PASGT FINALS REVIEWER

1. The stern shaft is a hollow tube which accommodates the bearings, the seal boxes, and the propeller shaft. TRUE OR FALSE?

2. A rotating fan-like structure that is used to propel the ship by using the power generated and transmitted by the main engine of the ship.

3. Construction Materials for Ship Propeller (2 answers)

4. A thrust block, also known as a thrust box, is a specialized form of thrust bearing used in ships, to resist the thrust of the propeller shaft and transmit it to the hull. TRUE OR FALSE?

5. Galvanic Corrosion is an electrochemical process in which one metal corrodes preferentially when it is in electrical contact with another, in the presence of an electrolyte. TRUE OR FALSE?

6. The stern glands thus seal the area between the stern tube and the propeller shaft. TRUE OR FALSE?

7. Using a compressed air chamber, the lube oil in the stern tube is completely separated from seawater by providing a controlled “buffer zone” between lip type sealing rings. TRUE OR FALSE?

8. Electrolytic Corrosion occurs when dissimilar metals are in contact in the presence of. An electrolyte, such as water (moisture) containing very small amounts of acid. TRUE OR FALSE?

9. The purpose of the Earth shaft Grounding is to protect the shaft and propeller. TRUE OR FALSE?

10. A device that prevents damage to bearings by protecting them from circulating current generated by the shaft and redirecting it into the ground

11. The purpose of air control unit in stern tube is?

12. Type of cavity that forms a thin stationary sheet at leading edge of the blades

13. When a sheet cavitation breaks down behind the blade it forms the

14. It seals the area between stern tube & propeller shaft

15. It occurs when dissimilar metals are in contact in the presence of electrolyte such as water

16. Controllable pitch propeller advantages except for?

17. In case of fire in scavenge space

It is a practice to check all parameters before starting the gas turbine to prevent

19. It is a hollow tube-like structure at the stern or rear part of the ship.

20. It prevents the leakage of oil into the sea or water into the stern tube.

21. A type of stern tube seal that uses a gland packing similar to a valve.

22. A type of stern tube seal that presses against a liner which is in contact with the shaft. It is supported by a garter spring

23. A type of stern tube seal that have a flat surface in contact with the shaft to provide sealing against the shaft through special springs.

24. These are placed between the propeller shaft and the stern tube to transfer the load of the shaft and the propeller to the stern tube.

25. A pedestal provided to support for rotating shaft with help of bearings

26. These are used primarily to dampen and absorb forces from the rotating propeller shafts.

These are attached to the blocks used to absorb the vibrations and shocks -

28. It is used to absorb thrust from the propeller shaft -

29. Its purpose is to transmit the torque produced by the rotating propeller through the housing hold-down bolts into the ship’s structure.

30. Purpose of alarm system onboard ship

31. Crankcase door relief valve is consist of?

32. Most common type of propeller

33. Formulation of distinctive bubble cavities

34. A cavitation that has the appearance of a stranded twisted rope and can be present at either the blade tips or the boss.

35. A propeller is said to be fully cavitating when the whole of the back is covered in sheet cavitation. This phenomenon is also called

36. A device that consists of a central hub with radiating blades placed and twisted

37. This propeller is often used in war ships where the cruising speed is half the full speed.

38. These types of propellers are generally used for low power vessels.

39. It indicates the distance the propeller would “drive forward” for each full rotation. –

40. The edge of the propeller blade adjacent to the forward end of the hub

41. The edge of the propeller adjacent to the aft end of the hub.

42. It is the degree that the blades slant forward or backwards in relation to the hub.

43. The transverse sweeping of a blade such that when viewing the blades from fore or aft shows an asymmetrical shape

44. Positive skew. Blade sweep in the direction opposite of rotation.

45. Negative skew. Blade sweep in the same direction as rotation.

46. It contributes negligibly to increase the efficiency of the propeller but plays an important role in reducing the propeller forces on the hull.

47. It is an arrangement by which an input speed can be lowered for a requirement of slower output -

48. It is used to transmit torque between two shafts that either tend to lie in the same line or slightly misaligned

49. These are equipment drive assemblies that contain hydraulically or pneumatically actuated components for connecting two shafts

50. These are a protection barrier for propeller shafts shielding them against line entanglement around main shafts.

51. This method uses a micro alignment telescope which generates a sight line between an illuminated reflective target at one end of the shafting and the telescope mounted at the other end.

52. These ensure safe and reliable operation of the engine and are designed to detect and alert Marine engineers to potential issues before they can cause serious damage

53. It protects large diesel, gas, and dual-fuel engines of all applications

54. It is a safety valve used to prevent excessive pressure buildup in the scavenge air system

55. It is a safety valve used to prevent excessive pressure buildup in the starting air system.

56. It is a phenomenon in ship’s propeller that can greatly reduce a ship propelling efficiency whilst at the same time lead to rapid degradation of the propellor.

57. It is a safety device used to prevent excessive pressure buildup in the engine’s combustion chambers or cylinders.

58. It is a safety device used to prevent the propagation of fire or explosion starting air system to the surrounding environment.

59. It consists of a fine mesh screen that is designed to absorb any flames or sparks generated within starting air system.

60. These are connected to display devices which may have minimum and maximum values marked on them

61. It is designed to relieve pressures in excess of 10% to 20% above normal. -

62. It activates one or more switches or valves, causing the machine to come to an unscheduled halt in a controlled manner.

63. It will cut off the fuel supply in the speeding Engine event more than the predetermined value

64. It removes the waste heat in the engine.

65. It will not allow the Engine to start if the Engine’s system hasn’t been operated.