20HP Bow Thruster, 24VDC Battery Bank

Any 3 phase motor is reversible by swapping any pair of wires (in theory). There is a wide selection of 440v motors out there, and the cables needed would be much, much smaller than what a 24v motor would need. Try searching eBay for "440v motor 3ph". Keep in mind that 20hp or anywhere close to that will be physically very large. You may get away with a smaller hp rating since you don't need to run it continuously.
 
fechter said:
Any 3 phase motor is reversible by swapping any pair of wires (in theory). There is a wide selection of 440v motors out there, and the cables needed would be much, much smaller than what a 24v motor would need. Try searching eBay for "440v motor 3ph". Keep in mind that 20hp or anywhere close to that will be physically very large. You may get away with a smaller hp rating since you don't need to run it continuously.

Does that hold true for both delta & wye configurations?

Ok, maybe I should verify if the winch uses all 3 phases. Pretty sure it's a hand lever that shifts the rotation, no switch

If a genset has to be fired up for docking maneuvers, I'm sure that's not an issue
 
Recursive said:
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Does that hold true for both delta & wye configurations?

Ok, maybe I should verify if the winch uses all 3 phases. Pretty sure it's a hand lever that shifts the rotation, no switch

If a genset has to be fired up for docking maneuvers, I'm sure that's not an issue

Yes, it would be true for both delta and wye. You can measure the voltage across every combination of wires when it's running to verify it's using all 3.
 
Ok, starting to see that maybe I'm looking for a solution that won't be easy

Saw this: http://abttrac.com/sites/default/files/ABT-TRAC AC Thrusters.pdf

ABT-TRAC has DC systems, but only up to 12HP. Their AC systems can perform as needed for my project, but the catch is that they require an AC diesel generator for the primary power supply

I'm guessing that if ABT-TRAC did not consider it worthwhile to try generating the AC supply with a inverter, possibly due to the power losses involved, then continuing to look for such a thing may just lead me to someone who doesn't know what they are doing?

The amp draw from a 24 volt battery bank to provide 10, 20 or even 40 horsepower can't be less than what a similarly-powerful AC system's inverter would be. Except that some losses in the proposed inverter will add amperage

I'm guessing a BLDC system won't be much different

I'm going to finalize this pursuit, by recommending either a very low-power 24 volt motor (less than 10HP), or make use of the genset for direct AC power
 
Recursive said:
Ok, starting to see that maybe I'm looking for a solution that won't be easy

Saw this: http://abttrac.com/sites/default/files/ABT-TRAC AC Thrusters.pdf

ABT-TRAC has DC systems, but only up to 12HP. Their AC systems can perform as needed for my project, but the catch is that they require an AC diesel generator for the primary power supply

I'm guessing that if ABT-TRAC did not consider it worthwhile to try generating the AC supply with a inverter, possibly due to the power losses involved, then continuing to look for such a thing may just lead me to someone who doesn't know what they are doing?

The amp draw from a 24 volt battery bank to provide 10, 20 or even 40 horsepower can't be less than what a similarly-powerful AC system's inverter would be. Except that some losses in the proposed inverter will add amperage

I'm guessing a BLDC system won't be much different

I'm going to finalize this pursuit, by recommending either a very low-power 24 volt motor (less than 10HP), or make use of the genset for direct AC power

Have you considered buying a used EV to be a donar? Leafs running go for 5k with clean bodies and $2-3k with bodywork damage (which you don't care about).

If you find a 2013+ you can take its HVAC unit and 12vdc DCDC converter as well.
 
liveforphysics said:
Recursive said:
Ok, starting to see that maybe I'm looking for a solution that won't be easy

Saw this: http://abttrac.com/sites/default/files/ABT-TRAC AC Thrusters.pdf

ABT-TRAC has DC systems, but only up to 12HP. Their AC systems can perform as needed for my project, but the catch is that they require an AC diesel generator for the primary power supply

I'm guessing that if ABT-TRAC did not consider it worthwhile to try generating the AC supply with a inverter, possibly due to the power losses involved, then continuing to look for such a thing may just lead me to someone who doesn't know what they are doing?

The amp draw from a 24 volt battery bank to provide 10, 20 or even 40 horsepower can't be less than what a similarly-powerful AC system's inverter would be. Except that some losses in the proposed inverter will add amperage

I'm guessing a BLDC system won't be much different

I'm going to finalize this pursuit, by recommending either a very low-power 24 volt motor (less than 10HP), or make use of the genset for direct AC power

Have you considered buying a used EV to be a donar? Leafs running go for 5k with clean bodies and $2-3k with bodywork damage (which you don't care about).

If you find a 2013+ you can take its HVAC unit and 12vdc DCDC converter as well.

That or a forklift. The very first thing I thought of after hearing this idea was to look into buying a second-hand forklift for the parts. Then I re-thought it and decided to see if there were some better alternative. Looks like my 1st hunch was the best one. Simply going by how much horsepower is involved, and what I would expect a forklift to need. I hadn't even got into battery bank voltages or cabling sizes, I just know that you can't make horsepower from thin air
 
ive got a 24v thruster i made about 10yrs ago from a lynch motor and an outdrive leg... it moves a 40 ton boat pretty well... draws a lot of amps for a short period more than 200 maybe 300...
lynch motor...curtis controller... thats it... belt drive.. get the gearing right for the prop...took me 3 changed of the small pulley...can alwys up the voltage for more rpm...
 
I know this an old thread but I was wondering what I would need to power a sailboat and haven't really found anything here like grins motor simulator. I found thunderstruck-ev.com, prices seem fair, when you click on a motor package theres a downloadable spreadsheet that gives a tonne of info, amps, volts, ah, knots, hp, range. weight of vessel.
im not saying buy their stuff but it will give you a quick idea of what youre going to need
 
Your “Captain” sounds like a real piece of work to want to replace a hydraulic thruster capable of continuous operation with an undersized electric unit that will shutdown from overheating in two to three minutes of operation.

I live on a 100k lbs 70’ planing yacht with a short keel and 18hp Wesmar 24v thrusters bow and stern. It is adequate for calm water and winds under 20 kts, but is seriously challenged when conditions are much worse. Dot even think of trying to fight a 3 to 4 kt cross current as it has overheat protection that limits it to 3 minutes continuous operation. How on earth does anyone think a 20hp electric motor is suitable for a 130’x18’ 103 ton vessel with an 8’ draft is beyond me! I would run away from this guy as fast as possible to avoid the damage to your professional reputation before the inevitable disaster arrives.

The only reason he gives for not fixing the hydraulic unit is to be Modern? He can’t be bothered to measure the tunnel or even photograph the existing unit to see how many props and how many blades are currently installed during the haul out? Is he just as ridiculous in everything else and where else is he cheaping out on repair and maintenance of essential systems? I’m sorry but this sounds like a maritime accident looking for a place to happen. I would suggest getting a maritime engineer to run the numbers before going ahead, but we both know that will never happen.
 
This is good advice...measure... Calculate...do the maths...
For most people who want long cruise time in any boats a hybrid system is the best option rather than fully electric....
Although those slow speed inland waterways boats can move along with pretty low energy consumption compared to sea going craft..
I have a 40 ton 20m barge which only needs to do 4 knots ... But pretty much needs 20kw continuous to do that ...
So my planned 130kwh lithium pack is good for 5 hrs cruising at 20kw leaving some capacity at both high and low end.
 
Hi,

I work on gas tankers up to 200 meters and sailing all over the world, on all these ships there are bowthrusters installed.
some electric and some hydraulic in combination with a controlled pitch propeller (CPP). (so the motor runs on a fixed speed)
We go up to 1500 kw of bowthruster power on the 200 meter vessels so also the very big systems are possible.
On some of the electrical supplied installations there is just going 3 phase to the forward then through a big sine inverter and than feeded into the electric motor. when we want to reverse there are contactors to switch 2 phases.

i think in you case the best would be an constant speed electric motor that would be just switched on by some relays. and a CPP system to operate the whole system and go from port to starboard and vice versa. When going this route you start up with 0 pitch so the start up current is minimal.
 
I walked out from that project, but I like the CPP idea. I'll keep that in mind for another day. Somebody else took over that boat, and it's just sitting now
 
WoodlandHills said:
Your “Captain” sounds like a real piece of work to want to replace a hydraulic thruster capable of continuous operation with an undersized electric unit that will shutdown from overheating in two to three minutes of operation.

I live on a 100k lbs 70’ planing yacht with a short keel and 18hp Wesmar 24v thrusters bow and stern. It is adequate for calm water and winds under 20 kts, but is seriously challenged when conditions are much worse. Dot even think of trying to fight a 3 to 4 kt cross current as it has overheat protection that limits it to 3 minutes continuous operation. How on earth does anyone think a 20hp electric motor is suitable for a 130’x18’ 103 ton vessel with an 8’ draft is beyond me! I would run away from this guy as fast as possible to avoid the damage to your professional reputation before the inevitable disaster arrives.

The only reason he gives for not fixing the hydraulic unit is to be Modern? He can’t be bothered to measure the tunnel or even photograph the existing unit to see how many props and how many blades are currently installed during the haul out? Is he just as ridiculous in everything else and where else is he cheaping out on repair and maintenance of essential systems? I’m sorry but this sounds like a maritime accident looking for a place to happen. I would suggest getting a maritime engineer to run the numbers before going ahead, but we both know that will never happen.

Yeah, pretty much.
 
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