Fishing Craft Technology

Unit 5 - Marine Engine and propulsion system

5.5. Outboard and In board Engine

Outboard Engine
Out boards Engine (OBE) is a machine which is fixed outside of the hull of the boat and which drives the propeller and moves the boat. They are integral mechanism, which has an internal combustion engine and the propeller unit coupled together as a compact unit. These easy and compact mechanisms give the following advantage for an out board motors.

• It is easy to maneuver.
• It is easy to maintain the boat fitted with OBE as the OBE can be removed from the boat and the boat can be beached anywhere.
• It is easy to handle the boat fitted with OBE.
• It can be fitted on any restricted space.

In India when the motorization of the fishing crafts have been started just after independence the traditional artisanal fishing crafts of India like canoes, catamarans etc were fitted with out board engines. The out board engines are powered with internal combustion engine run by petrol/ kerosene. Of late diesel engines were also used.

In board Engines
Because of its capacity an OBM can be utilized only on smaller crafts. For bigger vessels more power is required for propulsion. This is met by installing inboard engines. These inboard engines are mainly internal combustion engines installed inside the vessel hull, or bed plates which serve as the prime movers for navigating the vessels. The power developed by these prime movers has to be transmitted to the propeller for navigating the vessel. For this purpose a series of transmission machinery are used in a vessel. The propeller should be able to give both ahead and astern movement to the vessel. It should also give enough thrust for pulling the fishing gear.