Quote
Sir George Lewis: With regard to Hilsea Lines, more than half the work has been completed; but, the contractor having failed, a fresh contract is about to be entered into for finishing the works, which will include the widening of the Channel between Portsmouth and Langston harbours, a point of great importance for obtaining a greater scour of water through Portsmouth harbour. It is expected that those works will be completed in September, 1864.
— Hansard, Fortifications and Works Committee, 23 June 1862 source
Note
There’s a lot of reports of trouble at local pubs in 1862-1863. I imagine it’s as a result of this work going on.