Schottel optimises propulsion for Briese newbuilds

The four vessels will have aftship arrangements including nozzle support and streamlined body between rudder and hull. As a result, the vessels will carry a controllable pitch propeller (CPP) installation that cuts power by 3.7%.

The vessels feature an open and closed top design for variable cargo purposes. Each will have a length of 89.99m and a width of 14.80m, with a difference in draught between 5.30m (open) and 6.65m (closed, summer draught), and a carrying capacity of 3,400 tonnes (open) and 5,000 tonnes (closed).

Propulsion is provided by a Schottel CPP with a power rating of 1,60 kW and a propeller diameter of 3,500mm within the nozzle. The vessels, which meet the requirements of Finnish/Swedish ice class 1A, feature a new cross bow shape by Groot Ship Design, which is providing a design and basic engineering package for the new ships.

Schottel carried out CFD simulations to investigate the best performance of two variants in the aftship. Headboxes without struts and with two additional struts were tested. Prior model tests at the HSVA model basin as well as extensive calculations revealed features such as a non-separated flow around the struts and the small headbox, leading to a significant decrease in hull resistance.