Colin.....I presume that the 86,000 tonnes is a "gross tonnage". As you well know, one gross tonne is only 100cubic feet of empty space. Which is what these behmoths are mainly composed of. The gross tonnage could be almost doubled by simple adding a few (literally) feet to the beam, height and length...plus a few feet on to the "girth" of the hull. A comparison of "displacement" tonnages would be more informative.
Yes Bryan, it was GRT as that is the accepted measurement of passenger ships. However, a comparison between Gross Tonnage and Displacement tonnage can be very informative sometimes.
The old Queen Mary was 81,000 tons Gross while QM2 is no less than 151,000 tons Gross, almost twice as much. However, when it comes to displacement tonnage, which reflects the actual weight of the vessel, the two ships are much the same and in fact the earlier ship is quoted as 80,000 tons as opposed to QM2’s 76,000 tons. (The big American Nimitz class aircraft carriers displace over 100,000 tons!). Queen Mary was 1019 feet long (311m) with a beam of 118 feet (36m). QM2 is 1,132 feet long (345m) with a beam of 135 feet (41m). But Queen Mary had a deeper draught of 39 feet (11.9m) compared with QM2’s 33 feet (10.1m) and a rather fuller underwater hull form. Basically what this means is that QM2 offers a huge amount of extra usable space on a similar displacement compared to Queen Mary which reflects shipbuilding progress, particularly in respect of machinery, over the last 70 years.
Interesting comparison isn't it?
Colin