Practical

Question 1

What are used to correct soft iron errors?

Answer 1

• Flinders bar.
• Kelvin balls.

Question 2

What are used to correct hard iron errors?

Answer 2

• Heeling error magnets.
• Horizontal fore & Aft or Athwartship magnets.

Question 3

Why do we need hard iron correctors?

Answer 3

To correct the permanent hard iron errors throughout the vessel’s hull.

Question 4

Why do we need soft correctors?

Answer 4

To correct for the soft iron induced magnetism generated throughout the ships hull.

Question 4

What must be checked when looking at the appearance of the magnetic compass?

Answer 4

• Leakage
• Damage
• Lights
• Mirrors

Question 5

What must be looked at when maintaining the magnetic compass?

Answer 5

• Appearance
• Liquid
• Correctors
• Compass bowl & compass card
• Gimbal system
• Lens & associated mirrors
• Checking of lamps
• Position of corrector magnets

Question 6

What must be checked when looking at the liquid of the magnetic compass?

Answer 6

• Bubble
• Colour

Question 7

What must be checked when looking at the compass bowl & compass card of the magnetic compass?

Answer 7

• Liquid colour
• Bubbles
• Leakage
• Mechanical damage
• Condition card
• Freedom of card to rotate and move evenly

Question 8

What must be checked when looking at the Gimbal system of the magnetic compass?

Answer 8

• Freedom and ease to tilt fore & aft.
• Freedom and ease to tilt athwart ships.
• Securing’s are in good order and free of any corrosion.
• Lubricate as necessary.

Question 9

What must be checked when looking at the lens & associated mirrors of the magnetic compass?

Answer 9

• Lenses are clean and clear.
• Mirror is clean and clear, no degradation of silvering.
• The mirror is free to adjust (angle of tilt).
• There is an unobstructed view of the compass card and that it is clear to read.

Question 10

What must be checked when looking at the lamps of the magnetic compass?

Answer 10

• The power supply is working and in good order, no corrosion in the bulb holders.
• The lamps are in good working order and that at night the compass card is clearly visible.
• The dimmer control functions or that the sliding light gate is operating smoothly.

Question 11

What must be checked when looking at the position of corrector magnets of the magnetic compass?

Answer 11

• All weather seals on the corrector magnets are in place and in good condition.
• Corrector magnets are in place according to the deviation card entry at last compass swing by compass adjuster.
• Heeling error corrector bucket is free and in place with the chain adjustment secured as per the last correction entry in compass book.
• Flinders bar container is weather tight and in good order.
• Spheres are secure and tight.

Question 12

Why does the latitude need to be inputted into the gyro?

Answer 12

So that the correct damping error adjustment will be correctly computed by the gyro.

Question 13

Why does the speed need to be inputted into the gyro?

Answer 13

So that the vessels speed and the earths rotation are not accounted for as one to maintain that the gyro keeps aligned, perpendicular to the earths rotation.

Question 15

How do you carry out performance monitoring

Answer 15

• Select it on the radar display.
• A code will be transmitted then the scanner will receive this which will display a circle on the radar.
• Obtain the distance of the circle and compared to the manufactures standards.