FRANKFURT (Reuters) – Siemens Energy said on Monday a turbine that Moscow says is limiting capacity on the Nord Stream 1 gas pipeline was ready to be delivered, but Russia’s Gazprom needed to provide customs documents for the transfer to go ahead. “The transportation of the turbine could start immediately. The German authorities provided Siemens Energy with all the necessary documents for the export of the turbine to Russia at the beginning of last week,” the company said. “Gazprom is aware of this. What is missing, however, are the customs documents for import to Russia. Gazprom, as the custo…