 The Navigation Act obtained in April 1771 by the Thames Navigation Commission did not allow them to build locks below Maidenhead Bridge, but from 1802, several plans for locks in the First District of the Thames, stretching from Staines to Teddington, were drawn up.Stephen Leach took over the post of Clerk of Works for the First District in 1802, following the retirement of Charles Truss at the age of 82.Just before his retirement, Truss proposed locks at Molesey and Teddington, each having a weir with long tumbling bays, similar to modern practice.