RMS Olympic and RMS Titanic (being sister ships) shared physical dimensions in regard of length (882' 9'') and beam (92' 6'') and had the same draught (34' 7'').
At launch on October 20, 1910, Olympic had a GRT of 45,324 tons and a displacement of 52,067 tons. These are lower figures than those for Titanic when launched on May 31, 1911; namely 46,328 and 52,310 respectively.
Six months after Titanic sank White Star withdrew Olympic and returned her to her builders (Harland & Wolff) at Belfast to have her bulkheads raised higher and install her with a double skin, At the same time alterations and additions to her passenger cabins were carried out and, more importantly, extra lifeboats were added so there were places for all passengers and crew. With these changes her gross tonnage rose to 46,359 tons, 31 tonnes larger than Titanic's.
http://en.wikipedia.org/wiki/RMS_Olympic