SIGHT FLOW INDICATORS. As we mentioned
to follow the same safety and security guidelines used
earlier, you will use the sight flow indicators to monitor
during an MRG inspection.
the oil flow of the MRG bearings. If the oil flow is
Vent Fog Precipitator. While the MRG is in
reduced or if it disappears, this mayor may not indicate
operation, the vent fog precipitator should be inspected
a serious problem. In any event, you should investigate
hourly. Check the indicator light installed on a side panel
the condition immediately according to your ship's
of the power plant. This light serves two purposes: (1)
EOCC. In the following paragraphs, we will describe
to show that supply power is available, and (2) to
some of the problems that could cause these symptoms
indicate that the unit is operating. If the light is out, first
to appear and some methods that can help you to isolate
check the unit's circuit breaker to make sure the unit is
them.
on, then check the indicating light bulb to make sure it
Restricted or Reduced Oil Flow. This condition
is not loose or burned out. If the circuit breaker is on and
can be caused by a blockage (dirt) in the sight flow
the indicating light bulb is not loose or burned out, then
indicator itself, a partially unseated oil supply tube, a
have a GSE check the unit for proper operation.
small hole in the oil supply tube, or a blockage in the
Dehumidifier. The dehumidifier is used whenever
bearing oil passage. Of these conditions, blockage in the
the MRG is in an extended layup of 8 weeks or longer.
bearing oil passage is the only one that might indicate a
During this period the dehumidifier should be checked
serious problem.
daily for proper operation and to ensure the relative
A blockage in the bearing oil passage can result
humidity of the gear casing remains below 35 percent.
from the introduction of a foreign object, such as a rag,
Turning Gear. As far as inspections go, special
into the LO system. Dirt, or even the babbit of a
inspections of the turning gear will be limited to those
damaged bearing can also cause a blockage. Whichever
times when the equipment fails. Consistent performance
of these problems has occurred, the process of
of the PMS should allow you to keep this equipment in
identification is the same. To help identify the problem,
good working order and to limit any special inspections
you can use the following steps, keeping in mind that
resulting from equipment failures.
these steps are not meant to replace other already
approved troubleshooting procedures for your ship:
During any inspection, it is important for you to be
thorough, especially if you are performing an inspection
1. First, you must determine if the reduced oil flow
after a casualty. In the following section, we will tell you
remains unchanged at various speeds. For example, if
about some of the important steps you should take and
the oil flow increases at a slower speed, you can
the conditions you should check when you are
eliminate a blocked sight flow indicator, an unseated oil
troubleshooting the failure of an MRG component.
supply tube, or an oil tube with a hole in it as the probable
cause. With these conditions, the reduced oil flow would
Troubleshooting
remain unchanged. An increase in oil flow at slower
speeds could signify a bearing problem. A damaged
The MRG itself is not very complex. To identify a
bearing, for example, could possibly have moved
problem in the MRG, you can use the prescribed
because of the changing thrust requirements during
inspection procedures contained on the PMS
speed changes. A moved bearing could have, in turn,
maintenance requirement card and those for
covered or uncovered the bearing oil passage. If the
troubleshooting contained in NSTM, Chapter 9420,
bearing appears to be the problem, the engineer officer
must determine if he or she wants ship's force to
Associated Components," to help you pinpoint the
continue the investigation or call for outside assistance.
problem. The attached components, however, make the
2. Now, with the engineer officer present, you can
MRG more complex to deal with.
determine if the problem is associated with the sight
As we explained earlier, the attached MRG
flow indicator or its supply tube. You can do this by
carefully removing the sight flow indicator. First,
components include the sight flow indicators, shock
mounts and snubbers, pump angle drive assembly, and
inspect the sight flow indicator for a blockage. If you
detect no blockage, remove and inspect the oil supply
turning gear. In the following paragraphs, we will tell
you about some important troubleshooting lessons
tube for damage or shrinkage. If you detect no problems
learned by experienced technicians that you can use to
in these areas, then you must seriously consider a full
MRG inspection to determine if a foreign material has
deal with these attached components.
5-17
