China's coldest winter in decades meant state-owned energy giant Sinopec was desperate to unload heating fuel from a vessel headed to a northern port, yet freezing temperatures that have swept parts of Asia froze a thick sheet of ice and blocked access.

With the help of an icebreaker ship and a cannon loaded with hot water, workers spent 20 hours clearing a pathway for the tanker to dock and discharge its cargo of liquefied natural gas in Tianjin.