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    • UnderDawg

      A Few Simple Rules   05/22/2017

      Sailing Anarchy is a very lightly moderated site. This is by design, to afford a more free atmosphere for discussion. There are plenty of sailing forums you can go to where swearing isn't allowed, confrontation is squelched and, and you can have a moderator finger-wag at you for your attitude. SA tries to avoid that and allow for more adult behavior without moderators editing your posts and whacking knuckles with rulers. We don't have a long list of published "thou shalt nots" either, and this is by design. Too many absolute rules paints us into too many corners. So check the Terms of Service - there IS language there about certain types of behavior that is not permitted. We interpret that lightly and permit a lot of latitude, but we DO reserve the right to take action when something is too extreme to tolerate (too racist, graphic, violent, misogynistic, etc.). Yes, that is subjective, but it allows us discretion. Avoiding a laundry list of rules allows for freedom; don't abuse it. However there ARE a few basic rules that will earn you a suspension, and apparently a brief refresher is in order. 1) Allegations of pedophilia - there is no tolerance for this. So if you make allegations, jokes, innuendo or suggestions about child molestation, child pornography, abuse or inappropriate behavior with minors etc. about someone on this board you will get a time out. This is pretty much automatic; this behavior can have real world effect and is not acceptable. Obviously the subject is not banned when discussion of it is apropos, e.g. talking about an item in the news for instance. But allegations or references directed at or about another poster is verboten. 2) Outing people - providing real world identifiable information about users on the forums who prefer to remain anonymous. Yes, some of us post with our real names - not a problem to use them. However many do NOT, and if you find out someone's name keep it to yourself, first or last. This also goes for other identifying information too - employer information etc. You don't need too many pieces of data to figure out who someone really is these days. Depending on severity you might get anything from a scolding to a suspension - so don't do it. I know it can be confusing sometimes for newcomers, as SA has been around almost twenty years and there are some people that throw their real names around and their current Display Name may not match the name they have out in the public. But if in doubt, you don't want to accidentally out some one so use caution, even if it's a personal friend of yours in real life. 3) Posting While Suspended - If you've earned a timeout (these are fairly rare and hard to get), please observe the suspension. If you create a new account (a "Sock Puppet") and return to the forums to post with it before your suspension is up you WILL get more time added to your original suspension and lose your Socks. This behavior may result a permanent ban, since it shows you have zero respect for the few rules we have and the moderating team that is tasked with supporting them. Check the Terms of Service you agreed to; they apply to the individual agreeing, not the account you created, so don't try to Sea Lawyer us if you get caught. Just don't do it. Those are the three that will almost certainly get you into some trouble. IF YOU SEE SOMEONE DO ONE OF THESE THINGS, please do the following: Refrain from quoting the offending text, it makes the thread cleanup a pain in the rear Press the Report button; it is by far the best way to notify Admins as we will get e-mails. Calling out for Admins in the middle of threads, sending us PM's, etc. - there is no guarantee we will get those in a timely fashion. There are multiple Moderators in multiple time zones around the world, and anyone one of us can handle the Report and all of us will be notified about it. But if you PM one Mod directly and he's off line, the problem will get dealt with much more slowly. Other behaviors that you might want to think twice before doing include: Intentionally disrupting threads and discussions repeatedly. Off topic/content free trolling in threads to disrupt dialog Stalking users around the forums with the intent to disrupt content and discussion Repeated posting of overly graphic or scatological porn content. There are plenty web sites for you to get your freak on, don't do it here. And a brief note to Newbies... No, we will not ban people or censor them for dropping F-bombs on you, using foul language, etc. so please don't report it when one of our members gives you a greeting you may find shocking. We do our best not to censor content here and playing swearword police is not in our job descriptions. Sailing Anarchy is more like a bar than a classroom, so handle it like you would meeting someone a little coarse - don't look for the teacher. Thanks.

Mal Smith

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  1. I didn't realise that the boat with the T foil rudder was yours Chris, although that figures. :-) I was also a bit surprised because I understood that your previous experiments with it a few years ago were not entirely successful? I've been interested in using a T-foil rudder in order to do away with the seat carriage, which saves a bit of weight and simplifies the construction a bit. However, my experiments with models have shown that T-foil rudders are slow, at least,up to the point where they help you to survive beyond where you would otherwise have crashed. Using the foil to provide lift upwind may cancel out the added drag, but then you still need the seat carriage to move your weight aft :-(
  2. Did any notable technological advancements surface at the worlds? How did the big jibs go? Did Chris Mass' daggerboard flap work? I noticed some photos of a T-foil rudder, how did that go?
  3. I have to disagree. On an unstayed rig, whether you use the vang or the sheet will have little or no effect on how the mast bends (as opposed to a stayed rig where it does have a large effect due to the extra support points). What may change, however, is the way the rig responds to gusts. If using sheeting, the end of the boom is effectively pinned in position. When using the vang it isn't, so the rig is free to oscillate fore and aft. Also when using the vang the boom is free to bend in response to gusts as well. The combination of these two dynamic effects will change the way the rig behaves, but the average amount of mast bend and the shape of the bend will be much the same in both cases, for the same amount of leech tension.
  4. If you don't travel, and if sails are durable, sailing is pretty inexpensive. But "updates" is a misnomer. I did not see anything in the 2001 kit that was not available when the Laser was introduced. It was a direction shift that put more clutter on the deck. Add a two year lag for people to recognize that the boat is not simple any more, what year was the peak participation? +1. I think that the simplistic original controls on the Laser were a major point of difference between the Laser and just about every other class. Sure, everybody grumbled about them, but it was a big part of the challenge, and it did help to keep the price down. Now, the Laser is just like every other racing class and has to compete with them on an equal footing for class numbers. The original concept of simple 'seat of the pants' sailing was lost.
  5. So if the hull is flared at the BMS above the 1m tape end point, does the flared section have to remain above the 1m tape girth point for the extent of the 2m tape? If the flare was to start almost exactly at the end of the end of the 1m tape at the BMS, it would be easy to contravene this as shown in AndrewE's sketch in post no #3043. And perhaps it doesn't matter if the flare or spray chine drops down away from the BMS, but it is definitely not clear in the rule.
  6. Arne, My interpretation: the BMS is just a transverse plane. "Centred on the BMS" simply means that the midpoint of the tape sits somewhere on the BMS plane. Because the tape also has to lie on the hull surface to check for hollows, by inference, the midpoint of the tape is constrained to the BMS/hull surface intersection line. In order to constrain the tape to a point, the rules would have to stipulate a third plane or surface to form that intersection point, but they don't, so the tape can be slid sideways to measure for hollows anywhere across the hull as far as the sheerline. Mal.
  7. Sounds like a plan Jethrow.
  8. Chris, Great to hear that you are getting your IC back together. Just let me know when you want to pick up the plank. Not so sure about your last statement. I've been soundly trounced by the Log in light stuff! Mal.
  9. Chris, I've got an old plank and carriage you can have if you want. It's heavy, but solid and servicable. Needs hiking staps and i imagine the carriage may ned to be modified to suit your boat. But hey, it's free!
  10. Amati, 1) With respect to the 2000mm tape, centred on the BMS means that there should be 1000mm of tape forward of the BMS and 1000mm aft of the BMS. I only mention this because your photos do not indicate that. 2) Not the radius theory. Interesting fact: If my maths is correct, the minimum possible girth at the BMS is 1126.2mm, so the 1m tape can never reach the sheerline. This means it will always be possible to flare at least 63mm of the topsides below the sponson line.
  11. I have replied to AndrewE by PM, but I've copied the bulk of the PM below for general information: The spreadsheet grew out of a need I had to be able to ballpark some fast ferry hulls. I had noticed that for a range of hulls we had tested that there was a sweet spot (most efficient operating speed) for each hull which was dependent on the volume distribution/transom immersion. Initially I only wanted a method of estimating where the sweet spot was based on the shape of the curve of areas, however once I had developed a method for determining that it became apparent that I could use it to estimate the residual resistance. The key to it is the thing in the spreadsheet which I call the resonant velocity (Vr). The idea behind it is that a hull with an immersed transom has the same resistance characteristics as a longer hull in which the curve of areas has been extrapolated to the point of zero transom immersion, except that you then have to add in the transom effects. I developed the resistance formulas by trial and error, determined to use simple maths with no fudge factors. The residual resistance is broken down into a number of factors, bow resistance (the work required to part the waters, so to speak), stern resistance (pressure recovery), and a couple of components for the transom resistance. These are summed together to give the final residuary resistance value. There is an allowance for thickening of the boundary layer, but there is no form factor added so it's probably an underestimate, particularly for beamy hulls. The resistance formulas basically use mass flow based on the displaced volume of the bow half of the hull (Stem to Amax) and the velocity determined by the Vr calculation to get a resistance value at Vr, and then use scaling factors for other velocities. Frictional resistance is determined using the ITTC 1958 method. In the residuary resistance calculations the shape of the maximum cross sectional area (Amax) is approximated as a semicircular cross section of the same area. So for residuary resistance, the hull beam has no effect on the calculation. I had assumed that there would be an effect but after many attempts to include one, I had to conclude that if there is an effect, it is minor and largely indeterminate for the types of hulls I had data for. For the frictional resistance calculations I use the actual (approximated) wetted surface area and this is where hull beam comes into it, as for shallow hulls changing the hull beam has a large effect on the wetted surface area. I tried to set up the spreadsheet to use as few inputs as possible, so the hullshape used in the calculations is an approximation based on the key characteristics of the hull. The purpose of the spreadsheet is not to get exact resistance values, but to be able to quickly get approximate values for ball parking and investigation.
  12. Which is sort of my point. The IC is not really a planing hull. It's a long narow hull which dose not rise a lot even at planing speeds. Generally you sail it utilising the full waterline length. The whole point of planing is to reduce wetted surface area. At high planing speeds, there is a thing called the waterskiers paradox whereby the reduction in wetted surface area due to lift cancels out the increase in frictional resistance and the drag becomes constant over the high speed range. Anyway, the IC doesn't operate in the high speed range, which is why I don't think you can apply planing theories to determine IC resistance.
  13. FWIW, here's a link to my resistance calculation spreadsheet. It's based on Newtonian mass flow. Seems to work OK, but it's very general. Don't ask me to explain it . It was derived based on data for semi displacement hull forms. Maybe there are some useful ideas in it, maybe not. https://dl.dropboxusercontent.com/u/99666108/HullCalc5-120101.xlsx
  14. The only problem with that theory is that it doesn't apply for most of an IC's performance envelope. IC's aren't really planing boats.
  15. For people who would like to race at the the top end of the fleet, building your own boat with self imposed restrictions that will make it non competitive would seem pretty silly. But for some people, the challenge of designing and building your own boat is most of the fun and racing it is only secondary. If you are one of those people, if you actually get it built and make it to the start line, then you have already won your race.