 The canals faced competition from the Vale of Neath Railway after 1851, but remained profitable until the early 1880s, in the case of the Neath Canal, and the 1890s for the Tennant. An unusual aspect of the Tennant's success was that tolls were maintained, although tonnage dropped. Most canals at this time made significant cuts to tolls in an attempt to remain competitive with the railways. After 1883, the Neath Canal carried small amounts of silica and gunpowder, but traffic had virtually ceased by 1921. Navigation on the Neath Canal came to an end in 1934, and on the Tennant Canal soon afterwards. However, most of the infrastructure was maintained as the canals supplied water to local industries.
