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Pop Pop 16' canoe

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  • sydneygreenestreet
    Hi I m new to this forum but not new to steamboats of the conventional kind with pistons and moving bits. Alas I ve been put out to stud (I wish) and I m
    Message 1 of 15 , Jul 29, 2009
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      Hi I'm new to this forum but not new to steamboats of the conventional kind with pistons and moving bits. Alas I've been put out to stud (I wish) and I'm thinking of building a full size Pop pop powered canoe.

      Now some of you will no doubt have done this already so spare me the hassels and give me some clues on what size boiler(for want of a better expression)I'd need to drive a Canoe for me and my dog to cruise our local lake. I intend to burn used diesel sump oil with a vapourising burner.
      When I get the chance I'll post some pics of my steam launches I've built.
    • darylcanada73
      Welcome to the forum. You are very ambitious and I hope you succeed as I m sure you can....BUT....how big is your dog and how fast do you want to go???? The
      Message 2 of 15 , Jul 30, 2009
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        Welcome to the forum. You are very ambitious and I hope you succeed as I'm sure you can....BUT....how big is your dog and how fast do you want to go???? The putt putt engine is not noted for speed, power, rational behavior or efficiency. On the other hand it is pretty easy to build one that works. I don't know how much reading or research you have done so there are some links below in case you have not already found them.

        http://www.sciencetoymaker.org/........Lots of neat stuff here including some putt putt history.

        http://www.eclecticspace.net/....go to pop pop, then Jean-Yves pages. Jean-Yves is a member of this forum and has done a huge amount of work particularly in the math/physics part.

        http://www.youtube.com/watch?v=RvlM-_glZ_g......will show you some of my boats.

        Check out the files and photos on this forum too.

        Good luck.............Daryl

        --- In pop-pop-steamboats@yahoogroups.com, "sydneygreenestreet" <sydneygreenestreet@...> wrote:
        >
        > Hi I'm new to this forum but not new to steamboats of the conventional kind with pistons and moving bits. Alas I've been put out to stud (I wish) and I'm thinking of building a full size Pop pop powered canoe.
        >
        > Now some of you will no doubt have done this already so spare me the hassels and give me some clues on what size boiler(for want of a better expression)I'd need to drive a Canoe for me and my dog to cruise our local lake. I intend to burn used diesel sump oil with a vapourising burner.
        > When I get the chance I'll post some pics of my steam launches I've built.
        >
      • Jean-Yves Renaud
        First, I confirm the welcome. Second,I add just some words to Daryl s post concerning www.eclecticspace.net. Click on pop-pop and then on la page de
        Message 3 of 15 , Jul 30, 2009
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          First, I confirm the welcome.
          Second,I add just some words to Daryl's post concerning www.eclecticspace.net. Click on "pop-pop" and then on "la page de Jean-Yves" and then on "Powering a real boat. Don't dream".
          Third, Jorn and Eljoh, two Dutch students who I adviced, succeeded to run a boat during 20 minutes... at very very slow speed (on a day without wind).

          --- In pop-pop-steamboats@yahoogroups.com, "darylcanada73" <darylcanada73@...> wrote:
          >
          > Welcome to the forum. You are very ambitious and I hope you succeed as I'm sure you can....BUT....how big is your dog and how fast do you want to go???? The putt putt engine is not noted for speed, power, rational behavior or efficiency. On the other hand it is pretty easy to build one that works. I don't know how much reading or research you have done so there are some links below in case you have not already found them.
          >
          > http://www.sciencetoymaker.org/........Lots of neat stuff here including some putt putt history.
          >
          > http://www.eclecticspace.net/....go to pop pop, then Jean-Yves pages. Jean-Yves is a member of this forum and has done a huge amount of work particularly in the math/physics part.
          >
          > http://www.youtube.com/watch?v=RvlM-_glZ_g......will show you some of my boats.
          >
          > Check out the files and photos on this forum too.
          >
          > Good luck.............Daryl
          >
          > --- In pop-pop-steamboats@yahoogroups.com, "sydneygreenestreet" <sydneygreenestreet@> wrote:
          > >
          > > Hi I'm new to this forum but not new to steamboats of the conventional kind with pistons and moving bits. Alas I've been put out to stud (I wish) and I'm thinking of building a full size Pop pop powered canoe.
          > >
          > > Now some of you will no doubt have done this already so spare me the hassels and give me some clues on what size boiler(for want of a better expression)I'd need to drive a Canoe for me and my dog to cruise our local lake. I intend to burn used diesel sump oil with a vapourising burner.
          > > When I get the chance I'll post some pics of my steam launches I've built.
          > >
          >
        • Pete B.
          Good morning, A 3Pete...welcome! I m no where close to having the knowledge of Jean-Yves or Daryl when it comes to Pop-Pops. They both have years of research,
          Message 4 of 15 , Jul 30, 2009
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            Good morning,


            A 3Pete...welcome!

            I'm no where close to having the knowledge of Jean-Yves or Daryl when it comes to Pop-Pops. They both have years of research, practical experience and playing with the little boats. We have several other members who are also good resources. If you don't know, ask. You'll most likely get a sound answer. Please keep us posted on your project.

            Pete


            --- In pop-pop-steamboats@yahoogroups.com, "sydneygreenestreet" <sydneygreenestreet@...> wrote:
            >
            > Hi I'm new to this forum but not new to steamboats of the conventional kind with pistons and moving bits. Alas I've been put out to stud (I wish) and I'm thinking of building a full size Pop pop powered canoe.
            >
            > Now some of you will no doubt have done this already so spare me the hassels and give me some clues on what size boiler(for want of a better expression)I'd need to drive a Canoe for me and my dog to cruise our local lake. I intend to burn used diesel sump oil with a vapourising burner.
            > When I get the chance I'll post some pics of my steam launches I've built.
            >

          • sydneygreenestreet
            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
            Message 5 of 15 , Jul 30, 2009
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              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....
            • 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 6 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 7 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 8 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 9 of 15 , Aug 1 4:23 PM
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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 10 of 15 , Aug 1 5:52 PM
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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 11 of 15 , Aug 2 6:56 AM
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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 12 of 15 , Aug 2 8:24 AM
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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 13 of 15 , Aug 4 12:25 AM
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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 14 of 15 , Aug 4 6:29 AM
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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 15 of 15 , Aug 4 5:10 PM
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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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