Bow thruster powering

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7 months 4 days ago #3487 by Grace Olsen
Bow thruster powering was created by Grace Olsen
Calling all windlass/bow thruster folks - how do you get that much power up forward? I took my bow thruster off the boat to figure out why it doesn't work. I suspect the DC motor is fried - it smoked and dimmed the cabin lights when I tested it back when the boat was in the water. Seems like a fire hazard.

Now I'm getting to the bottom of what to do about it, and come to realize that my whole circuit is completely undersized. Anyone else solve this by putting a battery in their forward cabin? (Anyone else have a bow thruster??) A couple owners ago, someone basically just Tee-d into the windlass circuit (2/0  cable) to power the bow thruster. With smaller, 1/0 cable, even though the bow thruster pulls twice as many amps. I'm skeptical it would work even if the bow thruster motor wasn't cooked. According to Vetus, even the 2/0 is insufficient for a such a long cable run to the thruster. The windlass works fine and I haven't been too worried about it. 

So, as I go down the rabbit hole of replacing the thruster and the circuit, here is a sketch of what I have come up with. If you have a battery up forward, how do you charge it? Are there any problems I should be wary of?
I plan to use a trickle charger from the house, but have an emergency bypass switch in case the battery dies, then I can use the windlass off the alternator (via the house, not directly).
Also, anyone who has a thruster - what is the thrust rating? Do you like it? Do you use it? Should I just glass up the hole and forget about it? :)

Thanks for any insight!

 


- Grace


 
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7 months 3 days ago #3488 by Mark Popiel
Replied by Mark Popiel on topic Bow thruster powering
Hi
After several years of ownership we added an Exturn bowthruster. It is the most expensive upgrade we have done, and the most worthwhile. The bow gets blown around a lot while maneuvering, and the thruster controls that, so don't get rid of yours without careful consideration.
I can't help you with the electrical issues you have because the model we got requires 24 volts, so we have a pair of dedicated batteries for it, installed nearby. However, I will say that it makes sense to power your windless and thruster from a forward mounted dedicated battery, which will reduce the wire lengths and provide a power reserve. Also, it's helpful to move weight forward.
Nothing like 20 knots of wind on the beam to make you love your thruster!

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7 months 3 days ago #3489 by Mark Popiel
Replied by Mark Popiel on topic Bow thruster powering
(Part 2)
I placed the thruster batteries in the bottom of the locker opposite the forward head. Because they are wired to provide 24 volts they are charged by an 120 v A.C. charger.

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7 months 2 days ago #3490 by Gino & Carolyn Del Guercio
Replied by Gino & Carolyn Del Guercio on topic Bow thruster powering
Hello, we’ve owned our Brewer 44 for the past eight years and lived aboard for the past three. We have about 10,000 miles under the keel. In our opinion for a boat this size a thruster is unnecessary and a crutch. We see so many sailors these days who don’t know how to maneuver their boats or use lines properly because they always use their thrusters. Thrusters don’t always work and are ineffective in strong winds.
The best book I know about docking technique without thrusters is “Docking Techniques for Single Engine Boats” by Tom Tursi (American Sailing Association). Buy that book and save your money for something that will make your boat sail better. The drag alone from the thruster itself is slowing you down.
The following user(s) said Thank You: Cindy Ann Bowers

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6 months 4 weeks ago #3493 by Grace Olsen
Replied by Grace Olsen on topic Bow thruster powering
Thank you Mark for the validation!

How do you run the AC charger while you are off the dock? Do you have a generator, or a separate 24V alternator on your engine? I see the benefits of switching to 24V, but not sure how deep I want to go uprooting the system.

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6 months 4 weeks ago - 6 months 4 weeks ago #3494 by Grace Olsen
Replied by Grace Olsen on topic Bow thruster powering
Hi Gino,
Thanks so much for your feedback. I will absolutely check out that book!

I hear you on the logic of saving money for things that make the sailing better. I am curious though - where are you sailing mostly? Do you mostly spend time offshore, going anchorage to anchorage, or do you ever go into crowded city marinas and unfamiliar ports? Do you sail singlehanded and how comfortable are you docking singlehanded?

Maybe you can help me suss out how to handle my marina. I have been doing spring line tricks for two years to get in and out, but I haven't figured out a good way to dock without crew or someone to catch me.

The first year, I was in an inside slip with about 3 feet between me and my neighbor, but my finger pier was only 30 feet long. By the time I could reach a cleat to throw a pre-measured spring, I was already in the slip, too late. To get out, I would run a line from transom to aft dock cleat and doubled back to the chock. 1 Crew would ease it out as we backed out of the slip while another held the bow on. Then once we were clear of the neighbors, they'd hold the aft spring fast and I'd back into it to pivot the boat around. Once straight in the fairway (width about 50 ft) the crew would haul the line in like heck. I could do the whole shenanigan myself if someone cast off my bow and walked me back, but holy moly was it stressful to haul 100 feet of line near the prop. 

The second year, I got an outside slip with a 50 ft finger, but sharing a 30ft wide double berth with an Amel Super Maramu (15 ft beam). Accounting for fenders there were about 6" room for error, and I still couldn't back out straight enough without someone holding my bow on. Getting in was no problem until I hit reverse and the bow would blow off unless already sprung.

To top it off, the current induced by the nearby locks can hit 3 kts at peak, blowing sideways across the slips. Sometimes it's useful, like for straightening out in the fairway, and sometimes not.

What would you have done in these situations, if you didn't have crew or a neighbor to cast you off and catch you? How do you keep the bow from blowing off when you arrive in the slip and put it in reverse?

I'll definitely get the book - I would love to be confident enough to enter unfamiliar ports without spending the dough on the thruster - but just curious if you had any thoughts on these situations as someone who has gone 8 years without one.
Last edit: 6 months 4 weeks ago by Grace Olsen.

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6 months 4 weeks ago #3495 by Mark Popiel
Replied by Mark Popiel on topic Bow thruster powering
Hi Grace
I really only need the thruster when docking, so i can use 120 v marina power to recharge, and i use the 12 volt windlass at anchor, so the associated battery gets recharged with the rest of the 12 volt batteries, so it works out well. Alternatively, the 24 a.c. charger is small, so i can run it off our inverter, or from the generator. Finally, there are 12 volt to 24 volt chargers available, but I didn't go that route.
The following user(s) said Thank You: Grace Olsen

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6 months 4 weeks ago #3496 by Gino & Carolyn Del Guercio
Replied by Gino & Carolyn Del Guercio on topic Bow thruster powering
Hi Grace, we generally cruise New England in the summer and Bahamas/Caribbean in the winter. We anchor out as much as possible but do go into unfamiliar marinas on occasion. Its almost always my wife and I and we have a lot of experience with the boat and how she handles. That being said, we always make sure someone from the marina is on hand to help with our lines.
If I were single handing I might feel differently, but I still don’t think I’d install a thruster.

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6 months 4 weeks ago #3497 by Grace Olsen
Replied by Grace Olsen on topic Bow thruster powering
Ah, gotcha, so you always have someone with you. Shucks, I was hoping you'd have some top secret tips!

I ordered the book and will keep experimenting. If you pass through Boston, say hello to Goblin!

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6 months 3 weeks ago #3499 by DAVID JONES
Replied by DAVID JONES on topic Bow thruster powering
Grace,

While I originally was looking to buy a boat model like you have, I couldn't find one that met all my criteria. I did find a different 41 footer that has a very nicely installed bow thruster. While I've no idea yet how much I may or may not use it, as I'm honestly more in line with Gino and Carolyn, I can tell you how this system was professionally installed. The engine actually has to separate alternators, one for the house battery banks and one for the bow thruster/windlass. The bow thruster/windlass both run off two batteries under the forward vee birth so they are quite close to both units.

I will give you a great docking tip told to me by Pam Wall. Take a midships line that attaches just aft of the center of rotation of your boat. When you approach a dock you drop it on a cleat or whatever is used to tie boats and you leave the boat in forward at an idle and lock your steering as if you are trying to steer away from the dock. With the line in that position this will force the whole boat to just come alongside holding the boat onto the dock, even if you were initially a bit too far away. With the wheel locked in that position and the engine in idle forward, that combo will hold the boat there so you can easily just step off onto the dock and go about tying off. It's a really slick trick! If you are coming into a slip you use all the time, you can work out the right length of the line and bring the boat into position perfectly every time. Pam explains it much better than I do.

dj

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6 months 3 weeks ago #3500 by Grace Olsen
Replied by Grace Olsen on topic Bow thruster powering
Thanks DJ, for both the install knowledge and the docking tip. That is a great trick and you explained it very well. I have done that maneuver on boats with fin keels, but I haven't been successful so far with my Whitby. Reading through your explanation though is giving me some ideas for improving my technique - experimenting with the location of the midship cleat (it slides on the genoa track) might help.

The one time I tried this singlehanding was turning into a 30 ft slip (they really pack them in here). I discovered I was already in the slip before I could get the line on the cleat. Maybe if I was really savvy I could go forward from the wheel before I finished turning in...? 

I think I'm going to get the new thruster, but still intend to learn as many techniques as I can not to rely on it. I hope you like your 41 footer! What did you end up finding?

Thanks!

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6 months 3 weeks ago #3501 by DAVID JONES
Replied by DAVID JONES on topic Bow thruster powering
Oh one more thing Pam talked about was having like a boat hook attached to the midships line. I don't recall how she had it attached, but she did talk about an example where using it she would just drop it as it stayed attached to the line and then collect it once docked. Don't know if that will be of use to you. I'm also fairly certain Pam Wall's boat is a full keel boat.

I see no reason not to get the thruster. Well, there is the money aspect... But even if you don't use it often and you are working to perfect your docking techniques without, it's a nice back-up....

I found a Belliure 41. Not a well known boat on this side of the pond. It was built in Alicante, Spain. You may have heard of the Endurance 35? They also made an Endurance 38 and 40. Well the Belliure 41 is pretty much an Endurance 41. It's a Peter Ibod design. Lovely lines, stunning interior, all teak decks with NO SCREWS (YEAH), The previous owner was meticulous in maintenance so it has an almost new Yanmar engine (about 500 hours?), oversized standing rigging all replaced a couple years ago, heavy duty off-shore sails, cutter rigged (technically a double head sail sloop), It's a raised deck house, has fore and aft cabins and heads although it has an aft cockpit. It's very well designed for blue water cruising. Both head sails are on new roller furlers, the main is on a boom roller furler. (You did open up a pandoras box asking me, you know... LOL ... so I'm restraining myself)...

dj

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