Wednesday, February 16, 2011

Torque Rope Test Run

Loose-luff furling sails have grown in popularity with the rise in quality of torque ropes. Torque ropes refer to the category of rope that does not rotate (or not much) under tension. When you pull it tight, and turn one end, the other end turns. In a headsail application, this lets you use it in the front of a jib without a permanent furling unit with aluminum extrusions up the forestay, the kind almost all furling systems use. Instead, a Code Zero furler is used, either the continuous line variety, or a more traditional single-line style. The furling drum shackles to a spliced loop (reinforced) in the rope at the tack of the sail, and its counterpart head swivel shackles into the loop at the head. The only thing connecting the furling parts is the torque rope, enclosed inside the luff of the sail. While less-expensive low-stretch rope options can be used on a continuous line furler that wuill still roll up the sail if you're going to take it down immediately, if you're going to leave it up and furled, torque rope is the only way to make sure you get a tight roll, especially at the head, which can sometimes stick out unfurled and tempt the breeze to pry it open and unfurled.

Scott Loomis from our Stuart loft just installed a torque rope jib on an Aerorig that had no forestay. Rather than add metal weight, the owner chose a torque rope setup to hang the jib between the end of the forward boom and the top of the mast. The following photos show the result.

Here, the sail is at full deployment, sheeting nicely to the single-point sheet location.

Here is the sail furling:

And here is the head of the fully-furled sail:

Torque ropes have evolved nicely, and allow loose-luffed headsails without permanent stays. They need certain rigging changes, like (ideally) a two-to-one low-stretch halyard to prevent luff sag, and a strong attachment point on deck. With these, torque rope sails can serve as inner heavy-weather jibs behind a genoa on the forestay, or as Code Zeros or light genoas forward of the forestay. Both could be left up and furled when not in use, or easily removed for added safety.

Tuesday, February 15, 2011

Second of Two Killer Articles

Like Ed Baird, I've sailed all my life, though at a slightly less competitive level. As the father of kids moving into sailing, though, my priorities have shifted somewhat. His explanation mirrors mine, but like his racing, so much better.

Ed Baird discusses priorities as a sailing father.

Monday, February 14, 2011

First of Two Great Interviews

The first interview online caught my eye because he's a client -- Buddy Stockwell, with a Lagoon 38, proudly flying a Doyle Spinnaker. His interview on the fun and perils of cruising his cat around the Caribbean makes for a great read. Here's a sample:

Those “Blue Lagoon” dream destinations are still out there, but with the growing cruising population, in some areas down south cruisers have now moved in, become liveaboards, and are there in such numbers that they obscure the local culture and diminish the authenticity of what once was. Also, it is of note to mention that cruisers are now as diverse as the people in your subdivision back home. They run the gamut all the way from what we all usually envision as “nice folks out cruising” to dangerous criminals and the mentally ill. That is why one should be very cautious about become “fast friends” with new acquaintances while cruising. Just because someone lives on a boat does not mean anything at all as to what kind of person they are or whether you should allow them on your vessel or go aboard theirs. When you head out cruising, take you streets smarts aboard with you.

Interview with Buddy Stockwell, Indigo Moon

Friday, February 11, 2011

Sexy Squaretops with Downplayed Dangers

Lagoon and other catamaran manufacturers have begun offering square top mainsails with their boats. As a sailmaker with long experience with catamaran mainsails, I'm concerned the allure of these is blinding some people to possible risks. Comments about how the square top head adds light air performance and allows the sail to de-power in heavy air are technically correct, but there are potential down-sides no one's talking about. Like any innovation, such as early roller-furling units and in-boom furling systems, time will tell. Here are the issues of concern to me.

The flat head of the sail is supported by a diagonal batten that is not (easily) removable. If the head ring stayed against the mast, it would stick up out of the Cradle Cover, or Lagoon's lighter version of it, like a dorsal fin. Lagoon's OEM sailmaker, Incidence, has developed a system that allows the head ring to fall back away from the mast when the halyard is loose.

It uses a low-stretch cascading line that loosens when the sail comes down, and this slack allows the head ring to drift away from the headboard carraige so the head of the sail can be stowed. In reverse, when the sail gets to the top of the mast and the luff of the sail is pulled tight, the tight line pulls the head ring up against the headboard carraige, into proper position. This is just like a tack-area jackline used on some older boats, it's just located at the head.

Here is a photo with the head very loose so it can enter the cover:

Here it is getting closer to the spar:

Here it is tight against the spar:

In theory, this all works great and they may have have made it happen well in practice. I have supplied one sail in the manner and quickly realized that the system depends on the integrity of the line. You want a very strong, chafe resistant line on one hand, because it must bear the load of the second-heaviest corner of the sail, and it has to run through the stainless rings, and sit in the same place over and over. But you want it skinny and slippery so the line actually moves and allows the head to fall back when the sail is down. Even when this compromise is achieved, and Lagoon/Incidence may have done so, I caution people to carry a spare of that line, and check it frequently. If it did begin to fail, it's easily replaced. Even without the right line, it could be temporarily lashed or shackled to the head car(s) in a pinch. But in my experience, too many sailors just don't check things like this, and will only find out about the danger when it breaks while reefed and the head pulls back away from the mast in 30 knots.

Second, halyard tension is critical. If the halyard is loose from stretch, slippage, or just lazy hoisting at full sail or when reefed, it means the head of the sail will be lower, and the head jackline will be loose. This will let the head ring drift aft a bit and increase the load on the batten fitting and surrounding sailcloth just below it. This could lead to premature failure of the batten fitting or odd stretch to the head of the sail. Again, proper halyard tension prevents this, but in the real world, such things don't always happen.

In general, when one of my clients wants more area, I just increase the girths of the sails, exaggerating the width of the sail to provide the same area. Technically speaking, a higher-aspect flat-top will be more effective upwind -- but let's face it, these are large, heavy catamarans, and I don't yet believe this marginal aerodynamic improvement will mean much compared to a standard sail, and certainly not to an increased-roach sail, on a boat this big and heavy. Also, for the argument that says they de-power in light wind, that's also technically true, but when they de-power they are spilling breeze by twisting back to the profile of a normal roach sail. If there's little benefit in the flat-top in light wind, and it offers the same benefit in heavy wind, there's not much of a net benefit at all -- other than they look very cool.

On balance, this is something new and sexy that many people are rushing for, just like a beautiful woman at a bar. But like in that case, too, getting what you want sometimes has associated consequences you might not learn until nine months later. Incidence and Lagoon may have it figured out, and if they don't break, the concerns listed here are unfounded. They deserve to be commended for trying something new, and I can tell it sure helps sell boats, so just keep your eyes open!

Just make sure when you drop your main and the head cascades neatly away from the mast, it calls into a Doyle Cradle Cover!

I encourage anyone with more time sailing with these to post your experience, good or bad, to share what you know so we can keep making this product better.