- Engine:
- All Marine Propulsion, Marine Auxiliary, and Marine Generator Sets
The proper engine operation and maintenance outlined in the Operation and Maintenance Manual are key factors in obtaining the maximum life and economy from your Caterpillar marine engine. If the guidelines in the Operation and Maintenance Manual are followed, operating costs can be minimized and engine service life can be maximized.
Caterpillar has a recommended RPM range during "Cruising Speed". The "Cruising Speed" or RPM of the engine is 300 RPM to 400 RPM below the rated speed of Caterpillar marine engine. It is important to note that each vessel varies as to where the "Sweet Spot" occurs. The "Sweet Spot" refers to where the fuel consumption and vessel speed are optimized. Operating within the recommended "Cruising Speed" will help to provide the maximum engine service life and the most economical operation.
Trolling, operating with "Low Load" factor, or operating for extended periods with "Low Load" factor and minimum engine speed may cause excessive oil consumption, carbon buildup, unburned fuel buildup, cylinder glazing, and turbo slobber saturating the combustion chamber, intake, and exhaust systems. This buildup results in poor engine performance, power loss and will reduce the useful life of the engine over time.
To counter act these conditions, run the engine at full load and full RPM for 2 to 3 minutes in order to heat soak and burn off the unburned fuel and carbon buildup from the combustion chamber and exhaust system. Reduce the engine speed to the recommended "Cruising Speed" range and operate there for approximately 3 additional minutes. Perform this procedure at 4 hour intervals during trolling or operating for extended periods with the "Low Load" factor and minimum engine speed.
Ratings are statements of the engine's power and speed capability under specified load conditions. The Caterpillar rating system simply matches engines to particular applications. The Caterpillar rating system consists of the following standard ratings: "A" Rating, "B" Rating, "C" Rating, "D" Rating and "E" Rating.
"A" Rating
Unrestricted Continuous Load factor: 80 percent to 100 percent. Up to 100 percent of the time at rated speed. Typical hrs/yr: 5000 to 8000. Typical applications: For vessels operating at rated load and rated speed up to 100 percent of the time without interruption or load cycling (80 percent to 100 percent load factor). Typical applications could include but are not limited to vessels such as freighters, tugboats, bottom drag trawlers, or deep river tugboats. Typical operation ranges from 5000 to 8000 hours per year.
"B" Rating
Heavy Duty Load factor: 40 percent to 80 percent. Up to 80 percent of the time at rated speed. Typical time at full load: 10 hrs out of 12 hrs. Typical hrs/yr: 3000 to 5000. Typical applications: For vessels operating at rated load and speed up to 80 percent of the time with some load cycling (40 percent to 80 percent load factor). Typical applications could include but are not limited to vessels such as mid-water trawlers, purse seiner, crew and supply boats, ferries, or towboats. Typical operation ranges from 3000 to 5000 hours per year.
"C" Rating
Maximum Continuous Load factor: 20 percent to 80 percent. Up to 50 percent of the time at rated speed. Typical time at full load: 6 hrs out of 12 hrs. Typical hrs/yr: 2000 to 4000. Typical applications: For vessels operating at rated load and rated speed up to 50 percent of the time with cyclical load and speed (20 percent to 80 percent load factor). Typical applications could include but are not limited to vessels such as ferries, harbor tugs, fishing boats, offshore service boats, displacement hull yachts, or short trip coastal freighters. Typical operation ranges from 2000 to 4000 hours per year.
"D" Rating
Intermittent Duty Load factor: Up to 50 percent. Up to 16 percent of the time at rated speed. Typical time at full load: 2 hrs out of 12 hrs. Typical hrs/yr: 1000 to 3000. Typical applications: For vessels operating at rated load and rated speed up to 16 percent of the time (up to 50 percent load factor). Typical applications could include but are not limited to vessels such as offshore patrol boats, customs boats, police boats, some fishing boats, fire boats, or harbor tugs. Typical operation ranges from 1000 to 3000 hours per year.
"E" Rating
High Performance Load factor: Up to 30 percent. Up to 8 percent of the time at rated speed. Typical time at full load: 1/2 hr out of 6 hrs. Typical hrs/yr: 250 to 1000. Typical applications: For vessels operating at rated load and rated speed up to 8 percent of the time (up to 30 percent load factor). Typical applications could include but are not limited to vessels such as pleasure craft, harbor patrol boats, harbor master boats, some fishing, or patrol boats. Typical operation ranges from 250 to 1000 hours per year.
The information in this document contains best-practice operation instructions and should be readily available in the pilot house or engine area for all operators reference. Read, study, and keep the information with the literature and engine information.
Operating techniques outlined in this document are basic but very important. Required skill and techniques are developed as the pilot or captain gains knowledge of the engine and vessel capabilities. This knowledge will also assist the operator to operate the engine more efficiently and economically.
Important Safety Information: Most accidents involving product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly. Improper operation, lubrication, maintenance, or repair of this product can be dangerous and could result in injury or death. Do not operate or perform any lubrication, maintenance, or repair on this product, until you have read and understood the information provided in the specific Operation and Maintenance Manual for your engine.