How does motorsailing work?

[Deleted User YDKXO]

Genuine question and I'm interested to know. Say you're bimbling along at 6kts in your 56' Nordhavn motorsailor under power and you fancy going a bit faster so you think about raising the sails as well. Which direction does the wind need to be coming from and how strong does it need to be blowing before you go faster? I know this depends on many factors but are there any general principles to observe when motorsailing as opposed to sailing?

 

[starfire]

Genuine question and I'm interested to know. Say you're bimbling along at 6kts in your 56' Nordhavn motorsailor under power and you fancy going a bit faster so you think about raising the sails as well. Which direction does the wind need to be coming from and how strong does it need to be blowing before you go faster? I know this depends on many factors but are there any general principles to observe when motorsailing as opposed to sailing?

Generally, the other way round, you are bimbling along at 6kts under sail & the wind drops, you want to get where you are going before the pub shuts/can't get over the cill at the marina/whatever.

You start the donk, drop the genoa, center the main & sheet it in hard.

Using the main as a 'flopper-stopper'

If the wind is blowing enough to sail at a reasonable speed , you would not start the donk, that costs money & makes a noise

 

[Morpheous]

Basically they keep motoring, hoist the sails so it leans over a bit, they can then clean the boot lines while underway. They have a max displacement hull speed and no additional power is going to make them go any faster. they can tootle along slower with the sails as a helper. Also makes them feel like 'proper' sailors back in the marina.

 

[maby]

Basically they keep motoring, hoist the sails so it leans over a bit, they can then clean the boot lines while underway. They have a max displacement hull speed and no additional power is going to make them go any faster. they can tootle along slower with the sails as a helper. Also makes them feel like 'proper' sailors back in the marina.

There is a degree of truth in that, though it is just a little flippant as well!

There's no magic trick in it - just set the sails and run the motor at the same time. If you were initially sailing without the engine in light winds and going at less than hull-speed, you can run the engine and get up to hull-speed. If you are running under power and the wind comes round to a useful angle, but not strong enough to run under sail alone, then put up some sail, drop the engine revs and save some fuel!

A lot depends on the wind speed and direction - if you have a following wind of four or five knots and start the engine, throttling up to normal cruising revs, you will probably find that you now have a head wind of one or two knots and the sails are slowing you down, not helping. If you have four or five knots of wind off the beam and you start the engine, it will become three or four knots of wind off the quarter and still give you a useful extra boost - get it?

 

[andyjcox1]

That all makes sense, but time for a stupid question.....why don't you just do tht with a normal sail boat which I am presuming will be better under sail...why go for a motor sailor?

 

[Morpheous]

though it is just a little flippant as well!

Sorry, it is friday and nearly time to head down to the boat

 

[Morpheous]

That all makes sense, but time for a stupid question.....why don't you just do tht with a normal sail boat which I am presuming will be better under sail...why go for a motor sailor?

They are usually beamier, focusing more on comfort and accomodation rather than sailing performance. Another point I forgot is that sails are very good at stopping displacement boats from rolling under motor.

 

[maby]

That all makes sense, but time for a stupid question.....why don't you just do tht with a normal sail boat which I am presuming will be better under sail...why go for a motor sailor?

We do do it with a normal sail boat - the principle is the same in either case.

 

[Searush]

Generally, if I'm getting enough power off the sails to move the boat I switch the engine off. The peace & quiet is magnificent, and I have a lovely quiet motor these days. The engine gets switched on when the wind heads me or dies away so that progress is too slow to get me to the relevant tide gate (lots of them to avoid around Anglesey). It's also pretty pointless trying to tack into a wind AND a 3 kt tide.

I have also used the engine so I can point higher to make a headland or sandbank in a single tack. But I wouldn't normally raise the sails to help the engine, almost always the other way around, sails are my main & preferred form of propusion, the engine is just an AUXILIARY power source, offering better speed control & the ability to go straight into the wind or when there is no wind at all.

 

[DAKA]

I have also used the engine so I can point higher to make a headland or sandbank in a single tack.

surely putting the engine on has the effect of changing the wind direction even more on the nose making it even more difficult to point to a headland
Or do you just let the sails flap for the last 1/2 mile in order to make the headland without tacking ?
(serious question, not taking the whats er name , my engine was always on save the start/finish line )

 

[Garold]

Many sailors motorsail to keep to their passage plan if the wind direction and strength doesn't allow them to make their destination in a reasonable time period.

However, full sail + full engine revs doesn't = twice the speed.

As for the Nordhavn, I believe that it's a different proposition. Their idea is that you can go further, get to more distant places, on less fuel , and with the added safety factor of sail power if you need to rely on it when the engine breaks down. However, they won't be the best performing sail boat under sail.

Also, as mentioned before, dispalcement motor boats can rock and roll, so a motorsailor will often be a more comfortable passage maker than a pure displacement motorboat.

Each to their own I guess.

I am always seduced by the Nordhavns whenever I have viewed one, including their motorsailor.

Cheers

Garold

 

[l'escargot]

On older boats that don't point too well you can often sail closer to the wind with the engine running without pinching. You can go faster than if you were just sailing and and you get more speed from the engine at lower revs because the sails are still drawing. It can get you you straight to a destination that may otherwise have needed a tack and saves you time and distance without having to resort to just motoring.

 

[ian38_39]

On the Norfolk broads it is normally used so that they can go faster than the speed limit but look like they are sailing.

 

[MapisM]

I'd be tempted to simply answer "it doesn't" to your question...
I can see the point in both sailboats and mobos, but motorsailers are the worst of both worlds imho.

 

[maby]

I'd be tempted to simply answer "it doesn't" to your question...
I can see the point in both sailboats and mobos, but motorsailers are the worst of both worlds imho.

You need to distinguish between motorsailing and motorsailers - we have a thoroughbred sailing yacht, but still motorsail when the wind is in a favourable direction, but too weak to arrive in time.

 

[MapisM]

You need to distinguish between motorsailing and motorsailers

Yep, but the OP question was actually more focused on the latter (e.g.N56), I reckon.
And that was the idea behind my answer, anyway.

 

[Deleted User YDKXO]

Yep, but the OP question was actually more focused on the latter (e.g.N56), I reckon.
And that was the idea behind my answer, anyway.

Well yes you're right. I was trying to understand how motorsailing works from the point of view of a motorboat with sails like the N56 rather than a sailing boat with a motor like a normal yacht. I'm guessing that most of the time, owners of boats like the N56 will be cruising under power and only raise the sails when a combination of the engine and sails allows the boat to go faster

 

[AndieMac]

Well yes you're right. I was trying to understand how motorsailing works from the point of view of a motorboat with sails like the N56 rather than a sailing boat with a motor like a normal yacht. I'm guessing that most of the time, owners of boats like the N56 will be cruising under power and only raise the sails when a combination of the engine and sails allows the boat to go faster

The N56 will be stabilised anyway, like all Nords, so I imagine the sails will be raised if or when the wind is well aft of the beam.

I've heard experienced coastal delivery yacht skippers mention realistically the engine is running 80% of the time while on passage.

 

[vas]

The N56 will be stabilised anyway, like all Nords, so I imagine the sails will be raised if or when the wind is well aft of the beam.

I've heard experienced coastal delivery yacht skippers mention realistically the engine is running 80% of the time while on passage.

hm, pitty defies the reason, doesn't it?

I've to admit that I sort of liked the N56MS, and was thinking that when the kids grow and if I ever get to pension (20yrs and counting), I'd not mind such a boat (s/h of course) and cruise around the whole med and beyond. But not 80% on motor!

May have to opt for a nice cat instead...

cheers

V.

 

[AndieMac]

hm, pitty defies the reason, doesn't it?

I've to admit that I sort of liked the N56MS, and was thinking that when the kids grow and if I ever get to pension (20yrs and counting), I'd not mind such a boat (s/h of course) and cruise around the whole med and beyond. But not 80% on motor!

May have to opt for a nice cat instead...

cheers

V.

Funny you should mentioned the cat option. A guy I spoke to who had lived aboard a very popular, locally built 38' sailing cat, but who also was delivering this companies new boats from their factory pretty much full time, was the first to mention the 80% motor thing, but have since read a number of similar accounts.
Cats don't point to windward very well and the engines were needed to not only maintain speed but also keep charge in batteries even if the wind was in the right direction.
Cats dont perform well with extra weight either, and with his families liveaboard requirements (weight and storage) he sold the yacht and bought a Nordhavn 43, which he is very pleased with.

Regarding the Nord 56 MS, I've not seen or heard anything specific regarding this vessel, but imagine as the PAE (Nordhavn) owners were initially sailing yacht designers and builders many years ago before launching into trawler yachts, this vessel should have a reasonable pedigree.