NSTM Chapter 243, Propulsion Shafting Flashcards Preview

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Flashcards in NSTM Chapter 243, Propulsion Shafting Deck (25):
1

The primary purpose of propulsion shafting

Transfer torque generated by the main engine to the propeller and to transmit thrust developed by the propeller to the thrust bearings in the ship

2

Sections of shafting outside the skin of the ship are usually supported by bearings located in ___

Struts, skegs, and stern tubes

3

Sections of shafting inside the skin of the ship are usually supported on ___

Line shaft spring bearings

4

Shafting seal is usually a ___

Split inflatable seal installed aft of a stuffing box and gland

5

When propellers are unshipped due to a possible propulsion shafting or propeller related vibration problem, measure ___ for a fixed pitch propeller or the ___ for a controlled pitch propeller

Shaft taper runout
Aft facial runout of the after-most shaft flange

6

Whenever a magnetic particle inspection is accomplished, the shaft shall be demagnetized to ___

7.0 gauss maximum

7

Minor pitting can be removed up to ___ in depth

1/16"

8

The shaft outside diameter shall not be reduced more than ___ below the minimum design diameter

1/8"

9

Cracks associated with pitting shall be ___

Completely removed and repaired by welding

10

Cracks or pits detected in keyways that will result in less than ___ contact between the key and keyway throughout the entire keyway length shall be removed by machining not to exceed ___ on the width and depth

90%
1/8"

11

For ships possessing rotating coupling covers, prior to filling with corrosion preventive compound, verify the watertight integrity by ___

Pressurizing with air at 10 +/- 1 psi for a minimum of 10 minutes

12

Type of coupling used to connect nontapered ends of shafts without keyways, flanges, or bolts

Oil-pressure-fitted shaft couplings (SKF or OK couplings)

13

Consist of a thin inner sleeve, tapered on its outside diameter, and a thicker outer sleeve tapered on its inside diameter to match. The sleeves are positioned over the ends of the two shafts to be coupled, and oil is injected under pressure between the two sleeves to facilitate alignment and compressive friction fit over the shaft ends

Oil-pressure-fitted shaft couplings (SKF or OK couplings)

14

Sleeves which have pitting and/or cracking exceeding ___ in way of the shaft sleeve should be replaced

5/32" depth

15

Prior to machining the sleeve diameter, the refurbishing activity shall measure the current diameter of the sleeve in ___ radial increments and ___ locations

45 degree
3 axial

16

If the anticipated sleeve diameter at the end of the next ten year cycle winds up being less than ___ below the nominal design diameter, the sleeve shall be replaced

0.310"

17

If waterborne bearing sleeves are worn, pitted, otherwise damaged and rough to a depth less than or equal to ___ from the original design size, the roughness may be hand smoothed

0.030"

18

Heating sleeves to fit to shaft, should not exceed ___ and the heating rate shall not exceed ___

900 degrees F
200 degrees F per hour

19

When shrink fitting a sleeve, no ___ is allowed for installing the sleeve onto the shaft

Lubricant

20

The tolerance for the axial positioning of each end of a sleeve is ___ from its design location

+/- 1/2"

21

When installing sleeves on a shaft, they should be maintained at ___ for at least 24 hours

60 to 80 degrees F

22

The strain in the sleeve shall not exceed ___

16000 psi

23

Propeller shaft keyways are designed to have one be ___ bigger than the other to ensure correct orientation

1/16"

24

When in the drydock position, the ___ propeller key is at the top

Smaller

25

The final alignment of the main propulsion shafting should always be accomplished when the vessel is ___

Waterborne