Sail hull trawler conversion questions

Sep 8, 2020
15
NerwPort 27 Lakeshore Marina
Greetings all. I have a few questions which I hope this community can help me with. I have the opportunity to acquire a Morgan/Starrett Jenks 45 hull.
It has no mast, rigging, or other sail equipment. Engine status is unknown. The interior is in workable/repairable conditions, and it currently floats, with no leaks.

I assume it will need everything else. So, since I was looking at tolerable, poor condition trawlers in the first place, I thought I might ask some questions here regarding a sail hull conversion. I'm very new a figuring out these types of things, which is why I am asking questions, and have not yet said YES to taking the hull.

Based on the owners numbers, and what I could find published about the original boat, its a 28,000 lb hull, 12,000 lb ballast, with a LWL 31.42 feet.

My goals: Explore ICW passages, cross to Bahamas, build enough range to reach Caymans (700 nm). Blue water crossing may not be possible, I understand that.

What is the best option for putting an outboard on the hull for moving it to a marina for haul out and modification? Because the transom is so far above the waterline, I can't quite see in my mind the best way to achieve this.

The calculations I did give me a hull speed of about 7.5 kts. Does that seem appropriate? The current owner suggested a 50+ Horsepower engine be fitted. That seems excessive, but it is heavy, so perhaps not? Of course the dream would be hybrid diesel electric generator, and electric thrusters. But that seems a bit expensive at the moment. Its got a prop, shaft, and rudder already, just need to choose a suitable powerplant. It is my current thinking that an electric system with diesel genny could produce more range - exchanging sail power for solar electric generation. Its not as efficient, but its better than nothing. I fear there would be less room to carry 500 gal of fuel. I could be wrong.

Roll - I can only find a single video of this type of craft sailing. And I can find no videos of anyone talking about trawlerizing a larger boat such as a 45. Plenty of 12 foot and similar small sailboats, just attach an outboard and go! I read that without the mast, the boat will probably roll uncomfortably. I also read that reducing the size of the keel can help with this. Reducing the draft would be a benefit for my goals (6 feet currently to bottom of keel), but it may not help stabilization. Alternately adding a short mast could also help calm the roll, and be something to hang flags, cameras, radar from, definitely not opposed.

Finally, its an aft cockpit design, so adding a pilot house seems relatively straightforward? Build walls and roof area over the existing cockpit. What I would really love to do is cut a giant hole in the back, create an aft cabin, down to the waterline, change to a reverse transom with steps, and add a dive platform that would support the weight of two divers. Another dream.

Love to hear thought about this. If there is a more appropriate place on the internet to ask these questions, please advise.
 

dLj

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Mar 23, 2017
4,235
Belliure 41 Back in the Chesapeake
Well, in my opinion, this is the wrong way to go about making/getting a trawler. The hull was designed to be a sailboat and would work better that way. lot's of folk buy old tug boats or other work boats to make into trawlers and that seems a better use money/time than doing that to a sailing hull.

As far as moving the beast, rather than putting an outboard on it, I'd get an inflatable hard bottom dingy, or other small boat, and use that as a tug boat to move the hull you are looking at. I think you'd do better using a smaller boat as a tug rather then trying to attach something to the boat itself. I guess it depends upon where and how far you are going.

As the rest all seems like a not-so-good-way to go, I'll end my comments here.

I just saw a quite nice Bristol Trawler for sale on Yachtworld that I think would be a much better way to go...


If you wanted a project boat:


I've nothing to do with either, I just happened to be looking at Bristol sailboats and saw those. IF I was in the market for a Trawler, that first one is sweet!


dj
 

capta

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Jun 4, 2009
4,905
Pearson 530 Admiralty Bay, Bequia SVG
First, why would you want to haul all that keel through the water if you intend it to be a motorboat?
Second, most motor boats have very wide, buoyant bows to keep them from submarining when running into the seas or down wind.
Third, I'd guess if you did the modifications you are talking about, the stern would be way too heavy and she wouldn't handle well at all.
Lastly, I'd guess that all in, you are going to spend way more than you expect.
There are usually a bunch of motor boats for sale on the government auction websites that would make much better boats for your needs than any sail boat. Old fishing boats would also be suitable.
Sorry, but that's my take after googling the Morgan/Starrett Jenks 45 and looking at her underwater lines and those big overhangs.
 
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Oct 24, 2010
2,405
Hunter 30 Everett, WA
Moving the boat: Two years ago I moved my Hunter 30 by strapping a 2x4 on the back and mounting my Honda 2hp dinghy motor. It pushed us at 3 knots in dead calm. Then the wind came up and stopped us dead. (Then we sailed) Steering was no problem with the rudder. It worked great and I didn't need to mess with having 2 boats when it came time to put her in her slip. You would certainly need more than 2hp.

I haven't done this so the following is all just a guess. The good: sailboat hulls tend to be efficient at hull speed and slower. As is I would assume low to the water so less windage to toss you around.

The keel and rudder seem like they should be shortened for that part of the world. You didn't say if it was a fin keel or full keel. I don't think I'd remove it all because I like the stability they provide but certainly shortened.

Configuring propulsion may be challenging depending on your budget. You mentioned outboard. Modern outboards are quiet and way more efficient than they used to be. In the event of failure, parts are less expensive and easily available. An outboard could be mounted inboard if one built a motor well. I would consider keeping the prop in the same location. The downside of an outboard is gasoline.

For the rest, just limited by your own creativity and talent.

Ken
 
Jan 1, 2006
7,469
Slickcraft 26 Sailfish
If you do this I would definitely go with a short mast for a riding sail and for having a boom to launch a dingy, or other uses.
I have no idea what the boat looks like but the 45' hull with a 30' waterline seems like a problem for a trawler. If I can add it's a 40,000 lb. vessel with a short waterline. I would be inclined to take Capta's opinion.
 
Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
.... and it has a 6' draft. Not great for ICW.

Hate to be a dream crusher but I think you are getting good advice so far. Take a pass and look for a used work boat.
 
Oct 19, 2017
7,941
O'Day Mariner 19 Littleton, NH
The boat you want to end up with after all the modifications you described, is already out there. Be patient and keep looking. If you want something to call your own by practically building from scratch, those are out there too. This is the hardest, most expensive, biggest compromising, longest time sink way to do it.

That said, there are those who have done something like what you are describing and seemingly been happy. If you decide to convert this boat, I hope to follow along. I will cheer you on.

-Will (Dragonfly)
 
May 17, 2004
5,544
Beneteau Oceanis 37 Havre de Grace
I’ll pile on to the list of those cautioning against this idea. The long overhangs on that boat make it an efficient sailor, but when motoring without any heel the hull speed will be disproportionately low considering its overall length and weight. Without a mast it definitely would roll more than usual, and the hull shape won’t help with that. I can’t imagine any reason that cutting the keel would reduce roll; I would expect that to make it even worse.
 

PaulK

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Dec 1, 2009
1,353
Sabre 402 Southport, CT
Exploring the ICW with 6' of draft may be a short trip - or many short trips if you're able to get towed towed off the sandbar or out of the mud each time. This is not the boat for the kind of voyaging you say you want to do. Engine space is limited, engine access is limited. Fuel tankage is insufficient, and there is no rigging and there are no sails. You have a long boat so paying for slips and storage will be expensive. It has a short waterline so your hull speed is limited, as you suggest, to about 7.5 knots. Even slow trawlers generally seem capable of hitting 10 knots when they see a hurricane coming. Pushing all that ballast through the water all the time will require a lot of fuel, and reducing the ballast (or cutting the keel) will diminish the hull's stability. This could be simply uncomfortable, but might be dangerous. Do you really want to find out which it is 20 miles offshore in the dark? The overhangs fore and aft that increase waterline length under sail could be also be dangerous plowing into head seas under power. You have the sailboat disadvantages of deep draft, relatively narrow living space, poor propeller angle (inefficient drive), heavy displacement and limited speed. You have the powerboat disadvantages of having the engine always burning fuel, having to depend on a single engine, and constant noise and fumes, all coupled with limited speed. Without a rig there can be no sailboat advantages, and with this hull there can be no powerboat advantages. "Correcting" the insufficiencies of this hull (hulk?) will cost more than it would to start with a boat - like a trawler - that is better suited to what your goals are. Going after this one is a lose-lose proposition.
 
Sep 8, 2020
15
NerwPort 27 Lakeshore Marina
Thanks all for the advise. I appreciate the insight. I've been looking for about the last year, and haven't found the "right" option yet. This sail hull came along, didn't feel quite right so I thought I would seek opinions.

I'll stay away from this and keep looking. The only thing I have against trawlers/cruisers is that they don't look particularly pretty - like too many houses stacked up on a perfectly fine boat.
 
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Oct 19, 2017
7,941
O'Day Mariner 19 Littleton, NH
Without a mast it definitely would roll more than usual, and the hull shape won’t help with that. I can’t imagine any reason that cutting the keel would reduce roll; I would expect that to make it even worse.
Actually, and I just learned this, the keel is why it rolls. By lowering the center of gravity and lateral resistance, with a keel, there is a resistance to movement well below the surface, while the bouyant hull moves according to the wave action. This means there is an exaggerated roll, like lengthening the string on a pendulum that keeps the same swing and period. A tall mast acts as a dampener and slows down the period so the swing isn't as exaggerated.

Since much of the ballast in the keel is designed to stabilize the boat under sail, removing much of the keel could work, especially when adding a larger engine low in the hull. However, the hull form with rounded bilges may make for an uncomfortable ride, especially if the boat is lighter over all, resulting in more overhang coming out of the water. A lot of pitching as well as rolling.

-Will (Dragonfly)
 
Nov 8, 2007
1,578
Hunter 27_75-84 Sandusky Harbor Marina, Ohio
This hull is surely a big project. You would spend tens of thousands of dollars on parts and materials, and, probably years of your time getting it in shape. If I were considering such a move, I would retain a boat design expert to advise me. But I join the consensus that especially for a project boat and in today's buyers market, you are much better off buying a boat that conforms to your trawler dreams, and spending any additional time and money fixing it, and making it more exactly what you want.

I'm a mechanical engineer with a concentration in fluid mechanics. But I know enough to know that I am not capable of changing the design of a boat in a way that will work!
 
Sep 8, 2020
15
NerwPort 27 Lakeshore Marina
But I join the consensus that especially for a project boat and in today's buyers market, you are much better off buying a boat that conforms to your trawler dreams...
I agree. I'm happy people know more than I do, which is why I seek advise before plowing into a project.

I just really love the lines of a nice sailing vessel. I can't seem to find something that looks streamlined, but is not a pure sail boat without being gigantic. I'll keep looking. Surely someone has made something in the 40-60 foot range that looks better than a cabin cruiser, or an old tug.
 
Sep 8, 2020
15
NerwPort 27 Lakeshore Marina
Try a motor sailor....

dj

What is the difference between a "Pilothouse" sailboat with an 800 l fuel tank that can do 8+ kts under power, and a non pilothouse "motorsail" that is configured the same.

How does one tell if something is a "motor sail"? Is it simply the ability to motor for long periods of time/hold lots of fuel? I really love the idea of being able to do several hundred miles under power. I also very much like the sort of hybrid option to use sail if needed. It seems some are very easy to sail, with just a main and some sort of jib/genoa/whatever, and others are ketch or "proper" sailboats with an additional motor. Is the subject murky?
 
Jan 1, 2006
7,469
Slickcraft 26 Sailfish
"Motor Sailor" is a term that deserves a lot of discussion. My first inclination is that they don't really exist.
 
Oct 19, 2017
7,941
O'Day Mariner 19 Littleton, NH
It's a little murky. The idea is that the sail is both a stabilizing device and the auxiliary power to the motor. They are generally designed with more comfort in mind, ease of handling and less emphasis on sail performance. So they are "under powered" as sailboats, but a storm sail can make a huge difference in weather comfort and even shave a little of your fuel bill.

They are still sailboats, so knowing how to sail is required.

-Will (Dragonfly)
 
Jan 1, 2006
7,469
Slickcraft 26 Sailfish
Can you point to a good one. Because mostly I see bad sailing vessel and slow moving power vessels.
 
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dLj

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Mar 23, 2017
4,235
Belliure 41 Back in the Chesapeake
I'd agree with both @shemandr and @Will Gilmore above. The difference is at best murky. Generally I'd say a motor sailor is a boat that is a compromise, doesn't have really great sailing ability, typically from what I've seen has a smaller mast than you'd want as a sail boat, but will sail. Isn't quite a trawler but is laid out a lot more in that vein. Tends to have good living quarters, larger fuel tanks than sail boats and would commonly be run both under motor and sails for stability. You'd not run under motor and get the same speeds as a dedicated trawler, but certainly comfortable to live on likely cost less to drive than a trawler as you can use the sails for help running the motor.

Might indeed be a subject for conversation.

dj