Monday, January 19, 2009

The Protolateen Rig

Here's an interesting rig, found on outrigger canoes (especially double-outriggers) in Madura, Indonesia. Called variously the Madurese Jukung Rig (a simple descriptive term), the Primitive Oceanic Lateen (so-called by Haddon and Hornell), and the Protolateen Rig (by Horridge), it is a two-boom triangular sail with no mast. I'm posting a photo and line drawing of the same basic rig, though the two boats are somewhat different.

The prop that supports the upper boom (the blue and white stripped pole in the photo), and hence the whole rig, can't be termed a mast, since it's movable and neither stepped nor supported by a thwart. Depending on the point of sail, much of the rig's weight bears on the tack, the forward corner where the two booms meet, which rests on the bow of the canoe itself. Guys or shrouds are rigged from the sail's upper boom back to both stern outrigger booms, to keep the rig down and keep it from blowing overboard. And in some examples, another line runs from the upper boom forward and down through an eye at the forward outrigger, and then back to the helm station. I believe that when tightened, this line keeps the tack down when sailing on the wind. When running downwind, I think this line is loosed so that the tack can lift and the whole rig be oriented somewhat athwartships.

Adrian Horridge, whose book Outrigger Canoes of Bali and Madura, Indonesia I cited in my previous post, believes the Protolateen rig is the original rig of the Austronesian people, that that all other Pacific rig types (with the exception of Western rigs introduced much later) derive from it. I won't try to paraphrase his complex arguments, but the diagram below shows his theory for the diffusion and evolution of the various Pacific rig types.

The Protolateen rig is shown in A, and a slight modification, with the upper boom hanging by a short line from the prop, is shown in B. It's easy enough to imagine either of the next stages of evolution: the addition of a short mast from which to hang the upper boom (C), or stepping the forward end of the upper boom and turning it into a quasi-mast (with stays or shrouds), while doing away with the movable prop (F).

Two other interesting details to note:
  • In the photo, note the extreme forward extension of the outriggers, several feet beyond the bow of the hull.
  • In the line drawing at top, note the unusual nature of the stern outrigger boom. It's a two-part boom, each part made of elaborately curved and carved pieces and lashed to the hull at a significant angle from athwartships.

All of the art here is from Outrigger Canoes of Bali and Madura.


  1. Love this series on Jukungs (see that I have been talking it up). Keep up the good work.

    On a different subject, can you add Chine bLog to your blogroll? Thanks,


  2. This rig type is actually called as "Crab claw" BR Teddy

  3. Hi BR Teddy
    Although there are similarities, the rig described here is not the same as the one discussed in the Wikipedia article. The protolateen rig is tacked, not shunted. Consequently, the spar that serves as a kind of mast is "stepped" in the stern, not amidships.
    Although I've seen oceanic lateen sails called generally "crab claws," I feel that the term should apply only to those that have a deep concave shape to the leech so that the sail somewhat resembles a claw.

  4. Love this blog! I'm just getting caught up on the archives, so I hope you are still checking the comments.

    I see that this rig is non-shunting, but I don't exactly see how it works coming about (b/c the prop/sokongan would be in the way of the lower boom). Is this primarily a wearing rig (a la' East Indian Ocean settee rigs)? If the prop comes down pretty easily, I can see a drop-the-rig-and-set-it-up-on-the-other-side tacking maneuver. If the prop is pretty movable, I can also see how it might be used to shift the sail's center of effort up/down & forward/back. (The stub masts on some tacking outriggers seem to allow this too, although it would seem to take some hefty tackles.)

  5. Thanks Steve. The prop is easily dropped, but it remains in place and continues to support the upper boom when changing tacks. The rig is indeed a wearing rig. As the stern passes through the wind, the sheet to the lower boom is let go and the sail and lower boom blow free over the bow. As the turn continues, the opposite sheet is hauled in to complete bringing the sail around the front to the opposite tack.

  6. Why such long outriggers extending forward?

  7. KuKulzA28: I don't know why the outriggers are so long, but here's some speculation: they probamay bly contribute to tracking (straight-line directional stability), much as a keel or leeboards would. Given the shortness of the hull and the fairly large sail, this may be necessary to prevent excessive leeway when close-hauled or reaching.

  8. Reason for long outriggers is to prevent bow crashing in surf rises to crest before bow and lifts bow up out of trough before plunging