Sail handling on Adagio; an update on our boom furler experience

Adagio’s sail handling was designed to allow single-handed operation for all evolutions except spinnaker work. I.e., mainsail, jib/solent and reacher/code-zero handling requires only one person. When we set the 1800 sq. ft. spinnaker the conditions are good and we are both on deck. If double-handing, we generally strike the chute before dark, unless the conditions are very settled.

All sail control lines lead to Adagio’s cockpit winch pod, near the port cockpit stairway. All the lines lead through a custom “piano” of jammers and diverter blocks — thence to any of three winches — two powered, one manual [normally dedicated to main traveler].For all sail evolutions, the single-handing crew stands at the top of port stairs where we can see the entire rig with belayed line in the right hand, the left hand on the coachroof handrail, and the right foot controlling the hauling line on one of the two powered winches.

Adagio’s boom furling system: Compared to the competition circa 2000, and for our size main I think the Reef-Rite was the best choice of in-production systems. I am about six years out of date w/r/t competition. We are happy with our Reef-Rite boom furler, so haven’t been motivated to reassess the market. Our main is almost 1000 sqFt, which made Bob Graham a bit nervous. The only other option in 1999 was a Marten or Southern Spars custom carbon boom system. Reef-Rite customer service has been excellent, as well as ongoing engineering improvements (many of which we have incorporated).

My take is at 500 sqFt or less I would just do slab reefing. At around 1000 sqFt and up, I would do boom-furling again. Where the cutover is I’m not sure – I just know that our main is Really Big when we handle it w/o the furler. Two big guys have trouble carrying it, and its a relatively light mylar-dacron laminate (Bainbridge Cruising Laminate CL110p).

The mainsail design & build is critical for a boom-furler. A main that isn’t right will defeat the best furler. If you’re willing to consider buying your sails from NZ, you can’t go wrong discussing your case with Chris McMaster/Doyle Sails Auckland 649/307-9140. As of 2000 I think Chris had built more boom-furler sails than anyone, anywhere. Extremely smart, competent and honest.

We had a few issues with our original boom furling implementation. We made several important improvements in Auckland 2004 enroute to Alaska. The results have been excellent. The two critical changes were:

  1. a custom hydraulic lifting strut, which always lifts the boom to the height determined by the mainsheet — even in a heavy seaway. Inside the lifting strut is a sensor that provides direct readout of the boom height/angle at any B&G station.
  2. we modified our boom and deck layout to incorporate a single-line boom preventer that greatly streamlines triangulating the boom in 3D, including jibes. The preventer line leads from a max beam padeye p/s to a boom end block along underside of boom to mast turning block through underwing to turning block to under-cockpit turning block up to the cockpit winch pod {you may have to sketch that out for it to make sense, sounds complicated, actually very simple}.

The combination of main preventer + hydraulic lifting strut + instant boom height/angle readout has made mainsail handling safe, fast and robust. The hydraulic boom lifting strut is a “hydraulic spring”, which preloads the boom (150kg up vector at the mainsheet bale) comprised of:

  1. Bosch hydraulic accumulator, nitrogen pressurized to 1800psi
  2. Custom 2205 SS single-acting hydraulic cylinder [by Hydrapower, NZ]
  3. MDS L4 magnetostrictive position sensor inside the cylinder (reads out directly on B&G linear channel)

In theory Navtek will build something similar for you. In New Zealand (FWIW) I found their prices, lead times and technical support poor on all counts. I think we paid Hydrapower about NZ$3500 for the custom cylinder in 2004, and around US$1000 for the MDS sensor system. The Bosch accumulator was around NZ$1000. As I recall Navtec wanted > US$11,000 and six months lead time – if you could get their attention.

We retained Chris Mitchell to help us solve the problem: Applied Engineering Services Ltd, 649/846-2006, info(at)aes(dot)net(dot)nz.

Chris is the brains behind the “Millenium Rig”, and a heck of an engineer. If you need mechanical engineering and innovation, call Chris. If you decide you need something like Adagio’s system, for sure call Chris (unless you are an M.E. yourself). I did the load/pressure engineering [I can email you my Excel engineering calculations sheet], and had Chris verify my calculations. [I need to put up a PDF of the calculations on the site].

We have calibrated the position sensor to read out on any of our B&G displays as mainsheet bale height in inches, with zero = nominal furling position. We keep a log of +/- settings depending upon upwind/downwind and wind speed.

We also added a SS platform on the mast so one of us can stand right over the furling drum to inspect how the luff is rolling. That’s not really necessary once you get your operating procedures fully-sorted, but VERY handy while figuring it all out. 98% of our furling problems happen when the sail is nearly stowed in the boom. I.e., in the last 2 to 3 meters of the luff, when the boom is full and the mechanical advantage has gone from good to “awful”. Putting in the first 3 or 4 reefs has never been a problem, so long as the operator doesn’t do something stupid.

Another tip from Chris McMaster you’ll want to remember: keep LOTS of luff tension at all times. You want to see tension wrinkles in the sail radiating from the tack.

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