About Chinese Fishing Nets:
Kerala having about 590 Km of costal area is blessed with fish resources. Along with this, the backwaters also provide ample opportunity in fishing. Chinese fishing nets commonly known as “Cheena-Vala” are a common feature in the backwaters and river estuaries of Kerala and are widely used in coastal regions of Kollam, Alappuzha, & Cochin. Chinese Fishing Nets are fixed land installations, shore operated lift nets which consists of large wooden contraptions used to lower a net into the water to trap fish and prawns and raise it to extract the catch. A large net of about 20 square meter area is suspended from four diagonal wooden booms at the end of a crane arm which extends from the shore (or wooden platforms constructed on lake bed) over the water.
Problem: The Chinese Fishing net requires the labor of at least 3 men at a time to raise it. The net needs to be lowered and lifted about 20 times in an hour when the catch is good. External labor is hired when there is manpower shortage within the family. With the increase of cost of labor in Kerala, these rigs are becoming increasingly unviable.
Innovation by Mitraniketan:
The main component of the machine is a metallic winch, of base diameter 200 mm and 350 mm in length, which is used for winding/ unwinding of ropes. The rope that is used for pulling the net manually can be easily attached to the winch. This winch is driven by an electric motor delivering an output power of 1 HP (750 W) or 0.5 HP (340 W) @ 1450 rpm, through a pair of belt drives and gear drives for speed reduction and increasing the torque. The machine with 1 Hp motor can pull a load of 150 Kg at the rate of 0.5 m/s. The major innovation is the introduction of “one-way brake” system which prevents the falling of net to water due to power failure.
Mechanization of Chinese fishing rigs are carried out for the first time.
Single person can manage the entire operation on a rig.
Easy to install and operate.
Can be retrofitted to any existing rigs without any modifications on the rig. The traditional method can be used as a standby in case of power failure.
The fishermen testify that there is substantial increase in income from the Chinese fishing rigs after the installation of the motorized winch.
The winch with 1hp motor costs Rs. 18,500/-, and
0.5 hp version costs Rs. 15,750/-
The 1 hp version is more popular, and the average energy consumption is 1 unit per day.
Motorized winches for non-electrified and heavy fishing rigs are currently under development. The winch is run by a 2-stroke pertol engine having output power of 1.8hp.