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| MUSTELID gliding along Full Foresail - Roll Reefed Main - Driver |
All I wanted was a tall ship
Glide Rig: A Hybrid Rig for Row/Sailboats
Why name a rig? Any technical description is a mouthful, and few people appreciate mansplaining. A good name is evocative, calling to mind traditional associations. Or suggestive, offering a clear clue to the nature of its subject.
Gaff Rig, for example, suggests the spar itself and the sail's quadrilateral shape follows. It evokes robust working sail standing against the gale. The more initiated might recall its ability to scandalize—dumping half its area in a sudden gust. They might recall peak and main halyards, running backstays, and the tack-to-peak creases that indicate a correct set.
So, here is a rig in search of a name...
But first, the mandatory get-in-the-door question from The Commitments: “'Oo are your influences??”
Phil Bolger (of course) observed that most of us aren't out to win a race or even do much sailing to windward if we have any choice in the matter. Outboards and engines mostly handle the windward hemi-circle, so why expend design effort, gear and $$$ on maximal windward ability? He accordingly started to offer simpler, cheaper rigs.
That got us thinking. For a rowing, mostly downwind sailboat, we want a long, slim hull. These are easily driven but offer relatively low form stability. Ultra-shoal draft limits ballast stability. A snug, low-center-of-effort sail plan that is easily handled and reefed pairs perfectly.
On a row/sail craft, we primarily want the sailing rig to pull us down- or across the wind. Positioned well forward as a foresail—clear of a forward rowing cockpit—it should provide powerful lee helm and steady, balanced traction. For sailing upwind, however, the balance picture changes. We want the total CE moved aft to for weather-helm and good tacking.Quadrilateral and spinnaker-like sails work, but don't transition easily between the two modes.
Enter Frederick Ljungström, inventor of Ljungström Rig a boomless, double Leg o' Mutton (LOM) triangular sail attached along a shared luff to a rotating mast. Off-wind, it sets and handles much like roller-furling twin staysails, and like them, provides considerable upward lift.
Sailing into the wind, the sails are doubled, overlapping on the lee side and sheeted as one. This constitutes a half-reef, and a large aftward jump of its CE.
To reef, the mast rotates (we prefer righty-tighty, lefty-loosey), furling the sail snugly around the standing spar. No halyards, tack or clew downhauls, bunts, or nettles. Just roll it up and carry on! As a bonus, simple flat-cut LOMs furl tightly with minimal windage, forming conic sections similar to a Crab-Claw rig.
Since a slim hull cannot spread wide sheeting angles, we re-introduced booms along a loose foot. The result is a doubled variation of the Holopuni Quick-Rig (a great name!) which is similar to a setup offered on the SeaPearl 21.
Finally, three-masted junk schooners (e.g., CHINA CLOUD) inspired us with their fine control of their relatively low total CE, bow and stern maneuvers, and reduced area on each mast. Even on a smaller vessel (within reason), the advantages of multiple masts are striking.
Why Balance Matters When Rowing: Multiple sails give fine control over the balance of the helm. Especially when "motorsailing" (row AND sail), good balance leaves our hands free for the oars and reduces steering by stroke with ensuing fatigue. Even over a short haul, that makes a big difference! A driver - often set while rowing when the others are stowed - helps hold the bow up toward the wind. Where the bow want's to 'blow off' this is an asset.
A Problem on the Side—and a Solution
There is a catch with standard booms. They are fixed at the mast and sheeted toward their outboard end. As the sail is reefed, the clew moves inboard of the sheets, pulling laterally on the mid-boom, bending it toward the CE. Heavy spars and compromise arrangements are the usual fix.
Our solution? The Gliding Grommet.
We use a rope grommet that glides along a lightweight boom, with both the clew and sheets attached directly to it. A light clew/sheet outhaul is led through a turning block at boom's end, spreading the sail as desired.
When reefing, ease the outhaul, roller furl the sail as needed and make the outhaul fast. The grommet, clew and sheets are move inboard along the spar. The active, loaded portion of the boom automatically shortens, increasing relative strength. It absorbs the load purely in compression, avoiding mid-span bending stress. Cheap, DIY, and it works like a charm.
Glide Rig Specification
Mulling all this together, pulling out the main points and generalizing, we arrive at...
The "glide" emphasis is on downwind sailing and a strong balance shift for upwind sailing, supported by the working rig (I.e., without sail changes):- Foresail in 'cat' position (well forward) and,
- Sets large area for off-wind sailing
- Reduces area and moves CE aft for upwind sailing
- Main near amidships and/or,
- Backs up the foresail for downwind sailing
- Becomes the driving upwind sail
- Driver well aft
- A smaller sail for balance and riding
"Glide" can be used adjectivally in the usual manner... where we would say "That's a junk schooner, ketch or yawl", we can say "That's a glide schooner, ketch or yawl" or combine them, "That's a glide junk schooner, ketch or yawl."
With this in mind:
Two- or three-masted schooner, ketch, and yawl variants may qualify.
Main and driver with other planforms and rigging may qualify.
Rig particulars—such as specific sail planforms, unstayed masts, roller furling, the Gliding Grommet solution, and such—are handy but optional.
NOTE: We call the stern sail a driver... it seemed the better option among mizzen (confusing), jigger (???), dandy (too high-brow?) and spanker (let's not go there).
MUSTELID's Glide Rig
I would now call MUSTELID's a three-masted glide LOM ketch rig. Fore and main sails are of equal height. LUTRA's main will be slightly taller (also quadrilateral with a sprit in the mix), so I'd call her a three masted glide hybrid schooner rig.
We tested Glide Rig extensively in MUSTELID over a wide range of conditions, as documented in the video series, MUSTELID Venture.
MUSTELID's foresail is a Ljungström sail (double LOM) rigged and positioned as described above.
Her midships main is a single LOM boomed as described and set aft of the forward cockpit. In this position, it becomes the heart of any windward sailing we might do, with the foresail reefed (moving the combined CE aft) and doubled over to sheet as an LOM. We offset this one to clear the BIRDWATCHER cabin's mid-line companionway.
We set a small LOM driver dead aft for offwind sailing, to 'crank in' weather helm, hold the bow up when drifting and serve as a riding sail. It is a big help when rowing in headwinds, especially when we must row at an angle to the wind. This sail was offset opposite the Main to clear the rudder and tiller. In this position, it can be squared across the transom for a mid-line, downwind push.
It is sprit-boomed in pretty much the standard manner. The boom is longer than usual, extending forward of the mast. A U-sheet leading forward attaches one leg to the inboard end of the boom and one to the outboard. This gives us leverage to trim and make fast. The sail is fixed to the mast (no halyard)... to stow, we release the snotter and raise the outboard end of the boom alongside the mast. A light line fixed to the masthead is used to wrap and secure the boom and vertical, hand-rolled bunt of the sail.
Roll yer own and glide on, Friends!
