Rigged for Success: LOM/Ljungstrom + Quick-Rig Booms

 

MUSTELID's LOM Main and Ljungstrom Foresail

Live life as if everything is rigged in your favor.

-- Rumi

Rigged for Success: 
    LOM/Ljungstrom + Quick-Rig Booms

I'd like to share a suite of ideas toward a family of lesser known rigs for smaller vessels that I think show a great deal of promise. Part historical, part convergent evolution, part innovation, the result is a simple but versatile, robust rig that can be DIYed at low cost.

Leg o' Mutton (LOM) Sails

This tasty moniker simply means a triangular sail. They're commonly used for headsails (jibs, staysails, etc.), mains (often called Bermudan sails) and drivers (small sails set far aft).

Ljungstrom Rig (2 x LOM)

Ljungstrom Rig uses a pair of LOMs, joined along their luffs and set on a free-standing, rotating mast. No booms were used to avoid troublesome impacts with crew.

This configuration works similar to twin head sails off the wind. From a beam reach on up, the sails are doubled over to one side and sheeted as one.

Pros:

• Boomstrike is eliminated (the rig's original focus).
• Light, inexpensive spares and gear.
• Quick set/reef, roller un/furling via the mast.
• Sailing off-wind, one side can be jibed for 'instant' 50% reef.
• Sail area aloft catches higher, upper wind-flows.
• Low Center of Effort (CE).
• Twin sails tend to center down the wind.
• Potential for hands-free operation.
• Sail steering is straightforward (haul to the side you wish to sail).
• UV resistant fabric along luff and foot eliminate sail covers.
• At least in smaller vessels, the furled rig is easy to set and strike, and compact for storage.
  
  

Cons:

• Lack of a boom makes spreading sail difficult (especially on narrow hulls).
• No clew outhaul or vang options.
• In contrast to twin stays'ls (unless the mast is canted) it generates no bow lift.
  
  

Adding a Boom

The addition of a boom set under a loose-footed LOM allows spreading, a clew out-haul and vang, addressing the main cons.

Interestingly, this approach was taken by both the Sea Pearl 21 (adventurously sailed by Stephen and Ginny Ladd, among others), and is marketed as Holopuni Quick-Rig (by Holopuni Canoes). Convergent evolution?

Both of these designs lead their clew outhauls via track along the top of the boom and sheets to the end of the boom. When the sail is reefed, the upward pull of the clew at mid-boom is resisted by the end positioned on the mast and the downward pull of the sheets at boom's end. 

As a sail's belly is blown full, pulling the clew strongly toward the tack, the boom resists in compression. If it is deflected from straight by the perpendicular pull of the clew between mast and sheet lands, that strength plummets. Usual solution? A heavy boom or one made with expensive, exotic materials.

Hmm.

What if we oppose sheet and clew tensions by having them meet at the same point? They cancel out, unloading the mid-boom! The clew outhaul - led to boom's end, then turned back toward the mast to the clew completes the picture. A rope grommet - travelling along the boom - is the perfect attachment point... simple, cheap and DIY.

Principle parts of the rigging...
This platform and 'collar' are primitive but functional

How We Go About It

Rotating Mast and Gear

In our small-ish boats, we went with a thumb-sized dowel protruding from the rounded bottom of the mast. This is inserted into a hole in its step - a fixed plate of thick HMD (cutting board plastic). This secures the foot but it allows it to rotate with very little friction. The upper partners are simply a loose-fit, fixed square around the mast. The distance between step and partners should be between 10% (minimum) and 15+% (healthy) of the mast's overall length for adequate cantilever.

A gate can swivel open to free one face for raising/lowering or close and lock to contain it. 'Box' sides at the step hold the foot in place for lowering. A pin led through one side and into a corresponding hole in the lower mast prevents rotation against high winds or rock and roll.

Each boom requires an arrangement that fixes their height above the partners, yet allows the mast to rotate independently. 

Our solution is a platform affixed to the mast with a collar from boom's mast end, around the mast, set above the platform... the collar is not so loose as to slip below the platform, but not so tight as to grip the mast.

Booms

Booms can be quite light as compression span decreases as the sail is reefed, and diameter per unit of span increases - functionally speaking, reefing makes them stronger. Further, they are subject to no significant side forces along that span. Sea trials help settle in on a light boom with comfortable margins of safety.

Each boom has a rope grommet loosely fit around it (sized so it doesn't bind when pulled at a flat angle). 

We fix a pinch cleat for the clew outhaul at the boom's mast end, pinch horn down (10deg) toward the distal end. This allows the line to ride over the non-pinch horn (up and toward the mast), under control hands-free as it pays out while furling.

A ring seized to the distal end of the boom turns the outhaul back toward the grommet.

The outhaul leads from its cleat, through the grommet (helps control a slack outhaul) to the turning ring, and back to the grommet. We fix it to the grommet's upper side, allowing a tail which is tied to the clew. We prefer little play between clew and grommet.

The sheet is fixed to the grommet's lower side and led to deck level. A turning device (multiple or travelling for an improved lead?) leads it toward a clear, handy to the crew. We prefer enough friction on the cleat to hold in steady wind but ease in heavy gusts... no lock hitch.

Sails

We used light nylon fabric to build flat-cut sails. These are responsive, and furl neatly around the slightly tapered masts. They are stretchy enough to take on some belly (camber) when full of wind.

Downside is that camber can't be flattened easily in high winds. But reefing is so easy, we can reduce power that way.

For 2xLOMs we screwed the webbed luffs to the mast, but are now considering a pocket for easier installation and removal. Others have found that a simple lanyard from tack to mast is sufficient for furling.

Handling the Ljungstrom

We set the Ljungstrom sail well forward, where it can pull us bow down the wind. 

We don't typically vang our sails to flatten them. Instead, we vary the sheet leads and/or reef a little more than we might. This avoids extra gear, handling and the heavier booms required. Personal call, however. 

Furled Set Up

When furled, the sail is snugly wrapped around the mast. The boom(s), if any, are vertical. Sheets are left slack and hanging. One clew outhaul is marline-hitched once or twice along the mast, securing all the bits, then made fast at its pinch cleat (low).


Setting Sail

Unhitch the outhaul, then refasten to its cleat. Uncoil sheets and lead aft to their cleats. Both outhaul and sheets will go slack as the sail is unrolled. Unpin mast if locked.

Depending on wind, you might wish to round up. For downwind departures, you may have to work in stages, trimming sheets as you go.

Unroll the sail by rotating the mast (we prefer 'righty-tighty; lefty-loosey' as standard... we do this by hand, but various rope windings are possible).

Once unfurled as far as desired, haul the outhaul(s) for the curve you wish, then make fast. Trim sheets and fall off to heading. Backing sail is easy and effective. If you wish to open the sails, do so.

On the Wind

Here the sails are overlapped and are sheeted as one (outer one generally the focus of our attention). They handle pretty much as any boomed LOM.

Off the Wind

Sailing off the wind, the sail is typically balanced like a delta kite. All things being equal, it want s to hold the bow centered downwind. More belly is often a good trade-off against more area.

To steer using sail, haul the sheet on the side toward which you wish to turn (easy, now!). This shortens its force vector and directs it to that side. The opposite sail, now relatively stronger and with a longer lever-arm, works to rotate the hull that-away. Like the reins of a horse!

In a heavy gust, you have a 50% reef at hand. You can jibe one sail (lapping one over the other) or let it fly (this can be harder to retrieve... get a wide angle). But if this comes up, consider roller reefing ASAP. Consider that, in high winds, you don't have to set them wing and wing... they sail well as one.

Odd Situations

If a sudden squall has invited letting both sails fly (they're trailing down the wind from the bow), calmly roller reef until you can bring them in and under control.

If such a situation has reversed their usual sides, don't panic... just hand the sheets around the mast, or refasten them for a fair lead and carry on. The sails won't care.

The whole mast, sails and all, can be furled, hitched up and let over as a sea-anchor.

All in All

We found these LOM/Ljungstrom + Quick-Rig Booms to be simple, cheap, versatile and powerful. Each piece is DIY-able from scavenged materials. Nothing about them couldn't be made in the field, at a pinch.

The lightness of the spars is a BIG advantage, especially as we age. The masts should be manageable for as long as we're likely to be able to row.

In researching the history of the rig, the few who have used it are soberly impressed by its virtues. It is not the fastest rig out there, but its no slouch, and pays its way with easy handling and quick reefing.

I'm hoping to see more of these on the water in the coming years!

Full Ljungstrom / Reefed LOM
Sprit-Boomed LOM Aft

References

Sea Pearl 21 Review by Josh Colvin

About Holopuni Canoes by Nick Beck

Rigging MUSTELID and MUSTELID Voyage by Anke and Dave

Musings on Design for Solo Sailors

Capucine Trochet single-handing TARA TARA

The only way to see true reality is in solitude. One of the tragedies of human existence is that reality cannot be shared. What's real to you may not be to someone else.

― From A Steady Trade: A Boyhood at Sea by Tristan Jones

Musings on Design for Solo Sailors

As an adherent of the Buddy System, I look askance on solo, live-aboard cruising. That being said, many things - including simple inclination - can set us on a solitary course. Not just for the moment, but as a way of life. So it bears thinking about.

Sailing solo asks much more of us, and we need more from our vessels. What follows are my personal thoughts. They hardly amount to advice, much less any kind of yagotta. I offer them for your consideration.

To me, there is a big difference between ocean sailing and inshore that bears on a solo sailor’s needs. While offshore sailing has its own challenges, inshore has most of those plus constraints from proximal shorelines, rocks and reefs, highly variable wind and currents, and generally higher traffic. There are no inshore weeks of balanced sail and helm with little more than lookout duty for the single-hander. Inshore sailing is much more active.

A motor is a help, and at its best, goes a long way toward standing in for crew. It allows planned moves in mostly predictable time. The energy it consumes saves some of that drawn from our own, limited budget. Still, engines have their own costs, and sometimes fail or run through their own available energy. For the lone sailor, I would recommend considering it as an option rather than a codependency.

IMHO, the biggest threat to the single-hander is fatigue.

When sailing alone, there is no other to relieve the watch. To prepare food or drink. To lend a hand. To give a second assessment. To offer courage and moral support. We must guard our strength and sieze the opportunity to rest.

The second is hypothermia. Being in the wind means calories are blown to lee and gone. We can’t be relieved to go below and warm up. Even putting on extra clothing takes an extended moment away from the helm. Good clothing, put on ahead of need is essential, but also can be hard to manage, with sudden downturns of conditions or opportunity putting us in peril. Worse, hypothermia is insidious, dulling the mind and impairing decision by easy-to-miss degrees. As solo sailors, there is no other to note its symptoms. We must be alert to its signs and stay ahead of its advance.

These considerations and others can be helped by good design.

So what would I look for in a vessel that I can manage alone, actively sailing by day and anchoring by night, year-round? Here’s a wish list:

• Small Size - Small affords the best strength-to-boat ratio, both in terms of my own and the vessel’s. A smaller vessel has less mass, momentum, leverages and surface area reducing the stressor forces involved. At the same time, its greater mass-to-stressor ratio increases its relative strength. My required effort is reduced, both in terms of manipulating my vessel and onboard mechanics. Gear (e.g., anchors) and outfit (e.g. rig) are much smaller and lighter at every turn. Small is beautiful! (- E.F. Shumacher).

• Seakindly Motion - Easy motion with reduced, or at least smoothed (damped), roll, pitch and yaw, and lower angles of heel (stability) help keep fatigue down. These are primarily due to hull features, but weight distribution also plays a role.
  
  

• Ultra Shoal Draft - Every inch we shave from the hull opens options for shelter. When single handing near rope’s end, the ability to duck out of conditions can mean life or death. The simple ability to ground our vessel in a hard chance, in wading-depth water and its resourcesn in reach, saves a desperate swim ashore with the only the shirts on our backs
  
  

• Simple, Robust Everything - Single handers, even more than other sailors, are vulnerable to gear failure. A situation that arises is met by one person, rather than a team… when SHTF, we can only do so much alone. Simple, robust gear reduces risk of failure, and eases both assessment and subsequent address. If a quick fix is all that can be managed in a crisis, simple systems are more easily patched with a wider range of options. Redundancy increases safety-in-depth, and helps scale down crises.
  
  

• Handy, Balanced Rig - A rig that is easy to set, strike and balance are essential to the inshore single-hander. Time and energy are precious, rationed and not to be squandered on involved procedures. A balanced rig eases any self-steering system, freeing us from the helm and reducing the adrenaline rush when they are overwhelmed. Easy reefing with a good range of options reduces fatigue from transitions and sailing over- or under powered.
  
  A bonus is a rig that can be raised and lowered completely, if not by hand, then by easy, on-board, mechanical means (e.g., Thames Barge Rig, scaled down). This lets us reduce windage, especially at anchor, for better sleep.
  
  Consider Junk Ketch Rig for excellent reef and balance control. Not as easiliy lowered as some, however.
  
  

• ‘Efficient’ Human Propulsion - The ability to move through calms at an easy pace gets us into and out of harbor for both shelter and sleep. Options include oars, sculls and the Doi PowerFin. Pedal units are also possible, but much less simple. These need to be accomodated, not only by a design, but in terms of use and stowage.
  
  A hull’s shape determines how efficient - how easily driven - it is through water. Generally speaking, more slender, shallow hulls are more slippery, as are curvy ones. Retractable lateral resistance (consider off-centerboards for simplicity) can be cleared from the water when rowing or sailing offwind to reduce drag.
  
  Since rowing is upright, while sailing into the wind is often heeled, design constraints look for a balance according to priority.
  
  

• Interior Handling (Steering, Sail, Propulsion) - The ability to steer and manage sail and oar from within shelter is, I think, a huge advantage. We are far less exposed to the elements, less encumbered by gear (think foulies and PFDs), our galley is near at hand without the need to transition from deck. Eliminating the need for a cockpit potentially shrinks the boat.
  
  To my knowledge, this approach was pioneered for single-handing by ‘Blondie’ Hassler (JESTER and others) and extended by Phil Bolger (BIRDWATCHER and others), Sven Yrvind and Matt Layden.
  
  

• A Comfortable Interior - Inside the vessel is our ‘hole in the weather’. There should be a comfortable, warm, dry place to sit and sleep and cook. If an intimate guest is to be accommodated, they’ll need the same. If these areas overlap, they should transition smoothly, without much time or effort.
  
  Consider a simple, dedicated galley arrangements handy to the helm. At a minimum, space for pre-prepared food storage + thermos.
  
  

• Ample Carrying Capacity - The ability to carry plenty for any given leg of a voyage, including enough for unforeseen delays, takes pressure off any crew. Lone sailors are especially vulnerable if forced to press on for lack of provisions. Our safety margins are narrower to begin with… a forced march can quickly use up what’s left.
  
  
  

All these points work together to enhance and extend our physical ease, resilience and reach while reducing exposure and fatigue. Some, however, work at odds with one another. We seek a dynamic balance to meet expected conditions, leaning this way or that according to where and how we intend to sail.

Every vessel is a compromise, and these are no exception. The single sailor, even more than is generally true for two or more, must put themselves first and foremost among the vessels’ priorities. Exchanging ergonomics for lesser priorities (speed, windward excellence, size, etc.) is a fail-dangerouser bargain. Safety margins are vital, and trading them away is a poor bargain.

So there’s a set of criteria that I’d look for. 

If it were me. 

Which I hope it never is.

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Here are some current live-aboard, cruising solo sailors I admire and  from whom I’ve distilled the above approaches. The word that pops to (my) mind as the common denominator of these sailors is discipline… each has harnessed their energies and passions to surmount the challenges of singe-handing to forge a joyous lifestyle.

Note that, while some inshore sailing is part of any cruiser’s voyage, all I know of are passage based. In other words, close inshore risks are the exception, rather than the rule, and therefore are more easily managed.

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Matt Layden - Matt is a a designer / builder / sailor who solos long and deep -  with more coastal inshore sailing than most. A minimalist, he expemplifies the smallest end of the scale, down to his SAND FLEA(!)

His PARADOX and others hit all the points above. His approach is affirmed by the many versions built and sailed by ‘mature’ soloists.

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Sven Yrvind - Another pioneer of the small, robust, handy school, Sven has been sailing the course for scores of years. His approaches have kept him actively sailing well into his 80s!

He’s another whose designs merit close study. His rigs, are particularly handy and versatile.

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Holly Martin - Holly is a hands-on cruiser, circumnavigating in GEKGO, fixer-upper she transformed into a capable, cruising home. She’s pragmatic, inventive and ‘chill’.

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Kiana Weitzel - Kiana is soloing a larger Wharram catamaran, learning as she goes from near scratch. She provides a good look at simple sailing with the advantages (and some disadvantages) of a larger footprint.

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Shemaya Laurel - While not strictly speaking a live-aboard, Shemaya is a coastal sailor (considerable inshore sailing) for extended periods. In her case, fatigue and exposure are of particular concern, and she casually demonstrates how far preparation and pacing can take us.

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Yann Quenet - Yann is on his second circumnavigation in his 5 meter BALUCHON! He’s another who makes the very small end of the scale look both practical and inviting!

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Here are some designs that I think would either make good single-handers along the lines above or provide inspiration for them. They’re not by any means a definitive list, but serve as illustrations. Each have features to consider, if not copy!:

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Matt Layen’s PARADOX, showing the well-thought-out approach to a successful and compact cruiser. He sets a high bar! Not clearly shown here are his chine runners… fixed flanges running along about ⅓ of the chine providing enhanced lateral resistance (no keel or boards to handle and no extra draft!).

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BOB is a doodle of mine, inspired by Matt Layden’s PARADOX. It’s the simplest to build and gets the most interior on a given footprint. It won’t be as slippery as some others, but is exceptionally stable under sail, relative to its size. It would be my choice given how I roll.

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Phil Bolger’s BIRDWATCHER (and his enhanced BIRDWATCHER II) are another high water mark. The cabin is see-through and watertight, making this hull self rescuing from inside after a full knock-down!

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OLLIE is an early sketch toward John Harris’ thoughts on adapting Phil Bolger’s DOVEKIE. Note the small, aft cockpit with a dodger bar to set up a sheltered station. Rowing can be done from inside.

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FAERING CRUISER is another by John Harris. This one is exceptionally slippery making it easy to drive under sail and oar. Accomodations are accordingly scant for a live-aboard (a cockpit shelter helps), but a minimilist could do well with this one.

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Godfrey Stephens’ adaptation of Bill Short’s SAN FRANSICO BAY PELICAN. Lots of accomodation on a small footprint, these are surprisingly able sailors in rough water.

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EGRET by Ralph Monroe manages to be a small 29ft, and coud be scaled down if desired. As was, she earned her legendary reputation delivering mail year round in wild, Gulf Stream waters. Early proof that hard chines can produce a slippery, seaworthy hull.

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Fritz Koschmann aboard his Howard Chapelle designed Scow in SE Alaska.

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BALUCHON on it’s first circumnavigation.

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James Wharram’s well proven TIKI 21 and 26… lots of single-hander footprint in a small package. A large deck tent expands living space at anchor.

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MUSTELID is another of my designs… it’s in reach of single handing as is, though I’d shorten the forward cockpit for one rowing station and switch to ketch rig. Inside handling can be arranged. The mast-furled Leg O’ Mutton sails with Holopuni Quick-Rig inspired booms turned out to be fantastically simple and easy to handle (we later learned that SEAPEARL canoes offered a similar rig).