Homing yacht
Sailing

Homing yacht

Aviation Technology aboard a racing boat

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French yachtsman Marc Gullimo announced its readiness to participate in the coolest race of our time - the Vendee Globe, which will start from the French city of Le Sables d'Halon in mid-November this year. For him, this is not his first participation in this competition: in 2009, he already took third place with the result of 95 days 3 hours 19 minutes and 36 seconds.

For the 2012-2013 regatta, he perfected his well-deserved Safran yacht (naturally Open 60 class), which is reportedly the most innovative and perfect racing yacht of the decade (at least in her class). Why is this boat so curious?

For starters, the inertial navigation system used on it is familiar to pilots, divers, and... designers of guided missiles. What is it and why is it on a yacht?
This system was originally based on a feature of the fast spinning flywheel - it has a large moment of inertia
(hence the name of the system as a whole) and tends to maintain its plane of rotation in any external action. The inertial system includes several such
gyroscopes
in
cardan hangers
with sensors - when the position of a gyroscope unit is changed, the rotation planes of its gyroscopes are kept constant and the sensors record the rotation angle of the entire unit relative to the flywheels (and consequently the rotation angle of the entire ship or aircraft connected to this unit). Other elements of the inertial system include sensors (in the simplest version, spring sensors) that measure platform acceleration along any of the three axes. By integrating all sensors, the course and position of the platform as a whole can be tracked quite accurately - in any case,
divers
, for example, have virtually no other navigation aids (
GPS
does not work underwater). And they must also launch missiles from the underwater position, and (highly desirable) without miss. So today, inertial navigation systems for obvious reasons have reached a very high degree of perfection and accuracy. And the traditional flywheels in them are already being replaced by the latest
laser gyroscopes
with no moving parts, but this is another story.

An important feature of inertial systems is that they are independent of any external devices and fields, which favourably differ from radio direction finders, GPS and even ... a traditional magnetic compass.

Inertial systems operate confidently at the highest latitudes, where compasses can make serious errors. Of course, the inertial has its own problems - its data «creep»over time, accumulating a travel error, so wherever there is a need for particularly high accuracy, the data of the INS try to regularly check with some accurate reference points - for example, ballistic missiles after leaving the atmosphere spend astrocorrection (by stars).

But what is the purpose of the INS on a yacht equipped with satellite navigation? According to the boat's creators themselves, by «combining the inertial system with wind and course angle data at any given time, we hope to obtain important information about the boat's behavior, based on which we can further improve its design». Formally, there is a certain logic in this - by analyzing the inertial system records, we can obtain data on the exact position of the hull of the yacht (course, speed, roll and differential angles, even acceleration on any of the axes) at any moment of time. Perhaps by comparing this data with the anemometer you can actually get some useful information. But this is who in the Safran Group will interpret it, and for what purpose - isn't Safran building yachts?
And what is it that builds? No secrets. There are three things that the Safran Group does: aircraft and space engines, aircraft components and various defense systems. The Airbus 380, the Boeing 787 Dreamliner, the F-16 fighter, and all Mirage models are just a small list of aircraft that can't get off the ground without Safran group products. So I guess the French are playing around here. Sagem (a Safran group company) puts its inertial system there... yes, yes, that's where it is. On combat missiles. For example, on the latest AASM aircraft, designed to engage ground and surface targets. And also on modern warships.

And I believe that this system is used to test the reliability of this inertial in the most difficult conditions - salt water, high humidity, constant shaking and turbulence.

During the Vendee Globe race, the system should spend about 2,500 hours on board - in practice, this is equivalent to about 10 (or even more) years of service of a modern combat aircraft. One might say that Sagem gets a unique test site for almost nothing (and given the fact that the INS on board Safran is backed up, there's little doubt that it's the tests that are in progress - a yacht is not an airbus or a spaceship, for which duplication of such systems is required).
And the French have long been experienced in combining military and sailing. From Eric Tabarli's yachts, each carrying a naval flag and considered a training ship by the French Navy, to the L'Hydroptere winged sailing trimaran, which is also on the Navy's register.
However, we were distracted. Equipping the yacht with inertial required revision and the entire wiring system on board. The Safran Group has found two companies in the aviation industry that are involved in cable installation. That's why all wiring on board Safran is performed to the same standards as on combat aircraft. One thing that's confusing, however, is the weight savings for cabling made of aluminum, which is not very popular today: aluminum is a fragile material that can also be easily oxidized. For this reason, in aluminium conductors (and especially in their connections) cracks can occur, leading to loss of contact and increased resistance. What's more, these things are fraught with short circuits on board - you might remember that in the last Volvo Race they even led to fires on yachts. The French say, however, that they have important innovations in wiring as well - a special particularly plastic aluminium alloy has been used to make the wiring, eliminating cracking in the cables. As if this was the type of cables they put on board the latest American F-22 fighter.
But this is not the end of the list of innovations on board Safran. The yacht has received another unusual structural element, the titanium fin of the keel. This is the very first use of titanium in the history of yacht building. The choice of material was as follows: coal, steel, titanium and the assessment was based on three criteria: reliability, cost and final quality. It turned out that titanium was the best choice. Again, we don't forget that the Safran group includes Snecma, a renowned manufacturer of aircraft engines and gas turbines. Where titanium is a very important component. So








Safran has both the experience and the technology to handle this complex material (curious, by the way, that the keel is not normally welded in a neutral atmosphere, but electron-beam).





And to sum it up, here's the thing.



The
list of famous aircraft engineers
who worked on the boat is several times longer than the list of yacht designers themselves.


The amount of investment in a yacht that is not too young is much higher than the price at which a new Open 60 can be built. And all this for the sake of winning a very difficult, but not the most «media» competition?
As they say, do not talk nonsense! The newest systems, materials and technologies are being tested. And the place for them has been chosen with great intelligence - the heaviest race in the world, «Everest without oxygen». If it works there, it'll work everywhere.
And in this connection I would like to think about this - participation of a domestic yacht in, say, Volvo Race could become exactly the same range for our aviation industry, which has now begun to widely develop carbon fiber materials. Especially against the background of bad rumors about the fuselage problems of the first T-50. And in terms of the same navigation systems, you can learn a useful experience.


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