Bad Kitty: Cruising Cat Jib Alone?

[abouis]

I am the captain of a 44' cruising charter catamaran and I have been puzzling over the following: I have noticed hints in more than a couple of places that sailing a large sloop-rigged, no-backstay catamaran with the jib only (no main) could be bad for the rig and may lead to mast breakage. I find this hard to believe, I mean, many of these cats are sailed across oceans and the rigs are quite sturdy. Furthermore, I have personally sailed 44, 45 and 47 foot catamarans under jib alone with no problems.

However, one example is in the owner's manual for my Lagoon 440 (and I quote): "WARNING: Any sail combination different from these requirements may cause the mast to break. In particular, 100% genoa with 2 reefs in the mainsail is totally banned". Their requirements show both sails used at the same time and furled equally to varying degrees based upon wind speeds. Another boat owner I know cautions his bareboat charters to never sail his boat under jib alone "because it stresses the rig". Is there any validity to this?

I am not a reckless sailor and would not attempt to fly downwind under full jib in a storm, but I am concerned about flying our big gennaker downwind with no main if flying jib alone with no main is a bad idea. I figure the topping lift to mainsheet connection should provide a lot of support if I keep it tight and make up for the lack of a backstay. Other than that, am I in danger of losing my mast? Comments? Experiences? Etc?

Thanks in advance for any insight!!

[sailingdog]

Well, if the manufacturer is putting warnings about it in the owner's manual... chances are probably fairly good that there's a reason for it.

The main sail probably does exert a fair amount of balancing force for the mast, given that the mainsheet effectively pulls down on the sail, and the sail transmits that tension to the mast. Using the topping lift to mainsheet will offset some of the forces and work in lieu of a backstay to some degree. YMMV.

[Saildoggie]

Same subject I just discussed via email with a well known SCUBA Instructor and one that operates summer camps for teens and above.

Flew the spinnkaker several times with no main on the Voyage 440 I chartered in June, no worries at all, the owner also does it all the time.

We also sailed off the wind headsail only on legs that did not require the main, even though the effort to hoist it is NONE, electric winch from the cockpit.

The rigs have swept back spreaders and have the mast loaded with tons of pre-bend, the Voyage does have a baby stay, not sure about those dang Lagooneys, not my favorite design.

We also load the mainsheet up mostly to prevent the boom from flogging but it also loads the topping lift adding a bit of support.

I think Lagoon is covering their A$$ from some incident.

[Boasun]

If you are worried that much, then rig running back stays to ease your mind and increase the safety of your rig.

[abouis]

Originally Posted by Saildoggie

Same subject I just discussed via email with a well known SCUBA Instructor and one that operates summer camps for teens and above.

...

We also load the mainsheet up mostly to prevent the boom from flogging but it also loads the topping lift adding a bit of support.

I think Lagoon is covering their A$$ from some incident.

Funny, I just asked said well known SCUBA Instructor at said summer camp, before posting here. I ran a catamaran as part of his camp for a couple of years, before deciding to stay down here in the BVI to run a private charter cat.

In any case, your advice is good and agrees with what I've heard from other reasonable people.

Speaking of flogging booms, I recently added a line from the port quarter that clips on to the boom when I'm not sailing, and then I travel over to starboard, so the boom is still centered but no longer swings back and forth because of the triangle formed by the topping lift, mainsheet, and new line. Now, what would this line be called? Some sort of preventer?

[Saildoggie]

HEHEHE!!

Capt. Monk actually forwarded your email to me, small World eh???

Hope to toast a cold one with you soon, will be chartering in the BVI's first week of April and also 2 weeks at the end of June!

Also back for Foxy's Cat Fight end of October, gotta defend our first place finish aboard S/V Sanctuary, the smallest cat in the race!!

PM sent...

[pdqaltair]

out of column. I do know of one Stiletto that snapped a mast backwards that way.

Just a guess. Otherwise, sailingdog had the simple solution - make sure the topping lift is on. The pull from the topping lift balances the forestay load - the 2 reef main pulls much lower.