2 engines or 1 engine

[1971Lou]

i was always told i would be mad to go to sea in a 1 engined boat so what has now changed when people here are suggesting to go the one engined route. seems to me that people just say what suits them at the time. who do i trust. I am looking at a boat with 2 engines only because it is meant to be safer. i dont want to be left wth a lemon when the fuel price goes up.

 

[lookout]

umm, buy a boat with two engines; it's what you've always been told eh?

 

[gjgm]

I m not sure for how long a lemon will float anyway.
but at some point in boat size, if you want some speed, you ll have to have two engines. As Jez mentioned, The Windy Scirocco at 33ft copes well with a big single, and in Scandinavia they seem quite happy on 30-35ft on a single.. but maybe they dont feel the need for 35-40knts.

 

[Whitelighter]

I am looking forward to the answers to this thread as it is something I am debating right now - Single D6-370 or twin D3-190's? I can see the logic of the single, plus the boat goes well with this option but I don;t know how the UK market would react - the size of the boat is firmly in twind terratory.

In my experience, a lot of probablems with engines relate to contamninated fuel, and since most modern boats only have one tank for both units, what happens to one will more than likely happen to the second if fuel is the culprit.

I don't know, but I am interested to see what the rest of the forum think.

 

[1971Lou]

what about parking. is it easier with one or two. and if you get a fishing line on the props how do you get home without a spare or a belt breaks on one engine. that is what i was told. i am interesed as well as i always wanted just one engine to worry about.

 

[Kipper]

Most sports boats under 30 feet or 33 if its a Sea Ray mange on one engine without issue and as Jezz points out a lot of breakdowns are due to poor fuel. I would also suggest that many more are down to poor maintainance, I would be happy with one modern well looked after engine as long as the boat is ok for close quarter work.

 

[ari]

Plenty of people take to the air in single engined aircraft. Come to that, we all take to the roads in single engined cars, hundreds of thousands of them, and you rarely see them broken down.

However that said, I think most people on here are applying too much common sense in what is not really a common sense purchase. Truth is most people buying 30ft+ boats simply want twin engined boats. /forums/images/graemlins/cool.gif

 

[Whitelighter]

parking is a bit easier with two, but I never had any problems with a single engine boat (ok, was a bit smaller at 29ft) - it is just a different technique. As with all things though, if you want to pay the extra for the comfort go for it.

As for things round the props, the boats we are talking about are on stern drives, so rope or fishing line can be cut away from the relative safety of the swim platform or transom by raising the drive to its beach position (the props are virtually out of the water in this mode) - good idea to keep a knife on board.

Belts, yep I see the concern here. I suppose that since your service billas will be halved, you might be more inclinded not to cut corners to save money therefor reducing the risk a bit? I don;t know the answer. That is why we haven't ordered the boat yet.

 

[gjgm]

I think you supply what the customer wants. Question hangs over resale though -ok maybe not your immediate problem, but it would be if no one will touch the boats in the second hand market- it becomes your problem in the new.. Certainly with the marque I like, wrong engines make the boat unsaleable.
If performance was good, Id be happy with a single, but then I dont seem to be representative of UK boating habits.

 

[Nick_H]

true, a lot of problems are fuel related, but a lot more aren't. EDC control failure, plastic bag in the intake causing overheat, rope round the prop, for instance. With a twin engine boat you can still get home with any of these problems. I'd have twins every time, as the extra fuel and service costs are not that great in comparison to annual boating costs.

Singles are great for coastal stuff, and the only option for small boats, but offshore in a bigger boat there's no substitute for a bit of redundancy IMO.

 

[T43]

Clearly not rocket science is it, engine failure in a single engine boat @ sea will clearly require having to call for somebody to tow you unless you have a very good auxiliary engine attached somewhere. Caught in the wrong place at the wrong time can lead to panic or even an accident.

Having said that 2 engines can fail, but you would have to be having a really unlucky day.

Even with the on set of increased fuel prices I think most people with over 25 footers will opt for 2 smaller engines rather than 1 large one.

However if your boating is on non tidal waterways single engine option would be realistic.

 

[gjgm]

I also suspect that people are a bit more ambitious in thought than in actuality. If you are worried about a breakdown in the Solent, Seastart is alot cheaper than another Volvo.
Still, if you are regularly boating in remote areas, or do long passges, then even allowing for the fuel contamination issue, I can see some peace of mind in twins. But then not that many boats seem to venture that far.
On an off note, interesting to read that some cars are now without a spare tyre;statistically, it is so rare to have a tyre failure during a journey (as opposed to spotting it outside your house, I suppose), that a spare tyre is a waste of space.
Perhaps the facts about breakdowns dont erally favour twins. RNLI or Seastart must have some interesting stats. (Suppressed by Volvo? /forums/images/graemlins/laugh.gif)

 

[ari]

Agreed. I've had two total engine failures at sea, both in twin engined boats that got me home on one. (One was that an engine that dumped it's cooling water in the bilge so would not run without overheating, and the other was fuel blockage in the fuel pipe, and that was twin engines from a single tank! Somewhat nervewracking at the time).

My current boat is single engine but only because I can only afford a small sportboat, I'd have twin (and a bigger boat) if I could.

 

[lookout]

as long as the resale was ok, I'd go for a single if the performance was adequate. how do windys & botnia targas & such sell s/h with singles ( assuming a twin-option exists) ?

 

[Whitelighter]

That's just it, I am not sure what the customer wants today will be what they want in a years time. I would put a poll up, but it is wandering into the commercial things so I will askj you directly as you would look to move to a boat the similar size as ours.

For our launch demo, would you spec a single D6-370, which will do 35 knots easily and is quite unique in that class, or would you go for twin D3's that will do about the same (34knts). Cost is the same for either, boat is a deep V sports cruiser.

Or would you go all out and spec 260Hp D4's for 40knt + performance? (twin engines have twin tanks by the way, just in case it makes a difference)

 

[alanch]

The Dutch prefer steel single engined boats, we tend to go for twins in plastic. Why? Coastal fishing boats are almost always single engined. I have spent 40 years on the oceans with a single engine, but we did carry engineers to fix them! If you go to the expense of twins then fit twin fuel tanks, and a proper fuel filter/fuel treatment system.

 

[1971Lou]

is it possible to have 2 engines and only drive up rivers or around at slow speeds with only 1. if you can then that would be better than 1 big one and cheaper for fuel. how much energy do you need to get it to plane can you do that with one or would it wobble as it is off balance

 

[mainshiptom]

Two every time !

Broke down last time right after an engine service, I over filled one engine with oil and the oil pressure sensor decided to split and let all the oil into the bilge, Alarm sounded on low oil pressure (wander why), The other engine got us into Whistable where we got a quick repair,

I would never take my famly to sea with less then two engines, but having said that we have a rib with one engine that always plays up ! (maybe he is lonely?)

Tom

 

[Whitelighter]

For slow stuff then yes, you can troll on one engine. The boat needs a certain amount of power to get on the plane, and generally that power is split over the two engines. Using just one you wont plane and just use more fuel

 

[1971Lou]

i guess one would run the servo on the brakes so best to find out which one first