A method is described for maintaining a gaseous composition within a tube (that is part of tubular transportation system for transporting passengers or cargos via a capsule), where the tube is arranged along a predetermined route. The method comprises: (a) pumping the tube to a pressure that is below atmospheric pressure until the tube is substantially evacuated; (b) identifying a predetermined power value; (c) identifying a first percentage, x, of hydrogen based on the predetermined power value identified in (b) and a leak rate associated with the tube; (d) maintaining within each tube in the plurality of substantially evacuated tubes, a gaseous composition comprising a mixture of a first percentage, x, of hydrogen and a second percentage, (100-x), of air.