EarthBM

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About EarthBM

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    Corona Del Mar, CA and Deerfield Beach, FL

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  1. EarthBM

    TS42

    Has anyone chartered the TS42 in Martinique? Any feedback?
  2. EarthBM

    Art Allen

    “At any given moment, all sorts of objects are drifting in the ocean, a surprising number of them Americans. The Coast Guard plucks 10 people a day out of the ocean, on average. Another three die before they’re found. Which is to say that 13 Americans, every day, need to be hauled out of the water or off some crippled sailboat or sea kayak or paddleboard.” https://www.bloomberg.com/opinion/articles/2019-10-15/lifesaving-coast-guard-scientist-reflects-on-government-service
  3. EarthBM

    Halyard and reefing hooks

    Yes, just feels wrong to pay $1k for a piece of metal without any moving parts... are there no remotely actuated soft shackles or CF hook + Dyneema loop solutions?
  4. Are they worth it? I understand the idea — a masthead lock removes the 2:1 halyard compression purchase from the mast, and a reef hook removes the 1:1 compression load from the boom. On my Weta the halyard lock made sense — the mast was a two-piece featherlight CF tube. On my 35’ Dragonfly the single like reefing was kind of neat actually, especially when singlehanding, which is 99% of the time. It probably added to the weight as the mast and boom were overbuilt, but compared to other loads it didn’t feel too bad, although the original first-reef clew block was undersized and did break (aluminum just sheared off). A 50’ cat with a modern CF rig I sailed on recently had the reefs locked with titanium Karver (or Anthal?) hooks, at $1 boat buck each. See the picture. It looked like a neat solution, but a bit fiddly both hooking and unhooking (not dialed in new system, and without experience on my part). So the question is, for a large 40’-60’ multi, are there examples of mast or boom failure from too much compression? I imagine most dismasting come from sidestay failure, but I don’t know, never been in one. Alternatively, are there examples of “oh sh*t“ moments when the masthead halyard lock gets stuck, or less critically when the reef hooks won’t engage/disengage?
  5. Do you have a picture of this main halyard with loops in action?
  6. Yes it probably would. But the weight penalty from a Farrier-type folding mechanism is probably not that great. Dragonflies are heavy boats because their specific sideways folding mechanism requires overbuilding in a few areas and very heavy stainless waterstays. FWIW, I think all of that could be lightened a lot with proper numerical analysis, experimenting, and modern materials expertise. But since there also was a lot of nice wooden furniture, stainless steel fuel tank, etc. it mattered less. The Farrier/Rapido folding system is fundamentally clever because it takes advantage of the fact that the effort on amas is strictly one-directional. With that said, I agree that the execution would have to be near-aerospace-like, as I mentioned before in this thread. Especially with ama foils. But then again, this is 2019, we have space rockets landing with the pointy end on ocean platforms, monohulls fully foiling (multi in multihulls is really redundant if you think about it), fully rotating wing sails with computer-controlled hydrofoils, etc. Folding boats is not a new concept — Odin’s boat Skidbladnir could fold and be carried in his pocket...
  7. I see some skepticism here about the need for folding tris. I think it might be regional. In the areas where I sailed, Puget Sound had enough protected coastline to keep my Dragonfly 35 unfolded on an end tie, So Cal and South Fla not so much. Europe apparently is even worse, at least in places where you want to be. I estimate the ability to use a mono slip for a 50’ tri is worth about $500-1000 less in monthly docking costs in most places where the buyers with $$$ are. That’s $6-12k per year. Taking a conservative 10-15y useful life, the savings are between $60k and $180k. So as long as the system adds less than that to the cost it's worth it. FWIW, keeping my DF folded was not a factor in deciding to take it out sailing at all. Having to drive an extra half-hour to a marina with a side-tie would’ve been.
  8. I immediately regretted chiming in... Froude number just takes us back to hull speeds... as if it’s a one-dimensional problem. In fact the problem is at least two-dimensional — LWL/beam ratio clearly matters, although the speed x beam / LWL is pretty much always at subcritical levels. And then you start including chines and the conversation becomes just too complex. There is no closed-form solution so everyone’s opinions are equally worthless unless backed by empirical data. On that, I’m very interested in the comparison of Skateway and Zephyr.
  9. It’s the bow wave that matters, not the wake. it’s not at all about planing. It’s about the Froude number...
  10. Is it me or does the mast height look conservatively sized?
  11. EarthBM

    Cat tails from over the horizon

    I assume the polar is from a VPP. Any real world confirmation? I see a Li-ion house bank as standard. Do you know what system they are using?
  12. EarthBM

    Silly daggerboard question

    One way to notice the offcenter helm effect is when you look at your jib and think that it looks sheeted in way too much relative to the main (closing the slot), yet if you let some out you get weather helm back. And off course F18 points better than a Tornado or H16... life would be depressing without progress. The modern foiling cats only go upwind, so the rigs are more optimized for the narrower envelope.
  13. EarthBM

    Silly daggerboard question

    A tiny technical nuance... the reason why multihulls are generally less able to point upwind than monos is because the center of effort on the sail is not lined up with the center of effort on the leeward hull. So while there is an AWA point where the two are exactly balanced once you go up or down from there you get weather helm or lee helm (respectively) so you compensate for it with either your rudder (creating water drag) or sail trim (sacrificing max sail power). If you increase the water drag with the longer board this problem becomes a bit worse (unless your cat geometry is optimized for AWA 30).
  14. EarthBM

    Silly daggerboard question

    Well you have same AWAs, but better effective upwind angles because of less leeway. In exchange for drag. You have the same righting moment, but more resistance to the wind’s heeling moment in gusts. So you can carry more sail in gusty conditions. In exchange for drag. The benefit of 25% longer boards is that you can try and nail the optimal trade off for yourself. In exchange for $$$.
  15. EarthBM

    Cat tails from over the horizon

    Yeah, the line routing doesn’t make sense to me at all. Even with rollers — they are trying too hard to get the lines out of the way, even the jib sheets are going through a couple of those rings that add nothing. With that said, I quite liked the rest. The modern interior, the sense of a new cat smell. If they had a tiller (instead of, not in addition to the wheels) steering stations I’d be thinking really hard about this choice. Not sure about new-used value anymore actually. Boats are technology and you wouldn’t buy an iPhone X over the new 11, unless X came at a fraction of 11’s price. Between TS5, this Slyder, Asia Cat’s Stealth 14 the new boats seem more modern, fresher, and cheaper for what you get. FWIW, at the same €649k base px, TS5 wins. But there is nothing in Slyder 49 that prevents it from being setup on par with TS5. Don’t know Stealth 14 px.