ALIGN PROPELLER AND PROPELLER SHAFT.

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REPAIR-cont.

TM-55-1905-222-14 Landing Craft Mechanized (LCM-8) (ROHR and Gunderson Models) (1905-01-284-2647 AND 1905-01-284-2648) Manual

ALIGNMENT

TM 55-1905-222-14

6-24

ALIGN PROPELLER AND PROPELLER SHAFT.

INITIAL SETUP

Tools:

Equipment Conditions:

Tool Kit, Mechanics Rail

LCM-8 out of water.

and Marine

LCM-8 water-borne.

Dial Indicator

Materials/Parts:

Piano Wire

ALIGNMENT

ALIGN PROPELLER SHAFT.

a. Alignment of shaft and bearings is not

permanently fixed. The alignment changes

with every docking due to changes in the

keel blocking, temperature variations, and

the direction of the sun's rays relative to the

fore and aft line of the vessel. The

alignment of shafting and bearings is

affected by the temporary removal of

machinery attached to the shafting or in the

vicinity of the shafting because of the

redistribution of weights and stresses. The

alignment is not the same when the vessel

is waterborne as when it is in drydock. The

final alignment and bolting of the main

propulsion shafting should always be done

when the vessel is waterborne.

b. The primary purpose for providing correct

alignment is to eliminate shaft excited

vibrations and to prevent an excessive

pressure upon any localized portion of the

shafting bearing surfaces (journal bearing

areas). The longitudinal line connecting

the lowest extremities of all shafting

journals having the same diameter should

form a continuous-faired line when the

machinery is at

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