44ft trawler-one Lehman engine

I'm looking at 44ft of fiberglass, wood and steel plus liquids and it only has one engine and bow thrusters! Supposedly it burns less than 2 gal/hr at hull speed (8kts). I'm less worried about fuel consumption on this Mariner Tradewinds than ability to maneuver in tight spaces. I've owned larger boats but they had twins.

Anyone on here develop the skills to handle a boat this size on one engine?

A single depends on hull shape, rudder size and skills of the handler.

A 120 hp engine is plenty if you can stay below 8 kts.

My guess is at 8 knots it's burning near but above 2 gph.... drop into the 7's or around 7 and the 2 gph fuel burn may be true.

That's what sea trials are for. I gave a lesson many years ago on a larger MT with twin Lehmans. Might have been a bit bigger than 44. I suspect the rudders were small - she was a handful in close quarters with any breeze. That said, singles usually have larger rudders so no telling.

What sized thruster? 12v or 24v? If undersized, would be of limited value of course.

I like the idea of a single engine as it gives nice access on engine room.

Good luck. I look forward to updates of you move forward

Peter

Porchhound said:

Anyone on here develop the skills to handle a boat this size on one engine?

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Yep. Didn't have a bow thruster, but had a crew with a spring line. Just takes practice.

Much easier service access all around the engine.

(Different boat, now.)

-Chris

I had a 40 Albin with that same engine and a stern thruster and never had a problem in close quarters or in locks, or at fuel docks..

I wish my CHB 41 only had one Lehman, particularly when I service the impeller, injector, or oil cooler on the starboard engine.

Most sailboats have singles & no bow thrusters - it's doable, just need practice. When I got our first big boat, a 41' sailboat, I hired a captain for a half day to practice docking.

Edit: on fuel consumption, I agree 2gph seems low. I do 4gph with twin Lehmans at 8kts; a single would be more efficient, but not by 50%. Maybe 3gph?

Hi Porchhound,

Handling of a single screw vessel, particularly one with a bow thruster, is not difficult. DIFFERENT techniques than with twin engines, but no more difficult to master. Personally, I much prefer a single screw boat with a bow thruster, for lots of reasons, including the ability to maneuver in tight spaces.

WITH PRACTICE! Again, not difficult, and it simply takes time to learn the nuances of your particular boat. Some of the helm (and crew) actions during close quarter maneuvering are counter-intuitive, but certainly easily mastered.

And, as previously stated by others, that's what a sea trial is for. If the operator of the boat during sea trial isn't experienced enough to adequately display the boat's maneuvering performance, then doom on them, and doom on the seller.

Regards,

Pete

It is all about practice.
I learned on a single outboard boat as a teen, then on small sailboats without power.
The first bigger boat I ever handled was a 48' salmon troller. Fully loaded it weighed maybe twice what my 44' trawler weighs, though it had only one engine. No thrusters. Handling was easy by the time I first had to bring it into the dock, as by that time I had enough hours hands on that I had full confidence in my own ability. Then I had sailboats, all singles, no thrusters. Now I have twins, no thrusters.
None of those configurations are difficult to learn. They are simply different from one another. Time at the wheel is always going to be your friend.
You always need to consider that any trouble you might get into will be less serious at a lower speed, so judge your speed in close quarters by that measure and you will be good.
2 gph, if you measure your engine's efficiency that way, indicates that you are drawing less than 40hp from it. To achieve 8 knots on 40 hp, you are likely on a very lightweight boat. Conversely, if the boat is as heavy as you make it sound, and actually uses 2 gph, it is not going to achieve 8 knots.
My 44, weighing 44,000# does 8 knots most of the time and uses almost 4 gph to do so.
Just sayin.

Unless that boat is filled with helium and made of cardboard, I just don't see 36hp at 8 knots as being realistic. As said by others, likely closer to 4gph. The 2gph figure would be a for an economical cruise speed of 6.5 to 7 knots.

For a boat that size with the limited access to the under-sole engine space (it's not really an engine"room"), the single is great. Even if the bow thruster is undersized you should still be okay with some warping skills in heavier winds. The single will have a larger rudder than twins and the only modification you may wish to make would be to add a fishtail wedge to it for better maneuverability.

90% of the time docking should be no problem, but remember even with twins a small percent of the time caution or plan B is needed.

2 GPH is 30 -35 hp perhaps its 8 statute miles per hour -7K ?

I'll add that where you are and how you plan to use the boat makes a difference. If you plan primarily day-trips with friends aboard and are in a breezy area where the winds pipe-up in the afternoon, a single without a strong thruster will be stressful, especially if your slip orientation isn't great. If you plan to cruise and mostly anchor, close-quarter handling may be a non-concern.

I'm a fan of single engines, but make no mistake: they have shortcomings when it comes to close-quarter maneuvers. Threads like these seem to have a vocal contingent suggesting "once you learn the secrets, they are easy-peasy." There are definitely tips and tricks that make it easier and less stressful (and a thruster can be a God-send), but they are not all created equal and not all docking situations can be conquered. Having driven a LOT of boats over the years (including 3-hour <76-passenger dinner cruise boats on SF Bay), I'm rusty these days but in my prime, I can safely say I was in the upper quartile of close-quarter helmsmen, at least for this class of boat. Yet I do NOT share anywhere near the confidence of many who think most/many situations are manageable with special techniques. I know most of the techniques and I can tell you there are times where I've exhausted my arsenal of tricks and had to either abort or endure a pretty rough docking.

Bottom line - sea trial is the first step in purchase process so little cost to the buyer. Spend a few bucks and hire an experienced captain to put the boat through its paces. Ask around the brokerage - there will be someone who shuffles boats for boat shows. Those guys are the best at close-quarter maneuvers.

Peter

mvweebles said:

I'm a fan of single engines, but make no mistake: they have shortcomings when it comes to close-quarter maneuvers. Threads like these seem to have a vocal contingent suggesting "once you learn the secrets, they are easy-peasy." There are definitely tips and tricks that make it easier and less stressful (and a thruster can be a God-send), but they are not all created equal and not all docking situations can be conquered.

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I like my twins. But given calm enough conditions, I've found I can make a single do a whole heck of a lot. The issue is when there's too much wind or current and you can't take your time with a slow, elaborate maneuver.

My wife and I lived aboard and cruised an Albin 43 with a single 120 FL and no thrusters. Plenty of narrow spaces and cross-current places during that time - it most certainly can be done. Just requires thought and an understanding of the pivot point, prop walk, and windage. It’s actually enjoyable (other than the odd occasion of horror and abort!). It was very helpful that we came from a life of maneuvering sailboats……

Edit: on fuel consumption, I agree 2gph seems low. I do 4gph with twin Lehmans at 8kts; a single would be more efficient, but not by 50%. Maybe 3gph?

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Mine was under 2 gph at 6.5 - 7 knots which was about 1750 rpm.

On the 120FL in the Albin 43 and in the current MT34, I got and am getting slightly less than 2gph. (At 1750/1800 rpm).

Two completely different techniques for twins vs single. A single with a bow thruster will do everything you need, once you learn how to handle the vessel. Work with wind and current. learn to 'bump and fill'. Learn how to use prop walk to your advantage. Learn how to use momentum to your advantage. Learn how to put your stern into the wind.

As an example. If you want to pull up to a gas dock and side tie and the wind is blowing you off the dock, what would you do?

In my case, I back to Starboard. I always put the Stbd side against the dock. I would set myself up at a 45 degree angle with my stern and starboard to the dock. As I start to back into the wind, the wind and the prop walk will start straightening me (putting me perpendicular to the dock). Turn wheel to port, continue backing. As I get close, throw the boat in neutral and start hitting the bow thruster to bring the bow around and lay the boat along the dock on the Stbd side.

The momentum of backing significantly aids in the bow coming around and fights the wind. The wind, on the other hand, slows the boat down, as does the thruster. As I whack the thruster, not only does the bow move towards the dock, but the stern moves away a little. This also serves to slow some of the sterns back motion. If you time the whole thing, you kiss against the dock and very politely hand the midship line to the dock hand while your mate is hopping off of the back onto the dock to secure the stern. Walk forward and either the dock mate or your mate will be meeting you at the bow. elegant (hopefully)

Our KK42 had a single FL and was a full displacement hull. We burned just under 2gph at 7 knots. As previously mentioned, practice. One thing we learned was never go into a dock or slip that you couldn’t easily get out of if the winds or current change. We sometime had to abandon our plans just for that reason but we saved our selves a lot of grief and scratches.

Here is what I have on file from an actual 32-24 ft WLL and manufacturer info...it pretty well matches my boat. Different engine, drive train and WLLs will obviously differ.

Also, with a single, even with a bow thruster, you'll learn how to use spring lines to get on and off a dock.

It occurred to me, some other oddities with a single inboard, with a thruster.

You are pulling away from a dock where you're side tied. What do you do?

I turn the wheel all the way TOWARD the dock. This doesn't actually turn the boat into the dock as much as it bumps the stern AWAY.

bump the engine into gear and simultaneously hit the thruster to push the bow away from the dock. The entire boat stays perfectly parallel to the dock while it creeps away slowly away from the dock making forward movement. So the boat is basically creeping away diagonally at a 45 degree angle from the dock, while the vessel itself remains parallel. Once the stern is clear, hard left rudder to turn the vessel itself at a 45 degree angle. The rudder center and simply drive away.

Simple (hopefully)

Practice make reasonable...some people never get past that and others excel. Practice doesn't always make perfect.

But I worked with dozens of captains that could manage single screw, no thruster boats that with a tow on...could get both boats to virtually any dock in most conditions single handed. I also worked with many that couldn't.

So... I think many buy any boat they like...and add thrusters (which overcome many skill deficiencies or just plain reduce the stress) if you never get the hang of it or just want them.

psneeld said:

Practice make reasonable...some people never get past that and others excel. Practice doesn't always make perfect.

But I worked with dozens of captains that could manage single screw, no thruster boats that with a tow on...could get both boats to virtually any dock in most conditions single handed. I also worked with many that couldn't.

So... I think many buy any boat they like...and add thrusters (which overcome many skill deficiencies or just plain reduce the stress) if you never get the hang of it or just want them.

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Some people have the touch and some don't. Some have it just for certain types of boats, some can jump on any boat and just make it dance. Those without the touch can still do well, but they have to work a lot harder at it and much will just go out the window if they get on a different boat.

I handled a 40 ft sailboat for years without a bow thruster. Kind of a brute to back down and in any kind of wind, you really had to plan ahead. My 40 ft single engine Trawler with a bow thruster is a DREAM to handle around the docks! Much better at backing down and I can spin it on a dime when necessary with just one engine and the thruster. I still have to plan with a strong enough wind, but I feel much more confident with the Trawler!

Articulating rudder

And articulating rudder will make your boat handle as if it had an exceptionally powerful stern thruster, when you want it to.

Andrew

Single, no thrusters, 4 words, "practice back and fill".
If your boat back to starboard when the rudder is centered and you want it to back straight, port your rudder about 30 degrees and crawl back.
Once you can back your boat straight..... and become confident with 'back and fill', you are almost 'home free'.
One more bit of advice, neutral is a gear, use it as necessary.

Back and fill, back and fill... I have seen people with singles and thrusters out maneuver boats with twins. Just takes practice and experience.

Regarding fuel use, if your Lehman is a 120 I would say the GPH estimate is probably pretty close. Our 50,000 lb 46' boat has twin FL120s, and at 1400rpm we do 7 knots and burn a total of 2.0GPH.

Here's a thread that shows Floscan readings of a Ford Lehman 120 at various RPMs:

https://www.trawlerforum.com/forums/s6/lehman-120-floscan-readings-4512.html

We found those readings to be quite accurate.

rslifkin said:

Some people have the touch and some don't. Some have it just for certain types of boats, some can jump on any boat and just make it dance. Those without the touch can still do well, but they have to work a lot harder at it and much will just go out the window if they get on a different boat.

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I only ran a twin screw boat a couple of times and never docked one.
I've always had single screw boats.
But it's true about "the touch".
Just like backing a trailer, some will never get it.

rslifkin said:

Some people have the touch and some don't. Some have it just for certain types of boats, some can jump on any boat and just make it dance. Those without the touch can still do well, but they have to work a lot harder at it and much will just go out the window if they get on a different boat.

Click to expand...

Count me as one without the touch - just acquired ability. I've been in many circumstances where, hard as I tried, I was lucky to get out without a scratch. And I mean lucky.

Peter

1 engine

Porchhound said:

I'm looking at 44ft of fiberglass, wood and steel plus liquids and it only has one engine and bow thrusters! Supposedly it burns less than 2 gal/hr at hull speed (8kts). I'm less worried about fuel consumption on this Mariner Tradewinds than ability to maneuver in tight spaces. I've owned larger boats but they had twins.

Anyone on here develop the skills to handle a boat this size on one engine?

Click to expand...

My GB 36 has 1 FL 120, no thrusters. I can spin it, back it or come alongside. You just have to be aware of wind and current and be careful where you take the boat. And practice.

Bryant said:

My GB 36 has 1 FL 120, no thrusters. I can spin it, back it or come alongside. You just have to be aware of wind and current and be careful where you take the boat. And practice.

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If someone wants to make money, develop a couple of practice slip and rent out time.

OldDan1943 said:

If someone wants to make money, develop a couple of practice slip and rent out time.

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Or, investigate "Boat Master". Crunching sounds while practising but no actual crunching. My partner now understands what docking is all about, what causes what, why things need to happen to get into position, be it lining up with the slip, correcting, realigning, or whatever. Hours of non damaging fun and a real learning process. One version of the App is free to download, though I expect they get to plunder their way thru your device anyway.