Bowsprit mounted outboard

[Cowboy Sailer]

I have wondered about putting an outboard motor mount on a 17,700 lb sailboat that would serve as a backup or “get home” motor using the dingy engine. One would probably need a large vessel or fine pitch prop to get any useful thrust. Then I wondered about putting some sort of easy on-easy off OB mount on the bow to serve as a bow thruster. It could still be a useful forward or reverse propulsion device.
I have sketched up such a design and calculated the loads and material required to implement such a scheme. It would require a new bow pulpit and two people would be required to use it as a bow thruster.
A lot of people like big 15 hp outboards on their dingy and 15 hp is a serious back up to the diesel. A small OB would still be a very powerful bow thruster. Carrying a spare prop for a small OB and changing it to suit the proposed use is no big deal.
I would not mind carrying a motor to the bow when tied up at the dock or when the wind died and the diesel engine was not available for some reason and I just wanted to go a few miles. I would not want to go forward with a heavy cumbersome burden like a big OB on a long pole when the diesel quit because the rough seas stirred up some gunk in the tank and stopped up the fuel filters! I for sure would not leave it up there when I wasn’t using it.
Have any of you tried something like this? If nobody stops me I will probably try in next year. I have a little over six months until retirement. My wife is in complete agreement about living on a boat. The money is in the bank. We have already downsized our stuff. We have lived in three separate overseas locations by carrying two checked bags, our carry-on luggage and two excess bags each. Our USA house is rented. We are pumped! Here we come! I have a short timer's attitude!

[rtbates]

As for a bow thruster I've thought of a remote controlled trolling motor.

[AnchorageGuy]

How about using, oh I don't know, maybe a bow thruster? I can honestly say that after sailing and cruising a boat for 16 years with a bowsprit, there is no way I would want an outboard and all of the support you would need for that kind of a set up on the bow. Especially the added weight that far forward even for just the support that you might build. I can not imagine this in any kind of seas, let alone what it will do to the hobbyhorse affect and anchoring problems and so many more I can think of. Forget the bow and if you want to use an outboard to get home, either tow the boat with the dinghy or add a sliding bracket on the stern that would allow the outboard to be lowered into the water or raised for stowage.

[GordMay]

Methinks that Rube Goldberg would have loved it ...

[SilentOption]

For just a little more than the cost of buying an additional outboard and then modifying your bowsprit to support the motor low enough in the water to work as a thruster you could install a real bowthruster.
You may also find that stopping your boat just before entering the slip long enough to install the motor at the bow will have some sad results depending on wind and current. Sailboats, particularly, tend to not stay in one place long if there is any breeze or current. You would likely be rigging far from your slip and away from anything you could drift into.

Regarding a come home motor when your diesel dies.

My current boat is 44 feet long and very heavy. While bringing it home the first time the transmission failed about 20 miles from home on the ICW. We couldn't sail and I didn't want to get towed($$) so we used our dinghy. I was inspired by an old John Wayne movie when his landing support ship was disabled. All the small craft were put alongside and brought him home! Oh, where was I?
Yes, So anyway.
Our dinghy motor is a 9.9. We put the avon alongside and warped the boat the over the final leg of the trip at at over 5 knots steering from the helm. The last few miles were on the Chesapeake under sail and I left the avon alongside for maneuvering into the slip later.
It rode perfectly the whole way home.

Just another thing to think about.
One potential problem you might encounter with mounting an outboard on the stern of a larger sailboat is keeping the prop in the water. Especially in a following sea.


All that said, If you follow through with your plans please post photos!

[swagman]

Hi Cowboy,
I appreciate the desk planning exercise you are going through and the enjoyment you are getting from coming up with these ideas - and indeed as they are all sailing related they need our support and applause.
But have to say Chuck has possibly given the most pleasant and logical response anyone could.......your lack of experience is making it all so hard...
Truly suggest you suppress the desire to do too much more detailed planning until you've got some more practical experience. Doing it all that way round will see you probably finding the answers arrive before the questions do - which is equally enjoyable and a great way to learn.
Enjoy. Good luck. Love to hear when you hit the water.
JOHN

[Chief Engineer]

Being on the hip.

I once manoevered a 150 foot floating fuel dock into position with a pontoon boat and a 15 hp engine. Set up just the same. If you plan to do it with your boat, try practicing it once or three times so the learing curve isn't as steep.

As far as mounting it on the bow? I think it is impractical, cumbersome and as many of us are apt to do, we sailors sometimes complicate the bejaysus out of things.

I would like to see a sketch though

Originally Posted by SilentOption

Our dinghy motor is a 9.9. We put the avon alongside and warped the boat the over the final leg of the trip at at over 5 knots steering from the helm. The last few miles were on the Chesapeake under sail and I left the avon alongside for maneuvering into the slip later.
It rode perfectly the whole way home.

Just another thing to think about.
One potential problem you might encounter with mounting an outboard on the stern of a larger sailboat is keeping the prop in the water. Especially in a following sea.


All that said, If you follow through with your plans please post photos!

[svHyLyte]

Guys, Guys, Guys---

Your making this too hard. They figured this out in Thailand 50 years ago.

You can use a 327 Chevy with an Edelbrok Highrise Manifold, duel AFB 4-barrel Carbs, and a 30-30 Duntov CAM, mounted on a swivel that can be moved from place-to-place along the yacht's rail as needed:

[Ex-Calif]

Originally Posted by Cowboy Sailer

I have wondered about putting an outboard motor mount on a 17,700 lb sailboat that would serve as a backup or “get home” motor using the dingy engine.

Jerry - Most ideas have been tried at one time or another. Sailing and sailboats have evolved to the most practical, usable configurations over time.

New ideas can be tried. Practicality or lack of can be discovered.

The dinghy and outboard in themselves act as some sort of "emergency" aux power system. When the chips are down in bad weather and bad seas I would guess the dinghy or the bow mounted outboard have little practical use in the bailout scenario.

There are lots of other things to complicate on a boat before mounting an outboard on a bowsprit. The bow is generally quite high out of the water as well.

If I needed to self tow I would try the dink with the 15.5hp as a tow vehicle frst.

If you do set up such a rig we wold all love to see it.

[Microship]

I should mention my "redneck bow thruster" design (not yet tested). It is a pivoting arm hinged at the anchor launcher and normally lashed along the rail. When a bow thruster is needed, the business end (electric) is tossed in the water, and two lines are led aft to the winches for tensioning... which engages a deep VEE shape onto the stem.

This now holds the thruster solidly in place, and it can be driven left-right as needed. But unlike the Sideshift, it can go away when not in use, and unlike a tunnel thruster, it does not cost $15K (the quote for an 8" tunnel Lewmar, installed, on my boat).

I'll let y'all know how it works out. I need something, that's fer sure, if I am to continue docking without involving insurance companies.

Cheers,
Steve

[Cowboy Sailer]

From Microship

I should mention my "redneck bow thruster" design (not yet tested). It is a pivoting arm hinged at the anchor launcher and normally lashed along the rail.

Microship, now you are talking. I made a simple hinged arm to support an electric trolling moter beside my canoe. At the rapids it was stored inbord and I used my paddle. When we would hit a long boring strech of still water I stowed the paddle and deployed the trolling motor. It was quick and easy. It was also easy to move the trolling motor and battery to our sailing dinghy when that was the recreation vessel of the day.
I thought that a gasoline OB would be be easy to move from the "big" sailboat tender to the bow of the sailboat to be a "redneck cowboy bow thruster"!

Here is to redneck engineering!

I used to crew on a trailerable sailboat that was powered by a six horse OB that worked great. So that made me think that the OB should be able to also drag the boat forward or push it back while I controlled it from the bow like I was an Italian gondolier. I always wished for some help getting out of and returning to the slip. As crew, keeping us off the dock always seemed to be my responsibility! I wished I had a motor to control too!