Using one engine on a twin engined boat (Part Two)

[Prima]

I was just reading a VERY old thread about using one engine on a twin engined boat, and wondered what people's views were on this sixteen years later?

Here's the original question and thread:

Is it more economical to use only one engine when you can? Will the boat drift to one side? Is this dependant upon shaft or outdrives ?

Or should I just buy a twin engined boat with smaller engines ?
Read more at http://www.ybw.com/forums/showthrea...ne-on-a-twin-engined-boat#daF2eJ73lLz3V166.99

 

[kashurst]

I used to do this quite often when we kept the boat on a river to get each engine properly hot and put a bit of load on it. Since we have been sea based I have had to do it twice - not through choice. Once because we trashed a prop, another time an engine failed big style. Both times had to do a @ 25 mile trip on one engine. Previous boat had fuel consumption gauges. I found at slow speeds the amount of fuel used was pretty much the same if I used one engine or two.

On balance if doing river/ lake stuff with 5 or 6 knot speed limits it's better to alternate the engines running one at a time for an hour or two then changing over to get the engines working properly. However that can give a handling issue as the boat obviously wants to turn one way more than the other.

 

[rustybarge]

I remember some time ago on the boat design forum i suggested putting a v- belt pulley on each shaft between the gearbox output/ propshaft, and then using a simple jockey wheel to tighten the v-belt to send drive to both shafts while running on one engine at slow speed: just like a ride-on mower engages the cutter rotor.

At 6-7kts it only takes about 2.5-3.5hp/ton to push a typical 12m boat, so a simple V-belt off a agricultural implement should easily transmit 35-40hp required.

 

[NorthUp]

Most twin engine installations have contra-rotating props to complicate things ☺

 

[jrudge]

Don't bother. The boat won't go in a straight line and the power steering will be on one engine only. You will save pennies.

It has been asked before and really has little going for it. I did it a bit on my forte boat on upper Thames. Pain in the bum

 

[Portofino]

I,am kinda strugging with this whole buy a twin buying a fast planing boat ---then sometime later ,asking is it or request how is the best way to use one engine to keep below D speed and go D speed wise - seemingly way below what the thing was actually designed and presumably marketed speed to go . By running one engine ??
If I have understood the posts correcty ?
.
A bit like a guy who uses a car to use mostly in London ,s congestion charge zone buying the latest ferrari 815 -the asking /whingeing about -
Say on a Ferrari forum or any car /motoring forum --/

"do you think it's possible if I buy on e-bay chip that's shuts down one bank of my 850'Hp v 12 -6L ,I might duck under the congestion charge in my new 812 ? "
Will it harm the off bank ?

Answer is if the congestion charge is the issue buy a Nisan leaf .

So back to boats ( before Nigel accuses me of "should be on the lounge " )


or I,am I missing something pink elephant like in the corner?

 

[Prima]

I,am kinda strugging with this whole but a twin planing boat ---then sometime later ,ask is it or request how is the best way to use one engine to keep below D speed and go speed wise what the thing was actually designed and presumably marketed to go .
.
A bit like a guy who uses a car in London ,s congestion charge zone asking /whingeing about -
"do you think it's possible if I but a e-bay chip that's shuts down one bank of my 850'Hp v 12 -6L ,I might duck under the congestion charge in my new 812 ? "

Answer is if the congestion charge is the issue buy a Nisan leaf .

So back to boats ( before Nigel accuses me of "should be on the lounge " )
Effing but a single engined boat -- or I,am I missing something pink elephant like in the corner?

Instead of ranting, why not explain the exact reasoning behind your comments instead.

It's a reasonable question to ask. Particularly so if people like yourself only ever rant rather than help others to learn.

 

[Portofino]

Instead of ranting, why not explain the exact reasoning behind your comments instead.

It's a reasonable question to ask. Particularly so if people like yourself only ever rant rather than help others to learn.

Take a look at my recent infact today threads replays -just 1 day not wanting to labour a piont or "rant "
1- a guy with volt Meter issues
2 a guy with kad 300'temp issues

Sure some issues with privacy and drones --but hardly ranting ,just regurgitating local laws IMHO -championing personal data protection .

right ok this forum is degenerating into the wild west ,
Take a close look I know many big hits ive taken for team on hurricane ,s recent post

Here http://www.ybw.com/forums/showthread.php?484735-Grey-Mavic-Down

Look @ all the slag /hits I've taken , criminal,/less than plant life etc -from No regrets .
As it turns out IMHO the law is on my side -

Ps try to offer up resemblance of interlectual foil as opposed go for the man .

In this thread - one,s in the abscent of of other info gonna wonder why a planing boat needs to plod along on one engine .

Once armed with that nugget of a ango saxon info presume you will,get a more suitable /helpfull replay .

You know in Ferarri forum ,s and Rolls Royce /Bentley owner forums ,it's all a lot more friendly -to the piont ,no personsl attacks .
I guess it's because spectrum of user s on here is just too broad ,too wide -both intellectually and afraid to say financially .

How ever folks should not be rude to each others .
I feel your coment was rude to me ,

 

[Prima]

And I feel your logic is flawed. Plenty of V8 and V12 cars shut down half the engine when around town. So you shoot yourself in the foot with your own argument

I fail to see how I am being rude. Moreso the other way around I'd say

 

[Portofino]

But the F 812 doesn,t .

Ok we are a bit far apart to meaningful, continue .
But do have a factual look of my post re"helping others " it's not difficult !

With the drone thread I would like to think the participants and indeed none participants have learned a bit ,if indeed they may not like being dragged to "school" in a forum friendly way ,for those who wished to learn that is .

 

[Prima]

The infinite monkey theorem states that a monkey hitting keys at random on a typewriter keyboard for an infinite amount of time will almost surely type a given text, such as the complete works of William Shakespeare.

 

[rustybarge]

Just to get the thread back on track, I have a friend who worked as a ships engineer on coasters and other smaller ships, and he told me that they have all sorts of engines: the main one and many smaller wing engines which propel the boat when its not at full displacement.

So its common commercial practice with the big boys, so why not us?

 

[Prima]

Just to get the thread back on track, I have a friend who worked as a ships engineer on coasters and other smaller ships, and he told me that they have all sorts of engines: the main one and many smaller wing engines which propel the boat when its not at full displacement.

So its common commercial practice with the big boys, so why not us?

There seems to be many governing factors.

I just discovered this, which doesn't say one way or another, more a case of trial and error with different boats/hull shapes

https://www.passagemaker.com/lifestyle/strategies-for-long-range-cruising-with-twin-engines-2

 

[Prima]

Take a look at my recent infact today threads replays -just 1 day not wanting to labour a piont or "rant "
1- a guy with volt Meter issues
2 a guy with kad 300'temp issues

Sure some issues with privacy and drones --but hardly ranting ,just regurgitating local laws IMHO -championing personal data protection .

right ok this forum is degenerating into the wild west ,
Take a close look I know many big hits ive taken for team on hurricane ,s recent post

Here http://www.ybw.com/forums/showthread.php?484735-Grey-Mavic-Down

Look @ all the slag /hits I've taken , criminal,/less than plant life etc -from No regrets .
As it turns out IMHO the law is on my side -

Ps try to offer up resemblance of interlectual foil as opposed go for the man .

In this thread - one,s in the abscent of of other info gonna wonder why a planing boat needs to plod along on one engine .

Once armed with that nugget of a ango saxon info presume you will,get a more suitable /helpfull replay .

You know in Ferarri forum ,s and Rolls Royce /Bentley owner forums ,it's all a lot more friendly -to the piont ,no personsl attacks .
I guess it's because spectrum of user s on here is just too broad ,too wide -both intellectually and afraid to say financially .

How ever folks should not be rude to each others .
I feel your coment was rude to me ,

I couldn't be bothered to try and decipher that long winded and incoherent reply last night. Now that I have made an attempt to do it this morning, I am still none the wiser

I followed your link to the drones thread, and I see you just spout the same incoherent sentences there.

You talk about "the spectrum of user s on here is just too broad ,too wide -both intellectually and afraid to say financially", I've come to the conclusion that you feel belittled and frustrated by the rest of the members on here having a tad more brain power along with bigger pockets than you.

Go to night-school, get some qualifications, and improve your career prospects and your wallet, if that's how you feel.

 

[Momac]

I have not tried running on one engine (in a twin engined boat) . Obviously it is possible. I keep the boat on a river which is speed restricted so spend many hours going slow.
The main deterrent for me is my starboard engine drives the power steering and charges the domestic batteries. If both engines charged all batteries and powered the steering it might be worth experimenting with single engine running.
I imagine single engine running at slow speed on a river would save some fuel and, possibly more significantly, would cut down on time added to the hour meters (if alternating equally between engines).

 

[MapisM]

I just discovered this, which doesn't say one way or another, more a case of trial and error with different boats/hull shapes

https://www.passagemaker.com/lifestyle/strategies-for-long-range-cruising-with-twin-engines-2

Thanks for the link, but the article failed to impress me.
"Slow down and go farther" is hardly a difficult conclusion to reach, and I'd be tempted to reply that if you slow down and do NOT go farther, you'll enjoy an even better fuel economy...
...Not to mention the suggestion that by doing that, "You are being environmentally responsible".
These self-righteous security blankets are something you can find only in America, where there are folks who cross oceans on pleasure mobos (which is the least efficient way of travelling known to mankind) just for the sake of it, and pretend to save the environment along the road - as if sailboats were yet to be invented...

Bottom line, while I can see why you didn't appreciate Portofino's comment about the whole topic being completely pointless, when all is said and done, I can't see a lot of value in the idea, either...

 

[Prima]

Bottom line, while I can see why you didn't appreciate Portofino's comment about the whole topic being completely pointless, when all is said and done, I can't see a lot of value in the idea, either...

I'm inclined to agree, it was just that I stumbled across the previous topic and as a noob was curious to know the pros and cons of running them individually.

It's not that I didn't appreciate his comment about it being a pointless topic, more that in his long-winded and incoherent attempts to get his points across, I failed (or didn't bother) to read them - and why on earth he felt the need to link me to a drone thread still mystifies me

 

[Leighb]

Perhaps the best reason to run on one engine is to practice how it handles especially in/out of a berth!!
At least then you will have some idea of your options when one goes down for whatever reason.

 

[kashurst]

+1 on that - it does happen.
We bought our first boat in 2001, it was a Princess 37 1980 vintage with Ford Mermaid engines on shafts. We bought it through a broker at York marina on the river Ouse. Looking back now we knew next to nothing about boats, I certainly couldn't have told the difference between a planing hull and a displacement hull etc etc. We wanted a boat, we could afford this one and the location suited us - how hard could it be????

I think a lot of people start out like this unaware of the best designs of boat for different circumstances and how to get the best out of them. Also people buy boats for many different reasons, for example how many boats do you see in your marina that never seem to move? Some people just want a floating caravan, others want to go around the world at max power and everything in between.

We rapidly learnt a lot - including the use of one engine. The ford mermaids smoked like crazy unless they were properly warmed up which on a speed restricted river you just can't do. Also the boat was much much quieter using just one engine and the running engine warmed up properly and didn't smoke. The boat didn't have power steering so no problem there and the river is fairly straight so handling not an issue either. Split charge diode pack meant all the batteries were being charged regardless of how many engines were running. So you could argue we bought the wrong boat for the application but using one engine gave a good solution to gentle river cruising. It also meant that when we went out to the Humber estuary etc we could take full advantage of both engines. Each engine was generally run appropriately, warm and loaded, the crew didn't get gassed from the exhaust so everyone was happy.

A few years later when I did my Day Skipper Practical - I was surprised how much time we spent learning how to handle a twin engine boat with only one engine, getting in and out of moorings, coming along side etc. At the time it seemed a bit OTT. 16 years later I now know why you need to know how to handle a twin engine boat with one engine down.

 

[rustybarge]

A nifty way of running 2 engines on one shaft: back to back.