Page 39: of Maritime Reporter Magazine (June 2026)

PROPULSION

SRP-D with a propeller shaft with an eight-degree tilt.

The 98-degree variant induced lower losses at the other thruster than the 90-degree variant and therefore enabled a higher remaining force during DP.

sel can be quickly held in position with performance is a reduced Coanda effect only minor corrections being necessary. with the SRP-D. The second part of the

This prevents major corrections in po- research focused on propeller ? ow inter- sition having to be made which would actions. In this case, the additional eight- require more power. degree downward tilt is also bene? cial:

While 50 percent losses are observed 98-Degree Tilted Propeller when the 90-degree thruster is blowing

Shaft the wake into the second thruster (in-

Another independent study focused line thrust losses), only 20 percent thrust particularly on propulsion ef? ciency losses occur with the 98-degree thruster, during thruster interactions. The research which therefore enabled a higher re- was carried out on a model of a CSOV maining force during DP.

equipped with a Schottel SRP-D 98-de- Thorsten Tillack, head of hydrody- gree thruster on starboard and a regular namics and propeller design at Schottel, 90-degree thruster on portside. The ? rst summarizes the resulting advantages: part of the study measured the interac- “Overall, the SRP-D signi? cantly opti- tions between propulsion unit and hull. mizes thrust yield and thrust distribution,

It was found that the additional eight-de- since thruster-hull- and thruster-thruster- gree downward tilt of the SRP-D propel- interactions are minimized. Consequent- ler shaft could signi? cantly reduce thrust ly, the forbidden zones of the thrusters losses, both for azimuth variations and may be reduced, which leads to an addi- thrust variations. For example, CSOVs tional increase of the DP performance for with 98-degree thrusters experience only the vessel. Furthermore, the optimized 10 percent thrust losses in transverse thrust output is expected to result in fuel direction, compared to 35 percent with savings. As a result, SOVs operate much 90-degree thrusters. The study showed more ef? ciently, extending their operat- that a key factor for the improved system ing time throughout the year.” www.marinelink.com 39

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