 The oil-fired turbine emerged during the twenties, replacing the pre-war coal system and allowing tidy, near polished perfection in the engine rooms.Finally, interested passengers who were very often gentlemen aboard could be invited below decks by the chief engineer for a tour of the machinery.The very core the ship's energy system impressed these onlookers, such as that on board "Paris", where the 34,000-ton liner could be driven at with over 2,500 people hardly feeling the effort.