Rig a jib sheet on a 30' cat

[Hunky]

I need to rig the fractional jib on my cat, and I'm a rank amateur. I also live in a very rural area so nobody around here to talk with about it.

At this point I think it will be furling, is designed (not yet purchased) at 143 sq. ft., and I'm running all lines to cockpit. I altered the designer's plans by putting a cuddy cabin on deck since I'm above 64 deg. latitude and wanted a bit of shelter. The plans call for track just alongside and aft of the mast on a 9 deg. sheeting angle. But with other lines run from the mast, they would have to go under the track, which would mean I need to elevate it for lines crossing under it.

One fellow on the sailing anarchy forum suggested using an adjustable cascade as follows, with the ropes just delineating the center line and 8 deg. sheet angle, the blue diamonds -padeyes, the green line - floating primary block. My advantage is easy to route other lines and less hole drilling.

The second image is how the deck looks from a different angle. This image has the track laid on deck as another guy suggested, parallel to the center line, centered more or less on the 8 deg. (or 9 deg per the designer) sheeting angle. But again, I would need to get lines under it. The guy that suggested that track layout thought the cascading block idea was not necessarily easy, but the guy who did suggest it says he loves it on his cat. He said this: "Its simple and works very well. Get the best quality blocks you can afford, the adjustment can even be a tied off lashing if you are only using the same headsail all the time."

Happy to fill in any blanks I left, but curious what others think. Not sure I want to go self-tacking at this point, but I don't know.

3rd pic is old dwg of sail plan (newer has boom for main), but might show something.

thanks for looking, Jim

[Tupaia]

Limit the turns that a sheet has to pass through. There is always the chance of a jam when you need to let a sheet fly.

Is it possible to add a plate and some foot blocks at the base of the mast and take all the other control lines outboard of the sheets.

[Tillsbury]

If I were building a new boat of any type I would use low friction rings and lines for sheet leads instead of deck mounted tracks every time. So much more flexible and less junk on the deck.

[Hunky]

Thanks for the reply Tupaia,

The mast step will look something like this image, though my tube is smaller diameter as in second pic in OP, so will have some free standing sheave cheeks. Hoping to turn the halyards, 3 reefs, outhaul, just once, but get your point.

[Hunky]

Originally Posted by Tillsbury

If I were building a new boat of any type I would use low friction rings and lines for sheet leads instead of deck mounted tracks every time. So much more flexible and less junk on the deck.

Something similar to the cascade - floating block image above? Or other? If anyone can point me to pics or drawings..

thanks for input!

[Tin Tin]

looking at that sail plan with a blade jib, I would be very tempted to go with a self tacking jib, so easy to manage with a curved traveller set in front of the mast.

[Matt Johnson]

Google "3D jib sheeting". That's what you're looking for.

I wouldn't install a jib track on any new boat either (except self tacking).

Matt

[Tupaia]

Originally Posted by funjohnson

Google "3D jib sheeting". That's what you're looking for.

I wouldn't install a jib track on any new boat either (except self tacking).

Matt

I don't understand your thinking.

On a fractional rig as is the case here the gib is your accelerator pedal so you definitely need to be able to adjust the sheeting point fore and aft to control the depth and the twist. Using an additional slip ring or block on a billy or even a strop as a barber hauler when running is fine but a floating block as a primary lead control mechanism will result in some very disappointing 'pun' windward sailing.

[Matt Johnson]

Originally Posted by Tupaia

I don't understand your thinking.

On a fractional rig as is the case here the gib is your accelerator pedal so you definitely need to be able to adjust the sheeting point fore and aft to control the depth and the twist. Using an additional slip ring or block on a billy or even a strop as a barber hauler when running is fine but a floating block as a primary lead control mechanism will result in some very disappointing 'pun' windward sailing.

Pulling the floating block down has the same effect on sheet lead as bringing an adjustable car forward. Letting the floating block rise is the same as pulling the car back. To keep it inboard or outboard, then you use two legs in an A-frame to adjust position up, down, inboard and outboard..... 3D

Matt

[Tupaia]

Originally Posted by funjohnson

Pulling the floating block down has the same effect on sheet lead as bringing an adjustable car forward. Letting the floating block rise is the same as pulling the car back. To keep it inboard or outboard, then you use two legs in an A-frame to adjust position up, down, inboard and outboard..... 3D

Matt

I understand the mechanism. Just can't understand why you would choose such a system over a track, unless it is cost.

A track is reliable, positioning is repeatable and the lead to the winch is vertically constant. Forces are evenly distributed along the length and being fixed letting a gib sheet fly will be as predictable as it can be.

Replacing this with two multi-puchase billies that require several operations to achieve a similar result. In virtually all settings the vertical lead to the winch will be variable and if allowed to rise too far will result in riding turns on the winch. Such a system is also totally unpredictable if the sheet is dumped and forces are concentrated at two heavily load points.

[Cliffhanger]

Every boat is different of course but I know on my cat I would really struggle to tack with a self tacking jib. I need to backwind the genoa to complete the turn unless I am going really fast and a self tacker won't allow that. But then again it is a masthead rig with a high aspect ratio main and mini keels, so probably very different to your boat. But perhaps worth considering though.

[thinwater]

Personally, having had 3 cats with many different jibs, I would go with 10-15% overlap (but not more than that). This will give you a lot more power off the wind and is still easy to manage up wind. Blade jibs are nice if the world is all to windward/leeward and you use a chute off the wind, but otherwise, not so much. The fact that it is a cat does not change this.

I've had self-tacking jibs (see avitar, for example). No thanks. It cute for a few tacks, but around the circle the performance disappoints. I bagged the self-tacker and didn't use it for 10 years. I used the 120%.