Tugboat, or Tug, a boat with a powerful engine used to tow or push ships and barges. Tugboats are usually small and are used mainly in harbors, rivers, and canals. They are generally about 100 feet (30 m) long and about 25 feet (8 m) wide. Most tugs use diesel or diesel-electric engines of up to about 2,000 horsepower. Larger, oceangoing tugs, up to about 300 feet (90 m) long, are used to aid disabled ships.
When humans discovered fire, they learned to cook their food in a controlled environment. What came next? Flamethrowers, of course. What do flamethrowers have in common with their living counterpart -- fire breathers?
The Boeing B-29 Superfortress was the biggest, most expensive gamble by the United States during World War II, built with incredibly high expectations on a tight deadline. Read about the big advances in aviation technology brought about by the B-29.