High-Performance Propulsion Treats

BY ROBERTA PRANDI

Schottel introduced its HTG High Torque Gearbox, which will be incorporated into the recently launched Schottel Ecopeller (SRE) propeller for high performance marine applications.

The German company also launched the VarioDuct high-performance nozzle.

Schottel said that the design of the HTG gearbox enables bevel gears of the same dimensions to transmit up to 15% higher drive torque, while at the same time insuring the same safety margins required by marine classification societies. Also, the HTG allows for a more streamlined underwater housing, which increases the hydrodynamic propulsion efficiency, the company said.

According to Schottel, the new gearbox has low maintenance requirements and a high degree of reliability. Its design was studied to minimize the risk of damages, as for example the risk of flank fracture or scuffing has been considerably reduced, added Schottel.

Steffen Schaefer, head of Schottel’s advanced gear development, said that the designing phase of the new HTG gearbox included state-of-the-art calculation methods, while the manufacturing process employs the latest in milling technology thereby guaranteeing a higher process reliability.

“The new gearbox was thoroughly tested, including also the utilization of a new test bench to try bevel gear sets at full load,” Schaefer said. He added the new HTG will also be used in the SCD 200 propeller, where it can handle engine power outputs up to 360 kW—up from 330 kW, the previous limit with a conventional gearbox.

The HTG gearbox in combination with Schottel’s SRE propeller is meant to be utilized in high-performing marine applications, such as offshore supply vessels, yachts and ferries, and for power ratings between 1000 and 5000 kW.

The SRE propeller is available in a ready-for-installation assembly with integrated electric motor, or optionally with standard electric motors of the designated makers according to customers’ demands.

Schottel also recently introduced the VarioDuct SDV45 high-performance nozzle, available for the company’s Rudderpropeller range. The manufacturer said, the new nozzle offers higher efficiency at open-water speed combined with very good bollard pull values; given the same propulsive power, the VarioDuct SDV45 has a greater bollard pull than the thrust of previous nozzles and, at the same time offers considerably greater efficiency in the medium and high speed range.

The VarioDuct SDV45 nozzle can be optimally adapted to different vessel designs and applications and its small outer diameter also makes the nozzle ideally suited to shallow-water operation.