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Re: [Michalak] Motorsailers Revisted

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  • tom s
    you might want to consider researching some kind of catamaran or outrigger. much higher displacement speed, less heeling under sail. Malcolm Tennant has some
    Message 1 of 11 , Mar 4, 2013
      you might want to consider researching some kind of catamaran or outrigger. much higher displacement speed, less heeling under sail. Malcolm Tennant has some great articles regarding this.

      Sent from my iPad

      On Mar 4, 2013, at 3:51 PM, "prairiedog2332" <nelsarv@...> wrote:

      > For recent members I would like to revisit Jim's philosophy regarding motorsailers. In a nutshell he doesn't like the idea much. A hull that motors well with a bigger motor does not tend to sail well as the stern has to be broader and the run aft flatter and tends to drag at the stern when under sail and so don't often get used as much as a sail boat and mostly the sails are wasted as the motor is used most of the time.
      >
      > We had a discussion regarding Twister which he offers as a Power/Sail design. (The other being Fatcat2) Both have a wider stern and a bit straighter run aft than most of his other designs. I have to buck a fairly fast current going upstream around islands in the river to get to the lake. So wondered if it would work with an even flatter run aft to prevent the stern from bogging down with more power. He still hated the idea. And since then have to agree. With it's shallow draft you can still motor closer to shore and make headway easily. Still a bit nervous as sand can be ingested in the motor if getting too shallow.
      >
      > My Twister plans got stolen before I could build so bought another set. Still wondering if I "could" add a bit flatter run aft. As he mentions often when motoring the winds are just right for sailing and when getting to the lake the winds die and you end up motoring anyway. Often when looking out over our lakes I see sail boats either sitting still or motorsailing. Thing is at higher elevations and in hot weather there is not a lot "weight" to the air. So another reason for adding a larger sail area that is easily reefed like a junk rig.
      >
      > http://www.duckworksbbs.com/plans/jim/twister/index.htm
      >
      > Nels
      >
      >


      [Non-text portions of this message have been removed]
    • prairiedog2332
      I have Trilars plans. Twister meets my criteria regarding size and weight (16x16 350 lbs.) simplicity to build and trailerabilty. Can sleep two under cover
      Message 2 of 11 , Mar 4, 2013
        I have Trilars plans.
        Twister meets my criteria regarding size and weight (16x16 350 lbs.)
        simplicity to build and trailerabilty. Can sleep two under cover
        snuggled up if built with the extended bridge deck which one has been
        built. The pram bow and flat bottom aft gives more interior space than a
        multi-chine with pointy bow the same length. Yet the warped V entry
        makes for less pounding in a chop over a flat bottomed pram. Flat
        bottom in the aft section "might" get some semi-planing flotation going
        over a multi-chine hull? My thinking is a bit straighter run in the aft
        section might just give more semi-planing ability than the aft rocker
        shown on the plans. At the cost of some sailing efficiency if the stern
        drags at the corners when heeled under sail.

        I also want the ability to venture into backwaters and creeks for
        shelter overnight as well as trying a yuloh and even poling to do that.
        But mainly my post was to share what other folks may be looking at as a
        versatile design. Sort of a hybrid design option over just a sail boat?

        Nels


        --- In Michalak@yahoogroups.com, tom s <tdsoren@...> wrote:
        >
        > you might want to consider researching some kind of catamaran or
        outrigger. much higher displacement speed, less heeling under sail.
        Malcolm Tennant has some great articles regarding this.
        >
        > Sent from my iPad
        >




        [Non-text portions of this message have been removed]
      • prairiedog2332
        Made a typo in the previous post. Of course the Twister is 16x6 350 lb.There are some photos of a Twister here.
        Message 3 of 11 , Mar 5, 2013
          Made a typo in the previous post. Of course the Twister is 16x6 350
          lb.There are some photos of a Twister here.
          http://groups.yahoo.com/group/Michalak/photos/album/396809197/pic/list

          Couple things that caught my eye, With the broad transom there is room
          to mount the motor right on the centre line and off-set the rudder
          which I prefer. But the corners and bottom of the transom are almost
          dragging even with the bottom rocker shown in the plans and Owen's wife
          sitting forward on the bridge deck. Twister will handle up to a 5-6 hp
          4-stroke and these are not light and act as a lever back there on the
          stern. So chances are the corner of the transom is going to drag anyway
          under sail unless you use a smaller, lighter OB. And probably the
          helmsperson sitting forward more on the side seat in the cockpit and
          using a tiller extension. Owen has short removable side seats in his
          build - between the bridge deck and the stern flotation chamber - a nice
          mod.

          Bolger mentions in an article about his Brick design: "It's possible
          that running the bottom straight back to a perfectly rectangular stern
          would increase capacity more than resistance." (That is with no motor -
          just the helms person) So with less rocker you get more carrying
          capacity for the heavier motor plus it runs more level under power.

          But this can be overdone, too flat a run aft not only causes the transom
          corners to drag under sail but also pushes the bow down from the force
          of the sail and affects the steerage. Not so much with a pram bow but
          more so with a pointy bow. So am wondering if a bit of compromise with
          maybe half as much rocker than shown on the plans might help off-set the
          motor leverage?

          Another thing that occurs to me is that this is an unballasted design.
          So maybe going with a somewhat smaller low aspect sail area is a good
          idea and try to sail with the boat staying upright which the flat bottom
          helps in that regard. Jim mentions it is not a very fast sail boat
          anyway and the main purpose is to get some sailing experience and the
          chance to shut off the motor and enjoy some leisurely sailing or
          trolling.

          It does demonstrate the trade-off challenges required when designing a
          motorsailor. In my case leaning more towards the motoring ability in
          having to deal with going upstream on a river.

          Nels


          --- In Michalak@yahoogroups.com, "prairiedog2332" <nelsarv@...> wrote:
          >
          > I have Trilars plans.
          > Twister meets my criteria regarding size and weight (16x16 350 lbs.)




          [Non-text portions of this message have been removed]
        • John
          Maybe making the stern just a little wider will do the trick. Looking at the plan you could add 2 of width to the transom and maybe 1 to the aft cockpit
          Message 4 of 11 , Mar 5, 2013
            Maybe making the stern just a little wider will do the trick. Looking at the plan you could add 2" of width to the transom and maybe 1" to the aft cockpit bulkhead. Keeping the same hull flare your change would not change the looks of the boat. See how many square inches of additional area it will give you.

            In hind-sight the motor well of Hapscut could of been about 2" wider at the bottom. (1" either side of centerline)

            I can get 6.5mph on a fully loaded Hapscut (1000lbs) with a Nissan 4hp, 4 stroke outboard. A 3.5hp would push it also and save about 16 pounds of weight on the transom.

            I bet the least amount of trouble would be to widen the stern and not change the rocker. I recently got into some big waves and high winds and was glad I could sit at the transom and keep the bow out of the backside of the waves we were overtaking. If the rocker had been flattered I would of just plowed into the waves.

            --- In Michalak@yahoogroups.com, "prairiedog2332" <nelsarv@...> wrote:
            >
            > Made a typo in the previous post. Of course the Twister is 16x6 350
            > lb.There are some photos of a Twister here.
            > http://groups.yahoo.com/group/Michalak/photos/album/396809197/pic/list
            >
            > Couple things that caught my eye, With the broad transom there is room
            > to mount the motor right on the centre line and off-set the rudder
            > which I prefer. But the corners and bottom of the transom are almost
            > dragging even with the bottom rocker shown in the plans and Owen's wife
            > sitting forward on the bridge deck. Twister will handle up to a 5-6 hp
            > 4-stroke and these are not light and act as a lever back there on the
            > stern. So chances are the corner of the transom is going to drag anyway
            > under sail unless you use a smaller, lighter OB. And probably the
            > helmsperson sitting forward more on the side seat in the cockpit and
            > using a tiller extension. Owen has short removable side seats in his
            > build - between the bridge deck and the stern flotation chamber - a nice
            > mod.
            >
            > Bolger mentions in an article about his Brick design: "It's possible
            > that running the bottom straight back to a perfectly rectangular stern
            > would increase capacity more than resistance." (That is with no motor -
            > just the helms person) So with less rocker you get more carrying
            > capacity for the heavier motor plus it runs more level under power.
            >
            > But this can be overdone, too flat a run aft not only causes the transom
            > corners to drag under sail but also pushes the bow down from the force
            > of the sail and affects the steerage. Not so much with a pram bow but
            > more so with a pointy bow. So am wondering if a bit of compromise with
            > maybe half as much rocker than shown on the plans might help off-set the
            > motor leverage?
            >
            > Another thing that occurs to me is that this is an unballasted design.
            > So maybe going with a somewhat smaller low aspect sail area is a good
            > idea and try to sail with the boat staying upright which the flat bottom
            > helps in that regard. Jim mentions it is not a very fast sail boat
            > anyway and the main purpose is to get some sailing experience and the
            > chance to shut off the motor and enjoy some leisurely sailing or
            > trolling.
            >
            > It does demonstrate the trade-off challenges required when designing a
            > motorsailor. In my case leaning more towards the motoring ability in
            > having to deal with going upstream on a river.
            >
            > Nels
            >
            >
            > --- In Michalak@yahoogroups.com, "prairiedog2332" <nelsarv@> wrote:
            > >
            > > I have Trilars plans.
            > > Twister meets my criteria regarding size and weight (16x16 350 lbs.)
            >
            >
            >
            >
            > [Non-text portions of this message have been removed]
            >
          • prairiedog2332
            Thanks John for sharing your experience! 6.5 mph would really do the job! The thing is I think Hapscut has about 4 ft. more waterline length with the motor
            Message 5 of 11 , Mar 5, 2013
              Thanks John for sharing your experience!


              6.5 mph would really do the job! The thing is I think Hapscut has about
              4 ft. more waterline length with the motor well you added? That would
              make for a very easily driven displacement hull. Some of the currents I
              would have to deal with are in the order of 5 mph or so and Jim was
              kind to share that 5 mph is about the best you can get with the Twister
              design. I have a 5 hp Honda 4-stroke. Adding power would cause the
              stern to sink and dig a bigger hole in the water and not accomplish
              anything. Flattening the run aft would spoil the sailing performance -
              so he did not like that idea.


              My trailer and my building space restrict me to 16 ft at most. A Hapscut
              shortened is an idea but may end up with same same hull speed as Twister
              maybe. So thinking of a way to prevent the stern from sinking and
              digging a bigger hole somehow as being a possibility even if the
              sailing ability suffers.


              There was an idea suggested about adding a flat shallow box keel faired
              in to the after section of a sailing scow to improve motoring ability.
              It is in the files section in pdf format. Not sure if that idea was ever
              tried.

              http://groups.yahoo.com/group/Michalak/files/Sailing%20scow%20to%20motor\
              %20scow/

              Another thought is to add adjustable flaps to the stern and raise them
              and the motor when sailing. The idea is to get the stern to stay high
              enough to get into a semi-plane mode yet adding enough flotation to help
              prevent the transom corners from dragging and slow it in sailing mode.
              "Semi-planing" is always a subject of much conjecture. Jim mentioned
              that many photos showing a hull planing are not really planing.

              Can't tell from looking at the plans online - but looking at the photos
              - I think Twister's transom is as wide as Hapcuts? Hapscut has higher
              sides and wider at the top with more flare but seems to narrow down more
              towards the stern? But will look at that option for sure! Hoping this
              adds some info for the group and sorry for being so wordy. Will leave
              off for now. Am finding Yahoo very unfriendly when trying to post.

              Nels



              --- In Michalak@yahoogroups.com, "John" <goodman_clan@...> wrote:
              >
              > Maybe making the stern just a little wider will do the trick. Looking
              at the plan you could add 2" of width to the transom and maybe 1" to the
              aft cockpit bulkhead. Keeping the same hull flare your change would not
              change the looks of the boat. See how many square inches of additional
              area it will give you.
              >
              > In hind-sight the motor well of Hapscut could of been about 2" wider
              at the bottom. (1" either side of centerline)
              >
              > I can get 6.5mph on a fully loaded Hapscut (1000lbs) with a Nissan
              4hp, 4 stroke outboard. A 3.5hp would push it also and save about 16
              pounds of weight on the transom.
              >
              > I bet the least amount of trouble would be to widen the stern and not
              change the rocker. I recently got into some big waves and high winds and
              was glad I could sit at the transom and keep the bow out of the backside
              of the waves we were overtaking. If the rocker had been flattered I
              would of just plowed into the waves.
              >




              [Non-text portions of this message have been removed]
            • John
              Here is some information I shared with Jim concerning Hapscut. The bottom of my motor well transom measures 34 wide including the chine logs. It should of
              Message 6 of 11 , Mar 6, 2013
                Here is some information I shared with Jim concerning Hapscut.

                The bottom of my motor well transom measures 34" wide including the chine logs. It should of been at least 35"-36" to make the curve along the chine log more smooth and attractive. (I notice it. Others don't)

                Hapscut when fully loaded has an "at rest" water line of 15'-1" and a draft of 2.75".

                Here is the link to a video of my motoring into the wind with a slight chop: http://www.youtube.com/watch?v=4cpX4eaqS6M

                Having some type of trim tab on the transom sounds like a complicated mess. I built a model of Hapscut with a "sugar scoop" transom that can be seen in the Photo Album called "Hapscut". I thought it might work better than an engine well. The model showed me it would not work.

                Hapscut was the biggest boat I could build and store in my garage so I understand the limitations of available space. Twister should work well for you.
              • prairiedog2332
                Thanks again John, Hapscut is one amazing design and you and family have tested out the prototype very thoroughly and am quite certain Jim agrees with the
                Message 7 of 11 , Mar 6, 2013
                  Thanks again John,

                  Hapscut is one amazing design and you and family have tested out the
                  prototype very thoroughly and am quite certain Jim agrees with the added
                  transom width. The video was great showing what it can do under power at
                  less than half throttle with a 4 hp Tohatsu 4-stroke. Obviously the
                  15' waterline really helps and so does the bit narrower bottom with more
                  flare than Jim has done previously. Less pounding with that light draft
                  and getting the balance just right. Then just quartering a bit into the
                  bigger waves as you already mentioned.


                  I reviewed several of Jim's designs especially the earlier AF series.
                  They had narrow raised transoms - with lots of rocker - but back then
                  most people only had 2-3.5 hp 2-strokes which are less than half the
                  weight of today's 4-strokes. Of course the original sharpies had no
                  outboard motors so the smaller capacity back there was not a problem.


                  His only "true" motorsailer was the Petesboat.


                  http://www.duckworksbbs.com/plans/jim/petesboat/index.htm


                  Based on Jewelbox.


                  http://www.duckworksbbs.com/plans/jim/jewelbox/index.htm


                  Unfortunately neither link shows the underwater rocker profiles but
                  obviously the Petesboat - meant to plane - had a flatter run aft but
                  not as flat as say the AF4 as it was meant to sail as well as motor.
                  Pretty sure Jewelbox has more curvature aft than Hapscut. But the thing
                  Jim mentioned that caught my attention was he widened the transom on
                  Petesboat:-)

                  So I think I should build a scale model of Twister and see how wide I
                  could go and still keep a smooth curve to the topsides. So my conclusion
                  is that if planning to use a 4-stroke OB of 4+ hp a person might
                  consider looking at designs with a wider transom than some of his
                  earlier ones. This also allows one to mount the heavier motor on the
                  centreline and still have space for and off-set rudder. If you want to
                  use a lighter motor - like the Honda 2 then fine to off-set the motor
                  and go with an older design.

                  Nels



                  --- In Michalak@yahoogroups.com, "John" <goodman_clan@...> wrote:
                  >
                  > Here is some information I shared with Jim concerning Hapscut.
                  >
                  > The bottom of my motor well transom measures 34" wide including the
                  chine logs. It should of been at least 35"-36" to make the curve along
                  the chine log more smooth and attractive. (I notice it. Others don't)
                  >
                  > Hapscut when fully loaded has an "at rest" water line of 15'-1" and a
                  draft of 2.75".
                  >
                  > Here is the link to a video of my motoring into the wind with a slight
                  chop: http://www.youtube.com/watch?v=4cpX4eaqS6M
                  >
                  > Having some type of trim tab on the transom sounds like a complicated
                  mess. I built a model of Hapscut with a "sugar scoop" transom that can
                  be seen in the Photo Album called "Hapscut". I thought it might work
                  better than an engine well. The model showed me it would not work.
                  >
                  > Hapscut was the biggest boat I could build and store in my garage so I
                  understand the limitations of available space. Twister should work well
                  for you.
                  >



                  [Non-text portions of this message have been removed]
                • Joseph Stromski
                  Frolic2 might be considered a motorsailer also. From plan description: I intended this to be a multi skiff sort of boat with rowing and motoring abilities.
                  Message 8 of 11 , Mar 6, 2013
                    Frolic2 might be considered a motorsailer also. From plan description:
                    "I intended this to be a multi skiff sort of boat with rowing and motoring
                    abilities. You can't row a boat of this size in any wind or waves but in a calm
                    you can travel far if you have patience. I didn't fool around with a gadget
                    motor mount - I put the motor well right in the middle and offset the rudder
                    instead of the other way around. This worked out very well on the high
                    powered Petesboat. "

                    Best,
                    Joe





                    ________________________________
                    From: prairiedog2332 <nelsarv@...>
                    To: Michalak@yahoogroups.com
                    Sent: Wed, March 6, 2013 11:22:19 AM
                    Subject: [Michalak] Re: Motorsailers Revisted


                    Thanks again John,

                    Hapscut is one amazing design and you and family have tested out the
                    prototype very thoroughly and am quite certain Jim agrees with the added
                    transom width. The video was great showing what it can do under power at
                    less than half throttle with a 4 hp Tohatsu 4-stroke. Obviously the
                    15' waterline really helps and so does the bit narrower bottom with more
                    flare than Jim has done previously. Less pounding with that light draft
                    and getting the balance just right. Then just quartering a bit into the
                    bigger waves as you already mentioned.

                    I reviewed several of Jim's designs especially the earlier AF series.
                    They had narrow raised transoms - with lots of rocker - but back then
                    most people only had 2-3.5 hp 2-strokes which are less than half the
                    weight of today's 4-strokes. Of course the original sharpies had no
                    outboard motors so the smaller capacity back there was not a problem.

                    His only "true" motorsailer was the Petesboat.

                    http://www.duckworksbbs.com/plans/jim/petesboat/index.htm

                    Based on Jewelbox.

                    http://www.duckworksbbs.com/plans/jim/jewelbox/index.htm

                    Unfortunately neither link shows the underwater rocker profiles but
                    obviously the Petesboat - meant to plane - had a flatter run aft but
                    not as flat as say the AF4 as it was meant to sail as well as motor.
                    Pretty sure Jewelbox has more curvature aft than Hapscut. But the thing
                    Jim mentioned that caught my attention was he widened the transom on
                    Petesboat:-)

                    So I think I should build a scale model of Twister and see how wide I
                    could go and still keep a smooth curve to the topsides. So my conclusion
                    is that if planning to use a 4-stroke OB of 4+ hp a person might
                    consider looking at designs with a wider transom than some of his
                    earlier ones. This also allows one to mount the heavier motor on the
                    centreline and still have space for and off-set rudder. If you want to
                    use a lighter motor - like the Honda 2 then fine to off-set the motor
                    and go with an older design.

                    Nels

                    --- In Michalak@yahoogroups.com, "John" wrote:
                    >
                    > Here is some information I shared with Jim concerning Hapscut.
                    >
                    > The bottom of my motor well transom measures 34" wide including the
                    chine logs. It should of been at least 35"-36" to make the curve along
                    the chine log more smooth and attractive. (I notice it. Others don't)
                    >
                    > Hapscut when fully loaded has an "at rest" water line of 15'-1" and a
                    draft of 2.75".
                    >
                    > Here is the link to a video of my motoring into the wind with a slight
                    chop: http://www.youtube.com/watch?v=4cpX4eaqS6M
                    >
                    > Having some type of trim tab on the transom sounds like a complicated
                    mess. I built a model of Hapscut with a "sugar scoop" transom that can
                    be seen in the Photo Album called "Hapscut". I thought it might work
                    better than an engine well. The model showed me it would not work.
                    >
                    > Hapscut was the biggest boat I could build and store in my garage so I
                    understand the limitations of available space. Twister should work well
                    for you.
                    >

                    [Non-text portions of this message have been removed]




                    [Non-text portions of this message have been removed]
                  • prairiedog2332
                    Absolutely agree. And I hear Caroline would qualify as would Fatcat2 that is shown on the plans site as a Power/Sail design. I like the idea of the flat
                    Message 9 of 11 , Mar 6, 2013
                      Absolutely agree. And I hear Caroline would qualify as would Fatcat2
                      that is shown on the plans site as a Power/Sail design.


                      I like the idea of the flat bottom aft on Twister to perhaps give a bit
                      more weight capacity for a 5 hp 4-stroke over the multi-chine designs
                      back there in the stern? Plus the length matches my trailer and building
                      shed better. I guess the decision has to do with how you plan to use the
                      boat most of the time?


                      The above designs are certainly superior in sailing performance and
                      seaworthiness whereas I live on the river bank.

                      Nels



                      --- In Michalak@yahoogroups.com, Joseph Stromski <j.stromski@...> wrote:
                      >
                      > Frolic2 might be considered a motorsailer also. From plan description:
                      > "I intended this to be a multi skiff sort of boat with rowing and
                      motoring
                      > abilities. You can't row a boat of this size in any wind or waves but
                      in a calm
                      > you can travel far if you have patience. I didn't fool around with a
                      gadget
                      > motor mount - I put the motor well right in the middle and offset the
                      rudder
                      > instead of the other way around. This worked out very well on the high
                      > powered Petesboat. "
                      >
                      > Best,
                      > Joe
                      >




                      [Non-text portions of this message have been removed]
                    • prairiedog2332
                      After reflecting on this subject for some time it suddenly occurred to me that a design that has the water ballast option is the best way to go. DOH!
                      Message 10 of 11 , Mar 11, 2013
                        After reflecting on this subject for some time it suddenly occurred to
                        me that a design that has the water ballast option is the best way to
                        go. DOH!

                        Traditionally motorsailers have a small sail plan to compensate for
                        their lack of ballast when in motoring mode, which would mean dragging
                        weight that just burns more gas. So that brought me back the ballast
                        bags like used on wake boats to increase the size of the wake. So might
                        be an idea with Twister, Fatcat2, or other designs that motor well but
                        don't have water ballast as a part of the overall design to hold up a
                        larger sailplan when in sailing mode. So a ballast bag under the bridge
                        deck that is easily filled when wanting to sail and then emptied when
                        wanting to motor or to sleep to allow the foot space under the bridge
                        deck might be an option and worth the investment. Located amidships
                        might help keep the transom from dragging under sail and the crew can
                        relax in the upwind cockpit seat and keep the bow up going downwind. Of
                        course an option to consider after trying with no ballast as designed.


                        http://www.wakemakers.com/wakeboard-ballast-bags?gclid=CITMj-OE9rUCFVSVM\
                        godiloAUw


                        This might do the job for $60


                        http://www.wakemakers.com/straight-line-big-bag-150-ballast-bag.html


                        Ideally add the cost of a pump for about another $100

                        http://www.wakemakers.com/launch-pad-sumo-pump.html


                        Nels


                        --- In Michalak@yahoogroups.com, "prairiedog2332" <nelsarv@...> wrote:
                        >
                        > Absolutely agree. And I hear Caroline would qualify as would Fatcat2
                        > that is shown on the plans site as a Power/Sail design.
                        >




                        [Non-text portions of this message have been removed]
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