Sail-Drive in a Sailboat, Corbin 39'

[ontherocks83]

Also.....

with all that being said there are lots of people who have sail drives and love them. They certainly do have benefits and can make maneuvering in tight quarters much easier. It really comes down to what is more important to you. Do you want great handling and more maintenance or less "maneuverability" and less maintenance?

[openseas]

Thank you for all the advice

[colemj]

Originally Posted by ontherocks83

They certainly do have benefits and can make maneuvering in tight quarters much easier. It really comes down to what is more important to you. Do you want great handling and more maintenance or less "maneuverability" and less maintenance?

I don't see how saildrives increase maneuverability over shaft drives, other than they are usually fitted on boats that have more maneuverability to begin with.

Mark

[ontherocks83]

Originally Posted by colemj

I don't see how saildrives increase maneuverability over shaft drives, other than they are usually fitted on boats that have more maneuverability to begin with.

Mark

I could very well be mistaken. I thought all sail drives spun on a axis so it essentially gave you a stern thruster hence my comment, but I may be totally wrong.

[colemj]

Originally Posted by ontherocks83

I could very well be mistaken. I thought all sail drives spun on a axis so it essentially gave you a stern thruster hence my comment, but I may be totally wrong.

No, they don't work that way - they are fixed just like a shaft drive.

Interesting that you responded with many "facts" about saildrives, but do not even know how they work. In short, your understanding of them having a drastic increase in the number of failures possible, as well as ton more moving parts and a lot more maintenance requirements is also wrong.

Mark

[deluxe68]

Originally Posted by ontherocks83

I could very well be mistaken. I thought all sail drives spun on a axis so it essentially gave you a stern thruster hence my comment, but I may be totally wrong.

Some brand new boats are using this technology, it adds a lot of complexity.

[colemj]

Originally Posted by deluxe68

Some brand new boats are using this technology, it adds a lot of complexity.

Those aren't really saildrives - they are pod drives and the smallest one starts at 250hp. They are primarily fitted to powerboats - I don't know of any sailboats with them - definitely no small sailboat like a Corbin 39.

Mark

[deluxe68]

Originally Posted by colemj

I'm sorry, but bacteria (or other critters, or even just a stirred up bottom) and warm water cannot cause corrosion of a drive leg. Were all of the outboards and aluminum boats in the marina also corroded?

I'm not saying there wasn't problems with the 2 boats - just that the stirred up bottom and warm water had absolutely nothing to do with it.

Mark

The chemical change in the water could result in increased electrical conductivity.

From a dredging web site:

"Trailer dredgers are equipped with centrifugal dredgepumps, to remove soft seabed materials.

Maintenance dredging often involves removal of mud, which may contain gas.

This gas may be hydrogen sulfide, carbon dioxide, or methane gas, but other gasses can be present. These gases are often the result of the bio-chemical breakdown of organic matter in mud, or originating from sewage outfalls.

Dredgers often operate in areas where natural gases are trapped or dissolved in the dredged material. As the soil comes to the surface and is exposed to the vacuum in the dredge pump, the gas releases, expands and reduces the density of the mixture."

[colemj]

Originally Posted by deluxe68

The chemical change in the water could result in increased electrical conductivity.

From a dredging web site:

"Trailer dredgers are equipped with centrifugal dredgepumps, to remove soft seabed materials.

Maintenance dredging often involves removal of mud, which may contain gas.

This gas may be hydrogen sulfide, carbon dioxide, or methane gas, but other gasses can be present. These gases are often the result of the bio-chemical breakdown of organic matter in mud, or originating from sewage outfalls.

Dredgers often operate in areas where natural gases are trapped or dissolved in the dredged material. As the soil comes to the surface and is exposed to the vacuum in the dredge pump, the gas releases, expands and reduces the density of the mixture."

That still would not cause widespread corrosion of any primed and painted aluminum structures protected by zincs.

It would not cause any corrosion of any type of aluminum at all, but particularly not treated and zinced marine alloys.

The dredging reasoning just doesn't work in any way and was not the cause of any corrosion of a saildrive.

Mark

[Captain Bill]

Originally Posted by colemj

That still would not cause widespread corrosion of any primed and painted aluminum structures protected by zincs.

It would not cause any corrosion of any type of aluminum at all, but particularly not treated and zinced marine alloys.

The dredging reasoning just doesn't work in any way and was not the cause of any corrosion of a saildrive.

Mark

+1

Sounds like a marina with a wiring problem trying to blame someone else to me.

[deluxe68]

Originally Posted by colemj

That still would not cause widespread corrosion of any primed and painted aluminum structures protected by zincs.

It would not cause any corrosion of any type of aluminum at all, but particularly not treated and zinced marine alloys.

The dredging reasoning just doesn't work in any way and was not the cause of any corrosion of a saildrive.

Mark

The two boats that required new saildrives were fairly new boats but were plugged into shore power. The problem was discovered when the dredging company saw the increased water temperature. The maintenance manager for the Beneteau dealer (located in the same marina) looked at all of their boats in the marina by sending a diver down. I doubt if this guy lied to me just to get me to pay $40 for a diver.

[Jim Cate]

Originally Posted by colemj

Those aren't really saildrives - they are pod drives and the smallest one starts at 250hp. They are primarily fitted to powerboats - I don't know of any sailboats with them - definitely no small sailboat like a Corbin 39.

Mark

Actually, I think that they are indeed being fitted to yachts in the 40 foot +/- range. We had a dock neighbor in Hobart with a brand new AWB of that size which had such a device fitted. It didn't work,and his holiday cruise was aborted because there were no parts available in Oz at the time.

I was otherwise occupied at the time and didn't pursue it further... don't remember which sort of AWB it was, but French sticks in my mind.

But I agree that it is not likely that the subject Corbin would have such a thing!

Jim

[colemj]

Originally Posted by deluxe68

The two boats that required new saildrives were fairly new boats but were plugged into shore power. The problem was discovered when the dredging company saw the increased water temperature. The maintenance manager for the Beneteau dealer (located in the same marina) looked at all of their boats in the marina by sending a diver down. I doubt if this guy lied to me just to get me to pay $40 for a diver.

It doesn't have to be a lie to be wrong. There is no physical or electrical way dredging the bottom and increased temperature caused saildrive corrosion. It simply is not possible.

Plugged into shore power? Hmmmm….

Mark

[colemj]

Originally Posted by Jim Cate

Actually, I think that they are indeed being fitted to yachts in the 40 foot +/- range. We had a dock neighbor in Hobart with a brand new AWB of that size which had such a device fitted. It didn't work,and his holiday cruise was aborted because there were no parts available in Oz at the time.

I was otherwise occupied at the time and didn't pursue it further... don't remember which sort of AWB it was, but French sticks in my mind.

But I agree that it is not likely that the subject Corbin would have such a thing!

Jim

I don't know what an AWB is (average white boat?), but since the smallest engines these systems are mated with are ~250hp, any sized boat using them must be able to make use of that power. Not many sailboats can.

Mark

[Jim Cate]

Originally Posted by colemj

I don't know what an AWB is (average white boat?), but since the smallest engines these systems are mated with are ~250hp, any sized boat using them must be able to make use of that power. Not many sailboats can.

Mark

Mark, you seem to have a hard time accepting anything I say, so I went back into my logbook and checked. The AWB in question was a brand new Jeanneau 379. It had some manner of rotating saildrive sort of propulsion, and an engine of appropriate size for the boat. It did not work at the time, and I did not go aboard to inspect it, as we were frantically preparing to leave our boat and fly to the States. I didn't record all the details then, so I went to the factory brochure which describes the unit, which was fitted to a 29 hp Yanmar:

"The concept is simple: the engine is coupled with
a pivoting sail drive, capable of rotating 360°. The
joystick transmits the commands to a control box,
which uses the autopilot to lock the helm. Then,
a simple movement of the joystick controls the
orientation and the thrust of the pod, as well as
the bowthruster."

I don't know if you will accept this, but most folks would.

Jim