|Even though sailing boats are not readily associated with speed records, the modern wing-like sails are very effective at high speed. The real capacity of a sail's potential increases rapidly with speed. The greater the speed the greater the sail's real potential. The hydrofoil can also be very effective at high speed. It can lift a boat up thereby reducing water resistance by three times.
A combination of sails and hydrofoil is therefore very effective. Both scientists and designers agree that the future of the "speed sailboat" is inextricably linked to the hydrofoil.
WHAT IS THE PROBLEM?
A higher sailboat speed can only be achieved by ensuring a higher level of stability, which cannot be guaranteed by traditional types of boats. Multihulls offer a solution to this problem.
The problem of hydrofoil sailing boat stability is even more complicated. Up until now technical solutions have been found only for still water and uniform wind conditions. Under these conditions the speed of a hydrofoil sailboat exceeds 40kn (74 km/h). Still, up to now no appropriate hydrofoil sailing boat has been developed for open sea and real weather conditions. CATRI foilers offer the first feasible solution to this problem.
WHY LATVIA?The French have been more active than others in the field of sail-hydrofoil research. Very expensive hydrofoil projects take place regularly in France. Still, up till now, they have not been able to win in any significant competitions. Similar attempts have been made in Great Britain and the USA but again, no really practical solutions have been found.On the other hand, despite years of isolation from the international community, Latvia has made use of a number of stimulating factors - namely the results of Russian research in the field of hydrofoil application. A group of talented students from Riga started yachting-research as a hobby, but understood soon enough, that their only hope of competing with the outside world was in attempting to break the speed records. The theoretical basis of the "sail-hydrofoil" combination was worked out and the Latvians went for an unconventional angle of research - which turned out to be successful.
Latvian Multihulls: Brief History
- A group of enthusiasts from Riga Technical University builds a yacht with two connected hulls, not being aware of the fact that similar yachts are built somewhere else and that they are called "catamarans". L=5.5m B= 2.6m S=18sqm
- The third catamaran, built in Riga, achieves a considerable speed and becomes very popular. In all winds it passes the fastest yachts and pulls a water-skier without any problems. L=6.5m B=2.6m S=30sqm
- The first cruising catamaran is built. This catamaran makes the longest distance in the season and wins all races. L=9.3m B=5m S=60sqm
- A shipyard is established in the collective fishing farm Carnikava nearby Riga. The production of cruising catamarans for sale is started.
- The problems of offshore multihull stability and safety are investigated: the optimal length and breadth ratio and safety reserve in large heeling angles are determined; at the same time a safety device for an automatic release of sails at dangerous heeling angles is developed.
- The largest USSR offshore race in the Baltic Sea is held with course length of 1,000 nautical miles; about 100 offshore yachts take part. The Latvian catamarans finish first in all legs of the race. There is a similar result in all the following years.
- An unsuccessful attempt to acquire permission to participate in OSTAR (Single Handed Trans Atlantic) race. For this purpose a special catamaran, Centaurus 44, is built. In speed tests this catamaran reaches 24.9 knots and wins title of fastest yacht in the USSR for many years to come. L=13.3m B=8.1m S=140sqm
- A proa-type hydrofoil for speed records is developed and built. The speed of 27 kn is registered on a lake near Riga, which exceeded all the records of the limited classes. Thus began investigation for a broader application of hydrofoils in sailing.
- Permission from Moscow to organise export of catamarans built in Riga. Catamaran Centaurus 38 exhibited in Hamburg and Genoa. The Latvian catamaran builders and sailing teams and not allowed to attend these exhibitions!
- For the first time the Latvian team of Centaurus-38 receives permission to visit Germany, Sweden and Finland.
- The catamaran "Kuapo" the Centaurus 44 built for OSTAR 1976 crosses the Atlantic - from Riga to Boston and back. The skipper of the catamaran Valdis Greenberg is one of the three constructors of the first Latvian multihull.
- The shipyard for a serial production of multihulls is privatised - the shipyard CATRI is established. Transition to modern yacht consruction materials and technology. Training the staff in Germany.
- The prototype of the first hydrofoil-stabilised trimaran, the CATRI 26 is successfully tested and demonstrated in the Netherlands.
- Trimaran Catri 23 participated in the prestigious Düsseldorf Boot 2000 exhibition in a stand shared with the American foiling trimaran Windrider “Rave”. The second trimaran in that series after the trial in Engure was handed over to a customer in Switzerland.
- During International Multihull Meeting in Wismar (Germany) the first trimaran Catri 24 was shown. Five more were built later. Both 23 ft. and 24 ft. models with the same length, width and height of the mast and were designed as a single experiment with test models. The main purpose of the experiment is to find out the best parameters for future CATRI models.
- Catri 24 No.5 “TARDIS” became the most popular sailboat at the Southampton Boat Show after following Steve Walker's successful navigation from Latvia to England via the Baltic, the Kiel Canal, the North Sea and the English Channel.
- Experiences gathered from Catri owners and calculations made by Aldis confirmed the possibility of building a 100% foiling trimaran with superb stability, safety and price.
- Building of first CATRI 25 was started. This is the smallest production tri of the new series. Some new design improvements, as implemented by Aldis, to achieve stability and speed as high as possible.
THE CATRI SOLUTIONIf we compare a hydrofoil with an arrow, it is remarkable that up until now attempts have been made by attaching the feathers at the wrong end! All patents, issued in this field in recent years, have to do with moving hydrofoil stabilisation mechanisms, whereas the CATRI Foiler solution simply attaches the "feather" at the correct end of the arrow, thus making all kinds of regulating mechanisms irrelevant.
Tests have been carried out in order to control the working interaction of sails, hydrofoil and wind, and an optimal solution has been found. When designing a foiler for traditional sailing, the goal is not to lift the boat above the water. One needs to be aware of all the possible influences of the hydrofoil and achieve the greatest possible balance for the real sailing conditions. The CATRI 24 hydrofoil system took up to 90% of the full weight and at the same time was oriented towards the increase of the stability in both directions, the decrease in pitching and the neutralising of wave motion from the back of the hull. The NEW CATRI range, CATRI 25 & 28, are 100% hydrofoiling!