to check is the electrical control. Did the brake actually
action plan periodically requires that an inspection of
engage? If the brake engages, but you do not receive a
the disc assembly be made and the clearances between
brake engaged indication, just look at the PT speed to
the discs measured.
verify if it is slowing down or has already stopped. If the
Additionally, the externally mounted PT and shaft
FT has stopped, then your indicator light maybe out or
brake assemblies must be checked on a regular basis
the indicator switch may be bad. If the PT does not stop,
according to the PMS. These inspections will normally
then you probably need to contact a GSE to help locate
i n c l u d e checking the brake pad thickness
where the command signal is lost.
measurements, rotor condition, proper operation of air
or hydraulic actuators, and proper lubrication of vital
Failure to Release
When a brake fails to release, the most common
causes are a command problem, a bad position indicator
switch, or a bad indicator light, If these conditions are
Because the SSS clutches are reliable, problems that
not the cause, then you should check for a binding
require troubleshooting should be minimal. Like all
caliper and weak or damaged return springs.
other gear-driven assemblies, the SSS clutches have a
tendency to wear and produce noise with age. Normal
Failure to Stop Rotation
failures, however, are usually limited to faulty position
indicator switches and failures related to the PT brake
When the brake applies but does not stop rotation,
assemblies. For these reasons, we will not dwell on the
the most common causes are insufficient actuating
clutch assemblies. Let's move on and discuss some of
pressure, contaminated brake pads, a damaged rotor
the problems related to the installed brake assemblies
(disc), or a binding caliper piston.
and look at the ways in which you, the GSM, can better
ALIGNMENTS AND ADJUSTMENTS
The basic operation of both the PT and shaft brakes
are the same as the disc brake system installed in most
Basically, the only components that have any type
automobiles. They all require some type of medium (air,
of an adjustment or alignment check are the PT and shaft
oil, or air and oil) to force the caliper piston against the
brake systems. Normally, all of these adjustments or
brake pad which, in turn, is pushed against the disc. This
alignments are performed as requirements resulting
action slows the rotation of the disk until the disk stops.
from a PMS inspection.
Let's talk about some common malfunctions that may
occur in this system and the ways you can isolate the
REMOVAL AND REPLACEMENT OF
Failure to Engage
The removal and replacement of a clutch may be
performed by your ship's personnel if there is sufficient
There are several problems that can cause a brake
time or if a casualty occurs. Most of the time, however,
to fail to engage, Let's go back to the operating
the engineer officer will opt to have an outside activity
principles associated with this system. First, check to see
perform the work.
if there is sufficient air or oil pressure for operation. Its
On the other hand, the brakes and their subsystems
pretty obvious that if the activating medium (air or oil)
is missing, this condition should produce an alarm at the
can be easily maintained by your ship's maintenance
technicians and personnel.
Once you determine that the activating medium is
available, then you should try the manual control. If the
PROPULSION SHAFTING AND
manual control works, then you should consider an
electrical fault as the source of this problem. If the
Now that wc have discussed the MRG and propeller
manual control does not work, then you should continue
assemblies, we need to tie the MRG assemblies together
troubleshooting. If the pressure regulator is not working,
with a discussion of the shafting.
then the supply cutout valve (if installed) may be closed,
The size and class of a ship will dictate the number
or there may be a blockage or leak in the supply line.
of required propulsion shafts, bulkhead seals, and
These are all possible causes for the failure. The last part