New Propulsion System...

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DwayneJ
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New Propulsion System...

#1

Post by DwayneJ »

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Re: New Propulsion System...

#2

Post by Sabs28 »

Triied 3 times, Problem with video???? :banghead:
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Re: New Propulsion System...

#3

Post by gandrfab »

Worked for me.
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Re: New Propulsion System...

#4

Post by Sabs28 »

It worked on my home PC. :clap:

That is VERY COOL. :thumbsup: :thumbsup:
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"New"?? Propulsion System...

#5

Post by kmorin »

Guys this is just a 'dual prop' axial flow water pump, the same evolution of concentric shafts that Volvo brought to the inboard/outdrive 'leg' but in this case, applied to the Hamilton pump.

Axial flow is axial flow. This won't change the physics of pumps but it may give them more flow in certain torque ranges? The single impeller/propeller axial flow pump, Hamilton and the knockoffs in the US and Europe, really only makes good 'fuel sense' if the speed is high OR the water is so thin/shallow/shoal that drive appendages would be a liability.

Jets are not; "jets". They're pumps since there is no compressibility factor in the flow and no expansion so there is no 'jet' action to create thrust- they're axial flow pumps moving non-compressible liquid- movement by displacement.

So while these guys have a nice concentric shaft, dual impeller, pump; it's not going to change pumped liquid as propulsion. The real "push" will happen at the higher speeds, from developed head; below that there will be a drastic fall-off or fuel economy with steering poor at low speeds, and reverse is often humorous.

What this combination of mechanical properties likely provides is probably similar to the idea from which it is copied; the DualProp by Volvo. The two impellers may give more flow at different points of the engine torque curve (?), therefore giving different efficiencies at different speeds when compared to the high speed, single impeller, Hamilton pumps.

I doubt we're going to see the lower end of any outboard equipped with this pump anytime soon? Until these folks publish their performance curves we can't know much more, but this is mostly a combination of existing hardware.

Cheers,
Kevin Morin
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Re: New Propulsion System...

#6

Post by BWFLU »

I need #s. :popcorn:
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Re: New Propulsion System...

#7

Post by welder »

At least they put it on one of our Sponsors boats.

And one of our members, Tim, is in the interview.
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Re: New Propulsion System...

#8

Post by Napa Mike »

Well, I think it looks cool, and I look forward to hearing more about it and seeing some efficiency numbers.

I did find a web site

http://www.contrapel.com/

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Re: New Propulsion System...

#9

Post by StabicraftMarine »

Ha Fame! Good spotting Welder.

We are pretty happy with what we are seeing, enough to put our name behind it (so to VolPower NZ agent for Volvo)

You guys may have spotted the hull in photos I posted last year. The hull and these two units have been in shakedown for months. They have built many before for smaller hulls and pumping systems.

The Volvos are only just past their first scheduled service so they should start recording data soon (I believe they were fitting the last of the logging gear last week)

There is a lot to it that I don't (and probably won't) understand. What I do know is that the independent tests done here say theoretically it is a winner. The 10.2 was built to test the in the real world so, yes, we will all know if this will work.

I see the guys almost daily at the moment and being a bit of a gear head, enjoy talking to them and learning more. If you have any particular questions, ask me and I will see what they say.

Here is a video on the way the units work.
http://www.youtube.com/watch?v=GxlfHSu- ... r_embedded

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Re: New Propulsion System...

#10

Post by kmorin »

Well, slap me with a cold dead halibut- alongside the head :skillet: !!

these props/impellers are not fully axial (prop/fan/impeller) but they oscillate (rotate AROUND a small center) therefore avoiding the 'jet' pumps three or four limits, this won't need a stator behind the flow to keep the nozzle flow linear, the clearance issues are non-existent, and the fluid acceleration boundary layers' flow drag limits won't apply because there is no 'tip clearance'.

The transmission and shafting looks like it will be an issue for durability, but we'll see? The idea is NOT just an extension of the dual prop inside an Hamilton pump because of the drives/gearboxes/transmission that roll or turn these props/pumps in a series of concentric, but not purely axial, movements.

Reverse is still up in the air, and so is fuel to thrust, but the first link doesn't show the details that make this a 'different' drive, the real details are shown the 'how it works' video with narration. The key there is the two shapes form a continuing acceleration of the fluid, but AVOID most of the problems with a pure 'pump'. This acceleration is not (wholly) dependent on head pressure or a tail-end nozzle with its 'stator' to 'speed up' the exist flow- incredibly elegant idea.

By the way, it's pretty important to note that the idea that Hamilton Jet pumps have much nozzle and there fore thrust gain is sort of misleading. The real effect of these pumps comes from ramming water up into the pump as the boat moves. The gain from the thrust of the pump duct/ or 'nozzle' is very small compared to the head/speed/ram. The Hamilton pump will get more and more effective the faster it goes, because you're using the boat's momentum to get more and more water at higher speeds into the intake.

This set of 'props' not only turns on a shaft but the shaft sections appears to rotate, like a cam in the housing, so the fixed impeller Hamilton type propulsion limits won't be as limiting. What will be interesting is the comparative performance.

Tim, will you be installing conventional drives to be able to get an 'apples to apples' comparison in the boat shown? How will the new drive's inventors make comparisons without conventional drives in the same boat? I know they could use the fuel flow and speeds to make statements but won't a head's up comparison be needed?

What is the approximate amount of shaft oscillation in the drive?

This drive may have more impact in small hydro and industrial pumps than small marine drives in the end? I wonder if an open ocean boat with no draft limits is going to support a drive that will double the cost of the average drive system since the main gain is shoal operations? But if the fuel efficiency shows this improves over a conventional wheel, then its a matter of how small the design can be scaled economically?

It will be interesting to watch the sea trial numbers when they're published.

cheers,
Kevin Morin
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Re: New Propulsion System...

#11

Post by Napa Mike »

Thanks Tim:

The animation is really neat! I am sure it would take me years just to understand the animation. I bet you are subject to a nondisclosure agreement and, if it were me, I would be dying to talk about it. Let us know what is going on, when you are allowed to talk about it.

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Re: New Propulsion System...

#12

Post by StabicraftMarine »

kmorin wrote:Reverse is still up in the air
The gear boxes are built with reverse drive. The current boat works well but the guys have already learnt the set up (height) is not ideal for the hull. More will come as it is discovered, validated or rejected - innovation at its best.
kmorin wrote:By the way, it's pretty important to note that the idea that Hamilton Jet pumps have much nozzle and there fore thrust gain is sort of misleading. The real effect of these pumps comes from ramming water up into the pump as the boat moves. The gain from the thrust of the pump duct/ or 'nozzle' is very small compared to the head/speed/ram. The Hamilton pump will get more and more effective the faster it goes, because you're using the boat's momentum to get more and more water at higher speeds into the intake.
I'll poke up a graph from the testers that in layman's terms shows output efficiency. From my understanding, everything is a compromise and this looks like it fits very well across the range.
kmorin wrote:Tim, will you be installing conventional drives to be able to get an 'apples to apples' comparison in the boat shown? How will the new drive's inventors make comparisons without conventional drives in the same boat? I know they could use the fuel flow and speeds to make statements but won't a head's up comparison be needed?
Im not sure. Contrapel are a separate company with no affiliation to Stabicraft. They came to us to build a recognisable hull to demonstrate the technology. Personally I have been talking to and helping the guys with promotional work where I can but the direction they take is entirely at their discretion. I expect this is a question they will be asked a lot and it may be addressed one day.
kmorin wrote:What is the approximate amount of shaft oscillation in the drive?
This is hush-hush.
kmorin wrote:This drive may have more impact in small hydro and industrial pumps than small marine drives in the end? I wonder if an open ocean boat with no draft limits is going to support a drive that will double the cost of the average drive system since the main gain is shoal operations? But if the fuel efficiency shows this improves over a conventional wheel, then its a matter of how small the design can be scaled economically?
Testing and testing and little more testing will tell all I expect. They could have many uses, time will tell. At the flow rates they are seeing water to shore pumping (emergency orgs.) and farming could benefit from the tech. The guys have been working with certain organisations in mind and to their testing expectations.
kmorin wrote:It will be interesting to watch the sea trial numbers when they're published.
For me too Kevin. Its hard not to be excited with boats in general but anything new is always welcome in my books.
Napa Mike wrote:Thanks Tim:
The animation is really neat! I am sure it would take me years just to understand the animation. I bet you are subject to a nondisclosure agreement and, if it were me, I would be dying to talk about it. Let us know what is going on, when you are allowed to talk about it.
Mike
Thanks Mike. I'll always share what I can. Right now there is very little I know that I cant share but there isn't much more I know! It is very early days yet.

Regards,
Tim.
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Re: New Propulsion System...

#13

Post by Napa Mike »

Hey Tim:

Have you been on the boat for a test of reverse? I think you said that the gearbox has a reverse drive. Excuse my lack of technical knowledge, but does that mean water gets sucked up the back end and pushed out the forward intake to move the boat in reverse? And if so, how do you steer in reverse?

Thanks,
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Re: New Propulsion System...

#14

Post by StabicraftMarine »

Napa Mike wrote:Hey Tim:

Have you been on the boat for a test of reverse? I think you said that the gearbox has a reverse drive. Excuse my lack of technical knowledge, but does that mean water gets sucked up the back end and pushed out the forward intake to move the boat in reverse? And if so, how do you steer in reverse?

Thanks,
Mike

Every time I go out with the guys, I end up on a different boat. I should be selfish one day and demand a good go myself.

Reserve is driven through a gearbox reversing the props - the intake and outlets are reversed. Steering is best done via throttle (one can be reversed, one forward) but to be honest all that needs to happen is to get the boat a length away from what it is you are reversing from then as you will have seen in the video, the boat turns on itself in forward.

Interestingly, talking to one inventors (welder, he found the site all by himself!) , they have seen 70% thrust in reverse measured against the same unit in the same water just turned around.

I asked him about posting here and he was happy I did. He and I know that I don't have the grasp needed to answer everything but he has promised to answer any SOS's I send him when I get stuck.

So fire away.

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Re: New Propulsion System...

#15

Post by StabicraftMarine »

Kevin, the inventors dropped me an email last night for you. It relates to the point you raised about pressure heads in the Hamilton type units.

"The comment that the thrust in a water-jet is developed in the intake via ram is incorrect.
As the water enters the intake duct it diffuses (True of all intake ducts) and slows down. This is evidenced by an increase in pressure. (Higher pressure, lower velocity - Bernoulli) The reduction in water velocity in the intake duct is a net loss of thrust. All the acceleration takes place in the outlet nozzle. The difference between the loss in the intake duct, pump section and stator section subtracted from the "change in velocity" in the nozzle is the net thrust. Improvements in thrust can be gained by reducing the area of the intake duct so that the water diffusion is kept to a minimum. The trade off however is getting good water flow into the intake duct at low speed which can cause impeller slippage. At high speed where water feed is enhanced by the forward boat speed, it helps a water-jet to go faster as the can develop higher pressure head in the nozzle.

Because the water slows in a pressure pump forward of the nozzle, the weight of that water is added to the vessel, i.e it's carried forward with the vessel. This additional weight is factored into efficiencies for larger craft as it can impact the overall efficiency equation.

The Contrapel system conversely accelerates the water from out of the intake duct which is designed to be as low as possible and thus reduce the diffusing effect. Once the water is accelerated it's no longer considered to be entrained and thus does NOT add to the overall weight of the boat.

I hope that this clears up any misunderstandings about intake ducts and the ram effect. Ramjets in aircraft gain an advantage because the % of air goes up when rammed, (air is compressible, water essentially is not) giving a bigger bang through more expansion once the fuel is ignited. In a water jet there is no compression of water, and no expansion. The pressure rise is only via water slowing down! This equates to negative thrust. It is interesting to discover that the lowest pressure in a nozzle is where the diameter is smallest, which is also where the velocity is at it's greatest. (This is opposite to what most people think) One cant beat physics!
Thrust equals "change in velocity on a given mass". Speed the water up to greater than boat speed..... the overall thrust goes up. Slow the water down in the system below boat speed, removes thrust.

Regards
Barry Davies (Contrapel co-inventor)"

ENDS

Let me know if there is anything more you would like to know.

Regards,
Tim.
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Re: New Propulsion System...

#16

Post by dawgaholic »

Congrats Tim and Stabicraft! All I can say is business has got to get better or I gotta stop dreaming.... :thumbsup:
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New Propulsion System...misunderstanding terms

#17

Post by kmorin »

Tim, Barry thanks for the reply.

I’m sorry that Barry misunderstood what I posted, shown by his incorrect paraphrase of my post;
Barry: "The comment that the thrust in a water-jet is developed in the intake via ram is incorrect.”
That shows I’m not communicating very well!

I didn’t say or mean to imply the water-jet intake is where the thrust is developed. I’d hoped to convey the velocity gain aspect of the pump’s effectiveness at providing higher speed(s) was incremental and somewhat conditional on the velocity of travel and therefore intake volume flow. So I used the term ‘ramming water’ perhaps I should have said, really increase water flow instead of using the more colorful word ‘ramming’?

What I posted was;

“By the way, it's pretty important to note that the idea that Hamilton Jet pumps have much nozzle and there fore thrust gain is sort of misleading. The real effect of these pumps comes from ramming water up into the pump as the boat moves. The gain from the thrust of the pump duct/ or 'nozzle' is very small compared to the head/speed/ram. The Hamilton pump will get more and more effective the faster it goes, because you're using the boat's momentum to get more and more water at higher speeds into the intake. “

Poorly worded, but interesting to note that Barry posts a phrase very similar statement to mine?

Barry: “At high speed where water feed is enhanced by the forward boat speed, it helps a water-jet to go faster as the can develop higher pressure head in the nozzle.”

("water feed is enhanced" is essentially "ramming water into the pump" to me!)

Kevin: “The Hamilton pump will get more and more effective the faster it goes, because you're using the boat's momentum to get more and more water at higher speeds into the intake.”

Barry concludes with a statement: “Thrust equals "change in velocity on a given mass". Speed the water up to greater than boat speed..... the overall thrust goes up. Slow the water down in the system below boat speed, removes thrust.

I agree and didn't mean to imply otherwise, but a “given mass” is when the Hamilton pump boat stands still more or less fixed inlet flow. We have an “increasing mass” since in Barry’s words “where water feed is enhanced by the forward boat speed”. (italics mine) I was remarking about the increasing speed coming from “changing the velocity of an increasing mass”. I called this the ‘real effect’ and should have made it clearer, sorry mate.

I wasn’t attempting to say the force is expressed anywhere but the nozzle outlet, just that the nozzle outlet speed increase (IT IS MY UNDERSTANDING???) is most increased by the increase in mass which happens (only) at higher speeds and the associated higher flow rates in this design of pump. [Hence ‘ramming water’, not meant to imply compressibility as in a gas jet.]

If I understand correctly then Barry's new drive exhibits performance characteristics that are substantially different from its Hamilton 'ancestor'? So the range of performance of the new drives is much wider and much less prone to the limits associated with the Hamilton type pump? And since the Hamilton drive's limits are mostly experienced in lower speed the new drive is effective at low speeds as well as higher speeds????

A few questions about the drive physical elements: but they may not be for release at this time?
Does the drive have a bearing, on the aft end of the tail shaft, in the 'cone'?
Is that a lubricated roller or ball type steel element bearing or a water film 'cutlass' bearing type?
Do the two impeller/propeller's shape and radial (fluke) orientation act to 'counter weight' the other's eccentric side loads on the shaft(s) and on the fore (and aft) bearings?
In reverse; is the flow into the "flow chamber" from around the conic end element inside the illustrations?

thanks again for the information about your ingenious new drive system.

Cheers,
Kevin Morin
Last edited by kmorin on Tue Sep 18, 2012 6:06 pm, edited 1 time in total.
Reason: typo's
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Re: New Propulsion System...

#18

Post by StabicraftMarine »

This messenger might want shot... Information overload.

Seriously though, I am posting this to help everyone out there looking for more information.

Contrapel is getting good coverage around the world but this site is one of the few that has active and thoughtful consideration for the concept. Contrapel, Stabicraft and I appreciate that immensely and I hope all you AABer's do too.

The Contrapel team is about start the long drive north to display the boat at the Auckland International Boat Show (it is a four day drive) so Barry though prudent to quickly reply to KMorin (Kevin).

Kevin, Barry appreciates your thoughts a lot. He commented to me how impressed he was with your process and obvious knowledge. What is below is again taken straight from an email from him. If there is incorrect intonation, please forgive it, it will be due to the nature of talking through a third wheel - me.

Kind regards and I hope this is of value to you all.
Tim

From Barry 20 September 2012.

I've clipped below a white-paper that I used to confirm what I discovering in practice, with the Contrapel system


This text was taken from Mechanics of Fluids, Second Edition, A C Walshaw (Professor Emeritus, University of Aston in Birmingham), D A Jobson (Formerly Assistant Professor of applied Mechanics Royal College, Greenwich) and sets out the precise differences between waterjets and other propulsors such as propellers.

“ The basic difference between the propeller and the jet, apart from their conversion efficiencies, is that the former exerts a thrust by imparting a small increase in velocity to a relatively large mass of fluid, whereas a jet generally discharges a much smaller mass flow at a much higher speed. The question arises as to which one of these is fundamentally more efficient in any given circumstances?

The answer to this was established by Rankine in 1865, and his theory was elaborated by R E Froude who, with his father W. Froude, laid the foundations of resistance and propulsion and, indeed, of much of naval architecture. According to the Rankine/Froude momentum theory the propulsive element is assumed to be replaced by a hypothetical actuator disc...and which is assumed to accelerate the fluid axially without rotation.

Although this may appear to be a very abstract concept it come much nearer to describing how a propeller acts than the more popular but erroneous notion that a propeller “screws” its way through a fluid. A cordless section through a propeller blade encounters an on-coming stream which it deflects in a fore and aft direction, so that the axial component of the fluid velocity is increased. The various helical motions which are imparted to the fluid are merely parasitic in so far as they represent a useless waste of energy.

Considering the motion relative to the actuator, fluid approaches it with a velocity U. If we concentrate on the fluid which is destined to pass through it, the stream will contract as the fluid accelerates to its final velocity, V, say.

If the rate of mass flow is m’, the force or thrust exerted is:

T = m’(V-U)

And the thrust power is:

P=TU

Hence the work output or useful work done in time(t) is:

W₀ = Pt = m’t U (V-U)

During this time the actuator has increased the velocity of a mass (m’t) from U to V, so that the work input Wί which has been used to increase the kinetic energy of the fluid is;

Wί = ⅟₂ (m’t) (V²-U²)

Hence the ideal , or Froude efficiency :

ηF = W₀ / Wί = U ( V – U) ÷ ½ (V2 - U2)

= 2 ÷ 1 + (V/U)

For the Froude efficiency to be high, V should be only slightly greater than U, i.e. the increase in velocity necessary to produce thrust, should be a minimum. The cause of inefficiency is the jet energy of the wake; the useful thrust T is proportional to the increase of velocity (V-U), whereas the energy imparted to the fluid increases as its square, ½ u2jet , the energy rejected being ½ (V-U)2 per mass unit.

Thus the efficiency is a maximum when the increase of velocity is a minimum, so that it is fundamentally more efficient to obtain thrust by imparting a relatively small increase in velocity to a large mass flow.”

As all current water jets use a nozzle principle to accelerate a relatively small mass of water to high velocity, the inherent losses are high at low to mid speeds.

Following is a chart presented by a division of the US Navy (ONR- office of Naval Research) in 2006 comparing efficiencies between modern water jets and various propeller systems. At ten knots a waterjet has less than 50% propulsive efficiency compared to a conventional propeller. In the low to mid-range speeds water jets have very low propulsive efficiencies as predicted by the Froude model. It is not until relatively high speeds are obtained (35 knots and over) that water jets are able to begin to match propeller systems for efficiency.

The Contrapel propulsion system overcomes this problem by maximizing the mass output and minimizing the outlet velocity, through maintaining the lowest possible back-pressure in the outlet. The pleasant outcome was that equivalent high speeds have been achievable even though the gains I was expecting were mostly thought to be the slow-speed ranges.

Kevin, I've had Hamilton jets all my boating life (40 years) and am a great fan. I still have a jet-boat for hunting which is fitted with an alloy supercharged Toyota V8 (my creation which was built by me thirty years ago) The engine is coupled to a Hamilton three stage jet. I'm very fond of this boat as it has great memories for me. I've fitted 750 single and three stage units to alloy jetboats, which I started designing and building in the early 80's, so that we could explore Fiordland lakes, rivers and fiords. I built an alloy jet boat while living in London and fitted it with a 770 series 3 stage Hamilton powered by 350 cub inch Chev, and later purchased the 212 series unit to get comparative data against which to compare the Contrapel system. The 212 was powered by a 400 cub inch Chev. I'm not a boat builder, I've done this out of interest, so it's been quite a mission....so please excuse me if I appear a little short in my reactions at times.

To answer your questions, if I understand you correctly. The reaction forces of the two contra-rotating impellers not only removes the radial energy in the flow, they balance each other to produce a very quiet and extremely smooth unit. No vibrations can be detected. Not only this, the propellers are able to sustain massive damage to the leading blade edges, as well as huge clearances around the pump housing walls, with vitually no apparent loss of boat performance nor increase in vibrations. (This is not the case with pressure jets)

The propeller rotational speeds are extremely low, in fact we run them at less than half engine rpm! For example a 190mm diameter Contrapel running at 60mph has a propeller rpm of around 3000.

The 330 mm dia. units in the yellow boat featured on the TV clip are turning at 1,700 rpm @ 44mph. (That's an 8 ton boat)

I've never been a fan of the cutless bearing and the inability to dry-run in the garage before heading off on an expedition without removing the drive-shaft. There are no water lubricated bearings in my system. Furthermore the bearing supporting the inner shaft at the outlet is fitted behind the anti-ventilation cone and thus is not subject to flow or pressure. The units can be dry run for as long as you want by just putting the garden hose into a skin fitting which feeds the engine cooling.

Reverse in an enclosed system, particularly jets, is problematic, as the outlet becomes the intake...so it's like sucking through a straw. Reverse flow in a pressure jet only allows for "flushing" of the grill. The Contrapel system has two problems, the reduced outlet diameter which is still relatively very large compared to a pressure jet and the the hydrodynamic requirement of "balancing" the flow across the propellers (which are now going backwards). To overcome these issues the unit has a bi-pass gate which automatically opens underneath the propellers when the throttles are shifted into reverse. This enables the water to be drawn in from underneath the unit while in reverse, while an anti-ventilation cap "closes off the outlet" from the air, otherwise the units would draw in air and not reverse the flow. The result is a much more linear thrust force as a reversing bucket tends to lift the stern, and stir up the bottom in shallows. Tests that I've conducted show that I can expect in excess of 70% of forward thrust when in reverse. I'm still working on the system, however the mechanics and the way it works is very pleasing so far. A lot of what we know about boating will change from now on, as the Contrapel system gives so much more control over the boat at low engine rpm. At the end of the fishing season last year Paul and I trolled for trout all day long on one unit in the 8 ton yellow boat. We were averaging 1.2 liters of diesel per hour. At trolling speed the propellers are rotating at 300rpm and the boat has positive thrust and control.

I hope these explanations are of help Kevin and I'll pass them onto Tim who hopefully will post them for you to read.

Regards

Barry Davies (Contrapel Ltd)
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Re: New Propulsion System...

#19

Post by welder »

Tim, tell Barry THANK YOU for the reply , we will need more info. on this project as it comes up. Heck Barry just might have to send us a TEST boat to put some hours on it for him. :mrgreen:
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Re: New Propulsion System...

#20

Post by StabicraftMarine »

Barry actually gave me these numbers a while back but I have been too busy to post them up. The boat was fully fuelled, 2 up. Weight would have been around 8000kg.

RPM --- Knots --- Lph --- L/nm
1200 --- 5.99 --- 7.3 --- 1.21
1540 --- 7.82 --- 17.2 --- 2.2
1800 --- 9.5 --- 28 --- 2.94
2000 --- 10 --- 37.5 --- 3.75
2250 --- 15.5 --- 52 --- 3.35
2500 --- 17.6 --- 65.4 --- 3.7
3030 --- 29.7 --- 107 --- 3.6
3230 --- 33.5 --- 127 -- - 3.79
3500 --- 37.25 --- 164 --- 4.4

These numbers are on new gearboxes and still as-new motors. The motors still need to be properly broken in. The gear boxes were specifically designed for the units and motors. To be confident, the team need to do enough hours on them before removing them for a full inspection and bearing check. Once everything is signed off the numbers will be properly validated - and I will share (so long as I am allowed)

A (cough) glass Tiara 3200 Open running a pair of Volvo D6 310's running three blade 19,0 x 24,0 props(the Contrapel Stabicraft is running two D6 435's) got the numbers below. There are lot of hull differences and there is a heap of fendering to drag along with CP1. The Tiara is also beamer with a shallower deadrise.

These numbers came from
Performed by: Jason Hinkel
Test location: Holland, MI, USA
Test date: 2003-09-24

RPM --- knts --- L/hr--- L/nm
600 --- 4,3 --- 1,5 --- 0,3
1000 --- 6,4 --- 3,0 --- 0,5
2000 --- 9,7 --- 34,8 --- 3,6
2500 --- 15,1 --- 65,1 --- 4,3
3000 --- 23,4 --- 85,5 --- 3,7
3300 --- 27,3 --- 102,2 --- 3,7
3500 --- 29,4 --- 120,3 --- 4,1
3610 - -- 30,5--- 130,2 --- 4,3

So what do you guys think?
http://www.stabicraft.com

For your nearest dealer...
888 GO STABI (USA)
1800 178 224 (AUS)
0800 478 224 (NZ)

For the Invercargill, NZ factory - 0064 3 2111 828
Napa Mike
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Re: New Propulsion System...

#21

Post by Napa Mike »

That looks pretty promising Tim! For comparison purposes, do you have performance numbers for the Victoria Coast Guard boats with twin 200 outboards? (those boats look to be about the same size/weight as the boat with the Contrapel drive)
thanks,
Mike
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Re: New Propulsion System...

#22

Post by StabicraftMarine »

The Vic coast guard boats are smaller. The biggest we have sent lately was a 9.2m running twin BF250's. It weighs a lot less than the 10.2. Off hand it came in at around 3200kg so around half the 10.2's weight. I might be able to find the figures if you want? Honda were particularly interested in the boat as it was one of the first in Melbourne to get two 250's.

Tim.
http://www.stabicraft.com

For your nearest dealer...
888 GO STABI (USA)
1800 178 224 (AUS)
0800 478 224 (NZ)

For the Invercargill, NZ factory - 0064 3 2111 828
Napa Mike
Posts: 355
Joined: Fri Oct 01, 2010 2:18 pm
Location: Bainbridge Island WA

Re: New Propulsion System...

#23

Post by Napa Mike »

StabicraftMarine wrote:The Vic coast guard boats are smaller. The biggest we have sent lately was a 9.2m running twin BF250's. It weighs a lot less than the 10.2. Off hand it came in at around 3200kg so around half the 10.2's weight. I might be able to find the figures if you want? Honda were particularly interested in the boat as it was one of the first in Melbourne to get two 250's.

Tim.
Hey Tim:

I was really looking for something comparable to the boat with the Contrapel drive--so we could compare the Contrapel drive to outboard power. But, that said, we always like facts and figures--almost as much as we like pictures!

Thanks,
Mike
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Re: New Propulsion System...

#24

Post by welder »

Any more news on this system?
Lester,
PacificV2325, Honda BF225
2386
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Re: New Propulsion System...

#25

Post by JETTYWOLF »

-How did that Floridian slip into AAB without me noticing...Welcome "Bonita Springs Fla."

We need more of us!
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