Magnetic compass parts and correctors
Fitted on monkey island above the bridge.
Telescopic viewing arrangement is made for helmsman.
Magnetic compass parts:
Compass bowl
Compass card
Gimbal arrangement
Gimbal ring
Binnacle
Compass correctors:
Flinder bars
Quadrantal Spheres
Heeling magnets
Fwd and aft magnets
Athwartship magnets
Compass bowl
Fitted on the gimbal arrangement.
Inside compass bowl, compass card is fitted.
Inside compass bowl, liquid is filled. (wet compass card)
Liquid reduces friction effects.
Liquid helps to keep the compass card horizontal.
Compass card
Marked from zero(0) to 360 degrees.
Rides on a sharp pivot point.
Gimbal arrangement
Fitted on the binnacle.
Fitted at the same level as the compass card.
Provides the strength and stability to the compass bowl.
Gimbal ring
Ring around the compass bowl.
Gimbal ring is pivoted at forward and aft axis.
Binnacle
Cylinder like arrangement.
Made of non magnetic material.
Non Magnetic material – aluminium, brass, wood.
Upper part of binnacle – compass bowl, gimbal arrangement.
Lower part of binnacle – few holes in fwd and aft, athwartship direction.
Compass corrector:
Flinder bars
Cylinder like arrangement on fwd or aft side of the binnacle.
Contain soft iron.
Quadrantal spheres
Spheres like arrangement on port and stbd side of binnacle.
Made of soft iron.
Distance can be adjusted.
Heeling error magnets
Heeling magnets – inside a bucket or tube.
To correct the heeling error deviation.
F & A and Athwartship magnets
Parmanent magnet of 8” in length and diameter of 3/8” and 3/16”.
To correct “Permanent B” and “permanent C” coefficients.
For Permanent B, placed in F&A direction.
For Permanent C, placed in Athwartship direction.
