The prison's boarded floor, laid in the early nineteenth century and suffering from beetle and worm infestation was recorded during removal by Rupert Austin. The `condemned cell' sited over the portcullis slot for the gate was also recorded prior to its removal for storage. Considerable deposits of dust and decayed timber under the floor were excavated by a small Trust team to record levels overlying the gate vault.

No trace of earlier floors was discovered and it appeared that the original chalk block vault, together with deposits of compacted chalk rubble infilling the lower levels of the vault, had served as a floor for a considerable period prior to the laying of the sprung floor. The chalk block-work at the centre of the vaulting (i.e. at its highest point) was worn and abraded, indicating use as a floor. Larger chalk lumps protruding above the general horizon of vault infill were similarly worn. A number of nineteenth century features including brick walls for the sprung floor disturbed the vault surface. Piercing the vault bosses were original `murder' holes. These are visible on the underside of the vault and have been recorded, together with most of the gates fabric by John Bowen (The Archaeology of Canterbury 11 111-7).

The accumulated dust and debris below the sprung floor yielded a large number of small finds including a bronze medallion struck by Admiral Vernon and Commodore Brown to commemorate the sacking of the pirate stronghold of Porto Bello by six warships of the Engllsh fleet in 1793.