Trawler - Single Engine vs Twins

[mako]

Originally Posted by 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.

I don't know what thread you were reading, but if you peruse TF you'd pretty much see that the consensus is definitely for singles, not twin.

[tkeithlu]

In the discussions I've been aware of, twins are not overwhelming favorites. Conclusions have included, that 1. diesels are damned reliable and easily repaired, even at sea, and 2. most problems are fuel, which takes out both engines unless you keep the systems separate. In addition, there are not convenient ways of protecting either the props or the rudders in twins. Few twin trawlers have enough keel to protect either one. They are the first to hit bottom.

[bvisailing32]

Lots of great ideas, and experiences.

Probably several things would come into the equation.

For maneuverability, I think we would be OK with a single engine and a bow thruster to assist in docking and close quarters.

High freeboard and winds 90 degrees to a slip or dock could be challenging with a single engine motor vessel. No long keel like a sailing vessel to help hold your track. Especially when blowing strong off a dock or end tie.

Far away island cruising, how well you maintain your engine and systems, and how you manage your power input. The area where you are boating, and flotsman and jetsome or other debris in the water that will nicely glog filters, raw water intakes, etc.

Also, if you do wind up with a major engine problem, you need to think about getting parts, and possible a highly skilled mech to assist. How far away and time and money will that cost. Small jobs like filters and belts, bleeding fuel systems, etc, you can take care of on your own.

So far we prefer sailing vessels but over many years have also skippered motor vessels up to 65 feet. I liked the twin screws and the bow thruster but they were not my personal boats, so no cash was coming out of my pocket to maintain them.

I am not familiar with a get home engine or how it is set up with its own propshaft. But , it I had one, I would want it to perform and be able to make way and dock the vessel as well. That means into currents and seas that would be required for cruisers to get to a haul out or boat yard.

Interesting subject, as many of us are definitely getting up there in years, and who knows how much longer we will be able to continue handling sailing vessels that we can cruise on.


We are joining some long time sailing friends in a week for a grand and wonderful bbq party. Very avid sailors, and just heard from one of my
long ago students, Annette, who has had sailing vessels of her own, 35 to 38 footers and her own mooring in catalina.

So , she would single hand to Emerald Bay, Catalina from overtown, mainland socal' Well, she sent me an email and we are going to hear about her new POWER BOAT next week.


Aye, are all of us rag flappers going to being singing a new tune in the future years ?

Erica and I have talked about that every once in a while, and look at the trawler motor vessel cabin area room, no trimming sails, no reefing down, no heel, and just kicked back on helm watch .

Hmmmmmmm........easier passages and more room to party.

Well, not for while, we still love sailing and being part of the wind and the sea. Still have sailing trips scheduled along our calif. coast, and the BVI.

But that clock is still ticking, and the sun setting each day in west

[Capt Phil]

Grew up and cut my seagoing teeth on single screw commercial fishing vessels and towboats in the PNW. I don't recall any problems we couldn't fix over about a 25 year period.
After a number of years cruising aboard our ketch and living aboard we opted for a 54 foot twin diesel CAT 330's. Heaps of room to live aboard and burned 4 gal/hr from Port Townsend to San Diego which is pretty lean consumption at 1500 RPM.

[Scout 30]

Back when Bill Parlatore was the editor of Passagemaker Magazine this was one of his favorite topics. As I recall he was firmly in the single engine camp & I believe his reasoning was that diesels are very reliable these days & when they go down it's almost always due to fuel issues which takes down both engines if you have twins. There was also a lot of anecdotal evidence that twins tend to pull stuff into the props where as with singles the props are very well protected.

[Capt Phil]

Grew up and cut my seagoing teeth on single screw commercial fishing vessels and towboats in the PNW. I don't recall any problems we couldn't fix over about a 25 year period.
After a number of years cruising aboard our ketch and living aboard we opted for a 54 foot twin diesel CAT 330's. Heaps of room to live aboard and burned 4 gal/hr from Port Townsend to San Diego which is pretty lean consumption at 1500 RPM.
For ease of maintenance, fuel consumption, and room to work on your engine, I would opt for a single diesel. Twins are great for maneuverability but they cramp an engine room. Very easy to berth but with a little practice you can slide a single screw into just about anywhere. Remember, the wind is your friend!
Cheers, Phil

[roberthowell]

the one thing that will b almost impossible with a single will b reverse steering and that is because the rudder is about 1/10 the size of one on a sailboat as long as you are are going in bow first a single engine would b fine. owner choy lee 37 120hp ford leaman n

[Capt Phil]

Originally Posted by Scout 30

Back when Bill Parlatore was the editor of Passagemaker Magazine this was one of his favorite topics. As I recall he was firmly in the single engine camp & I believe his reasoning was that diesels are very reliable these days & when they go down it's almost always due to fuel issues which takes down both engines if you have twins. There was also a lot of anecdotal evidence that twins tend to pull stuff into the props where as with singles the props are very well protected.

Truer words were never spoken, Scout! The number of times I went over the side at Catalina with my hooka setup to untangle the mooring lead line from twin screw props is more than I can count on my fingers and toes!
Twins just seem to drag in everything. I had a fortunate outcome driving down the coast from Port Townsend years ago and ran over a floating line about 1 1/4" in diameter. Thank goodness one of the crew on the bow saw it and hollers LINE which gave me time to throw the vessel into neutral and it hung up on both stabilizers. We managed to floss it off and left it on the Coast Guard dock in Fort Bragg. It could have pulled one of the shafts completely out had my crew not spotted it. Phil

[ranger58sb]

Originally Posted by roberthowell

the one thing that will b almost impossible with a single will b reverse steering ...

Not a universal truth. Not to say it doesn't need learning, but prop walk can work in your favor for short moves at low speed, and steering in reverse can work to a certain extent if there's enough room to get some sternway on...

-Chris

[a64pilot]

I had a planing single engine sportfisherman years ago, smaller boat about 30'.
Docking was a crash, you really had no steerage, or just a little anyway as the rudder needed water flow from the prop to have any effect, and in reverse, it had essentially no effect until speed got higher than you wanted for docking.
If a 40' Trawler is like that, then I'd want a bow thruster, I have always been in admiration of how those guys can dock those big shrimp boats so well as they are single screw and are not small.

[Lepke]

I also have little trouble docking single screw, but twins make it easy. The open ocean is a bad place to find out you need more redundancy. Twice, 35 years apart, I came in on one engine. Both times because of abandoned line caught in the screw. Both times were in about 50° water and with gale or near gale conditions that would have made diving dangerous.
Twins do not mean more fuel unless the engines are barely adequate and have to run near full hp. The engine brand/model has much to do with economy and reliability. I cruise at 10 knots burning 8.5 gallons/hr. driving an 80 ton 83' boat. 7 knots at 4 gallons/hr.
Fuel with proper maintenance is a non-reliability issue. Commercial boats and ships almost never have fuel problems because of proper maintenance and where they buy the fuel.

[Scout 30]

Fuel usage is pleasure boat & commercial boats is not comparable. The fuel in pleasure boats typically sits for much greater periods of time leading to more water in the fuel due to condensation & as a result more stuff growing in the fuel. That's why fuel polishing systems on pleasure trawlers are more prevalent. I don't have an actual fuel polishing system but I do have an inline electric fuel pump & a twin racor with pressure gauge set up so I can filter/dewater my fuel regularly whether the motor is being run or not.

[climber49]

I appreciate all the comments. Don't stop however, more data is always good.

I've been a dedicated rag-waver for many years and hate to give up the sailing but agility and endurance are starting to lag. To keep cruising I need something I can handle, that doesn't require me to climb the mast, is easy to move around on, and that doesn't require a contortionist to work on the engine.

The engine room in the trawler I'm looking at is as large as the salon in my sailboat (a 30-footer) and I can reach everything with both hands. In the twin engines I've looked at one side of each engine is almost inaccessible. I can also straddle the prop shaft and work on the shaft seal. I love the idea of being able to sit comfortably and use a wrench.

The single prop is well protected. On the twins the shafts and props are hanging out like laundry on the line. I personally find that a bit scary. I can rework a fuel system up to the injectors but I can't straighten a prop or a shaft. On the twins I would have to do everything twice and generate twice as much waste and take twice as much time, and probably more given access issues.

The only advantages I see to the twins are maneuverability, which is not a big deal to me, and redundancy. That's my primary issue. I know diesels are reliable and that fuel issues comprise the vast majority of problems, as long as you do the proper routine maintenance. But......

Now I'm not paranoid, but everyone and everything really are out to get me. It's a fact and I know it. Therefore, when my engine quits and I can't fix it, what can I do? I don't think my dinghy with a 5 hp motor will push us very fast or very far. Sea Tow and Boat US may not be available if we are in the Bahamas and I don't want to get into a salvage tow. The auxiliary units I've priced cost almost as much as the boat so that really isn't an option. I guess I could keep a spare jib I have on my sailboat and try to rig it from the trawler mast, which might help out my dinghy if we are going downwind.

Of course there is no guarantee that if one engine quits the other one will be just fine. Maybe I need three engines? Then I won't be able to afford maintaining the third one so it won't be any good anyway.

What I am planning on is installing dual primary filters in parallel so I can switch them quickly and having at least 6 spares of 10 micron, carrying one extra complete water pump plus spares for at least two rebuilds, a full set of spare belts, hoses and clamps, a minimum of six engine fuel filters, four spare oil filters and enough oil for two changes, an oil change kit, extra coolant, extra transmission fluid, and an adequate set of tools. I am considering building a small fuel polishing unit so I can filter a tank either by recirculating or by discharging the cleaned fuel to the second tank.

What else can I do? Any suggestions on parts or other supplies? Maybe a spare fuel pump and set of injectors? I'm thinking about installing a jack plate for a 25 hp motor that would at least give me a couple of knots. Perhaps tow a small powerboat?

You can drive yourself insane playing "what if" and be afraid to leave the dock.

Any suggestions are welcome.

As I said, I'm not paranoid. Disaster is looming and my diesel is already plotting to blow up on me.

[jeremiason]

Originally Posted by climber49

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

We are moving from a Sailboat to a Trawler as well. We plan on doing the ICW, Cuba and the Bahamas.

Single diesels are great and are normally very reliable, efficient and easy to work on. Carry the right spare parts and almost anything can be repaired while underway. If you are close to land, mechanics are easily found.

If I was going around the world and had unlimited funds, I would definitely have twin engines or a PTO off the GenSet for safety, redundancy and close quarter manuverablity. But in your case it sounds like you will never be more than 100 miles from land so a single diesel engine sounds like the ticket.

The comments about backing a trawler are easily alleviated by installing or purchasing a Trawler with a Bow Thruster. The thruster becomes the boats rudder as you back. Since most power boats tend to dock stern in, I would not own a Trawler without a Bow Thruster. Yes, you can dock the boat without it, but why would you if a Thruster is available?

Good Luck and let us know what you end up buying!

[Cadence]

Originally Posted by jeremiason

We are moving from a Sailboat to a Trawler as well. We plan on doing the ICW, Cuba and the Bahamas.

Single diesels are great and are normally very reliable, efficient and easy to work on. Carry the right spare parts and almost anything can be repaired while underway. If you are close to land, mechanics are easily found.

If I was going around the world and had unlimited funds, I would definitely have twin engines or a PTO off the GenSet for safety, redundancy and close quarter manuverablity. But in your case it sounds like you will never be more than 100 miles from land so a single diesel engine sounds like the ticket.

The comments about backing a trawler are easily alleviated by installing or purchasing a Trawler with a Bow Thruster. The thruster becomes the boats rudder as you back. Since most power boats tend to dock stern in, I would not own a Trawler without a Bow Thruster. Yes, you can dock the boat without it, but why would you if a Thruster is available?

Good Luck and let us know what you end up buying!

Backing a trawler, single screw displacement, is not a problem with a barn door rudder with a good amount of leading edge on it. Most twins have postage stamp rudders, ever see someone dock a twin with the helm.