ENGINEMAN 1 & C
and dirt when new gears or bearings are wearing
in or after they have been opened for inspection.
Lint or dirt, if left in the system, may clog the
oil spray nozzles. The spray nozzle passages must
be open at all times. Spray nozzles should not be
altered without proper authorization.
Although the lubricating oil strainers perform
satisfactorily under normal operating conditions,
they cannot trap particles of metal and dirt which
are fine enough to pass through the mesh. These
fine particles can become embedded in the bear-
ing metal and cause wear on the bearings and
journals. These fine abrasive particles passing
through the gear teeth act like a lapping com-
pound and remove metal from the teeth.
EFFECTS OF WATER AND ACID IN
OIL.Water in the oil is extremely harmful. Even
small amounts soon cause pitting and corrosion
of the teeth. Acid can cause even more serious
problems. The oil must be tested frequently for
water, and periodic tests should be made for acid
content. Immediate corrective measures must be
taken when saltwater is found in the reduction
gear lubricating oil system.
Occasionally gross contamination of the oil
by saltwater occurs when a cooler leaks or when
leaks develop in a sump. The immediate location
and sealing of the leak is not enough. Additional
steps must be taken to remove the contaminated
oil from all steel parts. Several instances are
known when, because such treatment was
postponedsometimes for a week or lessgears,
journals, and couplings became so badly corroded
and pitted that it was necessary to remove the
gears and recondition the teeth and journals.
Saltwater contamination of the lubricating oil may
also cause bearing burnout.
Water, in small amounts, is always present
within the lubrication system as a result of con-
densation. Air which enters the units contains
moisture. This moisture condenses into water
when it strikes a cooler surface and subsequently
mixes with the oil. The water displaces the oil
from the metal surfaces and causes rusting. Water
mixed with oil also reduces the lubricating value
of the oil itself.
When the main engines are secured, the oil
should be circulated until the temperature of the
oil and that of the reduction gear casing approxi-
mate the engineroom temperature. While the oil
is being circulated, the cooler should be operated
and the gear should be jacked continuously. The
purifier should also be operated to renovate the
oil while the oil is being circulated and after the
oil circulation is stopped until water is no longer
discharged from the purifier. This procedure
eliminates condensation from the interior of the
main reduction gear casing and reduces rusting
in the upper gear case and gears.
Generally, lubricating oil will be maintained
in good condition if proper use is made of the
purifier and settling tanks. However, if the
purifier does not operate satisfactorily and does
not have the correct water seal, it will not separate
the water from the oil. You can check for the
presence of water by taking small samples of oil
in bottles, and allowing the samples to settle.
These samples should be taken from a low point
in the lube oil system.
Samples of lubricating oil should be tested at
every opportunity for acid, water, and sediment
content at a naval shipyard (or other similar
activity). With continuous use, lube oil increases
in acidity, and free fatty acids form a mineral soap
which reacts with the oil to form an emulsion. As
the oil emulsifies, it loses its lubricating quality.
Once the oil has emulsified, the removal of water
and other impurities becomes increasingly dif-
ficult. When the formation of a proper oil film
is rendered impossible, the oil must be renovated.
Sometimes, when a ship from the reserve fleet
is placed back in commission, the rust preventive
compound is not removed completely. The residue
of this compound may cause serious emulsifica-
tion of the lubricating oil. Operating with
emulsified oil may result in damage to the bear-
ings or the reduction gears. Since it is extremely
difficult aboard ship to destroy emulsions by
heating, settling, and centrifuging, you must make
sure that emulsions do not occur. At the first
indication of an emulsion, the plant should be
stopped and the oil renovated.
MAINTAINING FOR PROPER OIL
LEVEL.It is of extreme importance that the
quantity of oil in the sump be maintained within
the prescribed maximum and minimum levels.
Too much oil as well as too little oil in the sump
can lead to trouble. If the oil level is above the