Jump to content

Tom Lathrop

Members
  • Posts

    1,351
  • Joined

  • Last visited

  • Days Won

    24

Posts posted by Tom Lathrop

  1. Paul,  Bluejackets have a torsion box bottom structure with longitudinal bulkheads spaced on 7 1/2" centers and are about 10 inches high near the transom so placing bunks under a pair of these is not likely to allow any distortion.  Much stiffer than any stringer system could be.  Actually, that is how it developed when I found that a longitudinal bulkhead/torsion box system could be built lighter and much stronger than a stringer system. 

     

    I am more concerned about the long cantilever off the bow beyond the bunks and as the increasing deadrise lifts the bottom off the bunks.  This is usually taken care of on a trailer with support on the forward keel.  What are your thoughts?

  2. Wow, Egbert, just Wow! 

     

    To most people, your boat was finished over a year ago.  It looks really great but the real surprise is mostly under the skin with all your systems.  I'd love to see a systems description/list as well as your wiring diagram(s). 

     

    A finishing touch for me would be an accurate weight and a CG.  Performance data is hopefully coming up too.  Gotta have these before the fat lady comes on stage.

  3. Dave,  Do you expect to use the straps while sitting on the seat or on the deck?  Lapwing does not have a permanent strap and I have used some line from the transom gudgeon screws to the middle thwart.  I am able to hook my ankles under the high strap from the deck.   Worked OK although it takes a ton of wind to need it with two aboard.  Sailing singlehanded is different of course.  When racing other less stable boats, a hiking strap was absolutely necessary to keep the boat on its feet and teh crew out of the drink.

  4. I have had several centerboards rigged similar to Paul's and they work well, particularly on larger boats where the board is usually all up or all down.  My BRS LOON had Graham's standard up and down haul and I did not like all the lines and the necessity to adjust boat for every position other than full up or down.  Actually, I do like the lever are for all the reasons mentioned.  LAPWING's CB is lead weighted which gets rid of the down haul and the need to adjust it.  Nothings perfect but this is my favorite for these boats.

  5. Graham's method is probably the easiest although it does leave some waste.   If you need to keep the full length of the piece, grind the oval shape first and bang the tip down with a rawhide or other non scaring hammer.  Some buffing is usually required for best results.  I never buy ready made tips as I think they are too pointed for my taste and its easy to make your own.

  6. Southern Skimmer is a fun boat to sail, that is certainly true.  She can also be a hand full and is not tolerant of inattention by the crew.  In my opinion, the number of capsizes mentioned in the last few posts should be considered in deciding whether it should be called a family boat though.  I readily second the thought that the CS20 Mk3 makes a better case for family use.  The ballast makes it feel far more secure, especially when sailing single and takes little away in performance.  Skimmer is not a tender boat at all, which can lead to a false feeling of security because it is also a very powerful boat with lots of sail area compared to other CS designs.  Many of my favorite boats have the same characteristic of being unkind to inattention of the helmsperson, so I'm not being critical of the EC22 in this regard. 

     

    At this time, I regard the MK3 CS boats to be the high point in Grahams small cruising boat designs.  Not the best in all ways perhaps, but a happy combination that should provide the greatest satisfaction for most of us. 

  7. When I first saw the panel wiring, I thought it would be a problem because of all the crossing wiring.  If the load wires entered from the bottom, they could be routed to either the ground bus or to the individual breaker terminals with no crossovers.  This would allow better access to the breaker terminal screws for removing or installing breakers. 

     

    Would that solve your problem?

  8. I know this subject can be confusing sometimes.  I recommend that the table  below be used for wire sizes on a Bluejacket.  These gages are entirely adequate for our use and the columns of 3 to 6 core jackets should make the choice simple.  Egberts decision to use only a couple gages will make it less expensive than trying to match each load to its power needs is logical.  It will be overkill on most devices needs but that is not a bad thing provided the proper device fuse is used.   As the plans wiring diagram shows, I used 10 gage for the main feed to the power panel which should handle any device or combination of 12 volt devices you might want to install.  You do not need to get into ohms per foot and line loss if you do this. 

     

    http://www.engineeringtoolbox.com/wire-gauges-d_419.html

  9. Egbert,

     

    Sometimes it may not be good to study too much.  The AWG tables can be a bit confusing and not to be taken literally unless you know the subject.  The 22 or 25 amp rating for 16GA that you saw is for very short lengths internal to a device and the wire must be in free air (not in a bundle with other wires).  The power transmission capacity for 14 GA is about 6 amps which is ultra conservative and not to be take seriously for general usage.  The better capacity for rating for our purposes for these wires  is 15amps for 14 GA and 10amps for 16 GA. This is for the lengths of wire that we encounter in boats and when the wire is in a jacket with another loaded wire.  In a core with more loaded wires, these numbers are reduced even more.  Its all about heat that the wire may be subjected too.

     

    Best not to get confused and use the simpler conservative numbers I gave for our boats.  14 GA = 15 amps and 16 GA = 10 amps.

  10.  

    MisterMoon

     

    Do you have Anderson Bailers?

    Yes and it doesn't work below about 6.5 knots. Self bailing is the way to go! I'll install an electric bilge pump before the next EC. 

    Graham's boat is really nice. I'm sure he'll have a report of some of his thoughts when he gets home. Right now he's still sleeping in the boat on the beach in KL. 

     

     

     

    John,

     

    Something is amiss with your Andersen bailer in some way.  I have used them on every dinghy from a Spindrift 10 to 18 footers for 50 years and they always work unless I have done something wrong.  They work going upwind in the Spindrift 10 when wind was high enough to need bailing so the speed could not be all that high.  On CS boats, I put them on the other side of the keelson from the CB.  On the Spindrift 10 it was behind the DB but it worked anyway.

     

    Tom

  11.  

    Do instrument makers not still provide a proper in-line fuse with the equipment?  I generally think breakers are not the best for protecting an instrument. 

     

    I don't think you can buy a piece of electronics for a boat (or anything) that does not have its own fuse, either in line or in the case.  I put all the electronics on my Renegade (GPS, stereo, VHF) on one circuit.  The breaker was rated to protect the wires and each component was fused to protect itself.  I definitely would not use a breaker to protect a component.  Most use glass fuses rated only 2 or 3 amps.

     

     

    Its a few years since I needed to buy any new electronic instruments or devices for a boat or car and am glad to hear that nothing has changed in the fusing of these.  It is the only thing that really makes sense for safety of these devices. 

     

    "If the circuit uses 16-gauge (small) wire, which has an ampacity of 25A, the breaker will protect it."  I assume this was a typo Chuck.

     

    Most circuits on a house distribution panel have 20 amp breakers.  this is because most house wiring is 14 GA which has standard capacity of 15 amps and a 20 amp breaker will not blow unless the 14 GA wire is overloaded.  Lighting is not a problem and things like TVs have their own fuses.  Apply this same thinking to the boat and do not expect a breaker to protect an instrument powered from it.

  12. Do instrument makers not still provide a proper in-line fuse with the equipment?  I generally think breakers are not the best for protecting an instrument.  They are best for major failure like an accidental short on the line and rated for the wire gage.  Not unlike house wiring with a few exceptions.  For instance, my instrument panel is fed from a single fuse/breaker and the individual instruments are protected by fuses on a separate block. Nothing against breakers but I grew up with fuses. In my experience, fuses are quicker to react than a breaker which must live to work again.

  13. Thanks. I understand determining wire size from a device to the distribution panel, but I'm not sure how to determine the amps and wire size from the batteries to the distribution panel at the helm. Do I add the amps from every device connected to the panel? Seems this would be an exaggerated number as all the devices will never be powered on at the same time. Or, should wire size be determined by the total amps of the maximum number of devices that might be powered at the same time? The installer used 8 gauge wire to the helm with no breaker.

    Chuck

     

    True Chuck,

     

    I think you will find that using this method will not result in a gage of wire that is impractical from either space or cost in a Bluejacket with its normally small power usage.  In any event it is easy to provide for ample over size in gage.  Since I drew the wiring diagrams, most of us have shifted to LED lighting which greatly reduces a lmajor use of 12V power. 

     

    It is true that tinned wire is preferred for marine use but many (maybe most) boat manufacturers still use untinned wire without problems.  Solid wire is a no-no though due to vibration issues.  Speaking of vibration, strain relief is certainly advised in all mounted terminals and the attached sleeves of marine terminal connectors are generally good for that.  If there must be connections in the bilge, they should be in a heat shrink sleeve containing a melted sealant.

     

    I also strongly recommend making a  diagram of your wiring and make several copies to insure that one is available when you need to do anything to the system in the future.  This should eliminate the rat,s nest too often found on boats that have had several owner modifications.

  14. A good looking boot top, especially on a boat with warp in the bottom, is near a ratio of 6 at the bow, 2 1/2  to 3 midships and 4 at the stern.  This looks more balanced when viewed from the beam.  Straight at the bottom, of course.  Since its near impossible to maintain a small boat level fore and aft, having the bow a bit higher than the stern is best.

  15. Jarhead is probably going to switch to a canoe or kayak for the river part of the Ultimate Florida Challenge. 

     

    This is one of two changes in rules that I am not in favor of.  Changing boats makes the UFC a totally different race and a big handicap for those that don't change.  The other change was to eliminate the requirement for taking masts down at a bridge at CP1.  Both make the race much easier to design or buy for but take out a couple of the greatest challenges in the original races.  Chief did not ask me of course.

  16.  

    I've been sailing a Sea Pearl for 9 years. I've had it in some nutty stuff. One thing it took me awhile to figure out is that as its a displacement boat you can make hull speed often with far less sail than you think. Having up too much sail is a temptation that is to be avoided on a boat that can't recover. So far, knock on what little wood is in it, I have kept her on her feet. It will be nice when I finish the CS20.3 to have a recoverable boat. 

     

    So right Mike,

     

    My comments are not meant as a knock on the Sea Pearl, just recognition of what it is good at and what it is not best at.  I have sat helpless as a Seal Pearl slid by an EC 22 with much more sail aloft because of the Pearl's narrow beam and low wetted surface.  In light wind it kills the Core Sound boats.  When the wind picks up, its a different story as the CS picks up its skirts and moves away while the Pearl can get pretty cranky until reefed where its still limited by displacement speed. 

  17. Sure enough the tracker at 3:45pm shows Graham just north of Sanibel, Dawn just south of Sanibel and Alan down near Marco Island.

     

     

    A Hard Chance at Stump Pass. Sounds like a B Western. Maybe we will hear about it around the campfire.

     

    I sugar coated it a bit.  I think the Sea Pearl did not fare well at all.  Going into a rough pass with full sail in a Sea Pearl is not something I would want to do.  So some campfire tales are in order.

  18. I heard thru the grapevine that Graham spent the night in a motel, for whatever reason I don't know.

     

    mike,

     

    I said that since his spot showed him at the motel early this morning. He did stop at check point one and slept for the night.  Some minor repairs needed this morning due to a hard chance in Stump Pass in the breakers.  A Sea Pearl went over in the pass and apparently suffered significant damage but the skipper is OK. I just talked to Graham who is now in Gasparilla Sound and getting along well.  He is making this one into a cruise which I agree is a good thing.  He plans on stopping for the night at Pine Island before going on to Chokolosky tomorrow.  The CS 17 Mark3 is doing well with the wind vane working well when called on.  Some surfing over 11kts yesterday in strong wind.  A cold front is due soon and that will have its effect on whether he sails or takes a lay time.  He says that weather is beautiful now and it is really fun to not having to push all the time.

     

    You need to call up the proper race on the Watertribe chart site.  EC2016 in first column for most and UF2016 for Allan and Dawn.  Class in next comumn ( 1 for Dawn, 3 for Allen and 4 for Graham.  Then call up the boat in the third column (Roo for Graham, SOS for Allan, Sandy Bottom for Allan's mother Dawn).  Then specify what factors you want to look at in last column.  Also need to regenerate for all changes in view.

  19. I saw Graham this morning and he was doing final rigging and a few other bits before taking off for Mullet Key this evening.  Luckily Randy (who has sailed several EC events with him) will do the early driving of the 13 hour trip to the beach.  Of course Graham is single handing Carlita and Randy will be doing pick up at Key Largo.  Carlita is really stealth with that primer job.

     

    Allen's amas were very much restricted to a size that would fit inside the canoe along with the trailering rig and bike for the 40 mile portage.  Minus this restriction, longer amas and more sail would certainly raise the speed for other uses. Hiking would help too, if that is feasible with all the other variables that limit what can be done on such a race.

  20. Finished watching Dove yesterday and can say that the scenes of a small sailboat on the open ocean is the best I can remember having seen in a movie.  Really quite good and no need for any special effects.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.