From 1832 the Navy entered into a period of great technological change with the introduction of both steam and iron to shipbuilding. The first steam vessel built at Chatham was the paddle sloop Phoenix, launched in September 1832. From 1840 numerous trials were carried out with screw propellers, including the construction at Chatham in 1842 of the Bee, a curious small craft built with both paddle wheels and screw propeller. In 1849 the Admiralty suspended construction of all remaining sailing ships and Chatham’s first screw frigate, Horatio, was launched a year later.
The 1850’s saw traditional timber-hulled sail-powered warships fitted with auxiliary steam engines to form the ‘black battlefleet’ which fought during the Crimean War. In 1863 Achilles, the first iron-built battleship to be constructed in a Royal Dockyard was launched from Chatham – the start of an entirely new generation of steam powered metal-hulled ships.
Building in iron and steel released ship designers from the constraints on size inherent in timber construction and the largest ships of the fleet quickly outgrew the facilities of the age of sail dockyard. New machine shops were required to house the steam powered iron and steel working equipment now used in shipbuilding and buildings to construct ships’ engines and boilers were required. All led to the Victorian Dockyard extension – a huge civil engineering undertaking that created an entirely new dockyard to the north of the present Historic site – an area now known as Chatham Maritime.
Ship fitting out and repairing largely moved to the new dockyard extension. Shipbuilding generally did not – with No7 Slip used intensively through the late 19th century to build new generations of steam powered, armour plated battleships and cruisers.
The last battleship to be constructed at Chatham was HMS Africa, launched from No 8 slip (to the north of 7 slip ) in 1905. 1906 saw the launch of HMS Dreadnought from Portsmouth dockyard – a new generation of ship powered by steam turbines and with large calibre guns in turrets mounted in centreline turrets, Dreadnought changed the face of battleship construction, issued in a new age of naval competition with France and Germany – and led to battleship designs that were too large to be built on Chatham’s slips and launched into the River Medway