeed, an oar is the extension of the arm and the hand.

 

 

There are four different types of sails:

-         The square sail dates back to Ancient times in Northern Europe and was in use on Viking ships as well as on caravels, and more recently on schooners . This sail is not easy to manoeuvre in strong wind and during tacking. It is mostly for distant sea sailing.

-         The lateen sail is Mediterranean , it is the type of sail to be seen on galleys, xebecks, feluccas. The jib mostly used as bowsprit sail or stay sail s another form of lateen sail.

-         The fore-and-aft sail and the sail of a lugger are two types of sails used  on fishing boats and coastal shipping. They can easily be lowered or pulled up , thy allow easy tacking in coastal shipping.

 

The propeller appears at the end of the 19th century, with the development of the steam industry and later of the petrol engine. After the invention of the diesel engine in 1910, coal and petrol were abandoned in the 1920’s . They were dangerous and not well –adapted to fishing. They were replaced by gas-oil still used nowadays for engines from three hundred to twelve hundred horse power.

Towers are no longer moved by propellers but by two engine of the “voit Schneider” type made of rotors and blades much easier to manoeuvre.

 

Embarked technology.

 

You are now standing at the captain’s place on the bridge for a little journey through the first half of the 20th century.

Hold the helm to go on the port side and starboard while you keep an eye on the compass. The shatburn allows you to communicate with the engineer who is in the engine room; For astronomic sailing the sextants and the octants which are behind you in the window will be precious instruments to keep the reckoning .

If you have any problem with the longitude, observe the marine chronometer   will help you to return safely to the harbour.

As for the depth under the boat, you only need to trust the sounding lead

You will now move to your right on the bridge and you are going to sail into the 21st century with embarked technology.

The on- board computer will give you most of the necessary information : the marine map, the cape to hold, your speed, your fishing book, or the tide times for each port. The sounder will tell you how deep the sea is beneath the hull as well as the presence of fish shoals