Junk rig

This ship, the Keying, is an example of a Chinese commerce ship employing the junk rig. It traveled from China to the United States and England for trading between 1846 and 1848.

The junk rig, also known as the Chinese lugsail or sampan rig, is a type of sail rig in which rigid members, called battens, span the full width of the sail and extend the sail forward of the mast.

While relatively uncommon in use among modern production sailboats, the rig's potential advantages of easier use and lower cost for blue-water cruisers have been explored by individuals such as trans-Atlantic racer Herbert "Blondie" Hasler and author Annie Hill.

History

The origin of the name junk rig is not directly recorded, but it is popularly attributed to the name of the traditional junk ship, where the rig was in use when first encountered by Europeans. Though often thought of as applying to a Chinese ship, the chuan, the word "junk" itself was originally applied to a Javanese ship, the djong or jong. Some ambiguity exists in regards to the term "junk rig". It is often applied to both the unmistakable sail plan and a particular type of flat-bottomed hull with a stern and bow raised well above amidship. A hull referred to as a "junk ship" may carry a sailing rig that does not utilize a "junk sail", although it is extremely rare. A "junk sail" may be rigged on any type of hull capable of doing so. Paul Johnstone and George Hourani attribute the invention of this type of sail to Austronesian peoples from Indonesia. They were originally made from woven mats reinforced with bamboo, dating back to at least several hundred years BCE. They were adopted by the Chinese after contact with Southeast Asian traders (K'un-lun po) by the time of the Han dynasty (206 BCE to 220 CE). However, Chinese vessels during this era were essentially fluvial (riverine); China did not build true ocean-going fleets until the 10th century Song dynasty. A UNESCO study argues that the Chinese were using square sails during the Han dynasty; only in the 12th century did the Chinese adopt the Austronesian junk sail. Very little documentation detailing the construction and performance aspects of an ancient junk sail exists.

Comparison with Bermuda rig

Typical Bermuda rig

Typical junk rig

The junk rig is a simple and effective rig. The rig contrasts starkly with the Bermuda rig which is prevalent on Western sail boats. The cost to rig a boat with a junk rig would typically be a fraction of the cost of a Bermuda rig, due mostly to the lower number of parts and adaptability of the rig to cheaper materials. In its most traditional form the junk sail is carried on an unstayed mast (i.e. a mast without shrouds or stays, supported only on the step at the keelson and the partners); however, standing rigging of some kind is not uncommon.

Traditional junk rigs utilize a mast which rakes (slants) forward a few degrees from vertical. The forward rake of the sail encourages the sail to swing out, which makes the use of a preventer unnecessary. Another way to say this is that the sail is stable when swung out and doesn't return to the middle of the ship when the wind drops.

The junk rig appeals to shorthanded sailing crews for many reasons, especially because the rig reefs very easily. To lessen sail ("reef") usually all that is required is to let out the halyard. In contrast, reefing sail on a Bermuda-rigged boat would typically require crew to move about the deck, which increases the chance of falling overboard, especially during a high-sea state which is typical of conditions which would encourage reefing.

It is typical to run the halyards (lines used to raise and lower the sail) and sheets (lines used to trim the sail) to the companionway on a junk-rigged boat. This means that typical sail handling can be performed from the relative safety of the cockpit, or even while the crew is below deck.

Multiple variations of the junk sail plan exist including a square head, fan head, and split panel. Square headed junk sails have parallel yards and booms. Fan-headed junk sails have yards angled forward at varying degrees. Split panel junk sails separate the sail plan in to two sections, a main section behind the mast, and a smaller section forward the mast. This is done in an effort to mimic the effect of the "slot" created by separating the headsail and mainsail in Bermudan rigs, although the benefits of the "slot effect" are disputed. Hybrids between a Bermudan sail and junk sail exist as well, attempting to join the junk rigs ease of use with tried and true Bermudan triangular sail plans. Camber may be cut in to any of the junk sail plan variations in order to increase the possible performance on all points of sail, though doing so reduces the rigs simplicity.

A flat cut junk sail typically produces less drive than a similarly sized Bermuda rig at low angles of attack (e.g. when sailing upwind, close-hauled) and this is especially pronounced in light wind. A cambered junk sail can potentially out perform an equally sized Bermudan rig, producing near comparable speeds and an ability to sail closer to the wind.

The junk sail typically produces more drive than a similarly sized Bermuda rig when running downwind without a spinnaker. A junk-rigged boat can let its sails out athwartships (and beyond) which allows more possible options for trimming the sail while reaching. On a Bermuda-rigged boat the shrouds interfere with sails if the sail was let out until it was athwartship. The full battens of a junk sail prevent the sail from collapsing when running in light wind (dispensing with the need for a whisker pole.) On double-masted junk-rigged boats, the sails can be flown wing-and-wing (i.e. on opposite sides of the boat), even when on a broad reach, as can a Bermudan rig. The junk sail rig is well suited to downwind travel with its working sails.

Not only does a Bermudan sail rig incur more hull and rig stresses, and more intensive maintenance and care during use, but the Bermudan sail also resembles a triangle which is the most inefficient shape for sailing. More modern Bermudan rigs move their backstays further forward in order to make room for a "square head" main sail, as opposed to a "pin head", as such a sail plan performs better. Interestingly, some modern "square head" Bermudan main sails closely resemble a junk sail, minus the full battens. Until around the mid-1950's, when modern sailcloth became widely used, Bermudan sails were constructed using Egyptian cotton and had much shorter lifespans because the camber cut in to the cotton sails would lose its shape quickly.

Other benefits of the junk rig over the Bermuda rig include:

• Durability. Junk sails displace stress loads more evenly and efficiently across the sail resulting in lower strains overall.
• Safety. There is less danger from an accidental jibe due to a lighter-weight boom, which is simply the lowest batten, and from the balance of the sail itself. A Bermudan cruising boat would tie the boom to a rail for long distance downwind sailing. Junk rigs may do the same for increased safety.
• Control. The junk sail can be raised or lowered irrelevant from wind direction. Likewise the sheet can be released to cause a stall at any point of sail to slow or stop, should conditions require. A Bermudan sail must be raised and lowered while headed in to the wind. Slowing or stopping while reaching or running would require the boat to turn and head into the wind. Releasing the sheet would cause the sail to hit the shrouds, which are part of the standing rigging. Maneuverability in a junk rig is vastly beyond that of a fully stayed Bermudan sail rig.
• The sail can be constructed entirely flat or camber may be cut in to the panels for increased overall performance at the cost of higher rig stresses.
• A sail and rig can be constructed to fit any hull carrying an unstayed mast.

Other shortcomings of the junk rig compared to the Bermuda rig include:

• The shape of the sail depends on the flex of the battens, and the battens do the opposite of what would be most desirable: they bend only a little when the wind is light, and they bend a lot when the wind is strong. Consequently, the airfoil developed in light wind doesn't have enough camber to develop much lift at low wind speeds. Perhaps the chief shortcoming of the flat cut junk rig is that it typically produces poor drive to windward in light winds, but adding shape to the sail by cutting camber in the panels solves this problem.
• There are no production junk sail, rig, or boat manufacturers on the market. Almost every junk sail rig is experimental to some degree resulting in myths and marred reputations. The sails must be constructed by hand or found. Standardized parts, general repair advice, sailing classes etc. are virtually non-existent.

An interesting side note is that a small Bermudan sail can be constructed from a single cut, out of a single cloth, and still sail effectively. A junk sail, by definition, requires multiple individually cut panels sewn together.

Use with other ships

Filipino casco with a junk rig in the Manila Bay (c. 1906)

There are several ships in Island Southeast Asia that use junk rigs with local hulls instead of the Chinese junk hull. These include:

• Casco - a flat-bottomed barge originally used by the Tagalog people along the Pasig River and the Manila Bay
• Tongkang or "Tong'kang". A light boat used commonly in the early 19th century to carry goods along rivers.
• Twakow, a type of vessel with one mast and junk rig. They were a common sight in the Singapore river in the mid-19th century.
• Djong, the predecessor of chuan (the Chinese junk). The hull is pointed at fore and aft unlike the Chinese junk, and some are equipped with bowsprit and bowsprit sail.
• Bedar, a type of ship from Malaya.
• Pinas, a Malay ship. Formerly used western schooner rig configuration, but in the 20th century junk sails are used.

Among the ships used on the coast of China:

• Lorcha, a light Chinese sailing vessel. This ship combined a western-style hull of Portuguese influence, with Chinese-style mast and sail. The lorcha were found in the Gulf of Siam and in Philippine waters as well. The Vũng Tàu shipwreck consists of the remains of a late 17th-century lorcha from the South China Sea off the islands of Con Dao, about 160 km from Vũng Tàu, Vietnam.

Modern rigs

Modern junk rigs use the junk sail in configurations such as the catboat, ketch, yawl, schooner, or full-rigged ship.

Colvin Gazelle: schooner junk rig with conventional jib sail

Types

Each of the traditional sailing rigs can be achieved using the modern junk sail.

• the catboat, characterized by its single mast and sail, is easiest to handle and is most likely seen on sailing dinghies and small boats, including the sampan.
• the ketch, characterized by a two mast configuration with the largest main mast forward and the smaller mizzen mast aft. Both sails in the ketch are driving sails. For larger boats, this breaks down the sailing canvas into two smaller panels that are easier to handle compared to one huge sail.
• the yawl, characterized by a two mast configuration with the largest mast forward, is distinguished from the ketch by the smaller size of the mizzen mast, typically aft of the rudderpost in traditional sailing craft, but is not a driving sail. The mizzen mast is used to assist steering the boat and balancing the helm.
• the schooner, characterized by a two or three mast configuration, with the smallest mast forward and the main mast aft. The schooner rig is suitable for larger boats because it breaks down the sail into smaller canvas which is easier to handle. Some hybrid schooner rigs exist, for example the Colvin rig, which combine a fore-and-aft jib sail with junk-rigged main and fore sails. It is sometimes asserted that this improves the rig's ability to sail to windward.
• the ship rig, consisting of at least three masts, is suitable for the largest sailing craft. Modern junk rigged ships have multiple masts of equal size, where traditional Chinese sailing junks have 3 masts with a dominating main mast in the center.

Sail components

Components of the modern junk sail: including the spars, standing rigging, and sailcloth.

The junk sail is a low tech approach to sailing and requires only inexpensive components. Spars are typically of wood. Lines for running rigging are typically 3-strand cordage rather than dual core braid. The sailcloth materials are typically light canvas or tarpaulin, used Dacron from discarded sails, or even PVC sheeting.

The junk sail is composed of the following components:

• the yard in context with the modern junk sail is the supporting spar along the head of the sail from the throat and peak. The yard is a stout spar relative to the battens because it supports the full weight of the sail when the halyard is hauled and the sail is raised. It also elevates the peak of the sail when trimmed.
• Multiple battens support the sail from luff to leech. A fully battened sail is quiet and steady during raising and reefing, making the junk sail a convenient cruising sail. A flat cut junk sail with rigid battens stays flat in light and moderate winds, which detracts from the efficiency. In high winds the battens bend creating shape in the flat sail and an increase in performance. Flat cut junk sails work best in windy conditions, which is ideal for trade routes.
• the boom is the spar at the foot of the junk sail. It supports the sail directly at the tack and the clew, and holds the junk sail assembly down due to the tack line or downhaul. In some junk sails the boom is only partially in control of the trim of the sail, because the sheets are connected to both the boom and multiple the battens. Doing so enables a flat cut junk sail to improve windward capabilities by sheeting in some battens closer than others and creating shape in the flat sail. In such a setup the sheets connected to battens often join together in some way which enables a single line to trim the entire sail like modern Bermudan rigs. Cambered junk rigs are generally sheeted directly to the boom, as extra shape is not necessary.
• the sailcloth panels in a flat cut junk sail do not need to be expensive low stretch materials as is required in modern sails. Flat cut junk sails distribute loads more effectively and generate less stress compared to triangular sails. The flat cut junk sail makes use of a natural driving force created by a purpose made sail plan, as opposed to the high efficiency curves built into modern sails that depend upon Dacron, Mylar, or Kevlar to hold their shape. Cambered junk sail plans, depending on size and camber layout, may require more robust sailcloth due to the increased air pressure created by the added shape.
• the batten parrels are short lengths of line or strap that are responsible for holding the junk sail to the mast. They are quite long, allowing the fore and aft movement of the battens across the mast under the control of the running rigging.
• the tack parrel and tack line secure the tack of the junk sail. The tack parrel will hold the tack into its horizontal position (parallel to the deck) as a snotter tensions a sprit. The tack line will hold the tack in its vertical position (down to the deck). The tack parrel and tack line can be rigged with either standing or running rigging. The latter, if chosen, will rarely be adjusted.

Sail assembly

The modern junk sail assembled: showing the 4 corners and the 4 sides necessary to understand sail trim.

The junk sail has essentially the same sides and corner names as the traditional gaff rigged 4-corner sail. Knowing the names of the sides and corners help understand the running rigging and sail trim of the modern junk sail.

The 4 corners of the junk sail are:

• the peak or the top corner;
• the throat down the gaff from the peak, close to the mast;
• the tack at the base of the mast and boom, which is "tacked" on to the boat and does not move; and
• the clew at the end of the boom, connected to the sheet.

The 4 sides of the junk sail are:

• the head or top edge of the sail;
• the luff or front of the sail, would be the first part of the sail to "luff" or shake when sailing too close to the wind;
• the foot at the bottom, connected to the boom; and
• the leach or trailing edge of the sail, where wind telltales might be found.

Running rigging

The running rigging for the modern junk sail can be divided between the "pull ups" (halyard and topping lift) and the "pull downs" (yard hauling parrel, luff hauling parrel, and sheets). Not shown are optional downhauls for the yard, battens, and boom.

The running rigging for the modern junk rig can be divided into two groups—the "pull ups" and the "pull downs." This is important because the action of hauling one line in a group will be resisted by the opposite group. For example, when raising the sail via the halyard, the pull-downs must be uncleated and free to run.

The running rigging which pulls up the junk sail are:

• the halyard, whose purpose is to raise the junk sail up the mast. It is connected to the middle of the yard, runs up to a block on the mast, and down to the deck. Because it hoists the full weight of the junk sail assembly, the halyard is often rove in a multipart purchase (3:1 or 4:1) via block and tackle.
• the topping lift, whose purpose is to hold the boom and junk sail up off the deck when the sail is not raised. The topping lift also serves to tame the junk sail during reefing and dropping because the spars and sailcloth will all drop into the cradle of the topping lift.

The running rigging which pulls down on the junk sail are:

• the yard hauling parrel, whose function is to hold the junk sail yard close to the mast. It runs from the yard around the mast, and then down to the deck. The yard hauling parrel will control the lateral movement of the higher battens along the mast.
• the luff hauling parrel, whose function is to tame the wrinkles in the junk sail cloth as a result of the middle battens creeping forward when the sail is trimmed. It is rigged from the luff of the sail at the batten to the mast in shoestring fashion such that when it is hauled, it will pull the middle battens aft;
• the yard downhaul, whose optional function is to assist lowering the junk sail when it will not fall of its own weight.
• the batten downhaul, whose function is to assist lowering the junk sail in addition to the yard downhaul.
• and, the tack line, whose purpose is to secure the tack of the junk sail assembly in the vertical direction. It typically runs from the boom down to the deck or a block on the deck.

The running rigging that sets or trims the junk sail (controls the angle of attack relative to the direction of the wind) is the sheet. On a traditional Chinese junk rig, the sail is controlled by sheetlets—small sheet lines running from the battens to blocks that in turn are on lines running through a euphroe, a long piece of wood with holes in it. This helps maintain uniform tension in each panel of the sail. Western ship designers Tom Colvin, Michael Kasten and Herbert "Blondie" Hasler use the same technique, but others (such as Derek Van Loan and Phil Bolger) use a simplified design without euphroes.

Sail handling for the junk rig

Sail handling on the junk rig is ideal for cruising sailors, particularly when sailing short- or single-handed.

There is no need to point "head to wind" when raising sail. When the sheets are sufficiently eased, the junk sail will rotate around the mast to any point of the wind. While sailing dead down wind is inconvenient for making sail, it is still possible to raise the junk sail with the sail luffing.

Raising the junk sail is done by easing the sheets until the furled sail is blown down wind. This will take the pressure off the sail and ease the raising. Then it is important to watch the lines that may be working while the sail is raised, including the gaff hauling parrel, luff hauling parrel, downhauls, and the sheet or sheets. Junk sails utilizing wooden battens or similar heavy materials may benefit from using a 3:1 or 4:1 purchase to ease the burden, but the length of halyard will consequently be very long. The fully battened sail will remain calm in the lee of the mast during the hauling. Due to the weight of some junk sails and its many spars, the occasional junk sailor finds a winch is needed for the last few feet. There is probably already a standing tack line in place, so the halyard is hauled until the tack line is taut, although there is no need to tighten up the leech severely to avoid scallops as in trimming the triangular sails. After hauling and securing the halyard, the fore and aft position of the leech is set by hauling the yard hauling parrel until the halyard is close to the mast. A short pull on the luff hauling parrel may be needed to extend the middle battens toward the leech to control wrinkles in the sail. Some smaller and well planned larger junk sails may be pre-balanced and dispense with the need for a separate yard-hauling parrel and luff-hauling parrels at the cost of losing some sail controls.

Reefing a junk rigged sail is very easy. When sailing close to the wind, all that is needed is to ease the halyard. As the sail lowers by its own weight, the other running lines will also relax. The sail is lowered into the topping lift, or lazy jacks, until the desired batten is along the boom. Then the sail is then adjusted in some fashion to discourage the dropped sail from lifting off the boom by using a downhaul, luff-hauling parrel, or even simply tying the batten down. When reefing on other points of sail, it is helpful to ease the sheet first to take the pressure off the sail, and then ease the halyard and trim the other running lines. When sailing dead down wind, it may be helpful to use a downhaul to reef larger sails.

Emergency furling is fast and simple. When the sheets and halyard are let go, the sail will blow down wind, drop into the cradle of the topping lifts, while being steadied by the full battens. While this is fast and easy, it will also make a mess of the halyards, boom hauling parrel, yard hauling parrel, and downhauls if the rig employs such methods. For non-emergency furling, it is preferable to drop the sail with two crew so that the slackening lines can be hauled in and maintained in order. Alternatively, a single-handed sailor can lower the sail in stages and attend to the slack lines.

Points of sail

The points of sail: A. In Irons (head to wind); B. Close Hauled (against the wind); C. Reaching (across the wind); D. Broad reaching (downwind); E. Running (downwind).

The junk rig brings unique characteristics to each point of sail.

When close hauled, the flat cut junk sail comes under harsh criticism. In a racer/cruiser world that favors speed and sport, the criticism is quite valid. The flat cut junk sail is very inefficient when sailing up wind. The rig cannot "point" as close to the wind, and the craft loses ground by sailing a longer path. In addition, the flat cut sails do not generate as much power per square foot of sail area because of the flatness of the sail. With a practical flat cut junk sail, this is overcome by having larger sails. However, in a handicap racing situation, this criticism hits an extreme because the handicap is based on sail area: the handicap rating will punish the flat cut junk sail rigged boat severely. On a race course, the buoys are set to assure that the boats will battle directly upwind for half of the race. Thus the flat cut junk sail rigged boat must sail a longer race course to the up wind buoy, at a slower speed, and then is punished by its handicap rating. However cambered junk sails allow smaller sails to produce more drive and point much closer to the wind.

In a cruising environment however, sailing up wind is judged differently. Slowing down when beating to windward is sensible cruising. The junk rig is also self tacking. None of the running lines need to be touched to tack the boat through the eye of the wind: one simply puts the helm down, and the sails will swing over close hauled on the new tack.

On the reach, the criticism of the inefficiency of the flat cut junk sail seems to apply again, but only in very light winds. This can be overcome with a cruising spinnaker or gennaker on the junk rig, if sufficient standing rigging exists. However, in moderate winds, both the larger inefficient flat cut junk sails and the small efficient modern sails will generate sufficient power to drive the hull near its hull speed. In high winds, the flatness of the flat cut junk sail is a benefit, as the natural bending of most batten materials creates camber that improves windward ability. In a heavy blow, with the ease of reefing and natural affinity for high wind speed, the flat cut junk rig has a clear advantage.

When running, the junk sail rig shows its advantage. When cruising, many sailors seek the trade winds and maximize their downwind routes. The huge sail area cross section of the junk rigged sail spreads a powerful wall of canvas far greater than a modern rigged boat, which will require a spinnaker to catch up. The junk rigged boat sails more easily downwind because it is self-jibing (just as self-tacking): just put the helm over to windward, and around she goes without touching anything. If a junk rig is equipped with a luff hauling parrel, the center of effort on the junk sail can be adjusted by sliding the sail forward, which exchanges sail area from behind the mast to before the mast: this improves the downwind balance of the sail and tames the jibe. Directly down wind, a junk rigged boat carrying two masts or more, or standing rigging, can sail "goose winged" (also known as "wing and wing," or even "wing and wong" by cruising sailors such as Annie Hill) with great ease and success. In this cruising environment, the junk rigged yacht is fast, easy to use, and inexpensive to set up and maintain.

Heaving to in the junk rigged yacht depends on particular sail plans and rig choices. It can be as simple as heading the boat into the wind with the sails close hauled and puting the helm down when the forward speed is spent. Heaving to in severe weather on a multiple masted junk rig is done by dropping the forward sail or sails into their cradle and reefing the aft-most sail—which helps keeps the bow pointed into the wind. Heaving to with a flat cut junk sail in light winds can be difficult due to the lack of sail drive up wind.

Notable sailors

Annie Hill sailed a junk-rigged dory and wrote of its virtues in her book Voyaging on a Small Income. Her ship Badger was designed by Jay Benford.

Bill King sailed the junk schooner (i.e. junk-rigged boat with two masts) Galway Blazer II in the Sunday Times Golden Globe Race.

Joshua Slocum and his family built and sailed a junk-rigged boat Liberdade from Brazil to Washington, DC after the wreck of his barque Aquidneck. Slocum had high praise for the practicality of the junk rig: "Her rig was the Chinese sampan style, which is, I consider, the most convenient boat rig in the whole world."

Herbert "Blondie" Hasler sailed a junk-rigged modified Nordic Folkboat to second place in the first trans-Atlantic race and was the author of Practical Junk Rig (ISBN 1-888671-38-6).

Kenichi Horie sailed across the Pacific Ocean in 1999 aboard a 32.8-foot (10.0 m) long, 17.4-foot (5.3 m) wide, catamaran constructed from 528 beer kegs. The rigging consisted of two side-by-side masts with junk rig sails made from recycled plastic bottles.

Roger Taylor has completed a number of high-latitude voyages in small junk-rigged yachts named Mingming and Mingming II.

See also

• Lug sail
• Tanja sail, or balanced lug, a type of sail also invented by Malay people
• Lateen sail

Further reading

• Rousmaniere, John (June 1998). The Illustrated Dictionary of Boating Terms: 2000 Essential Terms for Sailors and Powerboaters (Paperback). W. W. Norton & Company. p. 174. ISBN 0393339181. ISBN 978-0393339185

External links

• Junk Rig Association
• Brian Platt's "The Chinese Sail"
• A collection of information concerning Chinese lugsails
• The Voyage of the Dragon King has detailed descriptions of sailing a junk rig, including a diagram and photos of the sheetlets and euphroe.
• Naval architect Dimitri Le Forestier Jonque de Plaisance Modern sailing junks plans
• Naval architect Tom MacNaughton's Coin collection and Silver Gull series designs
• Collection of information an links on today's junk rigged vessels: www.klicktipps.de/sailing-junk-rig.php