World's largest tanker arrives in the Thames - A general view of the "Tina Onassis" at her berth at Purfleet, Essex. The 43,000 ton tanker "Tina Onassis" has arrived in the Thames and is berthed at Purfleet, Essex. Over 750ft. Long, she is the largest tanker in the world and is named after the daughter of a Greek shipowner. The ship, which was built in Germany, has brought a cargo of oil from the Persian Gulf and is now on loan to a British oil Company. The "Tina Onassis", which took 15 months to build, is also the largest vessel over to come up the Thames - the previous largest being the "Dominion Monarch" - 27,000 tons. January 11, 1954.