SailNet Community banner
  • SailNet is a forum community dedicated to Sailing enthusiasts. Come join the discussion about sailing, modifications, classifieds, troubleshooting, repairs, reviews, maintenance, and more!

Low buck bow thruster??

32K views 53 replies 36 participants last post by  Erindipity 
#1 ·
I was thnking so I decided to ask here. Has anyone used a remote control electric trolling motor as a bow thruster? Im thinking it would be a great thing for close quarters maneuvering. Of course it would have to be kept coverd at the dock to avoid thousands of stupid comments.:confused:
 
#3 ·
Instead of the trolling motor, try "getting a wife", put her on the bow and let her tend the lines. Just think of marraige like an old boat: fun and exciting in the beginning but a lot of maintenance to keep it up!!!

(On second thought, maybe the the troller idea would be cheaper).

To answer your question, It would have to be one hell of a troller to push the bow of a sailing vessel. If you have a very small boat, maybe... but any boat of any size and displacement does not move really easy. Just my thoughts. I will say that my boat on a beam wind takes every ounce of energy I can muster (and often my wifes) to pull over the bow. A friend of mine with a high-end thruster on his taswell cannot get his to move in much more than about 12-15. My boat displaces about 25,000 lbs, I guess, with our junk on it (only 500 lbs without all our junk, HAHA).
 
#4 ·
Also, unlike a bass boat, which is what most trolling motors are designed for, a sailboat has a lot more underwater profile as a general rule.
 
#9 ·
I think compressed air is the way to go, something like the air brakes on an 18-wheeler.

Small holes in the hull, big push, big bubbles, scare the hell outta the fish!

Also, with good air pressure you could hook up a real air horn, just to let folks know that the village idiot -- oops, marina idiot -- is trying his hand at docking....again :)
 
#10 ·
I use a leaf blower on my boat. The engine is small, although a little loud, especially when submerging the blowing end in water to make the turns. The reason I use it instead of the trolling motor is that I have found it more useful in dead air. I can just blow in the sails and find that it moves the boat along rather nicely. It also works for cleanup in the cabin.
 
#12 · (Edited)
k1vsk said:
I have seem this question asked before elsewhere - presumably by you?
Guess you didn't like those answers but suspect you'll get the same comments here, if not worse.
Not me but thanks for your great reply...

Some of the motors have 60" shafts and well over 100lbs of thrust, about like a small BT. It's pushing the bow where there is little keel. Im sure someone has tried it, somewhere.

Man you people don't like to think outside the box...
http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?id=0036409018350a&navCount=2&podId=0036409&parentId=cat400009&masterpathid=&navAction=push&cmCat=MainCatcat21276-cat400009&catalogCode=IG&rid=&parentType=index&indexId=cat400009&hasJS=true

http://www.thrusters.com/thrusters/dcthrusters.html
So the real bow thruster is 24 volt and the redneck bow thruster is 36 volt. Anyone know how to convert foot lbs to HP?
 
#13 ·
Hello wildcard:

Who knew you would get such abuse.

I think that some may be overestimating the thrust needed to move the bow laterally. A little thrust applied continuously is what is wanted. Even in large vessels, bow thrusters generally don't develop a lot of horsepower, and an electric trolling motor that will produce 100 pounds of thrust could be quite effective, depending on the boat.

There are two problems; (1)mounting and (2) stowing when not in service.

If all else fails, you can put one of those little swivel seats that they put in bass boats on your foredeck and fish!
 
#17 ·
btrayfors:

"I think compressed air is the way to go, something like the air brakes on an 18-wheeler.
Small holes in the hull, big push, big bubbles, scare the hell outta the fish"

Actually, that's not really a bad idea, rather than boring great horrible holes in the bow, all that's needed is a couple of maybe 3/4 inch holes with appropriate fittings connected with high pressure hoses to a high pressure compressor. HHHHmmmmmmmm.
 
#18 ·
Not that I would ever install a bow thruster, I believe that (except for those that have to dock with high currents/winds and those that have to fit a 45' boat on a tight 30' slip), if you can't "park" your boat, maybe you shuldn't be "driving" it, and a smaller boat would be better.

WC the bow thruster I was kindly showing you is for any boat (mine happens to be flatt from bow to stern, but that model can be installed even i V shaped hulls), because it is installed facing down and the cutout actually works as a lid (covers the whole), and is retractable.

Another reason I don't have one is weight in the front, don't need it....

As for installing it is pretty easy, and the whole thing costs less than one might think. I posted the link because you posted the link with the price, so I was showing that your idea (not discussing if its good or bad) costs almos the same as the real thing.
 
#19 ·
The desire for a bow thruster has nothing to do with the NEED for a BT. I have run some big boats through some small holes many times without problems with no BT. I asked a simple question, Has anyone done this and I get a bunch of smartassed answers from people that are unable to think on there own. I imagine the first guy to make a cement boat got the same sort of comments.
 
#20 ·
cheap push

Wildcard
You might be on to something here.

I have noticed in any thread where the topic of bow thrusters comes up there is a lot of negative comment. There seems to be some sort of "Real sailors don't do bow thrusters" mentality. There was a thread a while back asking about the topic and the poster was promptly acussed of being handicapped. Turns out he had suffered a stroke and had difficulty with brute force docking manouvers, prompting apologies all around.
I can understand your reluctance to toss a couple of grand or more at the chandler then the same again at the boat yard just to have two ruddy big holes poked in your hull, and extra batteries, and wires the size of a horses' leg, and finding out the thing is drawing way too much current because it is the home of an entire colony of a particularly tenacious marine growth.
I can also see a few problems with the trolling motor approach but most of them centered around what to do with the thing when you are not actually using it, and in the case of my boat, where to mount the thing, my foredeck being crowded already.
I am getting the feeling you are not talking about a 40+ footer, that would be just silly, and you don't sound silly.
The idea of using a tractor type of propulsion for sliding into the slip is interesting as opposed to the usual pusher arrangment. Look what they are doing with Tug boats lately. Docking with the conventional system wherein directional control astern is is only available with a little too much sternway (unless you count propwalk which almost always seems to be in the wrong direction for the space and approach available) always seems to me to be like trying to perfect an art with enormous handicaps. I do watch openmouthed when I see it done sweetly but my blood pressure always goes up a bit when I see a pannel of judges on the dock during my approach.
I say go for it. There are a few complexities all right, but if it was done well it could be really slick. I imagine a neat clean bracket that fits up under the anchor rollers. If you have a self bailing anchor locker you could even separate the 'head' of the unit from the shaft/drive assy. and have everything but the drive swivel 90 deg. and retract into the locker alongside the hull out of the way. With 360 degree swiveling you could use it to get quite fancy in your manouvering, if there was't too much wind or current, and used merely as a thruster I'm sure that 100 lbs. of thrust would do a lot of good. I would be surprised if many people could pull more than 50 lbs. horizontally.
Incidentally, I believe that the thrust they are referring to in the specs you gave the address for is measured in pounds, not in foot pounds. Thrust measuments are simply push (or pull) and are measured in pounds, ounces, grams, kilograms, tonnes etc. Foot pounds (newton/meters etc.) are measures of thrust at a distance from center, ie. torque or twist. Horsepower is a measure of torque times revolutions over a unit of time which is, in it's pure form, the ability to achieve a certain amount of work in a certain amount of time. Crossing thrust over to HP. is fairly complex since there are so many variables such as the medium you are thrusting in, the efficiency of the machine (prop, jetdrive, wheel etc.) there are tables but they are only approx. It would be better to compare by power consumed or watts, (volts X amps). Watts are directly transferrable to HP. 1 HP = 745.6999 Watts.

Let us know how you do, this does have possibilities if done well.

fair thrusting to ya'
Feetup
 
#21 ·
Thank you for one of the few intelligent replys. It's a full keel 35 footer that does not like to turn to port in either direction. Electric motors can be found that have a long cradle for lack of a beter term. You just flip them up and they go down and lock in place. They can also be run by IR remote saving the extra wiring. I think it would fit nicely along the toe rail with a cover to avoid the afore mentioned comments.
Id just like to know if anyone has done it and how it worked?
Lack of ability? Hey, I have one motor why not two? Im not good enough to do it without any power nor are most so why fight it?
 
#22 ·
Since the resistance of water at zero speed is virtually zero, it takes almost no thrust to actually move a boat of any size. What you can't get with a small motor is acceleration and speed. As soon as the boat starts to move the resistance goes way up. However consider this. Most people would have a VERY hard time pushing with a100 lbs of force against a piling. Now imagine that you could do that, and do it continuously too. I think the reality is that even a small trolling motor will spin a 40 foot boat around a whole lot quicker than you might think! All of the issues come down to how to mount the thing. You only need to mount it sideways, and use forward and reverse if you just want to steer. It doesn't have to be centered either. So if you had a permanent stainless bracket with a wedge slot on one side of the bow, and a plug for the unit on deck, you could reach over the side and drop the motor into the bracket and plug it in when you needed it.
 
#25 ·
I know it's an old thread but I couldn't resist.

The low buck bow thruster is a great idea. All the ***** responses on this thread are typical. I doubt these folks would have the stuff to speak openly the same way at a bar. The vision of a lying prostitute getting pimp-smacked comes to mind.

I know everyone on this forum is the best boat handler ever created by God. Even God could not dock a boat better. In fact I'm sure all of you could dock an 80 footer under sail in a hurricane from the v-berth using nothing but your telekinetic powers while you make love to one of your super model concubines.

The idea of using a trolling motor as an occasional bow thruster has a lot of merit. These motors can produce a 100 pounds of thrust which is plenty to assist the bow of any 50 footer. I've helped dock an 80 footer using a dinghy with a 20 lb. thrust Minn Kota and it did just fine. A little slow but it was better than nothing. So the whole not strong enough argument is simply incorrect. And I would never let some dock kid or marina guy push on my boat with a skiff.

My rag boat is 50 feet and has a 65 hp auxiliary. Go ahead with the snippy comments, it is what it is. Reliable and very efficient. But it's not a Titan when maneuvering in confined quarters with a running current and high winds in an unfamiliar marina. A quick attach trolling motor on the bow would make things much more relaxed. All it would have to do is hold the bow. Not spin the boat.

Now before any of you experts tell me how easily it would be for you to dock your boat in a class 3 rapid during a tornado, let me say that I've never had an incident docking my boat. With the pulpit, anchors, and davits, I'm looking at about 57ft overall. It can obviously be done, but what harm is there in having an effective and cheap alternative to cutting a huge hole in your boat? Much of my sailing is 600 plus miles offshore. The last thing anyone needs is another hole in their hull especially at the cost of $9000 grand or more. I can afford it, but I have my principles. And my last concern is impressing the meathead in the slip next to me. I've got nothing to prove.

Over the years I've had to sail some boats in and out of marinas. I've come in and backed my boat into a slip entirely under sail, single handed. I've raced competitively since I was 7. I hold an unlimited Masters license, unlimited towing license, first class pilotage, every unlicensed deck endorsement the federal government has, and I've been Captain of a 580 foot petroleum tanker for over 15 years. I've literally spent more of my life on water than on land and I've got millions of miles under the keel, not thousands. Oh yeah, I've also docked a boat in a hurricane, multiple times.

Point being, who cares about your silly skills. The Op was asking a simple question about his idea. I stumbled upon this post because I was looking for a similar solution. For around a thousand bucks, I can quickly attach a trolling motor near the bow to help back into a foreign slip. What could be more relaxing. I'd rather keep a hand free for my beer or my super model's rear than have to back and fill like a maniac. Done that.

The Kota wouldn't have to extend off the stem as an eye sore. It could simply be attached farther aft, along side, as long as the thrust was deeper than the hull. A remote foot pedal from the cockpit would suffice as a control, and when your boat is all fast, disconnect the whole thing and chuck it in a locker. Easy money. The setup need not be an ugly behemoth. If the paint matched the hull it'd hardly be noticeable.

If I can't find a suitable option for this idea then I'll be talking to an engineer. I bet West Marine would be interested in my marketing ideas.
 
#33 ·
All the ***** responses on this thread are typical. I doubt these folks would have the stuff to speak openly the same way at a bar. The vision of a lying prostitute getting pimp-smacked comes to mind.
Wow! I don't think I have ever read an angrier, more combative, or more derogatory, first post in the nearly thirty years I've been participating in online forums (yes, going clear back to the days of usenet).
 
#26 ·
Do you always walk in with guns blazing? I've seen some angry people in my life and have seen many thousands of "opening" letters in places like this forum Yours is pretty awful.

BTW, Jeanneau (and others) already have your system out there for those that can afford it. Usually that is people who own 50ft boats.

So even my idea of a a 6 nozzle joy stick system with a jet pump is moot.

 
#32 ·
Do you always walk in with guns blazing? I've seen some angry people in my life and have seen many thousands of "opening" letters in places like this forum Yours is pretty awful.

BTW, Jeanneau (and others) already have your system out there for those that can afford it. Usually that is people who own 50ft boats.

So even my idea of a a 6 nozzle joy stick system with a jet pump is moot.
I have to disagree. I felt that luhtag made very reasonable points and that many of the snappy replies to the original post were inappropriate.

Using a trolling motor as a bow thruster is something I have thought about myself (independently of this thread which I was not aware of) and I think there is potential in it. It's not a slam dunk (otherwise everybody would have one) but I see no harm in discussing the problems with this approach, and how to potentially overcome them. I thought that is what Sailnet is about.

For those that disagree, make your point politely. Telling us about your superior docking skills or suggesting marriage counseling is not a useful contribution.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top