Marine Trader 40 Engine Size

[Tony B]

I am seriously thinking of going from sail to power.
I was looking at a Marine Trader 40 with twin 120 Lehman's. The idea of twins scares me when it comes to potential fuel consumption as I am not wealthy. I have seen some similar with single 120HP. How much extra fuel consumption will the twins cost to operate since I assume they wont be operating as hard as a single would. Could I just use one engine at a time with not too much loss of power or fuel efficiency dragging the other prop?
When it comes to motors, I am completely retarded.
Thanks in advance.

[Tom.B]

Go talk to the guys at Trawler Forum. Lot of the guys over there have both single and dual Ford 120's. Also check the Marine Trawlers Owners Association MTOA - Marine Trawler Owners Association (except it cost money to join... so I'm not a member there... yet). Besides, if you are going to be a trawler owner, you need to join us over there anyway :-D

[awpptdt]

I have a 40 with a single 120 and use 2.75 to 3 gal an hour at a hull speed of 8 knots. A friend of mine has a 44 with twin 120's and uses 5 gal. per hour at 8.5 knots. Add another 1/2 gal. per hour if you run the generator.

[Tony B]

Does anyone here ever run these with just one engine at a time?

I am going to sell my 1976 Allied 39 ketch in order to buy a trawler. If they are going to be that expensive to operate, I may try the Great loop in my ketch and pay quite a bit have my masts removed and stored somewhere in NY and then shipped to Chicago and reinstalled. Besides, the trawler idea is more appealing because of the additional space inside. I might just settle on a 36' trawler the only problem being a single engine in tight spaces. If it don't come with a bow thruster, one will be too expensive for me to put in and so just live without one.
My Allied will be listed with a broker by mid-week. It might take a while to sell it, but when it sells, I will own a trawler in less than a week. When I finally decide what I want I will own one in a week or less. I have always boat shopped that way. I am also willing to travel to buy one. When I bought my current Allied, I drove over 1200 miles to look at it. Made a deposit and drove 1200 more miles home. Made that 2400 mile round trip 3 more times between the closing and prepping for a sail across the Gulf of Mex.

[Rick R]

2.75 to 3 GPH at 8 knots in a 40 foot trawler sound about right, but you can reduce that by slowing up. Our 36 footer with a single Cummins burns 2 GPH at 7.3 knots.

Running a twin on one engine is not very efficient since there is a lot of drag from the stopped propeller. Better to buy a single engined boat. Twins burn only slightly more fuel than a single, but maintainence is twice as much. But don't buy a single engined trawler without a bow thruster.

[motion30]

my 34' with a 120 burns 2.4 at 8mph

[Tony B]

Originally Posted by motion30

my 34' with a 120 burns 2.4 at 8mph

We are just now at the looking stage. The more I think about it, the more I am leaning toward a 34.
This morning we looked at a Californian 34 with twin 85 HP diesels. I am used to sailboats so a single engine is no big deal to me. Twins are certainly better though. The admiral says the size is doable. We just didn't like the layout.
We are looking forward to looking inside a Marine Trader 34 soon. I know she will like the layout much better. This evening we are going to look inside a Marine Trader 32. My Allied ketch wont be listed till the middle of the week so we are taking this time to narrow down what we want. I am definitely leaning to the Marine Trader style and after this evening, I know she will also. Then it's just a matter of size. I pretty much am giving up on a 40. Too expensive to operate as far as fuel and transient slip fees go. Now lets see how small we can get - within practical limits. For every advantage to size there is also a disadvantage. We are looking for our equilibrium point.

[doug86]

I have a 40 MT with single 120. The topic of running a twin on just one engine has been beaten to death on the trawler forums for years, and most threads end with a consensus that it isn't really saving much fuel (perhaps 5% savings). If you run a twin on one engine, the keel isn't going straight through the water, and the rudders are not dead ahead, so there is added drag that eats up the small fuel savings. If you want to run one engine, just buy a single screw to begin with. My single FL120 on a 40 Marine Trader burns about 2.3 GPH at 7.25 kts.

The statement about the need for a bow thruster has not been my experience. I have cruised for 10 years with my single trawler, and never had nor needed a bow thruster. Learn to handle a single and you won't see any need for a bow thruster.

[Vyndance]

Originally Posted by Tony B

I am used to sailboats so a single engine is no big deal to me.

Let us now how that first day goes.