 In June 1857 the first stone of the new lock was laid at the present position, the central of the three, opened in 1858 together with the narrow skiff lock.The boat slide, separate, was added in 1869 and in the 1870s the weir collapsed twice causing enormous damage.After the weir had been rebuilt in 1871, sluice bays spanned around , similar to the tumbling bays.