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04-01-2014, 11:28
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#46
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Registered User
Join Date: Nov 2007
Boat: TRT 1200
Posts: 7,268
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Re: Sail Drives..Like em?
Quote:
Originally Posted by colemj
OK. You believe that. Don't pay attention to the other niggly differences. BTW, shaft drives are also gears encased in aluminum with the purpose of transferring power from the engine to the prop. So to me, outdrives look like shaft drives.
Mark
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Need to get them eyes checked
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04-01-2014, 12:06
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#47
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Registered User
Join Date: Aug 2011
Location: Lower Chesapeake Bay Area
Boat: Bristol 27
Posts: 10,461
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Re: Sail Drives..Like em?
Gaysus H, what a freaking circus!
If one were to buy a boat with a Saildrive that was installed in 2008 and supposedly has 20 hours on it should this person have anything done to the Saildrive before final immersion?
Wauquiez Gladiateur 33 w/Saildrive:
http://www.yachtworld.com/boats/1983...s#.UshqIXoo4fQ
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04-01-2014, 12:11
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#48
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Moderator
Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,156
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Re: Sail Drives..Like em?
We can sit around arguing about reliability, drag and serviceability all day, and I suspect that examples of both shaft and saildrive can be found that will support either argument.
For me, there is one undeniable difference that influences choice in a boat that is going long term/distance cruising: IF there is a fault within the gearbox itself (something that happens to both genres at times), in all the saildrives that I am familiar with, the boat must be removed from the water and the saildrive then removed from the boat to work on it. This leaves a big hole in the bottom, so that refloating the boat whilst the service is accomplished requires a temporary patch to be installed. This can be done: indeed, close friends of ours with a Bukh saildrive have had to do this so many times that they carry a readymade plug on board whilst cruising. Similar difficulties with a shaft drive can be dealt with with the boat still in the water. Neither option is to be enjoyed...
For those of us who sail in areas where travel lifts and even slipways are non-existent, this feature does influence our choices.
Oh... the argument that race boats use saildrives is, I suspect, more about being able to put the engine amidships than total drag. It would be interesting to get the opinion of an actual NA on the drag issue. I doubt if any of us really know enough to accurately compare the two genres' drag. (Sure wish that Bob P. still posted here!)
Cheers,
Jim
__________________
Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.
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04-01-2014, 13:09
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#49
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Registered User
Join Date: Nov 2007
Boat: TRT 1200
Posts: 7,268
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In a discussion on another forum Bob Perry said saildrives have less drag than shat drives. I have a hard time getting my head around that one but he may be right.
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04-01-2014, 14:04
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#50
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Registered User
Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,823
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Re: Sail Drives..Like em?
Quote:
Originally Posted by Jim Cate
We can sit around arguing about reliability, drag and serviceability all day, and I suspect that examples of both shaft and saildrive can be found that will support either argument.
For me, there is one undeniable difference that influences choice in a boat that is going long term/distance cruising: IF there is a fault within the gearbox itself (something that happens to both genres at times), in all the saildrives that I am familiar with, the boat must be removed from the water and the saildrive then removed from the boat to work on it. This leaves a big hole in the bottom, so that refloating the boat whilst the service is accomplished requires a temporary patch to be installed. This can be done: indeed, close friends of ours with a Bukh saildrive have had to do this so many times that they carry a readymade plug on board whilst cruising. Similar difficulties with a shaft drive can be dealt with with the boat still in the water. Neither option is to be enjoyed...
For those of us who sail in areas where travel lifts and even slipways are non-existent, this feature does influence our choices.
Oh... the argument that race boats use saildrives is, I suspect, more about being able to put the engine amidships than total drag. It would be interesting to get the opinion of an actual NA on the drag issue. I doubt if any of us really know enough to accurately compare the two genres' drag. (Sure wish that Bob P. still posted here!)
Cheers,
Jim
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Since real cruising boats have spare (in service in the other hull), getting to a location to haul out is not a problem.
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04-01-2014, 14:07
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#51
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Registered User
Join Date: Sep 2006
Posts: 9,398
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Re: Sail Drives..Like em?
Quote:
Originally Posted by Jim Cate
........Oh... the argument that race boats use saildrives is, I suspect, more about being able to put the engine amidships than total drag.
Cheers,
Jim
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Surely it's just as easy to fit a shaft drive engine amidships?
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04-01-2014, 16:33
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#52
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Sail Drives..Like em?
Quote:
Originally Posted by Jim Cate
For me, there is one undeniable difference that influences choice in a boat that is going long term/distance cruising: IF there is a fault within the gearbox itself (something that happens to both genres at times), in all the saildrives that I am familiar with, the boat must be removed from the water and the saildrive then removed from the boat to work on it.
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I am willing to bet I know more saildrives than you and I do not know of a single one that needs to be pulled out of the water if there is a fault in the gearbox. That is completely isolated from the water and can be worked on, or removed, without pulling the boat.
You do know that most saildrive gearboxes are identical to that manufacturer's shaft drive gearboxes, don't you? The only difference is the length of the transfer driveshaft.
I always enjoy the experts on the saildrive, catamaran and huntabenelina threads.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
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04-01-2014, 16:36
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#53
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Sail Drives..Like em?
Quote:
Originally Posted by thomm225
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Yes, you should throw it away and install a shaft drive immediately before touching water. The saildrive will fizz away, tear a giant hole in your boat, and cause so much drag as to make you move backwards. Especially if the boat is in or around Australia - where all saildrive boats spend their entire lives on the hard being repaired.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
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04-01-2014, 16:38
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#54
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Registered User
Join Date: Aug 2010
Location: From Cape Town now New Caledonia
Boat: Lagoon 440
Posts: 962
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Re: Sail Drives..Like em?
Mark
Love your sense of humour
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04-01-2014, 16:43
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#55
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Registered User
Join Date: Nov 2007
Boat: TRT 1200
Posts: 7,268
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Re: Sail Drives..Like em?
So with saildrives, if you run over some monofilament line and ruin your shaft seals you have to haul out to replace them. So when they put you back in the water and you run over some more monofilament you have to haul out to fix your seals. I'm not sure if this is a problem with shaft drives but I believe they're not as tender.
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04-01-2014, 17:21
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#56
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Moderator
Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,156
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Re: Sail Drives..Like em?
Quote:
Originally Posted by colemj
I am willing to bet I know more saildrives than you and I do not know of a single one that needs to be pulled out of the water if there is a fault in the gearbox. That is completely isolated from the water and can be worked on, or removed, without pulling the boat.
You do know that most saildrive gearboxes are identical to that manufacturer's shaft drive gearboxes, don't you? The only difference is the length of the transfer driveshaft.
I always enjoy the experts on the saildrive, catamaran and huntabenelina threads.
Mark
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Well, Mark, you sure are a bit tender on this subject! But my pals with the Bukh 3 cylinder engine and Bukh saildrive must have been wasting their time doing what they did when the Bukh authorized repairer in Pittwater pulled the bloody thing out to work on it. Should have called you... would have saved a lot of money and angst.
I don't claim to be an expert on saildrives, so I didn't know that the gear train was the same as in shaft drives. So, I am curious how the identical device manages two 90 degree plane changes, or why the clutches in the infamous Yanmar s/d give so much trouble and their shaft drive boxes manage to not have that reputation. Nor do I understand how one could remove the actual gearbox without removing either the lower unit or the engine. I'm ready to stand corrected if you explain it to me. As a non-expert, I enjoy learning new things.
Despite your rather shrill objections, I do believe that historically saildrives have exhibited some problems. There have been a few threads here on CF started by folks with s/d problems... just as there have been some similar ones associated with shaft drives. Neither are perfect, but to deny that problems do exist is not beneficial to the OP who was looking for some opinions. It may well be that newer s/d models have improved their performance, and I hope that this is true. The units on older boats, the sort of boats that many CF folks are buying, may not enjoy those improvements.
Cheers,
Jim
__________________
Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.
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04-01-2014, 17:21
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#57
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Registered User
Join Date: Dec 2007
Boat: Mahe 36, Helia 44 Evo, MY 37
Posts: 5,731
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Re: Sail Drives..Like em?
Quote:
Originally Posted by smj
if you run over some monofilament line and ruin your shaft seals
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This does happen with outboards.
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04-01-2014, 17:23
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#58
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Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
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Re: Sail Drives..Like em?
Or you put on line cutters and be done with it. Where do you run into so much monofilament line? I have not yet run into any in the past 30 years. Maybe I should buy a lottery ticket?
Yes, there are failure modes with saildrives that do not exist with shaft drives. The converse is true, of course.
If you don't want a saildrive, don't get one - but to pull up bogeymen constantly is not very logical.
The whole premise of this thread was a troll and we all got pulled in.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
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04-01-2014, 17:30
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#59
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Moderator
Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,156
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Re: Sail Drives..Like em?
Quote:
Originally Posted by DotDun
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Well, I've never said that I had a "real" cruising boat (with no spare engine and drive unit) but then I have been pretty busy cruising and haven't had time to chase down the proper ride!
And in fact, our friends with a Seawind 1200 who sat a saildrive down on a pinnacle rock and shoved it up into the hull, breeching the rubber seal and flooding one hull did managed to get from (IIRC) Whangaroa all the way to Whangerei with only a few extra pumps going full time... running on their spare engine.
Of course, if they had had a "half-boat" they could have slipped there in Whangaroa to fix it, thus avoiding that rather stressful voyage.
Boats are floating collections of compromises, and we all have to choose which ones matter the most to us.
Cheers,
Jim
__________________
Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.
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04-01-2014, 17:40
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#60
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Moderator
Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,156
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Re: Sail Drives..Like em?
Quote:
Originally Posted by 44'cruisingcat
Surely it's just as easy to fit a shaft drive engine amidships?
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Actually, you have a good point there! I suspect that with a shaft drive it is awkward to get enough prop clearance on those big sleds with their very flat bottoms no matter where you put the engine... unless you are willing to have a severe down angle on the shaft. The saildrive does make sense then.
I've heard that those boats are not good motorboats anyway, and with the prop so very far from the rudder (or worse yet not aligned with dual rudders) one looses the maneuvering advantage from propwash. This would be exacerbated with a severe down angle, of course.
But then, those boats are not too worried about motoring performance!
Cheers,
Jim
__________________
Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.
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