VALVE GP-TIRE 6G8018 - Caterpillar

Operating an engine above the engine's rating will reduce the service life of the engine before overhaul.
The following Table 1 defines the ratings for 3500B High Displacement Marine Engine.
Table 1
3500B High Displacement Marine Engine Rating Definitions
Rating Typical Application Typical Hours of Use Per Year Typical Load Factor Time That Is Allowed At Rated Power Interruption or Load Cycling
Continuous “A” Bottom drag trawlers (1)
Deep river towboats (1)
Freighters (1)
Tugs (1) 5000 to 8000 80 to 100% 100% No
Medium Duty “B” Crew boats
Ferries (2)
Mid-water trawlers
Purse seiners
Supply boats
Towboats (2) 3000 to 5000 40 to 80% 80% Some load cycling
Intermittent “C” Coastal freighters (short trip)
Ferries
Fishing boats (3)
Tugs (harbor)
Offshore service
Yachts (displacement hull vessels) 2000 to 4000 20 to 80% 50% Cyclical engine load and rpm
(1) Heavy-duty service
(2) The vessel must be slowed frequently for locks, sandbars and curves.
(3) Typically, examples of these boats move faster for cruising from the harbor and to the harbor: crayfish boats, lobster boats and tuna boats