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10-26-2015, 09:38 PM
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#1
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Guru
City: Punta Gorda, fl
Vessel Name: Escapade
Vessel Model: Nordic Tug 37 2002
Join Date: Jan 2015
Posts: 1,231
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Jet Thrusters - Does anyone have this system?
Saw this thruster system. Wonder if anyone has one and how well does it work?
http://youtu.be/JLDuwnnOCcY
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10-27-2015, 04:43 AM
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#2
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Senior Member
City: Pittwater
Vessel Name: Liberty
Vessel Model: 57 foot Halvorsen
Join Date: Aug 2015
Posts: 196
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Don't know any one who has them, but they certainly look impressive and easy to fit.
Would hate to break a line, could quickly flood your boat ?
Cheers Chris D Liberty
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10-27-2015, 09:17 AM
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#3
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Guru
City: Everett Wa
Vessel Name: Eagle
Vessel Model: Roughwater 58 pilot house
Join Date: Oct 2007
Posts: 2,919
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Your boat has hudraulic jet bow thrusters. Made by omnie thrust. Our thruster is the smallest they the are mostly on larger ships ferry. They are so so. The advantage is being hydraulic which can run for hours as long as the engine runs. The disadvantage I'd it takes to long to switch to the other side. The thruster has a hydraulic motor rated 2500 psi and the hose are 3000 psi, and the thruster is made of SS 3/8". The thruster is powered by the gen set which does not have the hp for what thrust is rated for.
The hydraulic has quick change hose coupling to power the get home. I changed the hydraulic pump to variable psi with a cable up to the pilot house so the thrust is 0 to 1800 psi. If the thrust I would change to standard propeller type as the pump is also reversible. But for now the work for our fair weather boating.
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10-27-2015, 09:46 AM
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#4
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Enigma
City: Slicker?
Join Date: Oct 2007
Posts: 16,563
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Re: Post #3...What?
__________________
RTF
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10-27-2015, 10:06 AM
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#5
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Guru
City: Pender Harbour, BC
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,791
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Me too...?
__________________
Don't believe everything that you think.
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10-27-2015, 10:39 AM
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#6
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Moderator Emeritus
City: SEWARD ALASKA
Vessel Name: DOS PECES
Vessel Model: BAYLINER 4788
Join Date: Feb 2011
Posts: 6,266
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The concept here is intriguing.
Take a high pressure, high volume pump and direct it's output where you need it.
This is opposed to the traditional thruster methodology of taking a low pressure high volume pump and installing it directly perpendicular to the hull.
The challenges are significant but not impossible to overcome. For example I did not notice sea cocks on these huge below the waterline through hulls. That seems like a risk to me, but the design could be modified to utilize a proper sea cock.
What I am wondering is if this concept of a pump and high pressure seawater stream could be used to provide roll dampening. If that worked out then it would provide an alternative to traditional fin stabilizers.
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10-27-2015, 10:45 AM
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#7
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Senior Member
City: Houston
Vessel Name: Alegría
Vessel Model: Overblue 48
Join Date: Jun 2015
Posts: 237
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The sizing tool on the site indicated they don't have a system large enough for a 50' cat. Seems if your boat is large enough to need thruster(s), they can't help.
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10-27-2015, 10:56 AM
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#8
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Technical Guru
City: Wilmington, NC
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 6,194
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It will not be as efficient as a prop thruster. Not that efficiency is a big deal for a thruster, it is that the gennie and main engine at idle simply don't have a lot of available hp. So factor in hyd system losses, big centrifugal water pump losses, piping losses, and the basic inefficiency of jet propulsion and your available 20-odd hp ends up being a few hp worth of thrust.
In other words, weak thruster.
Still a neat concept, and there may be apps were it could work very well.
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10-27-2015, 11:20 AM
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#9
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Guru
City: Sarasota/Ft. Lauderdale
Join Date: Apr 2014
Posts: 5,438
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Quote:
Originally Posted by Xsbank
Me too...?
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As I've said before, alcohol and the interweb don't mix well.
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10-27-2015, 11:23 AM
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#10
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Guru
City: Sarasota/Ft. Lauderdale
Join Date: Apr 2014
Posts: 5,438
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Quote:
Originally Posted by ksanders
What I am wondering is if this concept of a pump and high pressure seawater stream could be used to provide roll dampening. If that worked out then it would provide an alternative to traditional fin stabilizers.
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Between reaction times and maximum forces generated I doubt it can be made to work engineering and/or cost wise.
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10-27-2015, 01:04 PM
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#11
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Moderator Emeritus
City: SEWARD ALASKA
Vessel Name: DOS PECES
Vessel Model: BAYLINER 4788
Join Date: Feb 2011
Posts: 6,266
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Quote:
Originally Posted by Capt.Bill11
Between reaction times and maximum forces generated I doubt it can be made to work engineering and/or cost wise.
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I suspect you are correct. Someone had to have thought of that before.
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10-27-2015, 01:46 PM
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#12
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Guru
City: Powell River, BC
Vessel Name: Northern Spy
Vessel Model: Nordic Tug 26
Join Date: Feb 2012
Posts: 4,075
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I like this idea. Would want to know much more about the pump before I plunked any money down.
I always thought that an azimuthing eductor nozzle under the hull would be a interesting design concept. Two diametrically opposed educators mounted athwartships with a y-valve would even be simpler.
Good eductors move 4x the amount of water supplied as the motive force.
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10-27-2015, 02:00 PM
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#13
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Guru
City: Stuart FL
Vessel Name: Lucky Lucky
Vessel Model: Pacific Mariner 65
Join Date: Aug 2013
Posts: 2,760
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Gonna scare the crap out of the dolphins that follow my boat.
__________________
Howard
Lucky Lucky
Stuart, FL
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10-27-2015, 02:03 PM
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#14
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Guru
City: Seattle, WA
Vessel Name: Pau Hana
Vessel Model: 1989 PT52 Overseas Yachtfisher
Join Date: Aug 2012
Posts: 2,676
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A related idea-
Forward- 2 pumps, outlets mounted directly to the hull (port and stbd sides), fed by a common thru hull. Pumps are electrically activated as needed to provide thrust action.
Aft- as above, only the pump feed is directly below the pump itself.
A bit more complex, but there is not pressurised water flowing thru the vessel from a common centrally mounted pump.
__________________
Peter- Marine Insurance Guru at Novamar Insurance Group (206-350-5051) & tuna fishing addict!
1989 52' PT Overseas yachtfisher
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10-27-2015, 02:40 PM
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#15
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Moderator Emeritus
City: SEWARD ALASKA
Vessel Name: DOS PECES
Vessel Model: BAYLINER 4788
Join Date: Feb 2011
Posts: 6,266
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Quote:
Originally Posted by Pau Hana
A related idea-
Forward- 2 pumps, outlets mounted directly to the hull (port and stbd sides), fed by a common thru hull. Pumps are electrically activated as needed to provide thrust action.
Aft- as above, only the pump feed is directly below the pump itself.
A bit more complex, but there is not pressurised water flowing thru the vessel from a common centrally mounted pump.
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I like that Pete!
Then you'd need two solenoid valves, one per direction. The joystick turns on the pump and opens the proper solenoid valve
So, how many HP is a thruster for say a 45-50' boat?
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10-27-2015, 03:28 PM
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#16
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Guru
City: Seattle, WA
Vessel Name: Pau Hana
Vessel Model: 1989 PT52 Overseas Yachtfisher
Join Date: Aug 2012
Posts: 2,676
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Per Lewmar., somewhere in the 8-10hp range.
__________________
Peter- Marine Insurance Guru at Novamar Insurance Group (206-350-5051) & tuna fishing addict!
1989 52' PT Overseas yachtfisher
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10-27-2015, 03:43 PM
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#17
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Guru
City: kemah
Join Date: May 2015
Posts: 1,135
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Maybe you could point them down to add a bit of lift and another 10 knots.
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10-27-2015, 03:48 PM
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#18
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Guru
City: Stuart FL
Vessel Name: Lucky Lucky
Vessel Model: Pacific Mariner 65
Join Date: Aug 2013
Posts: 2,760
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How about a reversible pump (if there is such a thing) that would suck water thru one port and shoot it out the other. Then reverse the pump and move in the other direction. This would eliminate a thru hull and solenoids. I'm no engineer so don't laugh at me!
__________________
Howard
Lucky Lucky
Stuart, FL
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10-27-2015, 04:13 PM
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#19
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Technical Guru
City: Wilmington, NC
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 6,194
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To get the pressure needed, it really needs to be a centrifugal pump, and those are not reversible. Other pumps out there are reversible, but not as simple, compact and elegant as a centrifugal. Also, you want the suction line to be much bigger than the jet nozzle, so that screws up a reversible system.
I think they did it the best way: One suction, one pump, select thrust direction with remote operated valves.
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10-27-2015, 04:26 PM
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#20
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Guru
City: Thibodaux, Louisiana
Vessel Name: Gumbo
Vessel Model: 2003 Monk 36
Join Date: Oct 2007
Posts: 3,882
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Quote:
Originally Posted by what_barnacles
Maybe you could point them down to add a bit of lift and another 10 knots.
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Or connect a hose for a super anchor & chain washdown system
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