|The SBML 42 Pounder gun was first introduced around 1720 and was used on the lower gun decks of some line-of-battle ships until about 1839. It was also used for land defence. In 1853 a request was sent to the UK requesting to fortify Sydney harbour. Twenty 32 pounder and twenty 56 pounder guns were asked for and in 1854 twenty seven 32 pounders were despatched and five 42 pounders were substituted for the heavier 56 pounders. The five 42 pounder guns were mounted in the upper battery of Dawes Battery near the present site of the southern pylon of Sydney Harbour Bridge. A further five 42 pounders had been landed by 1861 and emplaced in new emplacements at Fort Macquarie (site of the present day Sydney Opera House).
Although the requirements for guns in the inner harbour became less necessary from the mid 1870s the guns remained in position. The five 42 pounder guns at Dawes Battery were still in position in 1901 when the Commonwealth government undertook a stock-take of all guns in the Country. In 1904 the obsolete guns were offered to Municipalities and Parks as display pieces. The 5 guns and carriages located at Dawes Battery were also available but the following letter was received by the Department of Defence from the New South Wales Treasury :
“In reply to your letter of 23rd ultimo, respecting the disposal of five pieces of smooth bore ordnance at present mounted in the old battery at Dawes Point, I am directed to acquaint you that it is the wish of this Government that the guns be left in their present positions, as historical momentoes of the early days of Sydney.”
When construction began on Sydney Harbour Bridge in 1925 the guns were temporarily removed to Taronga Zoo. Sydney City Council approved the reinstallation of the cannons at Dawes Point and they were returned and placed in the park below the bridge near their original emplacements. Still on their original wooden carriages the guns remained a familiar sight to Sydney’s visitors. The Royal Australian Artillery Historical Society called for the commemoration of Dawes Point with the cannon and landscaping to give some impression of the former fortifications. In 1995 Sydney Cove Authority (after 1999 Sydney Harbour Foreshore Authority) commenced excavation of Dawes Point Park. Work continued until 2001 when landscaping was completed and four of the guns mounted on metal supports. The fifth gun was mounted on a replica carriage and slide.
The Treasury, New South Wales, letter dated 14 March 1906 (Australian Archives