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March 14, 2005
Sailing dhows
A question from the Scarlet Manuka regarding the sailing dhows now replaced by motorised versions made me think a little about the rig. The great lateen rig carried on a single or double mast by the dhows of old is not designed for beating to windward, although they can lie fairly close to it - up to about 40* off the wind. The problem is that they cannot "tack" in order to work their way into the "eye" of the wind.
The rig was developed over centuries to take advantage of the monsoon winds that blow across the Arabian Sea and the North-western portion of the Indian Ocean. These blow steadily either from the Northeast or the Southwest, and the dhows could ride them either to Africa, trading as far South as Zanzibar and Pemba and bringing spices and slaves back to Arabia, or across the Arabian Sea to Pakistan and India. They voyaged in one direction with the monsoon and returned with the anti-monsoon. This allowed sailing on a broad reach - the fastest point of sailing for a rig of this type - with the need to work their way to windward in either direction.
European rigs, on the other hand, had to cope with the need to make headway against winds which were far from predictable or constant even when they were favourable. This is one reason why the lateen rig, popular among traders along the North African and Levantine coast, was soon dropped by this group working from Northern Europe. The square-rigged system allowed a ship to work to windward, a laborious and sometimes dangerous task, but an essential one if we were to leave purely "local" waters and trade further afield.
The lateen rig, with its huge spar boom, is very difficult to tack. It must be struck completely and then reset on the new tack in order to ensure the most efficient flow of air along it. This is not a practical situation, and so the dhow and its rather attractive rig has never really become the great oceanic voyager outside of its original habitat. Fast on the reach, seaworthy, and sturdy they may be, but they ultimately became the victims of their own success, giving way to the hardy and slower ships from the West.
I am told that there are still dhows trading under sail, but have not seen any. Should I ever do so - a photo will be posted!
Posted by The Gray Monk at March 14, 2005 08:33 AM
Comments
Great - I'll be on the lookout for that photo!
Posted by: The Scarlet Manuka at March 14, 2005 06:39 PM
Today's entry set me off thinking just how much man adapted to his environment in former times. Like developing different sailing techniques depending on which hemisphere he lived in and what kinds of wind he would find there. Then man invented the steamboat and thought he could go everywhere. I've always been fascinated how people could survive in the most adverse conditions. Take for example the Innuit in Greenland who used to build earth houses (that are houses dug into the earth) to survive the winter. Families would gather together there in one room because that kept them warm. They hardly even needed any clothes inside there. Nowadays with all our fancy central heating and everything we do not bother about such live saving strategies anymore. On the whole I think we could do with paying a little more attention to the world around us. Nature strikes back sometimes.
Posted by: The Scarlet Manuka at March 15, 2005 05:34 PM