Royal Navy warships have spent the past week shadowing four Russian Navy vessels that sailed through the Channel off the Kent coast. In a six-day operation with Nato allies, the Portsmouth-based frigate HMS Iron Duke tracked the Kilo-class submarine Novorossiysk and its supporting tug Evgeny Churov through the Dover Strait and into the Atlantic. The operation started at the beginning of September when Canadian warship HMCS Shawinigan escorted the diesel-powered submarine and her support vessel as they sailed from the Baltic and headed across the North Sea. The Canadian patrol ship handed over …