Siemens Podded Electric Drive Provides Operational Advantages
Siemens AB Marine Engineering has developed a new propulsion system within the power range of 5 to 30 MW per unit, which it claims is proven to offer a better efficiency level than conventional propellers, in addition to improved maneuverability, increased safety and improved handling. The Siemens Schottel Propulsor (SSP) is especially suited to cruise vessels, large ferries and passenger vessels, and cargo vessels including chemical tankers, icegoing vessels, large offshore structures and navy vessels.
Siemens reports that with this system, energy savings of more than 10 percent are possible due to the efficiency improvements of the combination of Schottel Twin propellers and the newly developed Siemens permanent excited synchronous motor, allowing maximum efficiency in transmission of electrical energy at minimum installation space. This statistic is based on tank tests and model simulations for a 70,000-gt cruise liner.
SSP Machinery The 14-MW Siemens Schottel Propulsor consists of a streamlined lower housing made from shipbuilding steel and cast steel. Two fins are welded to the lower housing to gain rotational energy from the forward propeller.
The lower housing of the unit is designed in such a way that it allows a safe underwater mounting of the lower housing so that no drydocking is necessary for dismantling of the lower unit.
The upper part consists of a cone type support structure flanged to the ship's structure and made fromTwo propellers and the propeller covers are fitted to the lower housing.
The lower housing is made up of: propeller shaft with water-lubricated sealings and pneumatic pressure safety device; bearings as roller bearing with 200,000-hr. lifetime; brake to block propeller; propulsion motor; bilge system; and alarm and monitoring sensors for motor, bearings and sealing systems. Installed in the upper housing are: the cable lead allowing 410 degree or optional unlimited azimuth steering; pneumatic compressors for sealing actuation; electric/hydraulic azimuth steering system; local indicators; and bilge pumps shipbuilding steel.
