Trawler - Single Engine vs Twins

[climber49]

We are moving from a sailboat to a trawler. Since we are getting older moving around on our 30-footer, going up the mast, etc., is getting too difficult.

My question is single diesel or twins. We are going to cruise the Bahamas, perhaps Cuba and maybe a bit beyond. A boat in the 34 to 40 foot size is what we're after. A trawler is also what we want. The go-fast option is not attractive - getting there is part of the fun.

A single has several advantages. The only two advantages I see to twins are redundancy and maneuverability. The maneuvering is not really an issue as we are used to a full-keel, single engine sailboat with no bow thruster. Therefore, redundancy is the only advantage I see to twins.

For the Bahamas, Cuba, perhaps Puerto Rico, etc., what does everyone think about a single diesel?

[Dulcesuenos]

I've driven a few larger trawlers that with just one engine functioning were very hard to steer in a straight line. May have had more to do with the rudder/ keel design but I'd say single and have alot of good spares.

Sent from my PLT1077G using Cruisers Sailing Forum mobile app

[Conall63]

Single.

Take care of your fuel, and all will be well.

Conall

[Tingum]

I have always preferred single screw. I like the protected running gear.

[Scott Berg]

As noted above, single with a protected prop/gear. If you are making longer passages than the ones you mentioned 'get home power' is an option. There are many threads covering options including hydraulic and electric belt drives assuming a working generator.

[MarkJ]

Real trawler, as in fishing boats, have always struck a chord with me because they use a single engine where landlubbers-on-water need 2 engines.

When i get older and crankerier I will get a single donk trawler. In a 30 to 40 ft size the dink outboard could push it. Maybe a method to get it over the stern would add the redundancy you would like?
But if it were a real problem fishermen would be adrift on a daily basis.

[montenido]

I recently made the switch this year from sailor to trawler. I went with twins because I wanted the maneuverability. I also like the redundancy. The windage on a trawler is much more than a comparably sized sailboat, so the twins come in very handy when docking in close quarters. Unless I had a bowthruster, I would go for twins.

Just my $.02.

Cheers, Bill

[iancoombe]

Having driven both I love a big single screw, gone are the days that I could enjoy two screws
I now enjoy being able input alternatives to achieve the desired effect.

[exMaggieDrum]

We have a lot of trawlers up here in the NorthWest, mostly for inshore protected waters but we also have hundreds who go up to Alaska every summer through some very unprotected and "challenging" open waters. There are many, many singles. Many are twins too.

Singles are far better with fuel from what I hear. They are easier to work on which is better for the owner and better for the labor from shops. You have double the maintenance cost for the same number of miles - oil, filters, etc. This really can add up even if you do the work.

Many of the long haul trawlers will have "get home" engines. They are not the most elegant solution but they do work and provide peace of mind to those who have them. Since you don't routinely use them they are low hours and relatively low maintenance. They don't take up as much room as a twin in the bay/room. But they are usually on "get home" as you usually can't steer as well with them and at lower speed. You need dual controls of some sort too.

Twins are great when docking of course. Usually you have more power. And use far more fuel. A lot of that is some boaters who have a lot of power like to push a big wake to get there and back fast. You can hear the sucking sound of money coming out of their wallets for fuel. Those with singles generally are more relaxed and take their time. Some one with twins can also keep the throttle back too of course.

I have seen many very capable cruisers dock very well with singles. Sailors do it all the time but we are envious when a twin comes in and there is a breeze up trying to pin you to the wrong side tie. If you are primarily going off shore you don't really need that.

IMO the primary reason to have twins is to have a backup if one engine packs it up. But really you are also likely to run out of fuel or have other fuel problems. The most important thing regardless of which configuration you get is proper maintenance - regular, thorough, and preventative.

I worked in a yard that mostly handled trawlers so have some experience but not as a skipper. I hated going in to the engine room of most twins. You could get to the sides in the middle but getting to the outboard sides was often an exercise in painful contortions.

Your plans sound wonderful though whichever way you go.

[ranger58sb]

Originally Posted by climber49

My question is single diesel or twins.

A single has several advantages. The only two advantages I see to twins are redundancy and maneuverability. The maneuvering is not really an issue as we are used to a full-keel, single engine sailboat with no bow thruster. Therefore, redundancy is the only advantage I see to twins.

Several thousand threads debating the topic on trawlerforum.com (sister site).

Originally Posted by exMaggieDrum

Singles are far better with fuel from what I hear.

Apparently only slightly better, assuming single and twin installations are each sized appropriately for the hull in question. IOW, if a hull needs 250 hp, one 250-hp or two 125-hp apparently gets pretty close to the same fuel consumption.

-Chris

[tkeithlu]

Love my large and very well protected single. The prop is between the keel and the rudder, and the foot to the rudder is the first to hit bottom while the prop is still two feet up. I'm careful with fuel filtering. Yes, she can be a challenge in narrow marinas, but with practice you can hover-turn without a thruster. The big rudder is a bear down wind, but an autopilot took care of that problem.

The math on get home engines, belts off the genset and the like is not good - most that I know of really don't supply the necessary HP. You're asking a tiny engine to turn a big wheel effectively.

[sailcrazy]

A previous thread raised a similar question, as we too are contemplating making the change from sail to motor. The general consensus that I read there was that a twin was very much preferred, although it is 2x the engines, parts , oil, and fuel. I'd like to know more, too.

[Cadence]

Originally Posted by MarkJ

Real trawler, as in fishing boats, have always struck a chord with me because they use a single engine where landlubbers-on-water need 2 engines.

When i get older and crankerier I will get a single donk trawler. In a 30 to 40 ft size the dink outboard could push it. Maybe a method to get it over the stern would add the redundancy you would like?
But if it were a real problem fishermen would be adrift on a daily basis.

I'm with you on the trawler being a single. I have only seen one built with twins, it was built for shrimping. A Lucander designed 73'. The builder/owner hated it after a short period of time. Sold her.

[JOHNMARDALL]

If you are going to have a genset on the new boat, you may want to order it with a power take off (PTO) for a hydraulic pump. You can then use the genset power to turn a pony shaft and prop as a get-you-home drive. The hydraulic system will also power the windlass and bow thruster that you will wish you ordered (if you don't).
Of course, there are a wide range of PTOs, hydraulic pumps, motors, windlasses and thrusters, but the most important starting point is to ensure that the genset engine, PTO and pump are big enough to drive the most demanding hydraulic device.
Or, there's always the option of two engines, or a big outboard on a jack plate, or just trusting to that one engine. It all depends on what you're going to do and where you're going to go. One engine off-shore or in the middle of a Great Lake in storm could be a bit nerve-wracking, but if you're staying close to home, good ground tackle and towing insurance may be all you need for an engine-out situation.

Decisions, decisions.

John Mardall
Vetus Maxwell Group.

[boatpoker]

My Great Grandfather ran whiskey from Scotland to Iceland in a 40' single cylinder, single engine diesel. He died in bed at 98.

I have well over 20,000 hrs/ logged on single diesel displacement hulls. Broke down twice. Fixed it twice and moved on. Would never consider a twin.

It is ALL about the maintenance.