Some of the heaviest towing jobs don't happen on land but on water. Tugboats, like the tractor vehicles that pull airplanes, must push or even pull vehicles several times their size. Not only do these jobs involve towing some of the heaviest vehicles and structures, but they also involve towing the longest distances.
Towing cables, called hawsers, run underwater from the stern of a tugboat on one end to the bow or front of the towed structure on the other end. These cables equip tugboats to pull wrecked ships, barges and even oil rigs from one place to another.
Take the Adriatic LNG terminal, the first offshore liquefied natural gas terminal. It weighs more than 300,000 tons (272,158 metric tons) and needed four tugboats to tow it 1,700 nautical miles (3,150 kilometers) an average speed of 4.4 knots (8 kilometers per hour) to its permanent location -- a process that took about three weeks [source: Edison].
To learn more about towing, and read about the heaviest buildings ever moved, browse the links on the next page.