A new engineer, Ralph Walker, arrived and announced that the whole canal would cost significantly more than the revised estimate.

The canal finally opened on 14 October 1824, by which time the Napoleonic wars were long over and the military need had greatly diminished.

[4] The canal was 13 m (43 ft) wide and carried the Thames sailing barges common on both rivers.

Complaints then came from barge-owners that the tunnel was slow to use, so in 1830 it was shut for two months while an open-air passing place was dug in the middle.

The ride through the dreary tunnel with the dark waters of the canal beneath us, and an insecure chalk roof above our heads, enlivened as it is by occasional shrieks from the engine's vaporous lungs, and the unceasing rattle of the train, is apt to make one feel somewhat nervous; and the first glimpse of bright daylight that breaks upon us, relieves us from a natural anxiety as to the chances we run of being crushed by the fall of some twenty tons of chalk from above, or being precipitated into twenty feet of water beneath, with the doors of the carriages locked and no "Nautilus belt" around our waists and not even a child's caul in our pocket.

This relief is however temporary, for the light only breaks in through a gap in the tunnel, and some more experienced traveller informs us we are only half out of it.

The canal towing contractor's home was converted into the ticket office for Higham railway station.

But in December 1999 a fall near Strood derailed a train, fortunately without causing serious injuries (but leaving a hole in the ground in an orchard).

It suffered bomb damage during World War II, and some areas have been back-filled or are choked with reed growth.

The Strood canal basin, long orphaned by the loss of the tunnel, was back-filled in 1986 and has now been built over.

There are now plans to fully renovate the canal and make it a focal point of development in Gravesend, to benefit the town while meeting the Thames Gateway project's demands for housebuilding.