Lazy jacks

[Jackdaw]

BTY: Yes, CDC, I could see the storm coming, but I could not estimate the winds, nor our inability to manage them. We were on our way in, but not making headway fast enough. That lake is known for surprise squalls. That was the first time I had seen anything like that out on the water, so was not able to know what we are were in for. I just don't see sailing as a nice pretty sport with everything being predictable. Yes, you plan and prepare, but things happen out there. Your systems have to be in place for when things go wrong.

+1 for that. While I noted earlier that the absolute need for them is a function of boat size, the ability to dump the main halyard and have the main quickly down and stay on the boom with zero work can be a lifesaver. On any boat.

 

[Dave Gibson]

@Dave Gibson ,

That's very interesting. What would be some of the design elements that Dutchman would design in (or out) of a mainsail that mainstream designer would not??

Thanks!

Everything! Consider that the Dutchman folds down like a Venetian blind. Grommets are installed in the sail, and heavy duty (300 to 500 pound test) nylon fishing line runs from your topping lift to special pockets at the foot of the sail. Simple, right? The most common problem I've seen (especially on Catalina) is having too far a space between lines. Three feet is ideal, four is doable... but I've seen five feet. That doesn't work. I even saw a sail with grommets install so that the mailsail flaked on opposite sides of the boom (grommets in column should be all odd or all even in number).

Again, Dutchman doesn't charge for this service. When I designed sail layouts, I usually had them back to the sailmaker withing hours. Why they all don't take advantage of this free service is baffling to me.

Many of you might be wondering why we design each sail instead of having a design for, say, a Catalina 42 on file. Well Dutchman does, but roach and batten placement varies from sail to sail, so I designed each and every one.

 

[19thol]

can someone explain what a "roachy" main is?

 

[Jackdaw]

Everything! Consider that the Dutchman folds down like a Venetian blind. Grommets are installed in the sail, and heavy duty (300 to 500 pound test) nylon fishing line runs from your topping lift to special pockets at the foot of the sail. Simple, right? The most common problem I've seen (especially on Catalina) is having too far a space between lines. Three feet is ideal, four is doable... but I've seen five feet. That doesn't work. I even saw a sail with grommets install so that the mailsail flaked on opposite sides of the boom (grommets in column should be all odd or all even in number).

OK, but that's grommet LAYOUT/design, not sail (shape/material/construction) design right? Is there anything in the actual DESIGN of the sail that works better/worse?

 

[Jackdaw]

can someone explain what a "roachy" main is?

Any part of a triangular sail that extends over the imaginary straight leech-line of the sail is 'roach'. It is key to understand this, as while roach gives you extra sail area, it also is unsupported by leech tension and needs battens for support.

It also explains:

Why furling mains, which can't have traditional battens, often have none and then often have negative roach to stop flutter.

Why genoas, which have hollow (or negative roach) don't have battens.

Why jibs (which CAN have roach) often have battens.

Max mainsail roach under rating rules adds about 15% to the P*E/2 area. The more you have, the more 'roachy' it is. Hollow with furling mains subtracts 5-10%. So a 20-30% swing using a furling main. Yea.

 

[Dave Gibson]

OK, but that's grommet LAYOUT/design, not sail (shape/material/construction) design right? Is there anything in the actual DESIGN of the sail that works better/worse?

Oh, sorry, I misread your post. Not enough caffeine at that hour.

Dutchman doesn't design sails. We left that to the sailmaker and the buyer to hammer out. We only designed Dutchman systems.

 

[DrJudyB]

@Dave Gibson ,

That's very interesting. What would be some of the design elements that Dutchman would design in (or out) of a mainsail that mainstream designer would not??

Thanks!

@Jackdaw: Dutchman doesn't design any mainsails per se. The saildesigner designs the mainsail and sends me the files. I send Dutchman a subset of the 2D details of the mainsail and the rig: luff, leach and girths, batten locations up from the tack, and spreader width. Dutchman determines where to install of the luff slides, control line grommets and bottom pockets. Dutchman send me back a drawing showing me exactly where to install the grommets. I send it to the production loft and they build the sail to specifications. Dutchman does a great job of laying out their system so it works.

@Daveinet: In my practical experience, the Dutchman system works on all mainsails, no matter how big the roach is, as long as the full battens are parallel to the boom. The system works fine on "fathead" mainsails with elliptically shaped heads. For example, cruising catamarans without back stays have large elliptically shaped roaches and full battens.

Square top mainsails have a diagonal batten, and, Of course, it is impossible to drop the last few feet if a square top mainsail without physically removing the diagonal batten. The diagonal batten in a square top is a bit of bother, for sure.

If I had a cruising boat, I'd install a Dutchman system (and low friction luff slides on an older, cantankerous mast). The Dutchman system doesn't force you to go carefully head-to-wind to douse or reef.

Ps. On our current boat, a 24 foot trailerable trimaran, we have a 240 square foot, square-top mainsail with 7 full battens, one of which is diagonal. We have a Tides marine system and an adjustable, halyard style topping lift. No Lazyjacks. I find it quite manageable for double handing even on very windy San Francisco Bay. It's down and under control (secured loosely to the boom not neatly flaked) in less than thirty seconds.

 

[Daveinet]

The Dutchman system hangs from a line that goes from the top of the mast to the boom. Am I correct? So if the roach is aft of the line between the top of the mast to the boom, is it not going to interfere with the roach part of the sail? Even with my pinhead sail, the backstay almost hits the top of the sail. My sail is not correct for my boat, as it does not have as much roach, as common with this boat. Most guys have an almost vertical leech. I'm not sure how the Dutchman system would work, without interfering with the sail.

 

[DrJudyB]

The Dutchman system hangs from a line that goes from the top of the mast to the boom. Am I correct? So if the roach is aft of the line between the top of the mast to the boom, is it not going to interfere with the roach part of the sail? Even with my pinhead sail, the backstay almost hits the top of the sail. My sail is not correct for my boat, as it does not have as much roach, as common with this boat. Most guys have an almost vertical leech. I'm not sure how the Dutchman system would work, without interfering with the sail.

@Daveinet
The Dutchman control lines hang from the topping lift, not the backstay. The Dutchman system doesn't have anything to do with the back stay.

Yes, the roach is always aft for the topping lift (for all mainsails with a positive roach) But the topping lift always stays on the same side of the sail. The topping lift moves with the mainsail and the boom (just like lazy jacks do). The topping lift touches but doesn't interfere with the roach.

I'll see if I can find a drawing to upload when I'm back at my office. I'm on my iPad now without convenient access to files

 

[DrJudyB]

 

[Daveinet]

The whole top have the sale would be well above the line from the boom to the mast.