Kirby Corp. said it had a profit of $56.2 million in the fourth quarter ending Dec. 31, compared with $31.6 million in the same period a year earlier. Revenue for the 2011 fourth quarter was a record $550.1 million, compared with $286.3 million reported for the same 2010 quarter. For the full-year 2011 the tank barge operator said it had a profit of $183 million, compared to $116.2 million in 2010. Revenue was $1.8 billion in 2011, compared ...