Tankers are actually not getting bigger, there has been more interest in smaller ones, there hasn't been a ship the size of Jahre Viking (Knox Knevis) and the Batillus class since the 70's/80's out of those only Jahre Viking still remains. Jahre Viking isn't allowed to sail the seas anymore partially because of her size and also because she's a single hulled tanker. As for size... well she is enormous. 260,941 GT 214,793 NT Length: 458.45 m (1,504.10 ft) Beam: 68.8 m (225.72 ft) Draft: 29.8 m (97.77 ft) Capacity: 564,650 DWT As for why she was so big, only one answer: greed a 100.000 ton tanker doesn't need 10 times the engine power of a 10.000 ton tanker, also the larger tankers get the more efficient they get in tems of water resistance and the like. I wonder if this all goes for starships as well especially warp power and so on, does a Galaxy which is about 6-8 times as big as a Connie need 6-8 times the amount of power to reach the same speeds or less like 4-5 times?