auxiliary engine · auxiliary system

Caterpillar 3516C

The Caterpillar 3516C is a high-speed, four-stroke marine diesel engine in a V16 configuration, part of Caterpillar's long-established 3500 family of medium-duty engines. In the marine world it is used chiefly as an auxiliary engine driving a generator to supply a ship's electrical power, and as a propulsion engine in workboats, tugs, offshore supply vessels and other craft where a compact, high-speed engine suits the installation better than a large, slow-running two-stroke. As a high-speed engine, the 3516C runs at far higher revolutions than the great two-stroke crosshead engines used for main propulsion in large merchant ships, which makes it lighter and more compact for a given power but means it is generally coupled to a generator or, for propulsion, to a reduction gearbox. Later C-series variants use electronic engine management and common-rail or unit fuel systems to improve fuel economy, control emissions and provide diagnostics, and they are offered in ratings and tunings to meet the applicable IMO nitrogen-oxide tiers and other emissions standards. Engines of this class are valued for their reliability, worldwide parts and service support, and flexibility across many vessel types. On board they typically form part of a genset package, complete with the alternator, cooling, and control systems, several of which may run in parallel to supply the ship's switchboard and share electrical load. In propulsion roles they drive the shaft through a gearbox and often a controllable-pitch propeller. Maintenance follows a planned schedule of oil and filter changes, cooling-water treatment, and periodic overhaul of components such as injectors, turbochargers and running gear. The 3516C illustrates the role of the modern high-speed marine diesel: a versatile, serviceable prime mover for power generation and for propelling the large fleet of smaller commercial and offshore vessels that support world shipping. Across its long production life the 3500 family has been continuously updated to raise efficiency and to meet successive IMO nitrogen-oxide tiers, and its very wide use means spare parts and trained service engineers are available in ports worldwide — a practical consideration that weighs heavily when operators choose auxiliary machinery expected to run for many thousands of hours.