THE OPERATIONAL SAFETY IN FISHERIES TECHNOLOGY

byFisheries Technology - 0

 


  • What is operations safety is the Condition to be from accidents, danger, risks, lose ,drowning etc. during working activities either on board ship or  ashore
WHAT IS A SMALL VESSEL/SHIP Is any craft design to float at water, a vessel, especially a large one propelled by sails or engine

PARTS OF THE VESSEL AND FUNCTIONS

1. Wheel house/Super structure is the part of the vessel/ship where the Navigation instruments are kept, so here is the place where master and his mates are . for navigating vessvessel
2. Lower deck is the place where by the fishing activities done and other activities
3. Gantry is the place used to hold warps durning fishing process
4. Fish hold is the place where fish kept
5. Propeller this is the part of vessel help for forward movement and backward    movement of the vessel.
6. Keel this is the backbone of the vessel/ship, which is located at the center lowest point of the hull of the vessel
7. Guard rails Used to protecting crews or peoples from falling in the water.
8. Bow rad; It’s used to secure the mooring ropes. Breadth; is the distance from the starboard side to port side at center of the vessel
10. Length Overall; is the distance from the Aft part to Forepart of the vessel
11. Standard water line; is line used to determine the loading capacity of vessel

IMPORTANT TERMINOGIES;

1 Right-hand side of the vessel is called Starboard side

2 Left hand side of the vessel is called Port side

3 Backward movements of the vessel is called Astern

4 Forward movements of the vessel is called Ahead

5 Wheel house/Super structure is always coloured with white colour in order to be seen clearof

6 Green light colours kept at right side

6 Red light colours kept at left side

7 Mast light is the kept at the mast (the long post in the vessel) (WHITE)

8 Stern light kept at back of the vessel(white)

9 The backward of the vessel is called aft part

10 The forward of the vessel is called forepart

TYPES OF  MATERIALS USED FOR VESSEL/SHIP CONSTRUCTION

 1.Steel vessel

 2.Wooden vessels

 3. Fiber vessels

4. Steel vessel; This is type of vessel which is made up by using  iron and carbon

5. Compound of steel is;

-iron {ALLOYS OF IRON}

-Carbon

-Chromium manganese

-Copper nickel

STEEL VESSEL

Advantage of steel vessel

  1. Its strong
  2. Stay for a long period of time
  3. Durability is high
  4. Resistance of fire  is high
  5. High loading capacity
  6. Resistance when is grounded damage

Disadvantage of steel vessels

  1. Its consume time
  2. It need high knowledge in construction
  3. Materials used is very expensive
  4. It get rust when not painted
  5. Its weight is very greater then other materials used
  6. Give condensation(sweat)

WOODEN VESSEL

Wooden vessel is a kind of vessel which construction by using timber

  Materials used in wooden vessel;�

  • Timber
  • Supper glue
  •  Cotton
  •  Nails
  •  Blanket

Advantages of wooden vessel

  1. Cheap in construction
  2. Materials used are very available
  3.  Not expensive then other materials
  4.  Time not consuming during construction
  5. Its not need high knowledge to construct

Disadvantages of wooden vessel;

  1. Low loading capacity
  2. Easy for catching fire
  3.  Low durability
  4. Poor resistance when it is grounded

Fiber Glass vessel

  •  Fiber Glass vessel; Is the type of vessel which construction  by using plastic raisin.
  • Materials used for fiber glass vessel;
  1. Sold particles
  2. Strong liquids
  3. Plastic raisin
  4. Chemicals

Material’s used for construction of plastic raisins is:

  1. Kelras
  2. Cores
  3. Carbon fiber
  4. Fillers.

ADVANTAGES OF FIBER GLASS VESSEL

  1. They resistible when they hit on the ground than wooden vessel
  2. Its very faster(high speed)
  3. Weight is less then steel

DISADVANTAGES OF FIBER GLASS VESSEL:

  1. Time consuming is high
  2.  Very inflammable(fire)
  3. It need high technology to construction
  4. Easy for  exploitation

BASIC PRINCIPLES OF STABILITY

Principle of Flotation Archimedes Principle

“Archimedes” Principle states that when a body is wholly or partially immersed in a fluid it appears to suffer a loss in mass equal to the mass of the fluid it ddisplaces

Relative Density

  • The relationship between weight and volume is called density.  It is defined as ‘mass per unit volume’.  One metric tonne of fresh water has a volume of one cubic metre. Therefore it has a density of 1.000 tonnes/m3. Salt water on the other hand, is heavier.  One cubic metre of salt water weighs 1.025 tonnes, and so salt water has a density of 1.025 tonnes/m3.
  • The relative density (or specific gravity) of a substance is defined as the ratio of the weight of the substance to the weight of an equal volume of fresh water. In other words, it is simply a comparison of the density of a substance with the density of fresh water

 SHIP STABILITY

  •  The stability of ship depend upon factor which tend to return it to its normal position
  • Ship moved from the position by force such as wind and sea waves
  • To up right a ship it depend by upward force and downward force
  • With a floating object such as vessel/ship “the volume of water  displaced is equal to immersed part of the ship and the weight of the whole ship is equal to the weight of the amount of water displaced.
  • Upright; is afloat of the ship.



From the diagram

M= Metacenter

G=Center of gravity

B =Center of Buoyancy

K = Keel

W-L= Water line

Definitions

  • Displacement

  • When a vessel is floating in water, the whole of the weight of the vessel is supported by the buoyancy of the water.  In order to provide that buoyancy the vessel sinks in the water, until the portion of the hull which is below the water surface pushes aside, i.e. 'displaces' a weight of water equal to the weight of the vessel.

  • This is the law of flotation; namely, a floating vessel displaces its own weight in water.

  • Center of buoyance (B) this is the geometrical center of the under water part of a ship. The force of buoyancy acts verticality upwards through the center of buoyancyIs 
  • Is the point through which the total force due to buoyancy may be considered vertically upwards
    • Center of Gravity (G); this is the center of the total weight of a ship
    • Metacentre (M); Is the point at which a vertical line drawn upwards through the center of buoyancy.
    • Metacentric height(GM);This is the distance between the center of gravity(G)and the Meta center(M)
    • It called positive when G is below M
    •  It called negative when if G is above M
    Freeboard

    •  At any draft the distance from the waterline to the deck is called the freeboard.

    Figure 1 Lightship


    Figure 2 loaded


    DRAFT

    When a vessel is floating in water the distance from the underside of the hull to the water surface is called the draft. 

    There are three states of equilibrium

      (i) Stable Equilibrium 

    (ii) Unstable Equilibrium 

    (iii) Neutral Equilibrium

    • Stable equilibrium - A ship is said to be with positive stability if, when inclined for small angle of heel, she tends to return to the initial position. The centre of gravity (G) must be below the metacentre (M), i.e. a positive initial metacentric height (GM). 


    • Unstable equilibrium –When a ship is inclined to a small angle tends to heel over still further, she is in unstable equilibrium. The ship must have a negative GM, i.e. G is above M.

    (Capsizing lever) Danger of Capsize) 


    Neutral equilibrium – G coincides with M. If ship inclined, she tends to remain at that angle of heel. GZ = 0. Moment of statically stability = 0


    (Danger of Capsize

    Correcting unstable equilibrium

    • Weight loaded below G of ship 
    • Weight discharged above G of ship
    • Remove Free Surface Effect 
    • Lower the weight in the ship
    List

     A list is ca used by you moving anything on the vessel to one side,examble when the ship is inclined by shifting a weight transversely within the ship

    HEEL

     A ship is said to be heeled when she is inclined by an external force,eg when ship is inclined by the action of waves.

    STIFF AND TINDER SHIP

    STIFF  SHIP
    •      Time period of a ship is the time taken by the ship to roll from one side to the other and back again to the initial position.
    • When the ship have large GM, the righting moment s at a small angle of a heel, will also be large .It will thus require a large moment to incline the ship ,and when incline  she will tend to return more  quickly to the initial position . The result is that the ship will have a comparatively short time period ,and  will roll quickly to the initial position – and perhaps  violently-from side to side time , the ship in this condition is said to be  Stiff, and that condition is not desirable.
    TINDER SHIP
    • When the GM is small, the righting moments  at a small  of heel will be also  small. The ship will thus be much easily to incline and will not tend to return  so quickly to the initial position. The time period will be long and a ship in this condition is said to be “Tinder”
    • The officer responsible for loading a ship should aim at a happy and medium  between this two  condition  whereby  the ship is neither too stiff nor too tinder
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