Treffry Viaduct, Luxulyan

Built between 1839-1842 in Luxulyan valley this viaduct was built to carry the tramway and leat across the valley.

It was visible that the leat was leaking through to the columns and possibly causing damage inside by washing out the fine aggregates.

We were instructed to carry out investigation work, to do this the granite sleeper needed to be lifted to expose the leat, each granite sleeper weighed between 1.5-2 tons. With the use of a gantry we were able to lift each sleeper and move them to gain access to the leat. Once exposed the settlement was cleared to expose the bottom, drilling through the joints we found the structure underneath to be solid and no voids were found as previously expected.

After making good to the joints the sleepers were manoeuvred back into place and filled around with granite dust lime mortar mix to fill any voids. Drilling also took place at the base of the columns, this was found to be solid throughout.