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Re: [bolger] How would Mr Bolger update Cynthia J?

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  • John and Kathy Trussell
    Like many of PCB s boats, Cynthia J was designed to precisely fit a specific set of uses (which, I believe, you have described with great accuracy). As
    Message 1 of 15 , Oct 6, 2006
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      Like many of PCB's boats, Cynthia J was designed to precisely fit a specific
      set of uses (which, I believe, you have described with great accuracy). As
      designed, I believe Cynthia J would, if capsized, float fairly high on her
      side, supported by the cabin and the bouyancy of the mast and gaff.
      Righting her would require a swimmer to grab the stringers on the bottom to
      pull her up or, more likely, a line to parbuckle the boat up. If capsize is
      a major concern, Cynthia J's reserve bouyancy would be improved by a)
      raising the companionway opening in the cabin bulkhead to the level of the
      seats and b) adding a bulkhead and decking in the back of the cockpit behind
      the seats (which would require raising the rudder head and running the
      tiller over the top of the deck). If you want to take a look at afurther
      development of the general idea, take a look at Michalak's Fatcat design.

      All boats are a balance between a series of compromises. I have found that
      it is easy to identify things on a boat that I think could be improved, but
      that it is usually not possible to improve the feature I don't like without
      degrading the features I do like. Most of the time when I try, I find that
      the designer was smarter than I am :>).

      John T
      ----- Original Message -----
      From: "graeme19121984" <graeme19121984@...>
      To: <bolger@yahoogroups.com>
      Sent: Thursday, October 05, 2006 11:49 PM
      Subject: [bolger] How would Mr Bolger update Cynthia J?


      > The designer got around to Otter ll himself, but to my knowledge
      > hasn't and is, I suppose, unlikely to get around to CynthiaJ ll. So,
      > guided by study of developments of other PCB&F designs over the
      > years, how would Cynthia J be improved/modified? Modified, that is,
      > to be a bit more suited to pursuits other than just pond picnic
      > daysailing with a gaggle of fun, kids, and family aboard. To really
      > be self rescueing at the least.
      >
      >
      >
      > RIG.
      > PCB&F wrote, when considering the Beach Cat design, of the issues
      > some have nowadays with the long footed gaff cat rig. I'd like to
      > keep the basic long foot rig to try it for fast and weatherly, but
      > there may be other worthwhile modifications. How about a Camper, or
      > other tabernacle; or a Wandervogel vang for instance?
      >
      > Place a stop on the mast to bear its weight at the partner and not
      > the floor, and so eliminate both the doubling of the bottom member
      > of frame #1 and the through-hull bolt located there.
      >
      > Place halyards cleat on the mast and eliminate their compressive
      > load transference that required the strengthening floor bolt in the
      > first place.
      >
      >
      >
      > BOTTOM.
      > Double or triple plywood layer. This should allow removal of most of
      > the bottom shoes, and also the irksome inside bottom stiffening
      > cleats that muck up a lovely flat cuddy floor for lying on.
      >
      > Sheath bottom in fibreglass before fixing bottom shoes etc.
      >
      > Will this be stiff enough?
      >
      >
      >
      > BOUYANCY/BALLAST.
      > As the flooded boat is reported difficult to get to remain upright,
      > and impossible to do so with the rig in place, these aspects need
      > attention. The increased bottom thickness already mentioned will
      > help put weight where needed, but is it enough? Transferring
      > flotation situated down low, as per the underseat foam blocks, to a
      > higher location also should help, but again is it enough?
      >
      > Also as in the changes from Otter to Otter ll, watertight
      > compartmentalisation seems required. The cuddy should be very flood
      > resistant, or watertight. Altering Frame #1 to a watertight bulkhead
      > will have very little effect on cuddy space. There's still enough to
      > lie down in. The space in front of the then Bulkhead #1 should
      > perhaps then be made a free draining flooded well? And perhaps the
      > large triangular foam block there in the bow could be done away
      > with?
      >
      > Bulkhead #3 needs altering by filling in the swinging cuddy doors
      > and replacing with cuddy access much higher up. Duckboard in the
      > bulkhead with decktop sliding hatch; or just a deck hatch, perhaps
      > hinged?
      >
      > Box-in the entire space aft of the cockpit seats from floor to rails
      > and make a huge bouyancy/storage compartment with top hatch access.
      > It may be more convenient to shorten the seats and box-in aft from
      > Frame #4 ( how many people are to be carried anyway? You won't be
      > able to stretch out on the cockpit floor any more, but a great
      > galley box and cooler could be built into the forward side of that
      > aft compartment.). Offset the rudder to allow a small outboard
      > mounted on the transom. Recess the end of the compartment in way of
      > the outboard.
      >
      > Fix foam blocks under aft compartment deck, and foam sheet under
      > fore part of cuddy deck as insurance.
      >
      > Use two ballast sandbags; one beneath each seat, both shifted to
      > windward side when under sail.
      >
      > LEEBOARDS.
      > I'd be inclined to try assymetrics, even though it seems PCB doesn't
      > think they're needed. They'd be even easier to shape, assuming the
      > designed ones are not merely flat plates
      >
      > YULOH.
      > Leave the outboard at home, take a yuloh and Cynthia J may just be a
      > very competitive Everglades Challenge short course entrant. What do
      > you think?
      >
      > What else could be done, or needs doing?
      >
      > Graeme
      >
      > http://groups.yahoo.com/group/bolger/files/CynthiaJ/
      >
      > http://groups.yahoo.com/group/Bolger2/files/Cynthia%20J/
      >
      > http://groups.yahoo.com/group/bolger_study_plans_only/files/Cynthia%
      > 20J./
      >
      >
      >
      >
      >
      >
      >
      >
      >
      > Bolger rules!!!
      > - NO "GO AWAY SPAMMER!" posts!!! Please!
      > - no cursing, flaming, trolling, spamming, respamming, or flogging dead
      > horses
      > - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
      > - Pls add your comments at the TOP, SIGN your posts, and snip away
      > - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
      > (978) 282-1349
      > - Unsubscribe: bolger-unsubscribe@yahoogroups.com
      > - Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com
      > Yahoo! Groups Links
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
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      >
    • Gene T.
      Graeme, Doubling or trippling the bottom will only help righting on a boat that is not flooded. Once the boat is filled, all that plywood becomes flotation
      Message 2 of 15 , Oct 6, 2006
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        Graeme,
        Doubling or trippling the bottom will only help righting on
        a boat that is not flooded. Once the boat is filled, all that plywood
        becomes flotation and will have the opposite effect. I think you need
        some dense weight down there, lead, steel, at least epoxy filled with
        something heavy. Then extra flotation to make sure you don't go right
        to the bottom! 8^D

        Sincerely,

        "A house ashore is but a boat, so poorly
        built it will not float ---- "

        ----- Original Message ----
        From: graeme19121984 <graeme19121984@...>
        To: bolger@yahoogroups.com
        Sent: Thursday, October 5, 2006 11:49:25 PM
        Subject: [bolger] How would Mr Bolger update Cynthia J?

        The designer got around to Otter ll himself, but to my knowledge
        hasn't and is, I suppose, unlikely to get around to CynthiaJ ll. So,
        guided by study of developments of other PCB&F designs over the
        years, how would Cynthia J be improved/modified? Modified, that is,
        to be a bit more suited to pursuits other than just pond picnic
        daysailing with a gaggle of fun, kids, and family aboard. To really
        be self rescueing at the least.



        RIG.
        PCB&F wrote, when considering the Beach Cat design, of the issues
        some have nowadays with the long footed gaff cat rig. I'd like to
        keep the basic long foot rig to try it for fast and weatherly, but
        there may be other worthwhile modifications. How about a Camper, or
        other tabernacle; or a Wandervogel vang for instance?

        Place a stop on the mast to bear its weight at the partner and not
        the floor, and so eliminate both the doubling of the bottom member
        of frame #1 and the through-hull bolt located there.

        Place halyards cleat on the mast and eliminate their compressive
        load transference that required the strengthening floor bolt in the
        first place.



        BOTTOM.
        Double or triple plywood layer. This should allow removal of most of
        the bottom shoes, and also the irksome inside bottom stiffening
        cleats that muck up a lovely flat cuddy floor for lying on.

        Sheath bottom in fibreglass before fixing bottom shoes etc.

        Will this be stiff enough?



        BOUYANCY/BALLAST.
        As the flooded boat is reported difficult to get to remain upright,
        and impossible to do so with the rig in place, these aspects need
        attention. The increased bottom thickness already mentioned will
        help put weight where needed, but is it enough? Transferring
        flotation situated down low, as per the underseat foam blocks, to a
        higher location also should help, but again is it enough?

        Also as in the changes from Otter to Otter ll, watertight
        compartmentalisation seems required. The cuddy should be very flood
        resistant, or watertight. Altering Frame #1 to a watertight bulkhead
        will have very little effect on cuddy space. There's still enough to
        lie down in. The space in front of the then Bulkhead #1 should
        perhaps then be made a free draining flooded well? And perhaps the
        large triangular foam block there in the bow could be done away
        with?

        Bulkhead #3 needs altering by filling in the swinging cuddy doors
        and replacing with cuddy access much higher up. Duckboard in the
        bulkhead with decktop sliding hatch; or just a deck hatch, perhaps
        hinged?

        Box-in the entire space aft of the cockpit seats from floor to rails
        and make a huge bouyancy/storage compartment with top hatch access.
        It may be more convenient to shorten the seats and box-in aft from
        Frame #4 ( how many people are to be carried anyway? You won't be
        able to stretch out on the cockpit floor any more, but a great
        galley box and cooler could be built into the forward side of that
        aft compartment.). Offset the rudder to allow a small outboard
        mounted on the transom. Recess the end of the compartment in way of
        the outboard.

        Fix foam blocks under aft compartment deck, and foam sheet under
        fore part of cuddy deck as insurance.

        Use two ballast sandbags; one beneath each seat, both shifted to
        windward side when under sail.

        LEEBOARDS.
        I'd be inclined to try assymetrics, even though it seems PCB doesn't
        think they're needed. They'd be even easier to shape, assuming the
        designed ones are not merely flat plates

        YULOH.
        Leave the outboard at home, take a yuloh and Cynthia J may just be a
        very competitive Everglades Challenge short course entrant. What do
        you think?

        What else could be done, or needs doing?

        Graeme

        http://groups.yahoo.com/group/bolger/files/CynthiaJ/

        http://groups.yahoo.com/group/Bolger2/files/Cynthia%20J/

        http://groups.yahoo.com/group/bolger_study_plans_only/files/Cynthia%
        20J./









        Bolger rules!!!
        - NO "GO AWAY SPAMMER!" posts!!! Please!
        - no cursing, flaming, trolling, spamming, respamming, or flogging dead horses
        - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
        - Pls add your comments at the TOP, SIGN your posts, and snip away
        - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
        - Unsubscribe: bolger-unsubscribe@yahoogroups.com
        - Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com
        Yahoo! Groups Links
















        [Non-text portions of this message have been removed]
      • captreed48
        As ... on her ... bottom to ... capsize is ... Well....capsize is a major concern. A friend of mine capsized his Cynthia J and could not get it upright. A
        Message 3 of 15 , Oct 6, 2006
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          As
          > designed, I believe Cynthia J would, if capsized, float fairly high
          on her
          > side, supported by the cabin and the bouyancy of the mast and gaff.
          > Righting her would require a swimmer to grab the stringers on the
          bottom to
          > pull her up or, more likely, a line to parbuckle the boat up. If
          capsize is
          > a major concern,

          Well....capsize is a major concern. A friend of mine capsized his
          Cynthia J and could not get it upright. A helpful park ranger boat and
          crew couldn't either but towed the boat submerged back to the launch
          ramp. By that time my friend was very hypothermic.


          I think bouyancy tanks in each quarter or across the entire transom and
          under the seats in addition to making the cabin watertight would vastly
          improve the situation. In that case the heavier bottom would help
          right her. (Not so if the boat isn't watertight..wood floats, but not
          very high.)

          Let us know how it goes.

          Reed
        • John and Kathy Trussell
          The standard approach for recovering a capsized dinghy is to put weight on the centerboard to lever the boat back on her feet. This doesn t work with
          Message 4 of 15 , Oct 7, 2006
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            The standard approach for recovering a capsized dinghy is to put weight on the centerboard to lever the boat back on her feet. This doesn't work with leeboards. If the leeboard is on the high side, it is too high for a swimmer to reach; if it is on the low side, a swimmer can't exert much force on it. Probably the best approach is to keep a length of line fastened to the gunwale amidships. If capsize occurs, throw the line over the high side of the boat, swim around to the bottom of the boat, and use the line to try to pull the boat up (with your feet on the bottom and pulling on the line).

            Obviously a boat floating high on it's side will be easier to right than one floating low. It would be relatively simple to add a bulkhead immediately behind the seats and deck in the space for substantial added bouyancy. If the seats were made wider to meet the sides and the joint between the outer edge of the seats and the side were made watertight (with fiberglass tape set in an epoxy fillet) the seats woud also provide some bouyancy (assuming thet the boat would float high enough on her side so that the inboard edge of the seat was above water).

            To make the boat truly self righting, it is necessary to add ballast either in the form of hard ballast or water ballast. If you are going to do that, it would probably be necessary to make the curve of the bottom deeper to float the additional weight.

            Another alternative is to add a 'Birdwatcher' cabin.

            All of these modifications a) increase the amount of plywood needed, b) increase the weight of the boat (degrading performance), and c) change the concept. If you want a small, self righting boat, maybe there are better designs than Cynthia J (see PCB's Old Shoe and Supermouse designs, for his approaches).

            JohnT
            ----- Original Message -----
            From: captreed48
            To: bolger@yahoogroups.com
            Sent: Saturday, October 07, 2006 12:22 AM
            Subject: [bolger] Re: How would Mr Bolger update Cynthia J?


            As
            > designed, I believe Cynthia J would, if capsized, float fairly high
            on her
            > side, supported by the cabin and the bouyancy of the mast and gaff.
            > Righting her would require a swimmer to grab the stringers on the
            bottom to
            > pull her up or, more likely, a line to parbuckle the boat up. If
            capsize is
            > a major concern,

            Well....capsize is a major concern. A friend of mine capsized his
            Cynthia J and could not get it upright. A helpful park ranger boat and
            crew couldn't either but towed the boat submerged back to the launch
            ramp. By that time my friend was very hypothermic.

            I think bouyancy tanks in each quarter or across the entire transom and
            under the seats in addition to making the cabin watertight would vastly
            improve the situation. In that case the heavier bottom would help
            right her. (Not so if the boat isn't watertight..wood floats, but not
            very high.)

            Let us know how it goes.

            Reed






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          • graeme19121984
            Hi Reed, is that your 15July95 MAIB Capsised ! article? Good article mate. Did you know Jim Michalak now includes it in one of his catalogues? I ve liked
            Message 5 of 15 , Oct 8, 2006
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              Hi Reed,

              is that your 15July95 MAIB "Capsised !" article? Good article
              mate. Did you know Jim Michalak now includes it in one of his
              catalogues?

              I've liked Cynthia J forever (and not just because from adolescence
              on I'll always have an elevated pulse at merely the mention of the
              name Cynthia, but that's another story :)). I assumed she'd float
              alright, but when I read in the article that a repeat Bolger
              prototypes builder, a guy in Bolger's books, Tony Groves, had that
              trouble self rescueing her I sat up and took notice. Presumably,
              Tony is a competent sailor, so that's not the trouble with righting
              the boat. He would have included the designed flotation foam,
              wouldn't he? So that's not the trouble either.

              I'm not sure, but I think in addition to the rig weight, it's the
              low, under-seat flotation that would tend to keep her rolling over.
              I think the foam block in the bow would float the bow end a bit, but
              would be almost neutral as to orientation. Then there's an awful lot
              of water to bail, a problem if it's warm; let alone icy.

              In addittion to extra watertightness, chambers and sandbags, maybe
              a little weight bolted to the lower bulkhead 3# frame member would
              help? A little weight to aid in self rescue, not self right.

              For self righting, how about a lifting Single Handed Schooner type
              keel at bulkhead #3? You could possibly go coastwise then. Put a
              bridgedeck across there to support it that's boxed in either side
              for, say, more cockpit coolers. ( Yeah.., the CJ rig could be
              dropped into Micro, but CJ has her own certain cuteness in styling
              that's not only in her perky rig.) If that seems too much space
              subtracted from the cockpit, CJ with her plumb sides would really
              suit the outside, ballasted, twin daggerboards from Centennial ll;
              if the loss of the pivoting leeboards positioning flexibility could
              be stood. Right there, at the high sided cockpit rail, that type of
              lightly ballasted daggerboard would be a cinch to raise or lower.
              The flare that causes some trouble in their use on Centennial ll is
              absent.

              Did Tony report his experience to PCB, as it seems both PCB and
              Bernie Wolfard were reluctant to include Cynthia J in the CSD
              catalogue?

              It would at first appear a quick and easy thing for PCB to improve
              the self rescuing of CJ before catalogue inclusion, but he didn't
              (note: self -rescuing, not -righting). CJ seems to be from an
              earlier period where PCB was happy to hop between dinkum sharpie
              designs arising from either his own flow theory, or Chapelleian
              aprioristic postulate. Perhaps a time came when he was no longer
              able to do so, and would not update such designs having firmly moved
              to a new sharpie paradigm. He updated Bolger Flow Theory conforming
              Otter #231 much later to Otter ll #375, but couldn't do so to
              Chapellian Cynthia J #289. If an exception proves the rule then he
              has a bob each way with the later Jesse Cooper #389; but even here
              he then could not update, and moved instead entirely to the new
              paradigm with AS29 #547.

              Graeme

              --- In bolger@yahoogroups.com, "captreed48" <captreed@...> wrote:
              >
              > As
              > > designed, I believe Cynthia J would, if capsized, float fairly
              high
              > on her
              > > side, supported by the cabin and the bouyancy of the mast and
              gaff.
              > > Righting her would require a swimmer to grab the stringers on
              the
              > bottom to
              > > pull her up or, more likely, a line to parbuckle the boat up.
              If
              > capsize is
              > > a major concern,
              >
              > Well....capsize is a major concern. A friend of mine capsized his
              > Cynthia J and could not get it upright. A helpful park ranger
              boat and
              > crew couldn't either but towed the boat submerged back to the
              launch
              > ramp. By that time my friend was very hypothermic.
              >
              >
              > I think bouyancy tanks in each quarter or across the entire
              transom and
              > under the seats in addition to making the cabin watertight would
              vastly
              > improve the situation. In that case the heavier bottom would help
              > right her. (Not so if the boat isn't watertight..wood floats, but
              not
              > very high.)
              >
              > Let us know how it goes.
              >
              > Reed
              >
            • graeme19121984
              ... needed, b) increase the weight of the boat (degrading performance), and c) change the concept. If you want a small, self righting boat, maybe there are
              Message 6 of 15 , Oct 8, 2006
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                --- In bolger@yahoogroups.com, "John and Kathy Trussell"
                <jtrussell2@...> wrote:
                >
                > All of these modifications a) increase the amount of plywood
                needed, b) increase the weight of the boat (degrading performance),
                and c) change the concept. If you want a small, self righting boat,
                maybe there are better designs than Cynthia J (see PCB's Old Shoe
                and Supermouse designs, for his approaches).
                >
                > JohnT

                Hi John,

                all you say is true, and the increased plywood pile would nearly
                complete AS19, a boat designed to serve close to the original
                intention, I think, of a group day sailer with a cuddy, but with
                much deck space for sprawling. However, for instance, in AS19 PCB&F
                wanted to get away from people being confined to the cockpit and I
                would like one that provides deep shelter. As PCB wrote about
                Cynthia J it is rare to find a boat nowadays that you can sit in. He
                has studied Herreshoff's Rozinante closely, and as Herreshoff
                observed about the Rozinante that cockpit type tops all.

                The sublime Anhinga could be got out from a slightly smaller pile of
                wood than AS19 requires. She has the best cockpit. Wonderful.
                However, she carries capsize and flooding concerns similar to the
                unrevised Marth Jane. Doing away with the aft ventilation, and a
                truly watertight hatch to the aft compartment might fix. The
                ventilation as designed is very elegant, as is the truly amazing
                system of apparent aft ballast COG shifting athwartships with
                associated negative pitching that leads to the flooding concern as a
                knock on effect.

                Modification to Cynthia J might be easier, and she has that rig. The
                boom on a gallows provides a great ridge pole for a cockpit tent.
                Makes a nice place to sit out a sunny day under with lots of
                ventilation and cooled sustenance close by. Carry the tent forward
                to the mast and both cudddy hatches could be off in the rain.

                Graeme
              • John and Kathy Trussell
                This is an example of conflicting demands. Big, deep, open cockpits are wonderful things for a crew to enjoy, but they are subject to flooding in a knockdown
                Message 7 of 15 , Oct 8, 2006
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                  This is an example of conflicting demands. Big, deep, open cockpits are wonderful things for a crew to enjoy, but they are subject to flooding in a knockdown or from a breaking wave. Bolger has expressed concerns about what would happen if Rozinante were flooded (he thinks she would sink due to the weight of her ballast). Possible solutions to the vulnerability of large, open cockpits are: a) a large volume of enclosed, watertight cabin and/or bulkheaded and decked area behind the cockpit; or b) enclosing the cockpit in a Birdwatcher type cabin.

                  I wish there was a way to have all the features that I want in a boat with none of the drawbcks, but I haven't found it yet!

                  John T
                  ----- Original Message -----
                  From: graeme19121984
                  To: bolger@yahoogroups.com
                  Sent: Sunday, October 08, 2006 11:06 AM
                  Subject: [bolger] Re: How would Mr Bolger update Cynthia J?


                  --- In bolger@yahoogroups.com, "John and Kathy Trussell"
                  <jtrussell2@...> wrote:
                  >
                  > All of these modifications a) increase the amount of plywood
                  needed, b) increase the weight of the boat (degrading performance),
                  and c) change the concept. If you want a small, self righting boat,
                  maybe there are better designs than Cynthia J (see PCB's Old Shoe
                  and Supermouse designs, for his approaches).
                  >
                  > JohnT

                  Hi John,

                  all you say is true, and the increased plywood pile would nearly
                  complete AS19, a boat designed to serve close to the original
                  intention, I think, of a group day sailer with a cuddy, but with
                  much deck space for sprawling. However, for instance, in AS19 PCB&F
                  wanted to get away from people being confined to the cockpit and I
                  would like one that provides deep shelter. As PCB wrote about
                  Cynthia J it is rare to find a boat nowadays that you can sit in. He
                  has studied Herreshoff's Rozinante closely, and as Herreshoff
                  observed about the Rozinante that cockpit type tops all.

                  The sublime Anhinga could be got out from a slightly smaller pile of
                  wood than AS19 requires. She has the best cockpit. Wonderful.
                  However, she carries capsize and flooding concerns similar to the
                  unrevised Marth Jane. Doing away with the aft ventilation, and a
                  truly watertight hatch to the aft compartment might fix. The
                  ventilation as designed is very elegant, as is the truly amazing
                  system of apparent aft ballast COG shifting athwartships with
                  associated negative pitching that leads to the flooding concern as a
                  knock on effect.

                  Modification to Cynthia J might be easier, and she has that rig. The
                  boom on a gallows provides a great ridge pole for a cockpit tent.
                  Makes a nice place to sit out a sunny day under with lots of
                  ventilation and cooled sustenance close by. Carry the tent forward
                  to the mast and both cudddy hatches could be off in the rain.

                  Graeme






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                • pvanderwaart
                  As a former Cynthia J. owner, I have mixed bag of comments and reactions. I never capsized mine, but I realized that it would be a major mess if it ever
                  Message 8 of 15 , Oct 8, 2006
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                    As a former Cynthia J. owner, I have mixed bag of comments and
                    reactions. I never capsized mine, but I realized that it would be a
                    major mess if it ever happened. My boat had the flotation as designed,
                    and eventually I bought, but never installed, some additional
                    flotation. My idea was to run a section of the rigid baulk as
                    purchased vertically in the cabin. I suppose that would have been
                    about 10" x2' section, about 3' long. My idea was that it would lift
                    the boat while it was on its side. Just a guess; no calculations, no
                    experience. In a letter to me when I bought the plans, PCB suggested
                    lining the interior of the cabin top with foam.

                    As to standing on a leeboard to right the boat, I think that could
                    result in major damage.

                    In the MAIB that arrived at my house yesterday, PCB says he would now
                    give the boat a mast slot like the Chebacco, etc. I did find stepping
                    the mast to be a little closer to the end of my range of capabilities
                    than I liked. He also suggested reducing the size of the cabin.

                    As to major modifications to the design, I wonder if it makes much
                    sense to take that approach. PCB's ply boat techniques have changed a
                    lot, and a new design to the same spec would be a lot different. And
                    there is little point in modifying it in the direction of Micro.

                    Peter
                  • graeme19121984
                    ... Peter, thanks for this news, you ve given cause for me now to subscribe. This is a must read. Then I ll read again your considered Cynthia J observations
                    Message 9 of 15 , Oct 9, 2006
                    • 0 Attachment
                      --- In bolger@yahoogroups.com, "pvanderwaart" <pvanderwaart@...> wrote:
                      >
                      > ...In the MAIB that arrived at my house yesterday,...

                      Peter, thanks for this news, you've given cause for me now to
                      subscribe. This is a must read. Then I'll read again your considered
                      Cynthia J observations based on use, here, and in the files.

                      Cheers
                      Graeme
                    • graeme19121984
                      Gene, Here s a rough comparison of two flat irons as is. No account taken of where the c.o.g. in each boat actually is. 400lbs added for crew and stuff.
                      Message 10 of 15 , Oct 11, 2006
                      • 0 Attachment
                        Gene,

                        Here's a rough comparison of two "flat irons" as is. No account
                        taken of where the c.o.g. in each boat actually is. 400lbs added for
                        crew and stuff. Michalak's estimate used for total constructed boat
                        weight of 35 lbs and 50 lbs per sheet respectively for 1/4 or 3/8
                        ply. No rig weight included. Go stormin' in CJ? Easy mod?

                        Cynthia J
                        Displacement to LWL 130
                        Hull Speed 5.01
                        Sail Area to Displacement 27.48
                        LWL to Beam 2.55
                        Motion Comfort 8.96
                        Capsize Ratio 2.37
                        Sailing Category racer
                        Pounds/Inch 275





                        Storm Petrel

                        Displacement to LWL 130
                        Hull Speed 5.19
                        Sail Area to Displacement 13.3
                        LWL to Beam 2.9
                        Motion Comfort 10.95
                        Capsize Ratio 2.08
                        Sailing Category cruiser/racer
                        Pounds/Inch 277

                        http://www.image-ination.com/sailcalc.html

                        Graeme




                        --- In bolger@yahoogroups.com, "Gene T." <goldranger02-boats@...>
                        wrote:
                        >
                        > Graeme,
                        > Doubling or trippling the bottom will only help righting on
                        > a boat that is not flooded. Once the boat is filled, all that
                        plywood
                        > becomes flotation and will have the opposite effect. I think you
                        need
                        > some dense weight down there, lead, steel, at least epoxy filled
                        with
                        > something heavy. Then extra flotation to make sure you don't go
                        right
                        > to the bottom! 8^D
                        >
                        > Sincerely,
                        >
                        > "A house ashore is but a boat, so poorly
                        > built it will not float ---- "
                        >
                      • graeme19121984
                        Ok, Ive read that MAIB article now and it hasn t changed my perspective on Cynthia J very much, if any. The boat would still be better, from a self rescuing
                        Message 11 of 15 , Oct 16, 2006
                        • 0 Attachment
                          Ok, Ive read that MAIB article now and it hasn't changed my
                          perspective on Cynthia J very much, if any. The boat would still be
                          better, from a self rescuing and comfort point of view, for updates
                          made along the lines of Otter ll and similar. Yep, there is little
                          point in modifying Micro in the current Cynthia J direction, and
                          losing the stability and offshore capability, but Cynthia J would
                          benefit enormously from small attention to bouyancy and ballast.

                          PCB suggests the increased bottom thickness, and some extra
                          flotation in the quarters, also the 290lbs water ballast Rick
                          included to stop her going over and flooding like Martha Jane un-
                          revised, and Anhinga. I think a bow well would be better than a mast
                          slot alone as he suggests. The forward frame, middle bulkheads,
                          companion way, and storage mentioned in earlier posts would be
                          worthwhile little modifications IMHO.

                          In this article I think PCB looks at this hull as a big family's day
                          sailing dinghy rather than the comfy camp cruiser she might be. He
                          observes that more than one up, indeed with only two crew, it is
                          hard to trim the boat as it should be. If the seating places two
                          crew's weight too far aft of the C.O.B might not correct placement
                          of stuff stored in the cuddy balance it?

                          On the other hand, if the cabin is shortened to allow forward
                          extension of the side seats a comfortable cabin is lost for little
                          gain. This hull is not of his advanced sharpie type as PCB implies
                          in the article. It is a flat iron, as I understand the term. It
                          follows H I Chapelle's doctrine for sharpies of a long, dead-flat
                          run to the turn of the bottom. As such, crew weight placed further
                          than just a bit forward of where the seats are now will have the
                          undesirable effect of burying the chine forward with all the bad
                          follow-on effects that PCB has warned of so often. So, if crew sits
                          forward extra weight will have to be placed in the stern, and the
                          cabin is gone. With more crew this could be easily arranged, and
                          would suit, but it then is a very high sided dinghy.

                          As a cuddy camper this boat would be so good. Awaken, coffee, then
                          so easily bulk sail is hoisted to ghost off on the day's adventure
                          with the breeze hardly stirred in morning's first light.

                          Graeme



                          --- In bolger@yahoogroups.com, "pvanderwaart" <pvanderwaart@...>
                          wrote:
                          > ...In the MAIB that arrived at my house yesterday, PCB says he
                          would now
                          > give the boat a mast slot like the Chebacco, etc. I did find
                          stepping
                          > the mast to be a little closer to the end of my range of
                          capabilities
                          > than I liked. He also suggested reducing the size of the cabin.
                          >
                          > As to major modifications to the design, I wonder if it makes much
                          > sense to take that approach. PCB's ply boat techniques have
                          changed a
                          > lot, and a new design to the same spec would be a lot different.
                          And
                          > there is little point in modifying it in the direction of Micro.
                          >
                          > Peter
                          >
                        • John and Kathy Trussell
                          Graeme-- It would be nice if all the things we want could be combined in a very short boat. Here are the problems that must be addressed in very smallboats.
                          Message 12 of 15 , Oct 17, 2006
                          • 0 Attachment
                            Graeme--

                            It would be nice if all the things we want could be combined in a very short boat. Here are the problems that must be addressed in very smallboats.

                            1) On small boats, crew weight makes up a very large portion of the boat's total displacement. Placement of crew weight has a major impact on performance.

                            2) A 'cabin' needs to be long enough so that an adult can lie down--for average folks, this is around 75 ". If two people are to sleep in the cabin, the sleeping area should be between 42'' and 48' wide at the head and at least 36" wide at the foot.

                            3) There are three possible ways to get a decent cabin in a very short boat. You can have a cockpit behind the cabin; this will put crew weight in the back of the boat, possibly trimming the boat down by the stern. You can stack the cockpit on top of part of the cabin (examples are Peephen, Lynx, and the origunal West Wight Potter). You can combine the cabin and cockpit, sailing from inside the cabin (Birdwatcher, Supermouse, and several of Michalak's designs).

                            4) One of the things that drove the Cynthis J design was to have a very simple boat which was styled to look sort of like a Cape Cod Catboat. (And I think that PCB was very successful in this regard.) I know that Cynthia J's looks were (and are) one of the main reasons that I continue to admire this design. The desire for this catboat effect precludes a Birdwatcher cabin (which PCB tried, without success on the Flatfish design).

                            If I were going to play naval architect and revamp Cynthia J, I would move the main bulkhead forward and add a bulkhead and deck to the aft end of the cockpit. This would move crew weight forward. I would then close in the seats and cut holes in the bulkhead to create two quarter berths (these would not be very satisfactory and would often be damp, but what can you expect). Lastly, I would beef up the bottom to as much as an inch, adding a fair amount of ballast. Even with all this, Cynthis J is a sailor for sheltered waters, and I would consider her a character daysailor with the capability for an occassional one night cruise.

                            JohnT
                            ----- Original Message -----
                            From: graeme19121984
                            To: bolger@yahoogroups.com
                            Sent: Monday, October 16, 2006 10:51 PM
                            Subject: [bolger] Re: How would Mr Bolger update Cynthia J?


                            Ok, Ive read that MAIB article now and it hasn't changed my
                            perspective on Cynthia J very much, if any. The boat would still be
                            better, from a self rescuing and comfort point of view, for updates
                            made along the lines of Otter ll and similar. Yep, there is little
                            point in modifying Micro in the current Cynthia J direction, and
                            losing the stability and offshore capability, but Cynthia J would
                            benefit enormously from small attention to bouyancy and ballast.

                            PCB suggests the increased bottom thickness, and some extra
                            flotation in the quarters, also the 290lbs water ballast Rick
                            included to stop her going over and flooding like Martha Jane un-
                            revised, and Anhinga. I think a bow well would be better than a mast
                            slot alone as he suggests. The forward frame, middle bulkheads,
                            companion way, and storage mentioned in earlier posts would be
                            worthwhile little modifications IMHO.

                            In this article I think PCB looks at this hull as a big family's day
                            sailing dinghy rather than the comfy camp cruiser she might be. He
                            observes that more than one up, indeed with only two crew, it is
                            hard to trim the boat as it should be. If the seating places two
                            crew's weight too far aft of the C.O.B might not correct placement
                            of stuff stored in the cuddy balance it?

                            On the other hand, if the cabin is shortened to allow forward
                            extension of the side seats a comfortable cabin is lost for little
                            gain. This hull is not of his advanced sharpie type as PCB implies
                            in the article. It is a flat iron, as I understand the term. It
                            follows H I Chapelle's doctrine for sharpies of a long, dead-flat
                            run to the turn of the bottom. As such, crew weight placed further
                            than just a bit forward of where the seats are now will have the
                            undesirable effect of burying the chine forward with all the bad
                            follow-on effects that PCB has warned of so often. So, if crew sits
                            forward extra weight will have to be placed in the stern, and the
                            cabin is gone. With more crew this could be easily arranged, and
                            would suit, but it then is a very high sided dinghy.

                            As a cuddy camper this boat would be so good. Awaken, coffee, then
                            so easily bulk sail is hoisted to ghost off on the day's adventure
                            with the breeze hardly stirred in morning's first light.

                            Graeme

                            --- In bolger@yahoogroups.com, "pvanderwaart" <pvanderwaart@...>
                            wrote:
                            > ...In the MAIB that arrived at my house yesterday, PCB says he
                            would now
                            > give the boat a mast slot like the Chebacco, etc. I did find
                            stepping
                            > the mast to be a little closer to the end of my range of
                            capabilities
                            > than I liked. He also suggested reducing the size of the cabin.
                            >
                            > As to major modifications to the design, I wonder if it makes much
                            > sense to take that approach. PCB's ply boat techniques have
                            changed a
                            > lot, and a new design to the same spec would be a lot different.
                            And
                            > there is little point in modifying it in the direction of Micro.
                            >
                            > Peter
                            >






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                          • graeme19121984
                            ... Me too. Graeme
                            Message 13 of 15 , Oct 17, 2006
                            • 0 Attachment
                              --- In bolger@yahoogroups.com, "John and Kathy Trussell"
                              <jtrussell2@...> wrote:
                              >
                              >I know that Cynthia J's looks were (and are) one of the main
                              >reasons that I continue to admire this design.

                              <long sigh> Me too.

                              Graeme
                            • pvanderwaart
                              On the subject of crew position, I agree with the notion that having the crew a bit too far forward is worse that having it aft. As designed, crew weight
                              Message 14 of 15 , Oct 18, 2006
                              • 0 Attachment
                                On the subject of crew position, I agree with the notion that having
                                the crew a bit too far forward is worse that having it aft. As
                                designed, crew weight causes the boat to pivot about a point near the
                                forward end of the lwl, and the new immersed shape is a heavier
                                displacement version of the original. (Note PCB kept the stern up out
                                of the water to make this possible.) I found the boat went upwind very
                                well with skipper plus two lightish crew, or one heavy one. The low
                                seating position is a plus.

                                I only sailed the boat solo once or twice, and was surprised by how
                                quickly she heeled with a light load.

                                If you look at the plans carefully, you will note the extreme
                                simplicity that PCB had in mind. He did not draw any blocks or
                                mechanical advantages, leeboard pendants, lifts or stops for the
                                swinging rudder blade, etc. Partly, I think this was to save drawing
                                board time. Partly, just for simplicity. My boat took 300-400 hours by
                                a average-skilled professional in a well equipped boatshop.
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