Single or twin? (or triple)

[longjohnsilver]

Not much happening hereabouts cept Byron staying up till all hours to reach 1000, I looked and he was only on 633 last week!!!

Anyway, back to important matters, well actually just plain bored so want to start a discussion about boats, must have been discussed many times b4 but in my usual alcohol induced stupor can't really remember much, (make my next a triple measure) but having a single engined boat I say that single is best, less maintenance, less to go wrong, much more space in engine room, easier to work on, better fuel consumption etc etc etc.

All fishing boats I see are also single engined and they usually seem to get home ok, spend more time at sea in a few days than most of us in a year, go out in almost all weathers.

So if twins are so good why don't they use them??

Never having helmed a twin engined boat I speak out of pure ignorance of course, all my mates with 2 say much easier to manouevre, but most of them stay firmly tied to pontoon!! And I always seem to somehow get into most spaces without 2nd engine or bowthruster (horrible noisy things!!).

Haydn I think tells of 4 gearbox failures, I read of twin shafts being pulled together by pot ropes and boats sinking, some twin engined boats being almost impossible to steer on one engine, limited access to sort out problems etc.

So which is best? I must admit when crossing the Channel I do pay particular attention to engine noises especially when in French bit, but it also means that I try and take every precaution to try and avoid problems happening in the first place and short of a complete engine explosion can probably cope with most problems (like being able to dive to clear ropes from props to carrying good supply of spares). I hope this doesn't come across as complacent cos it's not meant to, I just realise that if and when I do have a problem I have to be in a position to hopefully deal with it myself as there may be no other option.

So come on, I know that most of you out there have 2 lumps (and at least one on river with 3!) so give me a good reason why I should change my opinion.

 

[nickyg]

I agree with you john & its quite true what you say about fishing boats Whats good for the goose........ etc
But i must admit i have got one of those noisy things at the pointed end

 

[SaltyCod]

Well I have to agree with all you say, like you carry all the engine spares and saftey equipment to deal with most eventualities including Scuba gear. I run a TSDY. Last August whilst on a passage to Bembridge I was passing Ryde cruising at 24 knots when we heard an "enormous bang" and we stopped dead in the water. Trying to keep my cool in fear off panicking the crew I went over the side just with snorkel gear to check the props, I found we had picked up 5" thick braided "Ships Hawser" that had wrapped itself in a "Spanish Windlass" around both props and shafts, the heavy swell made it to dangerous to try and cut it off. I ended up being towed into Bembridge by a wonderful man with a cruiser by the name of "Blue Crystal" " (to anyone who has knows him, will know that he really knows his stuff and what a super guy he is) he really saved the day for me. The Harbour Master helped us in and also helped me cut the rope off which was nearly thirty feet long!.

So there you go, one prop or two sometimes it makes no difference.

I hope I havent gone on to much, this is my first post after months of just looking on. Is it courage or the "Jack Daniels"

 

[longjohnsilver]

Glad you've decided to join in Jeff, it's all pretty painless!!
(most of the time).

Hope you didn't suffer too much damage, bet it was difficult to cut off.

 

[hlb]

Well I think two's better. mainly cos its more fun. Like whilst waiting for locks or bridges, you can while away the time by wizzing around in circles,but not going anywhere. On a more serious note. I've come back home three times this year alone on one engine. One turbo bust, One gearbox caput and a broken fuel pipe. Except maybe for the fuel pipe, I cant see anybody carrying a spare gearbox or turbo. The fuel pipe took two days to find the trouble, which is a long time to bob about in the sea whilst looking.

Haydn

 

[coliholic]

I'm definitly in the "two are better than one camp", though agree that fishermen only use one but you have to ask yourself just 'cos they only use one, is that the right thing to do? Perhaps they're a bit short of brain power hence that's why they're fishermen??

I'm reminded of a (serious and true) meeting I had in about '85 or '86 with the Head of Maintenance with PanAm at Heathrow. We were discussing the merits of their recently introduced twin engined Airbus flights trans atlantic and I asked him what they're like to fly on. "No idea he told me, never been on it and don't plan to. I always fly on our 747's with four engines and that's because no-one builds a plane with five engines".

 

[Guest]

Re: One and a half

I would go for one engine for cheapness, plus an auxilliary capable of creeping home on if necessary. But then i'm usually not more than 10 yards from a riverbank.

 

[david_steward]

Re: This is easy...

After 30 seconds of thought I realised that this issue is a real no-brainer.

If you go out to sea, never mind the fishermen, follow the example of the people who go out when anyone else would be quaking in their boots.

RNLI lifeboats generally have two engines which is a good enough recommendation for me.

QED.



Dave S

 

[longjohnsilver]

Not so easy...

Ah but most of the crew tend to be the very same fishermen who go to sea daily in their single screw boats................

So where does that leave us?!! Not so QED!!!

 

[oldgit]

Re:I nearly had twins

When the twin mercruisers in my regal decided to stop both at the same time it was because both engines had the same single feed from the fuel tank.Water managed to go through 1 ltr main water filter plus 2 x further filters.Extracted about 5 litres when tank drained.

 

[Guest]

Cost can also be a major consideration. It would be far better to have one well maintained single than neglected twins. Whilst fellow boater extol the virtues of the improved manoeuvrability I constantly hear moans about how much it is all costing - more so if they are connected to a pair of sterndrives.
Me. Ive got a single diesel that is fully maintained and fingers that are permanently crossed.

 

[ArthurWood]

My choice is two, with separate fuel tanks for
1.)manoeuvrability 2.)get-you-home-ability, except in rare instances of both failing simultaneously.
Had engine fail on way to Abacos early this year at aptly named "Centre of the World Rock," ie in the middle of nowhere and no-one around. Without second engine we would have been in deep doo-doo.

 

[Deleted User YDKXO]

Well, the experts say most diesel engine problems are fuel related so providing each engine has its own fuel tank, I would say the more merrier as far as engines go. Also, despite the stories, my personal experience is that, if you're going to foul a prop, its usually only one not both
Whilst a twin engined boat might be difficult to steer on one engine, you can usually get yourself home on one engine although you might need a helping hand to slot into your berth.
There's another reason why, particularly, planing boats are fitted with twin engines and its to do with the height of the engines themselves and how this impinges on the accomodation. Its highly likely that the overall height of a twin installation is less than a single large enough to give the same speed
But it's a good point about the ease of maintenance of a single engine and, for sure, one of the problems of a twin installation is access to the engines. All the same I'd take a twin any day over a single

 

[Col]

A common misconception about twin engines, is that they are not actually twice as expensive to run.
If you think about it, two engine are not working as hard as one by itself.

The only thing in common on my twin ( petrol ) engined boat, is the fuel supply. so complete engine failure is only likely due to fuel problems.

Despite a careful maintenance schedule, I have three times had to limp back on one engine, once due to starter motor failure, once due to a burst coolant hose, and once due to over overheating caused by a water intake blockage.As there are seperate alternators and batteries for each engine, even a simple flat battery is easily over come by the changeover switch, whereby you can charge the battery from one engine, with the alternater from the other.

 

[david_bagshaw]

Isnt the reason why fishing boats have only one engine, COST & SPACE,

Same goes for big ships as well, after all when was the last single screw /engined passanger ship / ferry built?

David
www.yachtman.co.uk

 

[Guest]

Re: hello saltycod!

what a totally billiant name you have bagged yourself. And hi. More postings please.

 

[SaltyCod]

Re: hello saltycod!

Dear Matts.

SaltyCod is a nick name my children came up with, as they think I spend more time in or on the water. When they think I could be making better use of my time baby sitting.

 

[Guest]

Re: still easy

ah but the sklintyflinty fishiboaties have a nice twin screw boats when there's £25mill in the RLNI kitty. And I spect that they'd smarten up the fishig boats too if needs be, instead of ole fisheads all around. So, twin engines it is, and QED again!

 

[jfm]

Twin engines good, twin prop drag bad

Best answer is twin engines, but only when connected to Arnesons/Levis.

 

[Scubadoo]

But I thought the 747 had five engines, the fifth engine is in the tail fin - Not sure but I think it is design for takeoff or aux power.

RM.