World's largest Maxi-Trimaran Launched!

On Wednesday, 27th of August 08 the world's largest G-Class maxi-trimaran, Banque Populaire V was launched in Lorient, France. Measuring at 131ft (40 meters)long, the maxi-trimaran is the largest racing multihull ever built..

The trimaran was built at CDK Technologies shed and it took almost two years to be completed. It was a great feeling for the Team Banque Populaire to see their beautiful vessel land safe in water.



"The launching today pays tribute to a coordinated and committed team, and the reunion of the biggest French know-how in the field of marine construction." said Pascal Bidégorry, the team skipper.


Ronan Lucas, Director of Team Banque Populaire is very happy to see the boat finally on the water. He is sure that in time to come this boat is going to break many records. He adds "The Banque Populaire team, under Pascal, will test the trimaran ahead of its record breaking campaign". Read more...

L'Hydroptere (Water-Wings) - Flying on Water !

The ever-popular song 'My Dream is to Fly...' could just get its variation if the singer got to know about 'the Hydroptere' or 'L'Hydroptere' as it is known in French.


This could probably be the most innovative step in the world of sailing, considering that this sail-boat of sorts does faster speeds than well-powered speed-boats and at the same time...has its roots to nautical discoveries more than a century old!


L'HYDROPTERE - FLY-BOATING

From the Greek hydros (water) and ptère (wing), l’Hydroptère is a trimaran with foils. These underwater wings extract the boat’s hulls from the water when a certain speed is reached, which considerably reduces the ship’s hydrodynamic drag.

And by now all you regular readers of GiiraYachts.com would be knowing what 'less drag' leads to...higher speeds!...and we all love SPEED...dont we!?

HOW DOES IT FLY ?

Aware of the Archimedes Principle!?

Simply put, a vessel is pushed upwards with the same force as it pushes downwards with its own weight.

With the foils on the L'Hydroptere, the hull is raised and hence the trimaran 'frees' itself from the Archimedes Principle.


The foils then remain the only parts in contact with the water, which makes it possible to considerably lessen the drag and to have a potential for speed far above that of classical Archimedian boats.

The functioning of the foils is simple and based on the principle of dynamic lift, allowing the wings of a plane to make it take off.

The greater the speed of projection of the foil, the more the lift increases.
After a certain speed, the lift generated by the foils becomes superior to the weight of the boat and it causes the boat to be lifted out of the water.

V AUTOSTABLE FOILS

The foils used on the L'Hydroptere are designed to limit the lift in order to maintain stability.


The geometry of the foils used on l’Hydroptère is conceived so as to limit the increase of this lift, so that the boat stops rising and is stabilized a few meters over the surface of the water.

This very simple concept allows for an easy application, but the stress exerted is such that is was necessary to wait for the advent of high-tech materials such as carbon and titanium in order to be able to make a large-sized boat fly over the waves.

THE PROJECT'S STORY

Equally interesting to the concept is the story itself!

The original idea of l’Hydroptère was born in 1975, but the dream only started to materialise in 1994.

On 1st October, Alain Thébault and his crew make the prototype fly for the first time.


From this milestone, passion and daring have continued to power the project and have made l’Hydroptère today a technological jewel, and the holder of two world speed records.

From the first prototype launched in 1994 until today, l’Hydroptère’s teams, driven by their passion, have known how to benefit from technological innovations to build, improve and make a pioneer sailing boat fly, combining glide and perfection.



The story of this carbon bird is more than just an adventure that has gathered together skippers, engineers and technicians from the leading companies in the aviation and naval industries.

An extraordinary sport and human adventure linking sky and sea.

RECORDS

l’Hydroptère wins two world speed records, officially ratified by the World Sailing Speed Record Council:-

1) 500 meter speed record in Category D at an average of 44.81 knots

2) 1 nautical mile speed record, all categories, at an average of 41.69 knots



Click here for one of the most interesting and intricate websites on sailing ever...and a tribute to a winning concept and super-spirited team. Read more...

Osmosis - Blister on the hull

Osmosis is the condition of visible blisters on a boat's hull, caused by water absorption. The process of osmosis is the same mechanism by which plants and trees draw water up from the soil to their branches and leaves..

Main causes of Osmosis:
* Long periods afloat without lay-ups
* Warm tropical waters
* Fresh water is worse than salt water
* Coloured resins (including white - the most common) are worse than clear resins.


The process of Osmosis:
The fibreglass mouldings on a yacht hull are not completely waterproof. Individual water molecules are so small that they can find their way into the layers of glass and resin which form the boat's hull. Problems start to occur when water molecules merge with other chemicals inside the laminate.
These are chemicals such as water-soluble materials, emulsion binders for example. The water molecules can then have a chemical reaction with these substances, forming larger molecules of a new chemical, often acidic. Unlike the original small water molecules, these cannot pass through fibreglass and become trapped. This is the point at which osmosis starts.
Waterproof Fibreglass Mouldings:
A fibreglass, or glass reinforced plastic (GRP), moulding is made up of thin glass strands. On their own the glass strands are strong but flexible. When fused with resin it results in a more durable substance. Ideally the final moulding should have lots of glass and only enough resin to hold it together and seal in the glass strands, but most conventional mouldings have much more resin than this.


A typical moulded GRP yacht hull will have a thin coating of a special resin called gelcoat, on its outer layer. This forms the hard outer surface of the hull. Most yacht builders mould the hulls layer by layer, allowing each layer to set before putting on the next. The one exception to this process is vacuum bagging or resin infusion moulding. This is where dry layers of glass cloth and mat are laid in a mould, and held in place by either an inflated plastic balloon, or another close-matching mould. The resin is then drawn into the fibres by vacuum suction.

The process is more expensive, but is capable of producing very light, strong laminates with a high glass content, and most importantly, very few air bubbles.

Treatments for Osmosis:
The best option in most cases is to cut or grind open individual blisters, repeatedly wash out with hot water or steam, to remove the 'blister juice' from any blisters, dry thoroughly and fill with epoxy paste.

On older boats, if there are no blisters, and even if a moisture meter shows high readings, one option is to do nothing! If there are blisters but they are small, they are not likely to have any significant effect on the structural strength.

Go to your local 'Osmosis Treatment Centre' and have the gelcoat removed, the hull washed and dried out, and the hull recoated with epoxy. This is the most expensive course of action and should be taken as a last resort.. Read more...

Ilan Voyager: Exceptional Sailing Racing Multihull!

NIGEL IRENS developed the iLAN trimaran concept following experience with sailing racing multihulls. It is based on the use of a slender hull with transverse stability provided by small outer hulls. For a given load the concept offers exceptional fuel economy, speed and comfort.



iLAN Voyager is the 21.3m prototype built to demonstrate the advantages of the concept. She provides a comfortable ride at up to 28 knots with a single main engine of just 180kW. She went on to prove her speed, economy and range capability by making a record-breaking un-refuelled voyage around Britain. The 1,568-mile trip was completed in 72 hours at an average of 21.5 knots and required just 2,000 litres of fuel.


The vessel has since worked as a filming platform, able to follow racing yachts at high speed whilst giving a ride smooth enough for still and video photography. She is now operating as a tourist transfer vessel in the Cape Verde islands where she fulfills the need for a small, economical inter-island vessel which can operate in the prevailing rough sea conditions.


Nigel Irens is a leading yacht designer. He is perhaps best known as designer of the Cable and wireless Adventurer, a 35m trimaran motor yacht which completed a record-breaking circumnavigation in 1998, and of the record-breaking trimaran used by Ellen MacArthur to break the world record for solo circumnavigation in 2005.



Read more...