Asea Brown Boveri
Because of the limitations of traditional propulsion systems, the double acting ship concept wasn't seriously considered until the development of electric podded propulsion units which combine the advantages of the diesel-electric powertrain, already widely used in icebreakers, with the excellent manoeuvrability of azimuth thrusters. Initially developed as a co-operation between the multinational electrical equipment corporation ABB Group and the Finnish shipbuilder Masa-Yards in the late 1980s, the new propulsion unit became known as Azipod (a portmanteau of "azimuth thruster" and "podded propulsion unit") which is today a trademark of ABB Group.