NotSoFast

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  1. NotSoFast

    SailGP 2020

    2:58...3:09 / 1:27:55 Top speed 84.7 knots. How does that work? Some part of the boat far away from center of gravity really is that fast during a turn, or just a software glitch?
  2. NotSoFast

    Spindrift 2 2019 Jules Verne attempt

    Did anyone figure out what exactly was wrong with the rudders during the record attempt at high speed? 1) Hydrodynamics of the blade (ventilation, cavitation, etc) 2) steering mechanism failure (structural or just too much friction) 3) Jamming of bearings & ruddershaft (not suitable for vertical forces ?) or some other reason 4) contact of rudder blade and hull under load causing jamming 5) something else, what?
  3. NotSoFast

    Francis Joyon IDEC Asian tour

    Then looking at the tracker: https://trimaran-idec.geovoile.com/portlouis_hochiminh/2019/tracker/?lg=en At December 1st, 01:00 French time, speed is 11 knots and there is only 730 nautical miles to go. Over 40% of it seems to be in light air based on the tracker forecast. Can't make any sense from the claim (taken from from the link in above post) that last 900 miles is upwind in heavy air. I have to disagree on Joyon at that one. He must be tired and/or air is just too hot with no air conditioning.
  4. NotSoFast

    Francis Joyon IDEC Asian tour

    Seems I was both correct and wrong. I expected it would take 96 hours to finish. => wrong. After I wrote that above I found this: https://www.idecsport.com/en/idec-sport-in-indonesia/ That's something like 60 hours from now. So 96 hours is expected to be well after they finish according to Joyon. Yet 60 hours from now the center of the typhoon Kamuri is still on the eastern side of one Philippines island and it should take some time for the waves created at the western side to reach Idecs future track. But then on the same article there is also this:
  5. NotSoFast

    Brest Atlantiques 2019

    Actual Leader already managed to pass Macif once. How can you be sure that is not going to happen again? Are they both going upwind near Madeira, or passing the light wind zone and following closer to the same route of Gitana 17? Or having a different route separating them again? It's not over yet for either. As long as Gitana remains in good condition (no breakages) it will win (plenty of lead and a better weather for them). But they haven't finished yet so anything can still happen.
  6. NotSoFast

    Francis Joyon IDEC Asian tour

    Now light variable winds. Then a little better close to Borneo cost, and then heavy upwind toward the Ho Chi Minh made worse near the finish by seaway/waves caused by this: Not nice condition to sail upwind even when not facing the typhoon winds. Boat breaking conditions in 96 hours?
  7. NotSoFast

    Francis Joyon IDEC Asian tour

    https://trimaran-idec.geovoile.com/portlouis_hochiminh/2019/databoard/?lg=en&leg=1 Min instantaneous speed 29 November 10:00 UTC 0.7 knots. Max instantaneous speed after Sunda strait 20:30 UTC same day is 13.1 knots. 4 hour average speed 4.8 knots at 20:30 UTC. Not bad at all considering the wind conditions. Just 90 min earlier 0.9 knots. Wind is evidently quite variable and I would expect it to remain so for more than a day, maybe for several days.
  8. NotSoFast

    SailGP 2020

    If everyone else is caught by surprise, it is not the fault of the helmsman. It's the fault of those crew members who were caught by surprise due to not paying attention. It's the target here (in fully separating the tasks of crew members) that the helmsman should be able to only concentrate of driving the boat tactically as required in the situation (depending what other boats are doing, as well as any differences in weather in the course area), and not to worry if others can handle there job. The helmsman should be able to do all the manoeuvring he/she wants without causing handling mishaps.
  9. NotSoFast

    SailGP 2020

    In the coming season they have a 3 wing options, which the racing committee chooses from for each race. If they do their job, they'll all have a smaller wing then 30+ knot gust hits. In that case all wing trimmers should be able to handle it, but that has nothing to do with helmsman. If wave conditions mandate flying so high, in order to avoid slamming the hull, that the rudder pop out due to that, there is nothing any helmsman can do about that. Either the flight controller can prevent that or they can't. It has nothing to do with a helmsman, and I have no idea why you interpret that as if I had said I would do their job better than they have done. If the people in charge of the development plan decide that is an important issue to be solved, they can have a deeper heavier rudder in addition of a smaller wing size for all the boats. There is nothing I or any team member can do about that, and neither should I.
  10. NotSoFast

    SailGP 2020

    Just how exactly could Ben make sure of that? I thought it's wingtrimmers and foilpilots job to make sure that doesn't happen. Ben is only helming the boat, and can't capsize the boat no matter how hard he tries to if the ones I previously mentioned just keep doing their job. SailGP is not the same boat as AC50 was.
  11. NotSoFast

    Brest Atlantiques 2019

    The speed of sound in the water is 1500 m/s. If some marine animal hears the humming foil after sound has traveled only one second beforehand, it still has 60 seconds to react before the foil arrives if moving at 48.6 knots of boat speed. If they continue sleeping the entire concept of a reaction time is irrelevant. It's pretty clear the most significant warning signal is sound, nothing else, and foils are not silent when moving fast. Slow moving keels and daggerboards might be far more dangerous to marine life, as they can be more silent thus eliminating any warning. If there are marine animals with no hearing, the situation will be very different for them. But in that case it becomes a game of numbers, there are far more dangerous ships and powerboats with deadly propellers than foiling sailingboats. If you consider the foil more dangerous to marine life than a rotating propeller of a powerboat or of a ship please explain why.
  12. NotSoFast

    Brest Atlantiques 2019

    Six foils providing lift, looks like a lot of speed, and yet the main hull is mostly in sea hugging mode in the fastest of the ultime class. Just how fast does it have to go to make main hull fully flying too?
  13. NotSoFast

    Brest Atlantiques 2019

    According to this: https://www.voile.banquepopulaire.fr/passion/le-maxi-banque-populaire-ix source, both amafoils weight 400 kg, while rudders weigh only 40 kg each. Yet rudderfoils run deeper below the surface than amafoils, because the rudderfoils provide downforce when going fast, and losing that by surfacing would cause instant pitchpoling. That means main amafoils can withstand some eccentric hits without totally breaking into pieces, while substantially weaker underslung rudderfoils (supported only by even weaker shaft) can not, and since rudderfoils run deeper they can hit something that goes below mainfoils, and T-rudderfoils also extend further leeward than L-amafoils. Same weight for all rudderfoils might even suggest all 3 are identical, making any replacement possible with only one spare part. All ultimes are off course different, but I would think the structural sizing of parts are still rather close among each other as is use of L- and T-foils on amafoils and rudders.
  14. NotSoFast

    Greta Rides Again?

    The point is there is no one correct comparison. There are plenty of comparisons that are all correct with differing results. Pick the one you like, but don't expect everybody else to pick the same one. I did no claim about using a cargoship to transport passengers across the Atlantic being economically telable, whatever that even means. But there exist a perfectly reasonable reason to see such method as fuel saving way of crossing an Atlantic, compared to using a plane. But not very practical way since being too slow, and not enough passenger capacity can be produced if there were serious demand for most passengers (there is not, and not going to be).
  15. NotSoFast

    Greta Rides Again?

    100 MPG is not more efficient than an efficient passenger car, if the car carries more than 2 people. And the plane needs to be full of passengers to get such mileage as well as being the most efficient model. Not all modern planes can achieve that even full and only economy class seats too tightly spaced for even reasonable comfort level. No doubt a plane is far more efficient than an ocean liner. But if the ship is primarily used for carrying cargo anyway for the same trip, the increase in fuel consumption due to also carrying some passengers is far less than a full plane would have taken. You can even include the fuel consumption due to the added weight of some reasonable size passenger cabins for the cargo ship and the result is not necessarily reversed as long as you leave out swimming pools and such (heavy) luxury items.