MAN Energy Solutions, through after-sales division MAN PrimeServ, has completed a retrofit aboard Ambience, a vessel in the fleet of UK operator Ambassador Cruise Line.
The scope of the project covered the installation of selective catalytic reduction (SCR) systems, while two of the ship's four MAN 8L58/64 engines had their NA57/T turbochargers replaced with modern MAN TCA 66 units.
MAN said the order came about when Ambassador Cruise Line delegated Ambience to offer cruises in the key Norwegian Heritage Fjord market with its exacting Tier III emission standards.
The SCR will be available from just 15 per cent engine load, enabling clean operation, also during slow-sailing in the fjords as well as close to port and populated areas. The fully modular SCR system has been fully integrated into Ambience's engine control setup.
With its closed-loop system and a weather station that uses environmental data, the NOx reduction rate is maximised and ammonia slip minimised to just 10 ppm, which MAN said is comparable to that of a car. Low ammonia slip means a reduction in urea consumption, enabling the urea tank size to be minimised.