Twin Diesels versus single

Have learned from this thread and thank contributors. Know for blue water sail unlike coastal you have a different attitude. You stay well within expected service life and replace things then. Although on coastal boats folks will replace sails only when they fail or bag out. On ocean boats usually before 7 years with over weight non film sails and in less time with higher tech performance sails. Same with standing rigging. 7-8 years and a slight bit longer for rod. At least the terminals are replaced.. Doesn’t matter if it looks perfect.
Would thing with voyaging motor it would be the same. Beyond routine preventive maintenance you could make a pretty decent estimate of the service life per fuel burnt of the components . Would think (but don’t know) voyaging under powerfolks would have a similar attitude. Even to the level of their spares and specs. On my sailboats carried water in flats inspite of a watermaker and big water tank. Carried a dozen racors inspite of it being under sail 95% of time. Have work arounds for all the failure points you can think of in place before leaving.
Currently on power my concern is lightening strike. Twins or single no power. Fishing nets or other debris. Twins or single shafts/props entangled no propulsion. Think a single in a Kort behind a keel maybe safer in some settings. I understand why we’ve moved to computer controlled engines but think every time we add complexity we add potential single point failure spots. Don’t see twins totally eliminating that. If I went back to voyaging agree a different drive train and power source does add peace of mind. Easily could be a get home of some sort. But think the primary mode of propulsion needs to be a serviceable and bulletproof as possible. Here protection of the prop/drive shaft has merit. In larger boats possible with twins behind skegs but easier to do and more robust with a single behind a keel in smaller boats . Interested in hearing from power voyagers. Beyond direct engine troubles whats your read on the other reasons to lose propulsion?

Hippocampus said:

Beyond direct engine troubles whats your read on the other reasons to lose propulsion?

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Been watching a ton of videos, great loop, bahamas, etc recently. Beyond the guy with the failed mooring ball in the BVI and the tornado in Italy, it's been running aground, hitting something submerged underway, running over fishing nets or crab pots, failed hydraulic steering pump and one sail boat started taking on water due to a thru hull speed sensor failing. (In that case, I question how well that boat had been maintained in general. Was an old, ratty boat) There was one engine failure on a 40+ year old Tollycraft that had to do with seals/gaskets. The admittedly newbie owners were aware of some coolant/oil leakage but hadn't gotten around to addressing it and continued to run the boat. That engine had to be rebuilt. It was probably due anyway but they helped it along.

slowgoesit said:

We're the single engine Muirgen Peter referenced in the third post on this thread. We left Seattle Area 2 September of last year. We arrived here at our new home in Florida on 26 April.

• 6 months and 24 day later. 6,400 nm
• a little less than 1000 engine hours
• three oil changes
• speed varies between 6.5 and 7.5 kts
• Average fuel burn of 2.4 gph
• in the neighborhood of 2,400 gallons of diesel consumed
• longest non-stop "sprint" was across the Caribbean, 8 days, 1,250 miles
• groundings: two . . . no I don't want to talk about that
• Anchors dragged, 1
• chased by pirates, once
• macerator pumps replaced, 4
• electrical issues, 1 with generator, 1 with a nav light
• refrigeration issues, 2
• fish caught, lots, more than we could eat on the trip
• long lines snagged, 7

Engine failures . . . . nope, none, nada, zero, zilch. Like Peter said, we're aware of the probability of an engine failure, but it wasn't high on our list of concerns.

Add in the 2,200 nm trip to Glacier Bay, AK and back to PNW, and in and around trips in PNW. Over our 40 months and 10,000 nm during our ownership we've had zero engine problems that weren't caused by our selecting a fuel tank totally filled with air, . . . no, I don't want to talk about those either.

We love the access our single engine gives us in our stand up engine room.

Singles aren't for everyone, but we've never regretted having only one engine. YMMV

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Thank you so much for your list - it become so real with it..... specially, pirates chase....

Purchased with 46 hours on the engine, 8298 hours on the Hobbs now. Oil filters, fuel filters, alternator belts, and one front oil seal in all of those hours of operation, including a round trip from Seward Alaska to La Paz Mexico and back. I have never experienced a mechanical breakdown, and maintain to the highest level possible preventively. I average 1 gph at 7 knots, and .62 gph at 5.5 knots, slower cruise .4 gph at 4.5 knots. Size matters...