L01 & LO3

Question 1

How does a top heavy gyro work?

Answer 1

-Top heavy gyro rotor turns anti-clockwise (viewed from the south end) to cancel out the North end drifting to the east and remain on the meridian.

Question 2

How does a bottom heavy gyro work?

Answer 2

-Bottom heavy gyro rotor turns clockwise (viewed from the south end) to cancel out the North end drifting to the east and remain on the meridian.

Question 3

What is damping in azimuth?

Answer 3

When the spin axis moves out of the meridian the damping precession opposes this movement, bringing the spin axis back to the meridian.

Question 4

What is damping in tilt?

Answer 4

When the spin axis moves out of the horizontal, the damping precession opposes this movement, bringing the spin axis back to the meridian.

Question 5

How long does a north settling gyro take to settle once turned on?

Answer 5

30mins

Question 6

What are 10 items equipment that require input from the master gyro?

Answer 6

-Steering console.
-ARPA
-Auto pilot.
-Repeaters
-Off course alarm.
-ECDIS
-Rate of turn indicator.
-DP system.
-VDR
-Digital displays
-AIS

Question 7

What are the advantages of a fibre-optic gyro?

Answer 7

-High accuracy.
-High precision.
-No settling error.
-Roll and rate sensor.
-Compact
-Reliable
-Low power consumption.
-No maintenance.

Question 8

What is the formula for Latitude, course and speed error?

Answer 8

Tan Error= speed x cosLat

Question 9

What is a raster nautical chart?

Answer 9

-A scanned copy of paper charts.
-They aren’t seamless.
-They can be used on electronic displays but do not meet the requirements for ENC’s.
-Known as RCDS or ECS

Question 10

What is an electronic navigational chart?

Answer 10

-Uses digitised data which can be displayed as a seamless chart.
-Information is layered so that certain information can be excluded from the display.
-Symbols can be interrogated for more details.
-Voyage plans can be drawn up.
-Is up to IMO standards.

Question 11

What is an electronic navigational chart?

Answer 11

-Uses digitised data which can be displayed as a seamless chart.
-Information is layered so that certain information can be excluded from the display.
-Symbols can be interrogated for more details.
-Voyage plans can be drawn up.
-Is up to IMO standards.

Question 12

When/how should terrestrial fixing be used?

Answer 12

-Primary method when possible.
-Gyro/Compass errors are fixed
-Sector lights
-Transits
-Minimum 3 position lines cutting at less than 30 degrees.

Question 13

What must be taken into account for when Radar fixing?

Answer 13

-Coastal/ restricted waters only.
-High accuracy for ranges.
-Low accuracy for bearings.
-Lower powered Radars don’t always trigger the racons.

Question 14

What must be taken into account for when using Parallel index fixing?

Answer 14

-Good accuracy.
-Requires appropriate range scale.
-Coastal/ restricted waters only.
-Is is only an aid to navigation and does not replace position fixing.
-Reflection plotters can only be set for one radar range.

Question 15

What are must be taken into account for when using visual celestial fixing?

Answer 15

-Single sight only gives one position line.
-Position obtained only 3 times a day.
-Should always be used on ocean passage.
-Unknown index errors.
-Cloud cover.
-Incorrect identification of stars.

Question 16

What are must be taken into account for when using GPS fixing?

Answer 16

-15/20 meters accuracy.
-Global coverage is weather dependent.
-Solar activity may effect transmissions.
-Can be interfered by other signals.
-Signal can be selectively jammed by stations.

Question 17

With reference to STCW, what are the three levels of management?

Answer 17

-Management (Master, C/O, C/E)
-Operational (OOW, ETO, DSO)
-Support (AB, Cadet)

Question 18

What are the general safe manning procedures?

Answer 18

-Assess all tasks, duties and responsibilities to be taken onboard.
-Submit proposal with justification for minimum safe manning level.
-Identify skills and experience required.
-Consider some tasks and duties may be done at the same time.
-Establish working arrangements to ensure Master and capable crew of undertaking tasks and duties at the appropriate level.

Question 19

State 15 topics that should be made reference to in the Masters standing orders.

Answer 19

-Handing over the watch.
-Min passing distance.
-Safety rounds.
-Log book entry requirements.
-Voyage planning.
-Mooring procedures.
-Watchkeeping in port.
-Engine room manning requirements.
-Training of ship personnel.
-OOW as sole lookout.
-Compliance with IRPCS and importance of keeping a good lookout.
-Use of the bridge.
-When to call the Master.
-Navigation in restricted vis.
-Fitness for duty.

Question 20

What is gravity control?

Answer 20

Gravity is used to apply a force to make the free gyroscope North seeking.

Question 21

What is precession?

Answer 21

The resultant motion which is produced by combining the movement of the rotor spin with that of the applied force.

Question 22

What is gyroscopic inertia?

Answer 22

-The gyro spin axis maintains its direction in space no matter how the support system may be moved. Hence the spin axis can be considered to be pointing at a fixed star in space and will experience an apparent motion due to the rotation of the earth

Question 23

What is gyroscopic inertia dependent on?

Answer 23

-Mass of the spinning rotor.
-Mass distribution (the further the mass is from the axis the greater the inertia)
-Rate of spin, the faster the spin the greater the inertia.