Full-scale ice trials of the Finnish icebreaker Otso in March 1986 - Wärtsilä documentary

In March 1986, the Finnish diesel-electric icebreaker Otso was put through a series of tests in the Bothnian Bay to evaluate her icebreaking capability. This 13-minute documentary produced by Wärtsilä shows how the vessel was, among other trials, rammed into a 20-metre thick pressure ridge at full speed and beat the more powerful 1970s quad-screw icebreaker Sisu in the famous “horse race“ through the ice. Today Otso and her nearly-identical sister ship Kontio are operated by the state-owned shipping compan