Environmental pollution is the condition that results when chemical, physical, or biological agents in the air, water, or soil alter the natural environment in a way that an adverse effect is created on human health or comfort, fish and wildlife, other aquatic resources and plant life, or structures and equipment. The adverse effects of environmental pollution are economic loss, impaired recreational opportunity, and marred natural beauty.

Because oil pollution has a serious effect on our environment, there are strict regulations and water quality standards that apply to the navigable waters. Oil spill cleanup operations are both difficult and costly. Each year thousands of dollars are spent because of oil spills. The costs of oil spillage are not only in money. Each year, oil spillage affects our natural environment, damages the hulls of yachts or boats, pollutes our beaches, and destroys fish and wildlife. Much of this destruction can be avoided and many organizations, including the United States Navy, are doing as much as possible to prevent such pollution. Current oil and water pollution control regulations are defined in the Environmental and Natural Resources Protection Manual, OPNAVINST 5090.1 (latest edition).

Navy ships must operate according to existing federal, state, and local regulations governing the oil content of shipboard water discharge over-board (effluent). Specific regulations applicable to Navy ships are as follows:

1. When the ship is operating within waters 50 nautical miles from the U.S. coast line, the discharge of oil is prohibited in such quantities as to cause a film or sheen upon or discoloration of the surface of the water of adjoining shorelines (discharges greater than 15 to 20 parts per million of effluent may create a sheen), or to cause a sludge or emulsion to be deposited beneath the surface of the water or upon the adjoining shorelines.

2. Navy vessels operating in internal waters and territorial seas (up to 12 nautical miles) of foreign countries must abide by oily waste discharge regulations that are specified in the applicable Status of Forces Agreement (SOFA).

If no SOFA exists, vessels must operate consistent with the substantive oil waste discharge standards observed by the military forces of the host country. When the discharge standards for a foreign county are undefined, no oily waste shall be discharged within 50 nautical miles from land unless it is processed through an oil-water separator (OWS). Ships not equipped with an OWS shall retain all oily waste for proper disposal to a shore facility.

The discharge of oil or any oil mixture is not deemed unlawful when such action is required for the safety of the ship or its cargo and for the saving of lives at sea. In addition, the escape of oil or any oily mixture is not considered to be unlawful if it results from damage to the ship or from avoidable leakage. All reasonable precautions must be taken, after occurrence of the damage or discovery of the leakage, to keep the oil leakage to a minimum.

While in port, a U.S. Navy ship may dispose of oily bilge water by using one or more of the following methods:

1. Oil-water separator (OWS) system-Ships equipped with bilge OWS systems should use the OWS unless prohibited by state standards or local port authorities.

2. Oil disposal rafts (donuts) and oil ship waste offload barges (O-SWOBS)-Ships not equipped with bilge OWS systems should use this method to transfer contaminated oils and oily waste.

3. Permanent shore receiving facilities- Where adequate oil waste collection lines are provided, contaminated oil and oily waste can be pumped directly ashore.

In the event of an oil spill, the Naval Sea Systems Command has developed a shipboard oil spill containment and cleanup kit for quick response first aid capability. Quick reaction by a trained crew (oil spill party) can result in containment, and often, collection of the entire spill. Additional information can be obtained in the Environmental and Natural Resources Protection Manual, OPNAVINST 5090.1, and the Naval Ships Technical Manual, chapter 593.

SUMMARY

Lubricating systems of the pressure type are found in marine diesel engines. Pressure lubricating systems generally include pumps, strainers, pressure-regulating valves, filters, bypass valves, and coolers, in addition to the necessary piping and passages.

Even though the lubricating systems of various engines differ in some aspects of design, all the systems are quite similar with respect to oil flow. In general, the pump draws oil from the source of supply (oil pan, sump, or separate tank) and forces the oil through a strainer, a filter, and a cooler before the oil enters the engine. Upon entering the engine, the oil generally flows into a main oil header, which may be either a passage in the block or a separate line suspended in the block. The main oil gallery supplies oil to the various parts of the engine that require lubrication.

Ventilation of the engine crankcase is essential for efficient and safe engine operation. Unless the crankcase of an engine is properly ventilated, harmful vapors will accumulate in the crankcase. These vapors come primarily from two sources. Some of the vapors are formed when the lubricating oil comes in contact with the hot internal surfaces of the engine. Vapors so formed are explosive. These vapors must be removed from the crankcase; otherwise, a local hot spot within the engine might ignite the charge. Vapors may also accumulate in the crankcase because of the blow-by between the pistons and the cylinder liners. Blow-by occurs when the piston is compressing the air or the fuel-air charge during the power event. In all engines, products of combustion escape past the piston rings and into the crankcase during the power event. Products of combustion contain water vapor which condenses when it comes in contact with a cool surface. Such condensation causes corrosion and contaminates the lubricating oil.

Because of the importance of lubricating oil, the Lube Oil Quality Management Program was established. By following this program, you should be able to identify problems before they create a breakdown. Remember, planned maintenance of your ships diesel engine is always preferred over breakdown maintenance. If you are uncertain concerning any of the information in this chapter on engine lubricating systems, we recommend that you reread the sections in which you are having problems before you proceed to the next chapter.