Okay, single or twin??

Ski in NC said:

You did miss the obvious point. I was the one that stated my single gets first rate maintenance. And the reason for that is I know I count on that engine exclusively. If I had twins I would not be so anal. That is the point.

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That is what I thought you meant. Me personally, I would treat both types the same. Besides, how much more maintenance would an extra engine require?

mahal said:

Besides, how much more maintenance would an extra engine require?

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Twice?

menzies said:

There are more planes in the water than there are boats in the air.

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A light plane just went down in Volusia county (FL) this evening. It was a single though. I am pretty sure the pilot isn't wishing he had a twin.
1 killed, 2 injured in Volusia County plane crash | www.wftv.com

Twin engines in an airplane are vastly different than twin engines on a boat.

Two engines on an airplane cause lots of problems if one engine goes out. Since they are usually separated by a significant distance it pulls the aircraft toward the downed engine. It takes a better pilot to land a twin with one engine running, and would almost be better to cut both engines on final approach...

Operating a single engine on a dual-engine airplane requires extra training. Leastwise that's the story with my former-pilot-under training son (now an accountant) and Ambry-Riddle flight-school fees.

sunchaser said:

Speaking of phobias, I heard about a guy who was so OC about the singles vs twins discussion on TF that he removed two perfectly good engines and put in one

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Tom, that piece of information belongs in the Off Topic "Humor" section. Or a medical journal.
Amazing we are ploughing this well furrowed field again. I thought it was well settled twins are the preferred set up. They certainly were with us the day a fuel line to one of 2 Lehmans fractured.

Codger2 said:

Twice?

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My point is that when doing maintenance like oil change, it doesn't take twice the time to do two engines versus one. If you include time to purchase supplies, gather tools, warm up engine/s and clean up, I would estimate that doing a second engine will take an extra 20% of the time it takes to do one.

mahal said:

That is what I thought you meant. Me personally, I would treat both types the same. Besides, how much more maintenance would an extra engine require?

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Ok, so here is the question, do you change out perfectly functioning parts based on hours in service or wait for them to fail? As an example, would you change out the fresh water pump if there was nothing wrong with it other than high hours. A failure of the fresh water couple cause the engine to overheat and possible blow a head gasket or worse. The blown head gasket isn't very likely, but that's not a risk I'm willing to take with a single engine. While I do carry a spare freshwater pump, I also change it out based on hours of use. What about you?

Ted

markpierce said:

Operating a single engine on a dual-engine airplane requires extra training.

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That is incorrect. A multi-engine rating includes training to fly the plane on one engine. In fact, there may be more time spent on that aspect of flight than any other in multi-rating training.

I believe the attention the engine in a single or the engines in a twin get has zip, zero, nada to do with the number of engines in the boat but has everything to do with the attitude of the owner.

Each of the engines in our boat get our full attention when it comes to operations, service, maintenance, or repair. We do this because this is how we treat engines. It would make no difference if the boat had one engine or ten, each of them would be treated to the proper service schedules and inspected regularly for any potential faults and components with finite lives like pump impellers, oil, air, and fuel filters, oil and transmission heat exchangers, etc are changed on a schedule, not when they crap out. The schedules for some of these components are based on the normal lives of the components, however.

Based on most of the boat owners we know personally, single and twin, power and sail, I would say that the majority of serious cruising boat owners treat their engine or engines exactly the same as we do.

This isn't to say there aren't boaters out there who use having two engines as an excuse to be lax on service and maintenance. But to assume that this is a widespread reason boaters select twins is a bad assumption I think.

O C Diver said:

Ok, so here is the question, do you change out perfectly functioning parts based on hours in service or wait for them to fail? As an example, would you change out the fresh water pump if there was nothing wrong with it other than high hours. A failure of the fresh water couple cause the engine to overheat and possible blow a head gasket or worse. The blown head gasket isn't very likely, but that's not a risk I'm willing to take with a single engine. While I do carry a spare freshwater pump, I also change it out based on hours of use. What about you?

Ted

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You got me there with the fresh water pump. Although I've pulled both heads and had them serviced including new valves and springs. Nothing was wrong with the engines. It was more about me wanting to do things to the boat to make it more reliable even though I was told that the exercise would be futile. I also replaced the perfectly functioning raw water pumps and rebuilt the old ones for spare. I have replaced many other functioning parts due to age like coolers, hoses etc..., I probably don't come close to you in terms of the level of maintenance but I doubt many do including other single screwers.

Quote:
I said "Operating a single engine on a dual-engine airplane requires extra training."

Marin said "That is incorrect. A multi-engine rating includes training to fly the plane on one engine. In fact, there may be more time spent on that aspect of flight than any other in multi-rating training."

Why do you say I'm incorrect when your argument says essentially the same as I?

markpierce said:

Quote:
I said "Operating a single engine on a dual-engine airplane requires extra training."

Marin said "That is incorrect. A multi-engine rating includes training to fly the plane on one engine. In fact, there may be more time spent on that aspect of flight than any other in multi-rating training."

Why do you say I'm incorrect when your argument says essentially the same as I?

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Because your wording implied that once you got a multi-engine rating you then need extra training to be able to fly it on one engine. This is not correct; the multi-engine training includes learning to fly the plane in all phases of flight on one engine.

Marin said:

I believe the attention the engine in a single or the engines in a twin get has zip, zero, nada to do with the number of engines in the boat but has everything to do with the attitude of the owner.

Based on most of the boat owners we know personally, single and twin, power and sail, I would say that the majority of serious cruising boat owners treat their engine or engines exactly the same as we do.

This isn't to say there aren't boaters out there who use having two engines as an excuse to be lax on service and maintenance. But to assume that this is a widespread reason boaters select twins is a bad assumption I think.

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Think your assumptions are flawed based on where you boat. Given the remoteness of where you boat and likely the boat owners you know, everybody there has to play the game at higher level because of the added risk. Move to the average environment of serious cruisers and you will likely find a greater diversity of owner attitudes on PM.

Ted

O C Diver said:

Think your assumptions are flawed based on where you boat. Given the remoteness of where you boat and likely the boat owners you know, everybody there has to play the game at higher level because of the added risk. Move to the average environment of serious cruisers and you will likely find a greater diversity of owner attitudes on PM.

Ted

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Seattle-Tacoma-Victoria-Vancouverr-Nanaimo is remote? That's a new one on me. Most people here boat within 30-40 miles of one of those cities. So I very much doubt the percieved "risk" is any different to most boaters here than it is to boaters in California, the Gulf, or the east coast.

The folks doing the Passage, Haida Gwaii, SE Alaska, the west coast of Vancouver Island, sure, there's an increased risk. But the folks doing that are but a tiny fraction of the number of active boaters in this area. Most boaters here work Puget Sound, the San Juan Islands, the lower end of Vancouver Island, the Gulf Islands and the Sunshine Coast. Hardly what people here consider "remote."

The way I see it, you've got three affordable choices. Single vs. twins is may be more of an image thing. If you like to have more control, or at least have the illusion of more control, you might be a twin guy. Captain Kirk was a twins guy. If you're more of a "fling it" type individual and don't go in for the control image, you might be a single engine type. Captain Ron was a single type. Your other choice would be a no-engine guy. I've known a few of those, but the most famous was probably Captain Kangaroo. Definitely a no-engine type, and what about that side-kick of his, Mr. Green Jeans....a wannabe engine type if I ever saw one.

Best of luck with your choice, but have fun and don't let anyone make it a heavy decision for you. When you find your boat, it will likely have all the engine or engines you need.

Marin, Do you have a multi engine rating?

Maybe we can get by with one testicle, but I `d rather keep "the twins". I don`t think I need a special rating for them.

...and Mr. Happy will owe you a lifetime of memories.

Codger2 said:

Marin, Do you have a multi engine rating?

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I never carried it through to a check ride because it was expensive and I didn't need the rating for the commercial flying I did in Hawaii (crop dusting, aerial mapping and fish spotting). But I got a number of instruction hours in our Cessna 310 over there including single-engine work just to have the experience.

stubones99 said:

Two engines on an airplane cause lots of problems if one engine goes out. Since they are usually separated by a significant distance it pulls the aircraft toward the downed engine. It takes a better pilot to land a twin with one engine running, and would almost be better to cut both engines on final approach...

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Having bought several twin engine aircraft home on one engine I can safely say this is not the case and I have been very pleaseed to have the other engine to get me home. For a professional competent pilot asymmetric operations are practiced routinely and if they happen are not a great problem. The issue lies with pilots who are not recent and rarely fly multi engine aircraft. That's when you have problems if you loose an engine at a critical time.

As for boats I'd rather have two engines than one but wouldn't pass up a nice single engine boat with a good reliable engine.

80 posts and no discussion (or at least I haven't noticed it) of the tendency of single engine long distance trawlers in out of the way places to have an auxiliary engine (wing/kicker/get-home) mounted off center. These are usually Yanmar 27 hp on the Krogen 42s and Nordhavn 46s, and larger (Yanmar 40??) on the 48s and 50s.

In many ways this arrangement has the benefit of both twins and singles and is significantly less expensive than twins.

Bay Pelican said:

80 posts and no discussion (or at least I haven't noticed it) of the tendency of single engine long distance trawlers in out of the way places to have an auxiliary engine (wing/kicker/get-home) mounted off center. These are usually Yanmar 27 hp on the Krogen 42s and Nordhavn 46s, and larger (Yanmar 40??) on the 48s and 50s.

In many ways this arrangement has the benefit of both twins and singles and is significantly less expensive than twins.

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Marty I mentioned it in post 28. Bottom line, most if not all of the commonly known single brands built in the past decade have get homes. So they are essentially twins in disguise.

As example, how many single engine Nordhavns are without a well thought out spare installed engine and drive train? Answer is obvious.

sunchaser said:

Marty I mentioned it in post 28. Bottom line, most if not all of the commonly known single brands built in the past decade have get homes. So they are essentially twins in disguise.

As example, how many single engine Nordhavns are without a well thought out spare installed engine and drive train? Answer is obvious.

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Guess following that logic, the single with the 15' tender and 35 hp outboard is a twin also.

Ted

Roughin'it said:

Single,Bow Thruster, Vessel Assist.

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I prefer twins for all the reasons stated above, plus at least in most cases, the added power and speed you may need to get out of a bad situation.

Nothing says you can't putter around on one engine.

That said, the single will give you better efficiency and lower operating cost as previously stated.

As someone else mentioned.
If you're mostly inshore, vessel assistance is readily available, and you're not doing large open water crossings, and more than anything your budgetary constraints, the single may be the ticket.

OD

sunchaser said:

Marty I mentioned it in post 28. Bottom line, most if not all of the commonly known single brands built in the past decade have get homes. So they are essentially twins in disguise.

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Thanks, had forgotten the line in post 28. I feel there is a great difference between a single engine with an auxiliary and a twin engine boat. The main engine prop (on most) is protected by a keel, underway only one engine is used and generally the auxiliary is small taking up much less real estate in the engine room.

Our 27 hp Yanmar is tiny compared to the Lehman 135. Also a fraction of the cost.

When used for a get home the Yanmar gives us 4.5kts (flat water) and for docking the auto pitch max prop digs in and allows us to back in both directions.

O C Diver said:

Guess following that logic, the single with the 15' tender and 35 hp outboard is a twin also.

Ted

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The last few vessels we've tried to buy were all singles, for reasons as stated in the laborious singles vs twins threads seen on TF during the past few years.

With two primary caveats of course, a spare sizeable drive system and not planning on going faster than 10 to 12 knots.

I do like your idea though of towing a vessel assist boat behind us. Should it have one or two outboards?

sunchaser said:

The last few vessels we've tried to buy were all singles, for reasons as stated in the laborious singles vs twins threads seen on TF during the past few years.

With two primary caveats of course, a spare sizeable drive system and not planning on going faster than 10 to 12 knots.

I do like your idea though of towing a vessel assist boat behind us. Should it have one or two outboards?

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Doesn't matter as long as it has the right anchor.


Ted

Bay Pelican said:

80 posts and no discussion (or at least I haven't noticed it) of the tendency of single engine long distance trawlers in out of the way places to have an auxiliary engine (wing/kicker/get-home) mounted off center. These are usually Yanmar 27 hp on the Krogen 42s and Nordhavn 46s, and larger (Yanmar 40??) on the 48s and 50s.

In many ways this arrangement has the benefit of both twins and singles and is significantly less expensive than twins.

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Our boat has a version of this - a 9.9hp kicker which is not only great for fishing, but also a lifesaver when the main has a problem. Our little C-Dory had one too.

Never had a bad-fuel-related incident, but have had plenty of temporary overheats due to kelp wrapped around the sterndrive and blocking water intakes, belt failures, damaged props, and one sterndrive failure. In many of those cases we would soon have been on the rocks without the kicker. It's taken us to safety from as remote locations as the west coast of Vancouver Island near Kyuquot, west coast of Chichagof Island, and partway up into Glacier Bay - I'm very fond of it.

Well here is one person with twins that wishes he had a single. So I do not fit the category of "I like what I bought". Now don't get me wrong, I like my boat and I like my engines. I just don't think you will find a planning motor yacht with a single engine. So to put it briefly, I need the speed so I need the other engine.

For those that get a twin for maneuverability, that should be a bonus...not the main reason for buying one. A bow thruster is WAY cheaper and simpler than another engine. And after having significant experience with both configurations, I can maneuver a single with a bow thruster much better than a twin....and I'm pretty good with the twin. A single/bow thruster is just simpler....all the way around.

Another thing that was very briefly mentioned is engine room space....as it relates to maintenance. While I do not defer maintenance due to the cramped space in my engine space(I have a difficult time calling it an engine "room"), I do farm out a lot of work due to that space issue. I used to do pretty much all of my maintenance on my single engine boats. Now if it is a pain in the ass to get to...I call someone. Can I do it myself, most likely. Especially if I "had" to...in a pinch. But I am willing to bet there are people out there that defer maintenance just because it is difficult to get to. Something as simple as changing impellers on my boat is a multi hour job...especially on the port engine. Most boats I've had changing an impeller was a 15 minute job. I fantasize about boats like DeFevers where I can pull up a stool and sit next to my engine(s) and do whatever needs to be done. Changing an impeller on my port engine requires that I lay across the top of the motor(and using my hands as my eyes since you have to feel around down there...not enough room to get your head down there)...let's hope it's not hot!!! I also fantasize about the Tiara express cruisers where the entire deck lifts up and your engines are just sitting there...winking at you!! So for me it is space and simplicity!!!

I don't think the comparison to airplanes is all that valid. Airplanes are more complex and there is a lot more things going on(like gravity and impact with the earth) that aren't really a consideration in a boat.

Just FYI:
FAR part 23 requires that single engine airplanes stall at 61 knots or below. Coincidently, at the time those regs were made the speed limit of cars was 70mph(61 knots). The thought being that the landing speed in a forced landing situation should be close to crashing a car at the speed limit of 70mph.

The certification of light twin engine airplanes requires them to maintain a climb rate(I think the spec is 100fpm up to 5000 feet) on one engine at MGTOW and with the critical engine failed. And guess what....if they are not able to meet that specification, then they are required to have a stall speed of 61 knots or below...just like a single. I think a Piper Apache(PA23) falls into this category.

The only reason I mention this is because there is the belief that twin engines are less safe than singles and someone on this thread insinuated it. If you are proficient in the handling of an engine failure on a twin, it is a better alternative. There ain't no single engine airliners out there. There are also no on demand charters(part 135) IFR at night(human cargo) with single engines. IOW, ignorant paying passengers deserve the safety of two engines...and a qualified pilot(s).

Again...we are talking about impacting the earth at a high rate of speed...not just "getting home".

I was undecided on a single or twins when shopping for my current boat. Having no SeaTow in this area and very little boat traffic, I wanted the redundancy of twins. I also have a habit of running aground occasionally, so I wanted the protected prop and rudder.

On my limited budget, I was looking at 25+ year old 30 - 35 foot boats. Anything with twins had very tight access, and the engines were nearing the end of their life. I didn't want to have to rebuild or replace two engines in very tight quarters.

In the end, the motor sailer gave me the backup power and the prop protection. I'm slowly learning the manoeuvrability. It works for me.

Neither singles or twins are better, its just a matter of suitability to the owner and the boat.