A massive 7,000-tonne concrete caisson has replaced the temporary steel coffer dam, and three cranes - one of ten tonnes, two of 25 tonnes - were transported across Five Basin to Nine Dock by floating crane.
He sailed to the raid in HMS Campbeltown and landed by jumping over the ship's bow onto the caisson to conduct demolition work ashore.
We saw the bronze of a Civil War general on horseback, soldiers hanging onto an artillery caisson clattering to his side.
The caisson has been constructed inside a ‘cofferdam’ - a box-like structure built of pilings and a concrete floor.
It was impossible to resist the line of World War I toys - including doughboys with fixed bayonets and artillery attached to caissons that were pulled by teams of horses.
The port consisted of a series of caissons forming the outside wall, with various pontoons and jetties inside, mainly following the design of a bailey bridge (big meccano).
Some 30 million ft of lumber and 1 million steel reinforcing rods supported the original Wacker Drive, with about 600 caissons excavated to an average of 95 ft.
The seal course at the bottom of the caissons is 8 m thick and required about 6,000 m³ of underwater concrete.
While most of the army's accomplished horsemen served in the Cavalry, the Field Artillery used horses to draw its caissons , and officers needed to learn to ride adroitly.
These floats transported the great floating concrete caissons which formed the sea walls of the Mulberry Harbours.