Long-tail boat
Encyclopedia
Thai language
Thai , also known as Central Thai and Siamese, is the national and official language of Thailand and the native language of the Thai people, Thailand's dominant ethnic group. Thai is a member of the Tai group of the Tai–Kadai language family. Historical linguists have been unable to definitively...
, is a type of watercraft
Watercraft
A watercraft is a vessel or craft designed to move across or through water. The name is derived from the term "craft" which was used to describe all types of water going vessels...
native to Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
, which uses a common automotive engine as a readily available and maintainable powerplant. A craft designed to carry passengers on a river may include a lightweight long canoe
Canoe
A canoe or Canadian canoe is a small narrow boat, typically human-powered, though it may also be powered by sails or small electric or gas motors. Canoes are usually pointed at both bow and stern and are normally open on top, but can be decked over A canoe (North American English) or Canadian...
hull, up to 30 metres, and a canopy. There is much variation among these boats, some have evolved from traditional craft types, while others have a more improvised look—the sole defining characteristic is a secondhand car or truck engine.
This engine is invariably mounted on an inboard turret
Gun turret
A gun turret is a weapon mount that protects the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in many directions.The turret is also a rotating weapon platform...
-like pole which can rotate through 180 degrees, allowing steering by thrust vectoring
Thrust vectoring
Thrust vectoring, also thrust vector control or TVC, is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine or motor in order to control the attitude or angular velocity of the vehicle....
. The propeller
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
is mounted directly on the driveshaft
Driveshaft
A drive shaft, driveshaft, driving shaft, propeller shaft, or Cardan shaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement...
with no additional gearing or transmission
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
. Usually the engine also swivels up and down to provide a "neutral gear" where the propeller does not contact the water. The driveshaft must be extended by several metres of metal rod to properly position the propeller, giving the boat its name and distinct appearance.
Advantages to the inboard engine with a long driveshaft include keeping the engine relatively dry. Following the basic design pattern allows a variety of engines to be attached to a variety of different kinds of hull
Hull (watercraft)
A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...
s. This flexibility simplifies construction and maintenance while sacrificing the efficiency and comfort that might be expected of a typical mass-produced product.
Cooling to the engine is provided by a shaped metal pipe strewn underneath the rear running board which is used as a rudimentary heat-exchanger. This is then coupled to the engine using rubber or plastic hoses. Clean water is then used as the coolant.
Control is achieved by moving the engine with a lever
Lever
In physics, a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force that can be applied to another object or resistance force , or multiply the distance and speed at which the opposite end of the rigid object travels.This leverage...
stick attached to the inboard side. Ignition and throttle controls provide simple means to control this simple craft. Larger boats may include more than one "tail," with several operators piloting in tandem.
Long-tail boats are now often used to transport tourists. There are also competitions involving long-tail boats in certain provinces of Thailand.