Investigative test pitting by C Currie of CKCA to obtain information about the construction of the lock behind the early 20th century concrete facing, in advance of restoration works by the NT. Documentary evidence suggested the concrete facing covered a timber structure, although it was thought that the record was incomplete and the sides of the lock were actually of brick. The test pits revealed substantial timber braces and no evidence for brick remains, indicating that the documentary sources were indeed correct. Vertical timbers removed from the Navigation bank at nearby St Catherine’s Hill were also recorded, but were not studied in situ as they had been previously removed as a hazard to boats. The timbers were thought to be parts of vertical piles used to tie revetting timbers to the bank.