Highly flammable hydrogen showed up Thursday in a sunken barge in Germany's Rhine gorge, causing a new hitch in plans to reopen Europe's biggest inland waterway, dpa reported. Some 300 barges were stuck upstream from the site of the January 13 capsizing. Marine officials said hydrogen showed up in the seventh tank of the barge, which is loaded with sulphuric acid. Rescuers were pumping nitrogen into the tank to render the hydrogen harmless. Road, rail and water traffic through the gorge was stopped this week for fear that the Waldhof barge may blow up, either through the hydrogen igniting or its sulphuric acid reacting with the water. Main north-south rail lines and highways run through the gorge, which cuts through rugged hills. Five nations depend on Rhine shipping to deliver loads from Europe's biggest seaport, Rotterdam. Two empty barges are standing by for the next salvage phase, pumping out the cargo of the Waldhof, which is being held in place by floating cranes and cables. Once safe, the barge will be raised and taken away. -- SPA