Motor boat plus a sail boat equils a Motor sailer?

[niel12]

Thanks to all who participated in the Motor boat Versus Sail Boat thread i am wondering just how effective a motor sailer will be, would a motor sailer not be the real thing? i.e Nauticat!







He who follow the wind will discover beauty and pleasure that will last!

[minaret]

Guess I'll just have to post it again!

YouTube - ‪Sailing Wanderbird‬‏

Wanderbird doing 7.7 knots in 18 knots of wind on a close reach under plain sail only.
Later Nauticats are Sparkman and Stephens designs and sail pretty good.


Here's a little something from the Nauticat Email List -
I thought the group would like to know,
NC 44 Galaxsea took 2nd place in her division in the Great Pacific Long Pac race.
The long Pac is a singlehanded 400 mile ocean race from the Golden gate bridge to longitude 126.4 and back.
Galaxsea took 11th place out of a fleet of 30.
The results can be seen at the single handed sailing society's webb page.
Daniel Willey
NC44 Galaxsea

[capcook]

I have been wondering this myself... I don't think the Trawler/Motor sailers are very good designs, but was wondering if one could put more HP in a standard Cat and perhaps carry an additional set of props. One set for agressive motoring and another folding prop for sailing...

A lot of the sailing/motoring we are contemplating may be done with the Mast stepped (waterways and rivers), so we will want good motoring capabilities... Without a Mast, a sailing design would be much lighter. I was wondering if you could power say a 45' Orana or Lagoon to 15-18kts with say 100HP in each hull..

The typical Motor Cats carry around 200hp in each hull I believe, but are much heaiver... I do like the idea of having the ability to hi-tail-it if you need to but to also be able to enjoy the "zen" of sailing.... Thoughts ?

[simonmd]

The main theme of the 'sail vs motor' thread was basically the cost of sails/rigging vs larger engines and more fuel. Motorsailors have BOTH!

Not to disrespect them though, offering a more 'slow and steady' mode of transport than either a pure sailboat or powerboat, they can offer great accomodation and stability. For serious cruising, a great combination.

By the way, why is this in the Multihull section?

[David M]

I think of a motorsailor as a hybrid between sail and power and hybrids are not necessarily a bad thing. It depends on what you want to do with your boat. Don't let anyone knock you. If we had the same needs and desires then boats would all look the same.

[tsmwebb]

Originally Posted by David M

I think of a motorsailor as a hybrid between sail and power and hybrids are not necessarily a bad thing.

IMO, evidence suggests that it is an extremely popular thing. Motorsailor is a slippery term. I'm never quite sure what folks mean by it. Still, the average production "sailboat" today has substantially more installed power than the average "motorsailor" of the turn of the last century. Just looking at the motor side of the motorsailor equation it seems to me that the market has spoken -- the motor sailor is such a great thing that it is hard to buy a modern cruising sail boat that isn't also a good displacement speed motor boat. Certainly there are motorsailors that are pretty distinct but the concept is so ubiquitous these days that I wonder if the term makes any useful distinction in and of itself.

Tom.

[cat man do]

Originally Posted by capcook

I have been wondering this myself... I don't think the Trawler/Motor sailers are very good designs, but was wondering if one could put more HP in a standard Cat and perhaps carry an additional set of props. One set for agressive motoring and another folding prop for sailing...

A lot of the sailing/motoring we are contemplating may be done with the Mast stepped (waterways and rivers), so we will want good motoring capabilities... Without a Mast, a sailing design would be much lighter. I was wondering if you could power say a 45' Orana or Lagoon to 15-18kts with say 100HP in each hull..

Malcolm Tenant told me that this will work to some degree up to around 10 knots, on larger cats but then they tend to squat down aft if going much faster
I would agree and have observed this on several cats who thought they could just up the hp = more speed.
This is what a lot of french early gen powercat builders did as they already had the hull moulds

What you really need to do is to reverse the rocker to the horizontal down aft, but then this would affect the sailing ability, how, I am not sure.

The typical Motor Cats carry around 200hp in each hull I believe, but are much heaiver... I do like the idea of having the ability to hi-tail-it if you need to but to also be able to enjoy the "zen" of sailing.... Thoughts ?

The typical motor cat is built to do 20 knots into waves so is built heavier
it needs bigger motors for this speed
it therefore uses more fuel so needs to carry more
it needs more displacement to carry more fuel, larger motors and heavier build so loses speed and efficiency
The attempt to fix this is bigger motors
then it needs more fuel
And more displacement
and around and around we go.
A sailing cat these not be

perhaps if you take a sailing cat that already performs quite well under motor, say 8 -10 knots for a light 50fter with 40hp motors

Then you reverse the rocker to help prevent squat in the 10-14 knots range
And limit yourself to these lower speeds

And only put slightly larger motors in, around 65hp, so fuel usage is still low

And didnt put all the expensive mast, sails, winches etc on figuring that the capital outlay of these pays for a lot of fuel for the motors that you had already paid for, and no need for two sets of props

And if you had a low flybridge to steer from you will hear very little, if any engine noise, so you still get the zen like magic carpet ride*

I wonder if anyone is building such a vessel?

* I took a powercat ferry to Vanuatu 18mths or more back
It had 310hp x 2 and, when sitting up on the roof (no flybridge) you had to listen hard for engine noise.
It was quite surreal cutting through the water , 12 feet high at 16 knots with no noise

[niel12]

Thanks for all the views, i am of opinion that if one can make peace with a speed of arround 10 knots, be that motor or sail, a cat won't need too big motors and not too much fuel so one might achieve the best of both worlds?






He who follow the wind will discover beauty and pleasure that will last!

[harlie]

Cat man do is on the money with this. A sailing hull will squat when powered from below – the power on the sails lifts the aft pushing the bows down. Once you reach a certain speed (different for each boat) it will just squat in the rear and not go any faster.

To overcome this, designers have modified the aft section of the hulls to provide lift, this modification however involves squaring off the underline to the transom which results in a wider, flat transom (with chines) that is well below the surface – thus creating significant drag and significantly affecting sailing performance.

See the difference between the two Fusions
http://www.fusioncats.com/powercatamarans/

Perry made a nice motor sailer although heavy (like all Perrys), it was virtually the 43 with and extra 2 added to the sterns (flattened) for lift and handle the weight of the engines.
http://www.perrycatamarans.com/index.php?option=com_content&view=article&id=53&It emid=85

Spirited Designs have a brilliant 38’ sailer, modified to 40’ for flybridge powercat, and latest is 39.5’ for a motor/sailer called Crossover – 14kns cruise under motor with 75hp and if is 75% as good as the 38 under sail it will still be good…
http://www.spiriteddesigns.com.au/index.php?pageId=71288

Personally they are not for me but I can see the advantages...

[Unicorn Dreams]

The old Gulfstar motorsailers WERE a cross between their motoryacht with a keel and a mast added. Really big inside and a CC that does have a lot of windage.

There's one next to me in my marina, it's a 43' like me and has about 16" more free board than mine does..



'

[harlie]

Originally Posted by Unicorn Dreams

The old Gulfstar motorsailers WERE a cross between their motoryacht with a keel and a mast added. Really big inside and a CC that does have a lot of windage.

There's one next to me in my marina, it's a 43' like me and has about 16" more free board than mine does..



'

That sounds like a modification to a powerboat towards sail, we've got a few of those over here too, all older builds - Voyager comes to mind.

In recent times we've seen a lot of designers and manufacturers taking the sailing cat towards the hybrid which to me looks like a more efficient option

[dc9loser]

I owned a MacGregor 26X, trailer sailor which sailed pretty well, had a flat bottom and a 60 hp outboard and could do 20 mph under power. Of course it has water ballast and you would empty that for top speed when under power.

However, if you want the same capabilities on a bigger boat, good luck.

I think any pure sailing catamaran which comes installed with a couple of small diesels would be a great motor sailor, but you are limited to about 9 mph under power which is not bad - that is 180 miles a day which is all ya are going to do in a trawler anyway.