Figure 5-5.-Depth micrometer readings.
surface must be kept clean and free of nicks so
MAIN THRUST BEARING. The main thrust
correct depth readings can be taken.
bearing does not require any special cleaning. Its
cleaning is usually performed as part of the MRG
2. A depth constant (installation reading) is
cleaning. You should follow the cleaning tips we
inscribed on or near this flat surface. You
described earlier for the components of the MRG.
must use this reading every time you perform
Inspections and Tests
You must make sure you give the same care to
Most of the tests and inspections we will discuss
would give to the measuring flat surface.
are accomplished according to the PMS. Because of
casualties, however, you may be required to
BULKHEAD SEALS. You will usually inspect
participate in some unscheduled inspections. We will
the bulkhead seals at the same time you clean them.
now discuss some of the most common tests and
This inspection will require the complete disassembly
inspections performed on the components we just
discussed in the preceding paragraphs.
Once the seal cover is removed, pay particular
attention to the condition of the compression and
LINE SHAFT BEARINGS. The task you will
garter springs and the surfaces of the two
perform the most frequently on the line shaft bearing
(segmented) carbon sealing rings. These springs
(LSB) will be a visual inspection while the propulsion
should not be cracked or distorted. The sealing rings
shaft is in operation. You should perform this
must have an even wear pattern and should be free of
inspection once an hour to check for proper oil flow,
nicks and scratches. An uneven wear pattern on the
oil temperature, and leaking seals and covers.
face of the sealing rings is an indication of improper
garter or compression spring pressure or possibly the
The other inspection that you as a technician
binding of a ring segment. Remember, the condition
could be required to perform will be a bearing wear
of a sealing ring is only as good as the condition of the
measurement. This procedure is covered under the
journal surface on the propulsion shaft.
PMS, but here are some important tips you should
You should also inspect the surfaces of the two
sealing discs to make sure the discs have not slipped
1. All of the line shaft bearings installed on gas
from their correct position. (Remember, these discs
turbine ships have a machined flat surface and
are stationary.) Scoring on the sealing surface of
top of the upper bearing shell cap. This flat