These gigantic overpowering warships were certainly the most powerful ships from the 16th to the 18th century. They were similar to frigate in design, but also very expensive and luxurious. Many skilled sailors were required to control that enormous ship. There were usually over 850 men aboard. More than 100 guns were mounted on two, three or even four decks. Their weight was around 1,000 tons. Like many other ships in that period, ship-of-the-line had 3 masts. The fore-mast and main-mast were always square-rigged and the mizzen-mast was sometimes rigged with fore-and-aft sails. The modern battleships have been associated with this type of ship.