About 40 European river cruise vessels are or will be equipped with a SCHOTTEL propulsion concept with four SCHOTTEL Twin Propellers STP 200. The concept was specifically designed for river cruise ships, and in five years has consistently gained acceptance with its numerous advantages such as low-noise, shallow draught, increased overall efficiency and energy efficient operation, SCHOTTEL said.
Splitting the propulsion units from the conventional two to four Twin Propellers, reduces the draught of the ship to approximately 1.6 meters, and therefore the ships sail smoothly even in shallow waters. The highly elastic mounting of the STP effectively damps the pressure impulses induced by the blades. The reduced diameter of the propellers allows a spacious clearance between the propellers and the hull and results in a low structure-borne noise level.
The small propeller diameter of 1,050mm requires only minor tunneling of the ship’s stern. In contrast to high tunneled ships, these effective designed stern lines increase the overall propulsion efficiency significantly. Additionally, the propulsion system with four SCHOTTEL Twin Propellers 200 has a very low thrust-deduction coefficient thanks to the clearance between propeller and hull. Hence, almost the entire thrust can be converted into propulsive power.
One or two SCHOTTEL Pump Jets of the type SPJ 82 RD serve as additional drives in the bow. These are characterized by their compact and rugged design and are suitable as main and auxiliary drives.
The steering of the fourfold propulsion system ensures an increased operation safety: just like a dual propulsion system the steering is controlled via two joysticks, one for the two units portside and one for the two units starboard. Apart from a few details, the bridge does not differ from a double unit. This way, captains can easily change between a fleet’s different vessels.
The operational safety of the ship itself is guaranteed by the nine-fold redundancy of the propulsion system: the four SCHOTTEL STP 200 main propulsion units each have redundant control. The SCHOTTEL SPJ82RD ensures the redundancy additionally.
Currently the propulsion concept is available with four mechanical STP 200 in both a diesel-direct and a diesel-electric version as well as with four electric SCHOTTEL Combi Drives (SCD 200). The SCHOTTEL propulsion portfolio for river cruise ships also includes a variety of individually tailored concepts for different river cruise providers. These range from the traditional concept with two SCHOTTEL Twin propellers to river cruise vessels operating with SCHOTTEL Pump Jets as main propulsion units.