FAQ: Did the Enclosure of Titanic‘s A-deck Promenade Increase Her Gross Tonnage?
No.
Contrary to popular belief, the enclosure of the fore part of Titanic‘s first class promenade on A-deck did not make any difference to her gross tonnage.
Titanic’s gross tonnage (not a measure of weight but, rather, the total enclosed space) was calculated as 46,328.57 tons. By comparison, Olympic’s gross tonnage was 45,323.82 tons when she was completed in 1911. Titanic’s gross tonnage was therefore 1,004.75 tons greater than her older sister’s. It placed her as the largest ship in the world.
It is a popular myth that the enclosure of part of the A-deck promenade was largely responsible for increasing Titanic’s gross tonnage. In fact, her registration certificate (completed in March 1912) specifically stated that the ‘open space on promenade deck, abreast windows port side – 198 feet long’ was ‘not included in the cubical contents forming the ship’s register tonnage’ (the same applied for the starboard side). (If it had been included in the gross tonnage calculation, it would have added 720.51 tons, increasing her gross tonnage to 47,049.08 tons.)
The real reason for Titanic’s increased gross tonnage was the expansion of the first class accommodation on B-deck at the expense of the original enclosed promenade, which accounted for the majority of the increase. This passenger accommodation counted as enclosed space, whereas the enclosed B-deck promenade on Olympic did not. Other changes, such as an enlarged officers’ quarters deckhouse, contributed to a much lesser extent as well.
In March 1913, Olympic’s own gross tonnage increased to 46,358.70 tons, following a major refit which included expanding the restaurant and adding a Café Parisien on the starboard side of B-deck. These modifications ensured that the remainder of the enclosed promenade space on this deck was now counted as enclosed space in the gross tonnage calculation. She emerged from the refit with a higher gross tonnage than Titanic, even though her A-deck promenade was never enclosed.
