MAN Diesel is expanding its controllable pitch propeller portfolio to add two new, propeller hub-sizes – VBS2080 and VBS2240 – of 2080mm and 2240mm hub diameters respectively.
The move comes in response to the market demand for very large CP propellers up to and beyond 30,000kW and with diameters over eight metres.
These propeller sizes are typically destined for ConRo vessels, shuttle tankers and special vessels with high ice classes, and powered by MAN B&W two-stroke MC-C or ME-C main engines that directly drive a CP propeller.
The company states that the potential for improving propeller propulsive efficiency aft-ship optimisation is far greater than that for improving diesel-engine fuel-oil economy, and MAN Diesel has devoted more resources to its CP propeller program and associated aft-ship systems in recent years, with the aim of improving total propulsive efficiency by eight to ten percent within the next five years.
Backed up by industry demand, MAN Diesel focuses on low environmental impact and optimal fuel-oil consumption. While these two factors can play against each other in diesel-engine design, they go hand-in-hand with propellers since an increase in propeller efficiency results in lower propulsion power and fewer emissions.
The new Alpha propeller hubs, like the smaller ones, focus on reliability, low wear-rates and service-friendliness as they are serviceable from the aft-end, with no dismantling required.
Alpha is also the first CP market series from MAN Diesel where both the stern-tube system and propeller hub can operate on biodegradable oil, eliminating any risk to the environment and guaranteeing internal propeller lubrication, even in the event of seawater contamination.
