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Re: FastBrick and Tortoise Update (Virtues of Forefeets)

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  • 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 1 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 2 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 3 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 4 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 5 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 6 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 7 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 8 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.
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