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Re: [pop-pop-steamboats] Re: Pop Pop 16' canoe

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  • David Halfpenny
    Then click on the Union Flag symbols on the website to get the words in Anglais. It s not pukka Strine but you should be able to decipher it Bruce ;-) D ...
    Message 1 of 15 , Jul 30, 2009
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      Then click on the Union Flag symbols on the website to get the words in
      Anglais.

      It's not pukka 'Strine but you should be able to decipher it Bruce ;-) D

      --------------------------------------------------
      From: "sydneygreenestreet" <sydneygreenestreet@...>
      Sent: Thursday, July 30, 2009 11:51 AM

      > My real problem is my conversational french is not so hot, I am after all
      > Australain....
      >
      >
      >
      > ------------------------------------
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
    • Frank McNeill
      Hi Sydney, Your dog could provide more power than a pop-pop engine can for your boat. Go to for an article
      Message 2 of 15 , Jul 30, 2009
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        Hi Sydney,

        Your dog could provide more power than a pop-pop engine can for your boat. Go to <http://www.nasw.org/users/sperkins/hrsferry.html> for an article about animal powered ferries. After reading it you might want to trade your dog for a horse.


        --- In pop-pop-steamboats@yahoogroups.com, "sydneygreenestreet" <sydneygreenestreet@...> wrote:
        >
        > Firstly my dog is a large one....I have had a look and I'm thinking of using the coil style boiler with a lot of heat not worried about the effiency..... It looks like I'm going to have to do this by trial and error. I'm thinking of a coil of 12mm copper tube about 6 turns 150 mm dia, the object being to have to boil as little water as quickly as possible. Maybe a diaphram type will be better.....
        >
        > I've some experience with smaller coil type boilers, and it's to do with the heat/cooling areas....
        >
        > My real problem is my conversational french is not so hot, I am after all Australain....
        >
      • darylcanada73
        Sydney, Don t let these louts discourage you. I ve been hoping someone would do some experimenting with big coil engines. Big being 10mm and up. My main
        Message 3 of 15 , Jul 31, 2009
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          Sydney, Don't let these louts discourage you. I've been hoping someone would do some experimenting with big coil engines. Big
          being 10mm and up. My main focus has been on speed which means
          light weight and decent power to weight ratio. The problem is that
          so far more power has meant more weight and much longer pipes so
          a larger boat is needed and that means more drag. I have a couple
          of 18" boats with engines producing about 140mN and a couple of
          30" boats at 400 to 600mN and they all go about the same speed,
          2kph approx. So far diaphragm engines appear to be a poor choice.
          Daryl (also in the Commonwealth) Canada.

          --- In pop-pop-steamboats@yahoogroups.com, "sydneygreenestreet" <sydneygreenestreet@...> wrote:
          >
          > Firstly my dog is a large one....I have had a look and I'm thinking of using the coil style boiler with a lot of heat not worried about the effiency..... It looks like I'm going to have to do this by trial and error. I'm thinking of a coil of 12mm copper tube about 6 turns 150 mm dia, the object being to have to boil as little water as quickly as possible. Maybe a diaphram type will be better.....
          >
          > I've some experience with smaller coil type boilers, and it's to do with the heat/cooling areas....
          >
          > My real problem is my conversational french is not so hot, I am after all Australain....
          >
        • sydneygreenestreet
          Interesting, you refering to the Commonwealth ... How do I attach an MP3 file of Vera Lyn Singing There ll always be an England ? So a longer boat of similar
          Message 4 of 15 , Aug 1, 2009
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            Interesting, you refering to the "Commonwealth"... How do I attach an MP3 file of Vera Lyn Singing "There'll always be an England"?
            So a longer boat of similar beam to a shorter boat will require less power to get it to go faster that the shorter boat. ie a boat 12' by 4' will need more power that a 20' x 4' boat to travel at the same speed ergo a 16' x 3' canoe (you call them Indian canoes made famous by Nelson Eddy and Jannete MacDonald to me they are classed as yes you guessed it Empire Canoes)will need less power to travel at the same speed as an 8' x 4'6" snub nosed dinghy....

            Don't worry I'll not be disuaded by people who prefer drinking coffee to haveing proper tea....

            We went through the horse on treadmill era here to drive ferries but steam soon replaced them though we still have horse drawn trams (trolleys) on the Granite Island service (google it), very interesting technically at the points at the loops dont have blades, the cars are steered by the horse pulling them to the left. Which brings up another question, how many people remember the exact location of a tram stop 30 years after the tracks have been covered with asphalt?
            Now Gracie (my wonder dog, constant companion and holder of her own rail, tram, ferry and bus pass) does have the webbed feet typical of water loving dogs and when we go swimming she tows me along on the leash quite well but as for putting her on a treadmill, I think the RSPCA would go beresk...

            The object here I think is to flash boil as much water as quickly as possible so maybe the diapragm is really only good for smaller applications. I have 6m length of aluminium tube, I'm gonna have a fart around with it and a huge LPG burner and asseseseseses the results before I start on the copper... one other consideration is the vibration causing the copper to workharden and fail. It does in full size marine engineering practise something else to consider I guess.
          • KENNETH TAIT SR.
            Sydney, I sure do enjoy reading what have written, and discussed. I gather that you are on the other side of the pond, so to speak. My wife had an Irish
            Message 5 of 15 , Aug 1, 2009
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              Sydney,

              I sure do enjoy reading what have written, and discussed.

              I gather that you are on the other side of the pond, so to speak. My wife had an Irish grandfather that came across the pond during the potato faming. He used to tell us some funny stories of his antics when he was a boy back there. He told us of the donkey and dog carts that I guess were plentiful back then.

              Well as usual I got off the subject I was going to mention.  Many years ago I read about a ferry that used the car that was crossing the river for power. It was a flat deck barge on a cable that had a pair of rollers where the wheels rested on the deck. when the car was loaded they parked the rear wheels on the two rollers like on a dyno and they were used to power the ferry. I don't remember if it was hooked to a winch or to a propeller, or paddle wheel. Thought you might be interested in that little tidbit.

                                       Papa Tait Seekonk,Ma.




              --- On Sat, 8/1/09, sydneygreenestreet <sydneygreenestreet@...> wrote:

              From: sydneygreenestreet <sydneygreenestreet@...>
              Subject: [pop-pop-steamboats] Re: Pop Pop 16' canoe
              To: pop-pop-steamboats@yahoogroups.com
              Date: Saturday, August 1, 2009, 7:23 PM

               

              Interesting, you refering to the "Commonwealth" ... How do I attach an MP3 file of Vera Lyn Singing "There'll always be an England"?
              So a longer boat of similar beam to a shorter boat will require less power to get it to go faster that the shorter boat. ie a boat 12' by 4' will need more power that a 20' x 4' boat to travel at the same speed ergo a 16' x 3' canoe (you call them Indian canoes made famous by Nelson Eddy and Jannete MacDonald to me they are classed as yes you guessed it Empire Canoes)will need less power to travel at the same speed as an 8' x 4'6" snub nosed dinghy....

              Don't worry I'll not be disuaded by people who prefer drinking coffee to haveing proper tea....

              We went through the horse on treadmill era here to drive ferries but steam soon replaced them though we still have horse drawn trams (trolleys) on the Granite Island service (google it), very interesting technically at the points at the loops dont have blades, the cars are steered by the horse pulling them to the left. Which brings up another question, how many people remember the exact location of a tram stop 30 years after the tracks have been covered with asphalt?
              Now Gracie (my wonder dog, constant companion and holder of her own rail, tram, ferry and bus pass) does have the webbed feet typical of water loving dogs and when we go swimming she tows me along on the leash quite well but as for putting her on a treadmill, I think the RSPCA would go beresk...

              The object here I think is to flash boil as much water as quickly as possible so maybe the diapragm is really only good for smaller applications. I have 6m length of aluminium tube, I'm gonna have a fart around with it and a huge LPG burner and asseseseseses the results before I start on the copper... one other consideration is the vibration causing the copper to workharden and fail. It does in full size marine engineering practise something else to consider I guess.


            • Donald Qualls
              ... There are two factors at work here (maybe three). First, fineness ratio; generally, for a given displacement, the finer hull (longer and narrower) will
              Message 6 of 15 , Aug 2, 2009
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                sydneygreenestreet wrote:
                > So a
                > longer boat of similar beam to a shorter boat will require less power
                > to get it to go faster that the shorter boat. ie a boat 12' by 4'
                > will need more power that a 20' x 4' boat to travel at the same speed
                > ergo a 16' x 3' canoe (you call them Indian canoes made famous by
                > Nelson Eddy and Jannete MacDonald to me they are classed as yes you
                > guessed it Empire Canoes)will need less power to travel at the same
                > speed as an 8' x 4'6" snub nosed dinghy....
                >

                There are two factors at work here (maybe three). First, fineness
                ratio; generally, for a given displacement, the "finer" hull (longer and
                narrower) will require less power at any speed than the less fine,
                though refinements in the shape beneath the waterline can reduce power
                requirement, up to a point, for any fineness.

                Second, hull speed; there's a speed, for any given waterline length of
                displacement hull (that is, a hull supported only by buoyancy, not by
                dynamic forces), above which the power requirement for greater speed
                increases very sharply, and that speed is the one at which the trough
                following the bow wave just reaches the stern (since the speed of common
                waves in water is fixed, this comes to a specific speed for any given
                hull length). Hull speed is why the aircraft carrier is typically the
                fastest ship in a fleet, even though destroyers have much higher power
                to weight ratio; a modern supercarrier will have a hull speed in excess
                of forty knots, while a destroyer is limited to not much over twenty,
                and a tender (basically a miniature tanker, not much bigger than an
                oceangoing tug) may have to plug along at twelve to fifteen. A transom
                stern can help here, because it provides an effective lengthening of the
                waterline at speed when the water takes time to fill in behind the boat.

                The potential third factor is the one mentioned relative to hull speed:
                if a hull planes, that is, is partly supported by dynamic forces, it can
                go faster than hull speed without the precipitous increase in required
                power. This is why a tug with five thousand horsepower on tap can still
                only churn away at ten or twelve knots, while a runabout with as little
                as fifty horsepower can manage thirty-five (and with a couple hundred
                can go sixty): the runabout is using hydrodynamic lift to climb over the
                bow wave instead of wasting horsepower just building it higher and higher.

                This is applicable to pop-pop boats because every one I've seen is a
                displacement hull; even if the hull is correctly shaped to plane,
                pop-pop motors don't have enough power to climb up onto the bow wave, so
                none of them will go faster than hull speed -- which is pretty slow for
                a boat with a waterline length of, at most, a couple feet.

                For the application of a people (and dog) carrying canoe, it's unlikely
                an reasonably sized power plant will push a canoe significantly faster
                than a couple strong paddlers. Beyond that, wind forces on the hull's
                freeboard can be high enough to upset a paddler (I recall it being quite
                difficult to paddle upwind with a single person in the stern, because
                the available steering force was barely able to overcome the weathervane
                effect) and are likely to swamp the thrust available from even a fairly
                large pop-pop. On the other hand, if you have a canoe to experiment on,
                and the tubing and burner to play with, the worst you'll likely do is
                set fire to the canoe, sink an open bottle of LPG (which will pop up
                again when it gets sufficiently empty), and have to swim for land with
                your water dog towing you...

                --
                If, through hard work and perseverance, you finally get what you want,
                it's probably a sign you weren't dreaming big enough.

                Donald Qualls, aka The Silent Observer http://silent1.home.netcom.com

                Opinions expressed are my own -- take them for what they're worth
                and don't expect them to be perfect.
              • Jean-Yves Renaud
                Additional comments to message #1632 and 1634 from Sydney and Donald. 1°) The speed of a boat is stable when the hydrodynamic resistance is equal to the
                Message 7 of 15 , Aug 2, 2009
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                  Additional comments to message #1632 and 1634 from Sydney and Donald.
                  1°) The speed of a boat is stable when the hydrodynamic resistance is equal to the propulsive thrust. The hydrodynamic resistance is the sum of frictional resistance, wave resistance, and air resistance.
                  The frictional resistance and air resistance evolve with the square of the boat velocity.
                  The wave resistance is something much more complicated. For light displacement boats, when planning conditions are met it can decrease (and then increase again with the boat velocity). Unlikely to decrease for a canoe due to the shape of the hull.
                  Whatever, pop-pop propulsive power is so minute that there is no chance of planning of a canoe.

                  2°) To get the same thrust, 2 (or more) small engines are preferable to a big one because multiple engines are lighter and smaller, and because they develop a higher jet speed, which means a possible higher boat speed.
                  Go to www.eclecticspace.net (it is not a commercial site), click on "pop-pop", then on the English flag, then on "To know more…" and scroll down to open the 3rd document from the bottom of the list: It is entitled "Engine/hull adaptation". Look at the graph at the end of this document. It expresses clearly the limits of pop-pop propulsion.


                  --- In pop-pop-steamboats@yahoogroups.com, Donald Qualls <silent1@...> wrote:
                  >
                  > sydneygreenestreet wrote:
                  > > So a
                  > > longer boat of similar beam to a shorter boat will require less power
                  > > to get it to go faster that the shorter boat. ie a boat 12' by 4'
                  > > will need more power that a 20' x 4' boat to travel at the same speed
                  > > ergo a 16' x 3' canoe (you call them Indian canoes made famous by
                  > > Nelson Eddy and Jannete MacDonald to me they are classed as yes you
                  > > guessed it Empire Canoes)will need less power to travel at the same
                  > > speed as an 8' x 4'6" snub nosed dinghy....
                  > >
                  >
                  > There are two factors at work here (maybe three). First, fineness
                  > ratio; generally, for a given displacement, the "finer" hull (longer and
                  > narrower) will require less power at any speed than the less fine,
                  > though refinements in the shape beneath the waterline can reduce power
                  > requirement, up to a point, for any fineness.
                  >
                  > Second, hull speed; there's a speed, for any given waterline length of
                  > displacement hull (that is, a hull supported only by buoyancy, not by
                  > dynamic forces), above which the power requirement for greater speed
                  > increases very sharply, and that speed is the one at which the trough
                  > following the bow wave just reaches the stern (since the speed of common
                  > waves in water is fixed, this comes to a specific speed for any given
                  > hull length). Hull speed is why the aircraft carrier is typically the
                  > fastest ship in a fleet, even though destroyers have much higher power
                  > to weight ratio; a modern supercarrier will have a hull speed in excess
                  > of forty knots, while a destroyer is limited to not much over twenty,
                  > and a tender (basically a miniature tanker, not much bigger than an
                  > oceangoing tug) may have to plug along at twelve to fifteen. A transom
                  > stern can help here, because it provides an effective lengthening of the
                  > waterline at speed when the water takes time to fill in behind the boat.
                  >
                  > The potential third factor is the one mentioned relative to hull speed:
                  > if a hull planes, that is, is partly supported by dynamic forces, it can
                  > go faster than hull speed without the precipitous increase in required
                  > power. This is why a tug with five thousand horsepower on tap can still
                  > only churn away at ten or twelve knots, while a runabout with as little
                  > as fifty horsepower can manage thirty-five (and with a couple hundred
                  > can go sixty): the runabout is using hydrodynamic lift to climb over the
                  > bow wave instead of wasting horsepower just building it higher and higher.
                  >
                  > This is applicable to pop-pop boats because every one I've seen is a
                  > displacement hull; even if the hull is correctly shaped to plane,
                  > pop-pop motors don't have enough power to climb up onto the bow wave, so
                  > none of them will go faster than hull speed -- which is pretty slow for
                  > a boat with a waterline length of, at most, a couple feet.
                  >
                  > For the application of a people (and dog) carrying canoe, it's unlikely
                  > an reasonably sized power plant will push a canoe significantly faster
                  > than a couple strong paddlers. Beyond that, wind forces on the hull's
                  > freeboard can be high enough to upset a paddler (I recall it being quite
                  > difficult to paddle upwind with a single person in the stern, because
                  > the available steering force was barely able to overcome the weathervane
                  > effect) and are likely to swamp the thrust available from even a fairly
                  > large pop-pop. On the other hand, if you have a canoe to experiment on,
                  > and the tubing and burner to play with, the worst you'll likely do is
                  > set fire to the canoe, sink an open bottle of LPG (which will pop up
                  > again when it gets sufficiently empty), and have to swim for land with
                  > your water dog towing you...
                  >
                  > --
                  > If, through hard work and perseverance, you finally get what you want,
                  > it's probably a sign you weren't dreaming big enough.
                  >
                  > Donald Qualls, aka The Silent Observer http://silent1.home.netcom.com
                  >
                  > Opinions expressed are my own -- take them for what they're worth
                  > and don't expect them to be perfect.
                  >
                • sydneygreenestreet
                  No one has mentioned hull Squat the phenomenom that occurs when traveling at speed in shallow water.... Seriously I don t expect speed in excess of around 2
                  Message 8 of 15 , Aug 4, 2009
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                    No one has mentioned "hull Squat" the phenomenom that occurs when traveling at speed in shallow water....
                    Seriously I don't expect speed in excess of around 2 - 3 knots, serious paddlers can get considerably faster than this....Canoes are about as fine as you can get and move efficiently with little effort, just as any Canadian....
                  • David Halfpenny
                    ... From: sydneygreenestreet ... I learned a lot about canoes one day on the Cam. I was coxing (steering) a racing eight
                    Message 9 of 15 , Aug 4, 2009
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                      --------------------------------------------------
                      From: "sydneygreenestreet" <sydneygreenestreet@...>

                      > No one has mentioned "hull Squat" the phenomenom that occurs when
                      > traveling at speed in shallow water....
                      > Seriously I don't expect speed in excess of around 2 - 3 knots, serious
                      > paddlers can get considerably faster than this....Canoes are about as
                      > fine as you can get and move efficiently with little effort, just as any
                      > Canadian....
                      >
                      I learned a lot about canoes one day on the Cam.

                      I was coxing (steering) a racing eight parked at the bank, and past came
                      two big red-faced lads paddling furiously in a double canoe, throwing up a
                      mighty wake. Behind them was a slight young schoolboy on a scull boat (two
                      oars). He was waiting courteously behind them, just touching his blades
                      lightly in the water a couple of times a minute to keep up with the canoe.

                      OK, I can handle a kayak in choppy water, and if I were hunting beaver in
                      the northern territories I'd take the canoe every time, but the contrast in
                      mechanical efficiency was staggering! Rowing coaches use bicycles because
                      they have to to keep in sight of the crew.

                      David 1/2d
                    • Donald Qualls
                      ... Assuming the boats were similar in length, this is about what you d expect -- the finer scull requires a little less power at any speed below hull speed,
                      Message 10 of 15 , Aug 4, 2009
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                        David Halfpenny wrote:
                        > I learned a lot about canoes one day on the Cam.
                        >
                        > I was coxing (steering) a racing eight parked at the bank, and past came
                        > two big red-faced lads paddling furiously in a double canoe, throwing up a
                        > mighty wake. Behind them was a slight young schoolboy on a scull boat (two
                        > oars). He was waiting courteously behind them, just touching his blades
                        > lightly in the water a couple of times a minute to keep up with the canoe.

                        Assuming the boats were similar in length, this is about what you'd
                        expect -- the finer scull requires a little less power at any speed
                        below hull speed, but any attempt to exceed hull speed will soak up a
                        tremendous amount of power. Compounding this is the fact that a common
                        sliding seat single scull is several times more efficient in converting
                        muscle power into forward motion than a canoe with conventional paddles
                        (so is a kayak, come to that) -- that is, for a given amount of required
                        power, less effort is demanded of the rower than of canoe paddlers.

                        --
                        If, through hard work and perseverance, you finally get what you want,
                        it's probably a sign you weren't dreaming big enough.

                        Donald Qualls, aka The Silent Observer http://silent1.home.netcom.com

                        Opinions expressed are my own -- take them for what they're worth
                        and don't expect them to be perfect.
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