Barlow rail was a rolled rail section used on early railways. It has wide flaring feet and was designed to be laid direct on the ballast, without requiring sleepers. It was widely adopted on lightly trafficked railways, but was ultimately unsuccessful because of maintenance difficulties.
It resembles the bridge rail used for Brunel's baulk road, but was of tapering form, rather than with the flat base of the heavier bridge rail intended for laying onto timber.