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What is Hobikisen?
 
Mechanism
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Mechanism of Hobikisen
Fishing Process by Sightseeing Hobikisen
Moving Image of Operation
 
 
The Mechanism of Hobikisen
 
Hobikisen is said to be similar to kites in dynamics.
 
Three ropes tied to the yard (tsurinawa) generate not only towing power but also lifting power for sails. The balance among three powers (wind power, gravity and drag) makes the boat to sail in a stable manner.
 
Benefits of tsurinawa ropes:
 
P.
The masts will not break.
Q.
The boat will not turn over because sails are pushed by the wind.

R.

The mouth of the net opens in three dimensions.
S.
Moving the boat sideways becomes easy because lifting power lifts the boat.
T.
Speed is can be increased.
   
  You may now know that the idea of tsurinawa ropes created a very innovative fishing boat.
 
No. 5 in particular, the maintaining the high speed, was indispensable to catch shirauo and lake smelt wandering in the lake. The primary purpose of inventing hobikisen must have been to devise a fishing method that could tow the boat with maintaining a certain speed.
 
Now letfs compare between hobikisen and kites.
 
 
Comparison between hobikisen and kites
A kite flies by lifting force produced by the difference in air traveling over the top of the kite and that passing underneath. For hobikisen, making tsurinawa ropes shorter than dashinawa helps generating lifting force.
E
Net (Water pressure)The flyer holding the kite string
E
Tsurinawa and dashinawa ropesKite string
E
SailKite
E
Boat (Weight)Kite tail
 
The comparison above will make you understand that a boat drifts sideways in a stable manner as long as there is a certain degree of wind.
 
When small and light boats were used as hobikisen before the advent of powered-boats, fishermen were said to be able to feel their boats gliding over the water due to buoyant force increased by lifting force.
 
 
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