Recently, labor saving for train maintenance is strongly called for. This requires, among others, extension of air hoses that are used in quantities. Current air hoses have several drawbacks in that the outer rubber surface is not resistant against sunshine or ozone and the reinforcing cloth lacks strength. To solve these problems, we have developed an air hose made of synthetic rubber and cloth that features long durability. Aging tests proved that the newly developed hose withstands use for more than thirteen years.