This article is based on a paper by E. Hohener and E. Faber, of Sulzer Bros. After a brief review of icebreaker propulsion systems from the 1950s onwards, the article describes a Sulzer proposal to use direct-coupled slow-running two-stroke engines of their RTA and RLB series for the large icebreaking merchant ships expected in the future exploitation of the Arctic. Such vessels might have individual shaft powers of about 37 MW <50,000 shp>. Arctic ships trading to other parts of the world would have to meet a variety of ambient conditions and power requirements; these are discussed. In a triple-screw system proposed by Sulzer, two low-speed engines would be arranged in tandem in each shaft line, with the after engine driving a c.p. propeller through shafting and a separate thrust bearing. The forward engine is linked to the after one by a shaft that incorporates a hydraulic cone-bolt coupling of the Lohmann & Stolterfoht Separex type; the coupling is engaged and disengaged with the engines stopped, and can only be engaged with the two crankshafts in a particular angular relationship. When running in open water, at less than half the installed output, the forward engine would be disengaged. Two RTA84 eight-cylinder engines could provide a total of 47,425 kW per shaft at 87 rpm; the two engines in each pair could have unequal numbers of cylinders to suit the operating conditions concerned. The proposal and its potential advantages are discussed in some detail.

  • Supplemental Notes:
    • Shipbuild. Mar. Engng. Intl., 106 <1983>, p.182 <Apr.> (3 pp., 2 graphs, 3 diag.)
  • Publication Date: 1983


  • English

Subject/Index Terms

  • Subject Areas: Marine Transportation;

Filing Info

  • Accession Number: 00685089
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Aug 14 1995 12:00AM