SO 42.1 Mainsheet System Block Design

[bsafreed]

I recently purchased a 1994 SO 42.1 and want to refit the rigging starting with the mainsheet system blocks. I'm interested if anyone has re-designed the block system from what was delivered from the factory or has suggestions. Currently, I have a mid-boom system with a cheek block, mast collar block, 3 single blocks on the boom and a single block/becket on the traveler. Harken Compuspec suggests adding an additional single block on the boom and changing to a double block/becket on the traveler.
Thank you....Brian

[bsafreed]

I spoke with Garhauer marine in CA, who were very helpful over the phone. Mark, the sales person, mentioned he was familiar with the Jeanneau and Benneteau boats of this size. He suggested a 6:1 design. This is using a triple block on the traveler, a single block with becket (fwd of the traveler, a single block aft of the traveler, a single block at the most forward location on the boom. Image below. 
Any advice from the board on the upside or downside of this design would be appreciated.
Thanks, Brian

[MartyB]

If you currently have a 4-1, going to a 6-1 will make it easier to pull the boom in if you have to do this manually. You will need more line by about 50% of what you have. If the current sheet is 25', you will need about 35-40'.

Another option if you want to fine tune a bit more, altho not sure where it would go in your case, is to do a 4-1 on on initial run of line, this gives you a 24-1 to fine tune. BUT< if you have a dodger, this would probably not work.

Marty

[bsafreed]

Marty,

The SO 42.1 has a dedicate winch for the mainsheet. I have a Bimini but no dodger and no current plans to install one.

Reason I'm looking into upgrading the system is the age (16yrs) and deterioration of the current 4:1 Harken blocks.

I plan to be solo sailing most of the time so I was opting to increase the purchase for ease of handling and to increase the capacity of the loading.

Perhaps a 5:1 would be a preferable compromise.

Thank you,
Brian

[davideso37]

A couple of points worth considering. If you are planning on a lot of solo sailing is the mainsheet winch on the cabin top? If it is I would consider staying with 4:1 on the current traveler but bringing a single fall back to the boom end and down to a central block on the cockpit floor that you can release quickly from the steering position. The one fall on the boom end will give the same power as 2 falls on the cabin top. If you want extra fancy you could put a 4:1 fine tune on the last fall that leads to the cockpit floor but that is not necessary for cruising. If the winch is not on the cabin top and you can reach it easily from the steering position then what you propose looks fine.
Regards
David

[bsafreed]

David, thank you.

The main sheet originates at the becket on the traveler block, through the 4:1, down to the mast block, cheek block, through a clutch then to the cabin top self-tailing winch.

I need some help to follow your suggestion, and I apologize for my ignorance on the fall system. I do have a bimini top so running a fall line from the end of the boom to the cockpit may be an issue.

As you can see I am looking to re-design this system. For example, Jeanneau is using a clutch in this system. This is not supportive of a quick release from the helm by any means.

Regards,
Brian

[MartyB]

Brian,

Could you do something on par with a German system, when a main line is run back to the helm area, and a winch/jam cleat equal is operated from there?

My brain is not functioning right now on the how to lead a line aft, but I have seen it done. An hour with a rigger might be some well spent money to figure out the best option. I will admit, and you are figuring out, Bimini's and Dodgers can make the mainsheet especially a hard thing to configure to a better way if you will.

marty

[debenboy]

You may find "mainsheet improvements" in the Hints & Tips section of the main site some help.

On my SO36i I have switched the fall of the mainsheet to the starboard side and installed a Spinlock swivel powercleat in line between the clutch and the winch. I have also added an extra turn in the system to make it 4:1 rather than 3:1.

The clutch is left open when sailing and the powercleat used instead. Once the loading is too high to pull in by hand I use the winch.

As I tend to sail a lot singlehanded, I also installed fixed powercleats for the traveller control lines (I use the clutches for other lines), and tie the ends of the control lines together round the base of the wheel pedestal to keep them handy.

The mainsheet is rather stiff and unwieldy and I am thinking of moving to Maffioli swiftcord or similar instead.

The real killer on all these systems is friction, so invest in top quality ball-bearing blocks, and quality rope.

[MartyB]

www.jeanneau-owners.com/hintsandtips/36igermanmainsheet.html

There is a link to someones switch to a german mainsheet sytem they did.

Also, an email to the Harken folks, might net a solution too.

[davideso37]

Brian,
Harken compuspec suggestion is fine for the cabin top traveler. My suggestion was with regard to the single handed of light crewed sailing. If you read all the post there are many concerned with yachts rounding up to windward and this is best alleviated by dumping the mainsheet promptly. That is not easily done from the helm if your mainsheet is wrapped around the self tailing winch on the cabin top. It is not easy even with a dedicated mainsheet trimmer if the sheet has too many wraps around the winch. Trust me on this. We had a windy race last night and I took over the mainsheet trimming. Two wraps around the winch was the most I had on the winch to be able to drop the mainsheet fast enough. Even with a full crew there was lots of encouraging words exchanged. Sure with cruising you will not carry as much sail but in my experience there will still be many occasions when you need to dump the mainsheet. My first suggestion was to bring the mainsheet to near the end of the boom and take it to a snatch block on the floor. In our case the mainsheet come in front of our bimini. If your bimini is too far forward to allow for this then you need some other way to bring the mainsheet back to the helm position. The German system is one but in my opinion it will be difficult to dump quickly because both sheet ends are brought to self tailing winches and releasing heavily loaded (little mechanical advantage) sheet will be difficult. Perhaps the power cleat suggestion above might be the simplest and work if you can bring the mainsheet to a position where you can release it from you single handed sailing position.
I like the combination of the cabin top traveler and the mainsheet lead to the cockpit floor so it is adjustable from both the cockpit floor and the cabin top because 1. It spreads the load on boom and increases the safety factor. 2.It keeps the traveler out of the cockpit 3. It gives the option of aggressive mainsheet trimming from the cabin top 4. It has the safety factor of being able to be released from the helm position. 5. There is less mainsheet swinging around in the cockpit than in full boom end system. 6. The load on the cabin top traveler is reduced so it is easier to adjust by hand.
We only use our cabin top traveler to pull the boom to windward in light airs. With the amount of mainsail we carry the traveler dump is not enough so in heavy airs we centre the traveler and just play the mainsheet. Light air adjustment we can do with a 4:1 fine tune we have on the cockpit end of the mainsheet and heavy air adjustment is mostly from the cabin top winch where we can dump more mainsheet quickly.

Listen to me carefully I will say this only once. Either get a mainsheet system you can dump from your helming position or learn how to say "Sorry" for shouting at your crew.

Regards
David

[bsafreed]

David, It would be great to see an image of your system. I doubt my bimini is too far forward. Thank you, Brian

[davideso37]

Brian,

I have put a post on our boat blog page.


www.3gwiz.com.au/passion/blog/

Regards

David