Joakim

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About Joakim

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  1. Joakim

    Battery system upgrade?

    Which one? Since around 2005 D2-55 (starting from D2-55C) has had 115 A as standard. Early models had 60 A.
  2. Joakim

    I noticed you write very knowledgably about orc rating I wonder if you could give me some advice? I am looking to buy a farr 30 to sail hp 30 in uk, the farrs  i'm looking at are all sailed under orc, my concern is that the displacement on the certificates show 100-150kg more than the specification displacement, are these boats heavy or could there be an issue with measuring? Is there anything I can do to check short of weighing the boat.

    cheers jon jrgpowell@yahoo.co.uk

    1. Joakim

      Joakim

      Which specification displacement are you comparing to? E.g. OD rules define the "builders weight" without mast etc.

      Have you checked that there is nothing added in the measurement inventory of the ORC certificate?

      ORC certificates are very likely to give an accurate displacement for Farr 30. It has been raced a lot in ORC and also with good success. Certainly any problem with displacement would have been corrected long time ago.

      You can measure the freeboards and compare to the ones in the certificate.

  3. Joakim

    Hanse 400 vs Caliber 38

    Teak deck was on option (8000 €). Probably most boats are without one. Don't know about the ones sold to US.
  4. Joakim

    Used Asymmetrical Spinnaker

    3 is plenty for the size of your boat for handling an asymmetric or even a symmetric. Forget furling and socks. There's no need for them in the sail sizes we are talking about. Especially for W/L racing they are just too slow. For W/L racing I would definitely go for a symmetric setup with your boat. Of course it takes some time to learn, but I have raced double handed First 31.7 OD on W/L with good success against fully crewed boats. We had no problems with the spinnaker, but lacked some speed upwind starting from med wind. The worst problems were with tacking the 150% genoa in med wind when it was too early to go for 110%. I haven't tested a boat like that with an asymmetric, but I'm quite sure it will be very slow on a W/L course unless you install a long bow sprit and have a much bigger kite, which will not be any easier to handle than a smaller symmetric one.
  5. Joakim

    Can a shower be installed into a small sailboat?

    Why would you need a shower inside the boat? I live in my sailboat 4-6 weeks every year (2-4 weeks when I had a 22' boat, the same 4-6 weeks when I had 28' boat, mostly with family of 4). There is warm water and place for the shower in the current boat (35'), but I haven't installed the pumping system to remove water. I do have a shower in the cockpit, but I don't use it for more than cleaning the anchor and the cockpit. Many of my friends have a shower in the head, but none of them use it. Some use the one in the cockpit. There are showers or saunas in the marinas or you can wash yourself in the sea.
  6. Joakim

    All electric boat setup / Moonwave

    Tender boats suitable for ~5 HP outboard need a short shaft while you definitely want to have a long shaft for a sailboat. Charging of small outboards, even 15 HP, is very limited. Especially when you use them in a sailboat with typically rather low RPM. E.g. the current Honda BF15 and BF8 have 6 A as manual and 12 A as electric start. Very likely you can only get half of that at typical sailboat cruising RPM.
  7. Joakim

    All electric boat setup / Moonwave

    You have more information here about J/88: http://www.jboats.com/121-j88/459-j88-oceanvolt Note that the panel powers are maximum power. It's not possible to get even close to that. Sun can shine directly to only one side of a sail at a time and when it does, it can't shine directly to the bimini and half of the bimini is likely shadowed by the sail. 7 kWh batteries for 20 nm. That is possible at the given 4.7 knots speed, IF there is no headwind (or waves). That equals to 1.5 kW electrical power, which is less than a 2 HP outboard provides at prop shaft. The speed will drop (or power increase) quite easily with headwind. They also claim that you could "solar sail" 50-60 nm at 6.5 knots. What would that mean? That's 9 hours and you would get only 0.8 kW from the battery. With 1000 W from the panels the whole 9 hours (totally unrealistic!) it's 1.8 kW in total. That would be no more than 5 knots. So the extra 1.5 knots must be from the wind.
  8. Joakim

    Trickle Solar Charger

    Of course they work much better with PWM chargers. A 32 cell panel will have it's MPP at 15-16 V vs. 17-18 V for 36 cell panel. With a some voltage drop from the cabling it still is high enough for charging lead acid. A proper PWM charger has very small voltage drop and is equal to no charger controller as long as there is no need to limit charging. A 50 W 32 cell panel will have about 3.2 A MPP current and a 50 W 36 cell panel only about 2.8 A. Thus a 32 cell panel will be more efficient with a PWM charger than a 36 cell panel. Victron MPPT charger has bad limitations for 32-34 cell panels and even a bit for 36 cell panels. It's designed to work well only with higher panel voltages. There is no point of using a MPPT charger with a 32 cell panel. They all need a clearly higher panel voltage than charging voltage to increase current. Some can work in PWM mode when the voltage is not high enough, but Victron MPPT doesn't seem to. But why use a MPPT charger that would almost always be in PWM mode anyway and thus is unable to increase current?
  9. Spinnaker pole makes a spinnaker (symmetric or asymmetric) work much better anywhere close to dead downwind than a kite tacked to centerline (even with a long bow sprit). Planing boats and other fast downwind boats have their best downwind VMG quite far from dead downwind and have rather small AWA in all situations. Displacement hulls are newer fast downwind (unless they are very long) and have their best VMG at or very close to dead downwind starting from medium wind. Only in light wind they benefit from hotter angles and would have the spinnaker pole close to forestay anyway. With a CL asymmetric it is almost impossible to sail close to dead downwind, which is also a tactical drawback. You can sail the hotter angles with a spinnaker pole (but would be slower). Chainplates has nothing to do with a spinnaker pole vs. bow sprit. Outboard chainplates just make the use of an overlapping genoa impossible.
  10. Joakim

    Two ton of carbon

    Smaller (24 vs. 27 m LWL), lighter (58 vs. 84 tonnes) and narrower (6.4 m vs. 7 m and narrow ends) than the Swan 100. Probably only half of the RM of the Swan.
  11. Joakim

    Two ton of carbon

    We don't know what kind of boat has the mast OP lifted. These two have about the same mast length and both are carbon. Also the two boats are about equal in LOA and probably also they have about the same maximum righting moment while sailing. At least Selden uses 30 degree RM for loads on their rigs. WOXI has only 1635 kgm/deg vs. 3112 kgm/deg for Swan 100 S, but WOXI has canting keel, which causes 26.9 degree list fully canted, and 2552 litres of water ballast. All in all they have probably rather equal RM at 30 deg and the weight difference of the rig comes mainly from fiber rigging, differences in CF qualities and safety factors. Star is a small boat with low RM. Also their masts break very regularly.
  12. Joakim

    Two ton of carbon

    2 tonnes is a lot for a 42 m carbon mast. WOXI has P=39.4 m, BAS=2.2 m and maybe another 2 m below deck? That's about 44 m. It weighs 1050 kg including spreaders and standing rigging. http://data.orc.org/public/WPub.dll/CC/118263.pdf A few other Super Maxis are also around 1100 kg. Then again this Swan 100 has 3050 kg carbon mast (rod rigging)! http://data.orc.org/public/WPub.dll/CC/30254.pdf
  13. X-41 has chainplates at rails and thus can't use bigger than 105% jibs. It's a displacement hull and really needs the spinnaker pole for going downwind. Original OD configuration had symmetric and asymetric kites with spinnaker pole. Most race with symmetric only now. I guess with much bigger asymetric and 1-1.5 m bow sprit it would be OK up to 10-12 knots, but above that it will be faster with a spinnaker pole and symmetric kite.
  14. Joakim

    Vesper Cortex

    What's the expected life of this system? The handset is basically a mobile phone and they typically last only a couple of years and can fail quite easily when dropped etc. Can the battery be easily replaced? Can you even get a new handset after 5-10 years? My current VHF is from 2005 and there are plenty of much older ones still going strong although without DSC. Simrad/B&G has also just released a VHF/AIS transponder combo. It can already be bought unlike Vesper. Unfortunately it uses separate antenna outputs for VHF and AIS.
  15. Joakim

    Calibrating TWS

    If you have boat speed 1 knots off, you have much bigger problems with that error itself than what it causes to TWS. Unless you have a correction or transducer installed very high above the mast, you will have much bigger error downwind due to air accelerating over mainsail and kite.