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Re: FastBrick and Tortoise Update (Virtues of Forefeets)

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  • pseudospark
    ... Jon, Your post and photos prompted me to dig out my Sept 1, 2003 MAIB with PCB s Fastbrick article. I ve a question for anyone who can answer. Normally
    Message 1 of 16 , Feb 1, 2005
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      --- In bolger@yahoogroups.com, "adventures_in_astrophotography"
      <jkolb@d...> wrote:
      >
      > Some photos of my 12' FastBrick project have been posted.

      Jon,

      Your post and photos prompted me to dig out my Sept 1, 2003 MAIB
      with PCB's Fastbrick article. I've a question for anyone who can
      answer. Normally flatbottomed square hulls are not considered to be
      useful or safe in anything more severe than a light chop. (I don't
      say this from experience, just from what I've read...all my boats
      have flat bottoms but they are of the pointy front variety.) For
      example, Jim Michalak cautions against rough water on his scow
      hulled craft. The only real difference I see between, say Harmonica
      or Campjon, and Fastbrick is the forefoot. So, can someone quantify
      the benefit of forefeet on little boxy craft?

      I've been toying with a design that has a hull not unlike Fastbrick
      without the forefoot and wonder if something would be gained by
      adding one.

      Steve H
    • Nels
      ... Hi Steve, If you go back a few posts to 41713, you will see mention of a Watervan. It has the same forefoot design so you might be able to contact the
      Message 2 of 16 , Feb 1, 2005
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        --- In bolger@yahoogroups.com, "pseudospark" <shansen@t...> wrote:
        > So, can someone quantify
        > the benefit of forefeet on little boxy craft?
        >
        > I've been toying with a design that has a hull not unlike Fastbrick
        > without the forefoot and wonder if something would be gained by
        > adding one.
        >
        > Steve H

        Hi Steve,

        If you go back a few posts to 41713, you will see mention of a
        Watervan. It has the same forefoot design so you might be able to
        contact the owner.

        There are some photos in Bolger2 - this might work:

        http://tinyurl.com/4wy97

        Cheers, Nels
      • pseudospark
        Thanks Nels, I ll look at the Watervan you mention. However, what I d really be interested in is a semi-quantitative explanation of what the forefoot does to a
        Message 3 of 16 , Feb 2, 2005
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          Thanks Nels, I'll look at the Watervan you mention.

          However, what I'd really be interested in is a semi-quantitative
          explanation of what the forefoot does to a scow/jonboat type hull.

          Thanks,
          Steve H

          --- In bolger@yahoogroups.com, "Nels" <arvent@h...> wrote:
          > If you go back a few posts to 41713, you will see mention of a
          > Watervan. It has the same forefoot design so you might be able to
          > contact the owner.
        • Bruce Hallman
          ... The Bolger writeup for Watervan gives your explanation: OCR ed from the excellent magazine _Messing About In Boats_, [everybody should subscribe!] and
          Message 4 of 16 , Feb 2, 2005
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            > However, what I'd really be interested in is a semi-quantitative
            > explanation of what the forefoot does to a scow/jonboat type hull.
            >
            > Thanks,
            > Steve H

            The Bolger writeup for Watervan gives your explanation:
            OCR'ed from the excellent magazine _Messing About
            In Boats_, [everybody should subscribe!] and pasted
            below:
            ===========================================
            Watervan
            Design #632
            6.92M x 2.46M (22.7 feet x 8.07 feet)
            This boat was designed primarily for
            Australian rivers and lakes, although capable
            of alongshore or even offshore passages in
            reasonable weather. In fact, she would have a
            better chance in heavy weather than most small
            power cruisers if she was prudently handled,
            doors and windows secured, etc.
            The specification called for a queen-size
            double berth, a dinette convertible to a second
            double berth, a comfortable helm seat and for-
            ward view underway for two or three other
            people, enclosed toilet room, workable galley,
            standing headroom throughout and a cruising
            speed of 20 mph with as little wake and noise
            as possible, all inside the dimensions given
            for convenience in trailer hauling. Her owner
            originally proposed her to be powered with a
            diesel waterjet, but when the cost of the power
            plant became clear, he decided to settle for the
            90 hp, four-stroke outboard motor which is
            also a good deal lighter and less intrusive on
            the cabin.
            The van configuration seemed to be the
            only way this roomy a cabin could be packed
            inside these dimensions. She's what we call a
            cutwater garvey. The slender ski-like cutwater
            under the bow gives buoyancy and dynamic
            lift forward to carry the flat toboggan bow of
            the garvey hull well clear of the water and to
            allow the profile curve of the garvey bow to
            be a very gentle sweep for low drag and mini-
            mal spray making. The cutwater is extended
            to the stern as a box keel, again floating the
            hull proper higher in the water for reduced
            wavemaking and channelling air trapped un-
            der the hull away from the propeller. (This also
            works with a waterjet intake and is more reli-
            able in that respect than the usual slight
            deadrise.) The shape is the same we've used
            for quite a few boats in recent years, except
            that most of the others have the upper part of
            the hull curved in to a blunt point above the
            cutwater. These pointed bows are mostly "to
            make them look like boats," there's no func-
            tional advantage to speak of over the rectan-
            gular bow. In this case, there was no question
            of getting the specified layout in any boatlike
            style, and this shape is very straightforward
            to assemble as well as being roomy and buoy-
            ant.
            The forward helm and viewing seats
            would be unworkable in a normal garvey with-
            out the cutwater. The bow would have to be
            too abrupt a curve to float the weight of people
            in the bow. It would plow at low speed and
            drive hard at planing speed if it could get up
            at all. With the cutwater to lift the bow it be-
            comes workable, although she is still fastest
            if everybody doesn't insist on sitting in the
            bow.
            A hull like this is very dry. The
            sharp-lined cutwater doesn't make much spray,
            and what it does make is trapped under the
            fiat hull. There are shallow skids along the
            outside edges of the bottom to retain some of
            the air that would otherwise be forced out at
            the sides. The boat rides on a cushion of foam
            trapped on each side of the box keel. There is
            actually some cushioning effect; in spite of the
            large flat areas, these hulls are less noisy and
            rough riding than most in choppy water, in-
            cluding many deep-vee hulls with big, flat
            strakes and spray deflectors. This is not to
            claim that they are quiet or smooth! That is
            not doable on these proportions at these speeds
            on an uneven surface like water, except by
            means of foils, which have their own draw-
            backs.
            One item on the wish list was the ability
            to keep running at night, at cruising speed.
            without too much risk. Hence the twin, pow-
            erful off-road headlights, which brilliantly
            illuminate the water for hundreds of feet ahead
            without any reflection on any part of the boat.
            The square-across bow also incorporates ven-
            tilation intakes with efficient baffling to allow
            them to be open in a downpour of rain. The
            vent outlets are in the deck (or roof) at the
            stern, also well baffled and located where ed-
            dying fumes from the motor can't reach them.
            The motor, and all the fuel, are in watertight
            compartments in the stern, where no spills can
            reach the cabin. The large doors opening from
            the cabin to the motor recess are specified to
            be gasketed and dogged airtight whenever the
            motor is running.
            She can be opened up in all directions in
            good weather, from the big bow gate from
            which anchor handling is done, the sliding
            windows at the sides and the sliding sunroof
            overhead, to the entrance doors on each side.
            These last open inwards to clear floats,
            lock-walls etc. A series of folding platforms
            allows outside access to the stern and conve-
            nient boarding from small boats. The propane
            cylinder for the stove is in an airtight recess in
            the galley, opening only to the outside.
            We've found that there is not much point
            in arguing about the aesthetics of something
            like this. You like it, you hate it, or you can or
            can't quite tolerate it. But we will argue with
            conviction and from experience and expertise
            that there is nothing unseamanlike about it. It
            can't be compared with anything of equiva-
            lent space efficiency because there is nothing
            afloat that can match her. But she will run
            faster, with less disturbance behind her, with
            better control and no more discomfort in rough
            water, than most small, fast power cruisers.
            She is not a clumsy floating house. Any ob-
            jections to it have no objective basis. The ef-
            feet on the scenery of a fleet of them is legiti-
            mately arguable.
          • Nels
            ... The shape is the same we ve used for quite a few boats in recent years, except that most of the others have the upper part of the hull curved in to a blunt
            Message 5 of 16 , Feb 2, 2005
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              --- In bolger@yahoogroups.com, Bruce Hallman <bruce@h...> wrote:
              The shape is the same we've used
              for quite a few boats in recent years, except
              that most of the others have the upper part of
              the hull curved in to a blunt point above the
              cutwater. These pointed bows are mostly "to
              make them look like boats," there's no func-
              tional advantage to speak of over the rectan-
              gular bow.

              I believe both Col. Hasler and FIJI are examples of what he speaks of
              as "curved in to a blunt point" and in the Hasler write-up in MAIB he
              gives more details on this type of bow configuration, derived partly
              from Japanese "Yamoto" boats or something like that?

              They are a lot more sophisticated than they look and definetly
              carrying the "skid" the length of the hull is something to consider
              as in Clam Skiff. If this skid is solid wood it would offer extra
              protection when grounding as well as adding lift at speed.

              Cheers, Nels
            • Bruce Hallman
              ... Hasler [& Yonder & Motor Sailer & Working Tug, etc.] have box keels and are displacement hulls. Fiji (& Topaz) have cutwaters at the bow only and are
              Message 6 of 16 , Feb 2, 2005
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                > I believe both Col. Hasler and FIJI are examples
                > Cheers, Nels

                Hasler [& Yonder & Motor Sailer & Working Tug, etc.]
                have box keels and are displacement hulls.

                Fiji (& Topaz) have cutwaters at the bow only and
                are planing hulls.

                Fastbrick, Watervan, Microtrawler, Bee, Hawkeye, etc.
                have cutwaters and full length 'shoes' and are planing hulls.
                They look superficially the same, but are really
                different. Clam Skiff might even be included in this
                catagory.

                Champlain, Sitka Explorer, Windermere, Motor
                Sailing Cargo Boat, fall in between, but are displacement
                boats.
              • pseudospark
                Hi Bruce, Thanks for posting the text. This is perfect. What issue was this in? (I m sure I have it, my collection goes back to 1990 - the only problem is that
                Message 7 of 16 , Feb 2, 2005
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                  Hi Bruce,

                  Thanks for posting the text. This is perfect. What issue was this
                  in? (I'm sure I have it, my collection goes back to 1990 - the only
                  problem is that I have them archived 3 deep in a floor level
                  cabinet.)

                  In looking at Fastbrick, it has the forefoot but not the box keel
                  per Watervan, Clam Skiff and the tugs.

                  The design I've been playing with is a loose adaptation of Jim
                  Betts' Gypsy's Poke (which he never took beyond the cartoon stage).
                  A forefoot and perhaps a shallow box keel might go well with this
                  creature.

                  Steve H.

                  --- In bolger@yahoogroups.com, Bruce Hallman <bruce@h...> wrote:
                  > The Bolger writeup for Watervan gives your explanation:
                  > OCR'ed from the excellent magazine _Messing About
                  > In Boats_, [everybody should subscribe!] and pasted
                  > below:
                  >
                • Nels
                  ... The article can be seen here: http://groups.yahoo.com/group/bolger/files/Watervan/ Another difference with some of the designs Bruce mentions is that the
                  Message 8 of 16 , Feb 2, 2005
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                    --- In bolger@yahoogroups.com, "pseudospark" <shansen@t...> wrote:
                    >
                    > Hi Bruce,
                    >
                    > Thanks for posting the text. This is perfect. What issue was this
                    > in? (I'm sure I have it, my collection goes back to 1990 - the only
                    > problem is that I have them archived 3 deep in a floor level
                    > cabinet.)
                    >
                    The article can be seen here:

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

                    Another difference with some of the designs Bruce mentions is that
                    the "Garvey" shape has some deadrise near the bow in some of them.
                    And the run of the aft sections will be the deciding factor for the
                    design's ability to plane easily or sail without dragging the stern.

                    I believe that Bolger likes the idea that these hull-shapes are very
                    practical for plywood construction, as there are no compound curves
                    and yet they perform very well.

                    Fastbrick will plane:-)

                    Cheers, Nels
                  • Stefan Gutermuth
                    Hey , -- Just a few comments from the builder of the only Water Van in the Northern Hemisphere. The boat is a joy to operate above 10 Knots. Below 10 knots,
                    Message 9 of 16 , Feb 2, 2005
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                      Hey , -- Just a few comments from the builder of the only Water Van in the
                      Northern Hemisphere.

                      The boat is a joy to operate above 10 Knots. Below 10 knots, because of the
                      nose heavy design, it tends to wander, and a 2.5 to 3' wave, square on, will
                      ship some water over the bow. Above 10, through 16 knots the wandering goes
                      away, the bow comes up nicely, and she runs very dry, even in 3' to 4' chop
                      and swells. At 18 knots she starts to plane and by 20 knots the Water Van
                      levels out and feels like she's riding on a cushion In fairly calm water,
                      with the Suzuki DF 115, she will easily cruise at 25 knots.

                      The forefoot / box keel is almost 3' wide for most of its length, and runs
                      6" below the main hull. There are 2 mini keels at the outboard edges of the
                      main hull, about 2" wide and 3" down. It appears that turbulated water and
                      air is trapped between the box keel and the mini outboard keels; effectively
                      creating a slippery foam cushion at the 10 to 18 knot range.

                      Stefan Gutermuth, V.P.
                      John O'Hara Company
                      Ph: 973-673-4676
                      Fx: 973-673-7141
                      Cl: 201-970-8007
                      stefan@...


                      -----Original Message-----
                      From: pseudospark [mailto:shansen@...]
                      Sent: Wednesday, February 02, 2005 6:57 PM
                      To: bolger@yahoogroups.com
                      Subject: [bolger] Re: FastBrick and Tortoise Update (Virtues of Forefeets)




                      Hi Bruce,

                      Thanks for posting the text. This is perfect. What issue was this
                      in? (I'm sure I have it, my collection goes back to 1990 - the only
                      problem is that I have them archived 3 deep in a floor level
                      cabinet.)

                      In looking at Fastbrick, it has the forefoot but not the box keel
                      per Watervan, Clam Skiff and the tugs.

                      The design I've been playing with is a loose adaptation of Jim
                      Betts' Gypsy's Poke (which he never took beyond the cartoon stage).
                      A forefoot and perhaps a shallow box keel might go well with this
                      creature.

                      Steve H.

                      --- In bolger@yahoogroups.com, Bruce Hallman <bruce@h...> wrote:
                      > The Bolger writeup for Watervan gives your explanation: OCR'ed from
                      > the excellent magazine _Messing About In Boats_, [everybody should
                      > subscribe!] and pasted
                      > below:
                      >






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                    • pseudospark
                      Hi Stefan, Thanks much for the first hand information. Sounds like a great boat. Steve H
                      Message 10 of 16 , Feb 3, 2005
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                        Hi Stefan,

                        Thanks much for the first hand information. Sounds like a great boat.

                        Steve H

                        --- In bolger@yahoogroups.com, "Stefan Gutermuth" <stefan-g@m...>
                        wrote:
                        > Hey , -- Just a few comments from the builder of the only
                        > Water Van in the Northern Hemisphere.
                      Your message has been successfully submitted and would be delivered to recipients shortly.