 In the Battle of Langshan Jiang (Wolf Mountain River), the Wuyue fleet under Qian Chuanguan brought with them more than 500 dragon-like battleships and used "fire oil" to burn the enemy fleet.It was a great victory and they destroyed more than 400 enemy ships as well as capturing more than 7,000 men.Lin Yu goes on to explain appearance of the new weapon and the device used to deploy it