The U.S. Coast Guard new Offshore Patrol Cutter (OPC) will have MAN’s 28/33D STC engines installed as the main propulsion.
Lex Nijsen, Head of Four-Stroke Marine, MAN Diesel & Turbo, says, “We are very pleased to have won this major order within such a key, domestic market. It’s a breakthrough for us as this is the first time that the USCG has ordered MAN 28/33D STC engines. Indeed, the engine’s sequential turbocharging (STC) concept continues to make inroads into the Navy and Governmental segments where its inherent power characteristics offer a maneuverability that matches such demanding applications well. This success was achieved in great part through close cooperation with our longstanding partner and licensee, Fairbanks Morse Engine (FME).”
The OPC program is the replacement platform for the 13 Famous class and 14 Reliance class cutter vessels, making the order the largest vessel procurement order in the Coast Guard’s history. Each of the new 360-foot cutters will be powered by two MAN 16V28/33D STC engines, developing 7,280 kW eachat 1,000 rev/min.
FME will produce and test the engines at its Beloit, WI, plant, while Eastern Shipbuilding Group Inc., based in Panama City, FL, will design and construct the OPC ships. Initially, the USCG has ordered 9 ships with plans to ultimately produce 25. Delivery of the first ship of the class to the USCG is scheduled for 2021.
The 28/33D STC Engine The MAN 28/33D STC engine offers compact power that sets itself apart with a high power-to-weight ratio. All engines are fully compliant with current environmental standards, producing NOx emissions that fulfill IMO Tier II (+ Tier III with Selective Catalytic Reduction) and EPA Tier 2 regulations. Maintenance costs and servicing downtime are kept low thanks to high engine availability.
The sequential turbocharging (STC) concept operates with twin, high-efficiency MAN TCA33 axial turbochargers – specially developed for the MAN 28/33D STC engine – with the option to switch the second turbocharger off at low engine loads. Using the very simple STC system allows the engine to be operated at its optimum operating point over the whole applicable load range.
High efficiency at full and part loads results in a substantial air surplus, thorough combustion without residues, and low thermal stress of combustion chamber components. STC also delivers decreased smoke emissions, low vibration and reduced part-load fuel consumption. The overall result when using an STC system is an extended operating envelope at low engine speeds, which gives a power reserve for ship acceleration, ship turning, sprints or towing.