For 500 years, commodity traders have been trying to conquer the treacherous waters of the Russian Arctic passage – aware of its potential as a lucrative short-cut shipping route.The path is blocked all winter and only smaller cargo vessels manage to navigate through the icebergs for two to three months each summer. But last week, the first commercial supertanker has succeeded in traversing the strait. Carrying 70,000 tonnes of gas from Murmansk in Russia destined for Ningbo in China, the feat has moved the difficult Northern Sea Route a step closer to rivalling the dominant Suez Canal in the south.