Propulsion Shaft Alignment

Question 1

The primary purpose of ______ is to transfer the torque generated by the main engine to the propellar and to transmit the thrust developed by the propeller to the thrust bearing in the ship.

Answer 1

Propulsion Shafting

Question 2

What is shafting supported by inside the skin of the ship?

Answer 2

Line Shaft Bearings

Question 3

A split inflatable seal installed aft of a stuffing box and gland which is designed for the alternate use of the split face type seals or conventional packing

Answer 3

What is the most common seal found for surface ships?

Question 4

The term “shaft alignment” when used in the marine field generally involves two of the following functions:

Answer 4

• The first is the aligning of the bearings that support the shaft.
• The second alignment function is the alignment of the shaft flange to the output flange of the reduction gear, main motor or directly to the slow speed diesel

Question 5

The major factor influencing shaft and bearing alignment is:

Answer 5

• Hull deflection
• Various loads and ballast conditions
• Hull speeds
• Heavy seas

Question 6

What is Hull Deflection caused by?

Answer 6

Daily and seasoal temperature variations

Question 7

• Vessel is in the water
• All permanent ballast are in place
• Fuel, water and temporary ballast tanks are filled to normal average operating levels, 1/2 to 3/4 filled
• All major machinery weighing over 1000lbs is either installed or simulated
• Make final alignment immediately prior to sea trials.

Answer 7

DO NOT ATTEMPT final alignment of propulsion engines/shafting unless the following conditions are met:

Question 8

Refers to the distance the face of the hub is out of perpendicular to the shaft centerline.

Answer 8

Face runout

Question 9

Refers to the distance the driving bore of the hub is out of parallel with the shaft centerline.

Answer 9

Bore runout

Question 10

Any eccentricity or perpendicularity errors must be accounted for in the _____ process.

Answer 10

Alignment

Question 11

The bore to pilot diameter eccentricity error should be no more than ____ inches or as specified by the manufacturer.

Answer 11

0.002 inches (0.05mm)

Question 12

The flange face run should be no more then ____ inches or as specified by the manufacturer.

Answer 12

0.002 inches (0.05mm)

Question 13

Move the engine and marine transmission to their approximatefinal position within ____ of the companion flange without engaging the flange pilot.

Answer 13

0.3 inch (8mm)

Question 14

How do you check bore alignment?

Answer 14

Take measruements of the diameter gap at four equally spaced points on the flanges diameters, A, B, C & D

Question 15

What is shafting supported by outside the skin of the ship?

Answer 15

Bearing located in struts, skegs and stern tubes

Question 16

This procedure is concerned with eliminating shaft vibration and noise, ensuring that no bearing is overloaded and that there is no excessive stress on the shaft.

Answer 16

Aligning of the bearing that support the shaft

Question 17

In this phase of alignment, reduction of loading on reduction gear and engine bearings is of importance.

Answer 17

Alignment of the shaft flange to the output flange of the reduction gear, main motor or directly to a slow-speed diesel.

Question 18

An appropriate method to account for shaft droop utilizes a _______.

Answer 18

load ring, turnbuckle and sling

Question 19

The alignment of the line shafting to the marine transmission output flange must be within specified tolerance for_______.

Answer 19

satisfactory transmission service life

Question 20

What is the first step if a bearing alignment check and realignment procedure is needed?

Answer 20

Ensure that the ship is docked in as close as possible to the configuration of the hull when floating

Question 21

What are two methods used to establish a new bearing line?

Answer 21

• Sag and gap method
• Bearing reaction readings

Question 22

This method of establishing a new bearing line requires the aft coupling bolts and the shaft-to-reduction gear coupling bolts to be removed.

Answer 22

Sag and Gap Method

Question 23

This method for establishing a new bearing line involves lifting the shaft with a hydraulic jack.

Answer 23

The Bearing Reaction Readings Method

Question 24

What is the preferred method for establishing a shaft line?

Answer 24

Laser/Optical

Question 25

The ___ is the part of the alignment process that aligns the shafts centerlines from side to side.

Answer 25

Horizontal move

Question 26

The _____ is the part of the alignment process that aligns the two shafts centerlines into their proper up and down positions.

Answer 26

Vertical Move

Question 27

For safety purposes, what should be covered prior to removing to prevent spraying or splashing or pressurized fluids?

Answer 27

• lubrication fittings
• plugs

Question 28

Where are the bearing used to support sections of the shafting outside of the ships skin?

Answer 28

• Struts
• Skegs
• Stern Tube

Question 29

What supports shafting on the inside of the ships skin?

Answer 29

Line shaft bearings

Question 30

What is the purpose of the first function involved in a shaft alignment?

Answer 30

Align bearings and support the shaft

Question 31

What can the shaft flange be aligned to during an alignment?

Answer 31

• output flange of reduction gear
• main motor
• slow-speed diesel

Question 32

When should you NOT ATTEMPT to make final alignment of propulsion engine shafting?

Answer 32

When fuel, water and temporary ballast tanks are empty