(MLSG). This concept also highlights the role of
SEAWATER SYSTEM
standard depot level maintenance.
The seawater system has two modes of operation:
(1) foilborne and (2) hullborne. The PHM seawater
MAINTENANCE REPAIR LEVELS
system serves the following three primary purposes:
1. Cooling machinery
The maintenance repair levels for the PHM are
organized into three groups. These three groups,
2. Lubricating propulsor bearings
arranged in increasing order of complexity are
3. Combating fires and other conditions involving
organizational level maintenance,
overheating
intermediate level maintenance, and
The seawater system consists of four pumps. These
pumps provide cooling seawater to the diesel engines,
depot level maintenance.
the SSPU heat exchangers, the SSPU bleed air coolers
In the following paragraphs, we will briefly describe the
of the compressed air system, the heat exchangers of the
maintenance levels used on the PHM.
hydraulic power system, the heat transfer chiller of the
environmental control system condenser, and the gun
assemblies. As indicated earlier, seawater is also
Organizational Level Maintenance
supplied to the hullborne diesel engine propulsory for
bearing lubrication and to the fire-extinguishing
Organizational level maintenance is the routine
systems for fire-fighting purposes.
maintenance that is performed by the MLSG with the
help of the PHM ship crew. Certain organizational level
BILGE DRAINAGE SYSTEM
tasks, such as daily preventive maintenance that cannot
be scheduled for in-port periods and limited corrective
maintenance, are performed at sea. Normally, the PHM
The bilge drainage system provides the PHM with
crew will perform underway maintenance by using only
a means for dumping fluids from the bilges and voids.
the standard test equipment and tools that are carried
This system also provides a method for storing these
aboard the PHM and the significant BITE. The onboard
fluids until they can be off-loaded to a receiving facility.
repair parts of the PHM are very limited in number and
The bilge drainage system consists of electrically
variety. Usually, they consist of fuses, bulbs, and critical
driven fixed bilge pumps, a portable bilge pump, fluid
modules and parts.
storage tanks, a transfer pump for off-loading, and fluid
Most routine organizational level maintenance
level switches in the bilges, voids, and storage tanks.
actions are accomplished in port during 2-day weekly
upkeep periods that follow each PHM mission. During
these upkeep periods, the PHM crew, with the MLSG,
PHM SYSTEMS MAINTENANCE
performs preventive maintenance scheduled for
The PHM is supported by a progressive ship
completion weekly. They also perform corrective
maintenance concept. This means that the individual
maintenance required to restore systems and
PHM is designed so it will acquire significant
equipments to operational standards.
maintenance support from external sources. This
concept clearly conforms with the PHM's mission,
Intermediate Level Maintenance
physical characteristics, and specified manning levels
that demand that onboard maintenance be kept to a
Intermediate level maintenance is conducted in port
minimum. As a result, the overall maintenance concept
by MLSG personnel. The MLSG facility consists of a
for the PHM gives primary consideration to the
complex of containerized mobile facilities. These
accomplishment of maintenance tasks while the ship is
facilities provide diagnostic skills, special tools, test
in port.
equipment, technical manuals, and other maintenance
In other words, the basic concept of progressive ship
resources not available aboard the PHM. The PHM is
maintenance for the PHM de-emphasizes corrective
scheduled for a 7-day technical availability period each
maintenance at the shipboard level and emphasizes the
month to allow the completion of more extensive
role of both the organizational and intermediate
maintenance tasks. The ship is also scheduled for a
maintenance levels of the mobile logistic support group
15-day restricted availability period each quarter to
