A sakia (alternative spelling sakieh, also called Persian wheel; Arabic: ساقية, sāqīya), tympanum or tablia is a water wheel, somewhat similar to a noria, and used primarily in Egypt. It is a large hollow wheel, normally made of galvanized sheet steel, with scoops or buckets at the periphery. Its unique characteristic is that water is dispensed near the hub rather than from the top. It is a method of irrigation frequently met within various parts of India.
Sakias range in diameter from two to five metres. Though traditionally driven by draught animals, they are now increasingly attached to an engine. While animal-driven sakias can rotate at 2–4 rpm, motorised ones can make as much as 8–15 rpm.
A (animal driven) sakia can pump up water from 10 metres depth, and is thus considerably more efficient than a shadoof (which can only pump water from 3 metres).
The earliest evidence of a sakia is from a tomb painting in Egypt which dates to the 2nd century BC. It shows a pair of yoked oxen driving a compartmented waterwheel, which is for the first time depicted. The sakia gear system is already shown fully developed by this point. An episode from the Alexandrian War in 48 BC tells of how Caesar's Egyptian enemies employed geared waterwheels to pour sea water from elevated places on the position of the trapped Romans.
Sakias later became more widespread during the Islamic Agricultural Revolution and were in large-scale use in the medieval Islamic world, where Muslim inventors and engineers made a number of improvements to the sakia. For example, the flywheel mechanism used to smooth out the delivery of power from a driving device to a driven machine, was invented by Ibn Bassal (fl. 1038-1075) of Al-Andalus, who pioneered the use of the flywheel in the Noria, Sakia, and chain pump. In 1206, Al-Jazari introduced the use of the crankshaft in a noria and saqiya, and the concept of minimizing intermittent working was implied for the purpose of maximising their efficiency.
- ↑ Water lifting devices book description
- ↑ Oleson 2000, pp. 234, 270
- ↑ Oleson 2000, pp. 234, 270
- ↑ Oleson 2000, p. 271
- ↑ Donald Routledge Hill (1996), "Engineering", in Roshdi Rashed, Encyclopedia of the History of Arabic Science, Vol. 3, p. 751-795 .
- ↑ Thomas F. Glick (1977), "Noria Pots in Spain", Technology and Culture 18 (4), p. 644-650.
- ↑ Ahmad Y Hassan, Flywheel Effect for a Saqiya.
- ↑ Donald Routledge Hill, "Engineering", in Roshdi Rashed (ed.), Encyclopedia of the History of Arabic Science, Vol. 2, pp. 751-795 , Routledge, London and New York
- Oleson, John Peter (2000), "Water-Lifting", in Wikander, Örjan, Handbook of Ancient Water Technology, Technology and Change in History, 2, Leiden: Brill, pp. 217–302, ISBN 90-04-11123-9
- Fraenkel, P., (1990) "Water-Pumping Devices: A Handbook for users and choosers" Intermediate Technology Publications.
- Molenaar, A., (1956) "Water lifting devices for irrigation" FAO Agricultural Development Paper No. 60, Food and Agriculture Organization of the United Nations, Rome.
- Description at the Sakia.org website.