MAN Diesel & Turbo has secured an order from Danaos Shipping to supply their Kappel propulsion system for the two 8500 twenty foot equivalent unit (teu) container vessels; CSCL Europe and CSCL America.
The propulsion package is comprised of fixed pitch Kappel propellers, propeller boss caps with fins, and engine-power limitation.
The vessels will be powered by MAN B&W 12K98MC-C main engines, at a capacity of 68,520kW at 104 revolutions per minute (RPM), and a propulsion upgrade will limit the engines to 44,000kW at 89.7 RPM, enabling a speed of more than 23k.
The new propellers are based on MAN Diesel & Turbo’s Kappel design, which feature forwardly swept propeller blade tips that reduce tip vortex, resulting in less drag of the blades through water.
The design also results in lower pressure pulses being exerted on the hull, allowing smaller clearance between the hull and propeller blade tips; this means an enlarged propeller diameter, increasing its efficiency.
Engine Power Limitation (EPL) reduces the power output of the engine by changing the governor settings, which facilitates the improvement of other efficiencies, such as propeller upgrades and engine tuning.
It also helps in reducing the weight of the propellers, while decreasing both the propeller cost and the overall cost of the upgrade package.
The installation of a low-load tuning method, such as the Turbo Charger Cut Out or a propeller upgrade addresses the torsional vibrations, which affect the propulsion drive train and ensure the NOX level complies with IMO regulations.
The MAN Diesel & Turbo upgrade package underlines all the necessary calculations and class approvals.
The vessels, with an upgraded propulsion system, are expected to have reduced fuel consumption at the new optimised speed of 18k.
Danaos technical director and deputy chief operating officer Dimitrios Vastarouchas said: "At Danaos we look forward to have the vessels upgraded.
"Our R&D Department has conducted very thorough investigations before concluding what the right upgrade solutions for these vessels are and we are confident that the vessels will be highly competitive in the market once upgraded".
Image: Danaos container vessels will be upgraded with MAN Diesel & Turbo’ propulsion system. Photo: courtesy of MAN SE.