The Swan Bells are a set of 18 bells hanging in a specially built copper and glass campanile in Perth, Western Australia. The tower is commonly known as The Bell Tower or the Swan Bell Tower. Taking their name from the Swan River, which their tower overlooks, and forming a sixteen-bell peal with two extra chromatic notes, they are the second largest set of change ringing bells in the world, the largest being Christ Church Cathedral, Dublin, which has nineteen bells. Twelve of the set are historic bells from St Martin-in-the-Fields church in Trafalgar Square in London; six others, cast in recent times by the Whitechapel Bell Foundry, round off the set. The St Martin-in-the-Fields bells were donated to the State of Western Australia as part of the 1988 Australian bicentenary celebrations; the additional bells were cast with a subsequent donation of metals mined in Western Australia. The six newer bells include five that were presented to the University of Western Australia, the City of Perth and to the people of Western Australia by the City of London, the City of Westminster and a consortium of British and Australian mining companies, and one bell commissioned by the Western Australian Government. History of the St Martin-in-the-Fields bells The St Martin-in-the-Fields bells can be traced to before the 14th century. They were recast in the 16th century by order of Queen Elizabeth I and again between 1725 and 1770 by members of the Rudhall family of bell founders from Gloucester. Due to be recast leading up to 1870 instead they were tuned and restored at London's Whitechapel Bell Foundry and donated to Western Australia, on the initiative of local bellringer and businessman Laith Reynolds. They are rare in that they are one of the few sets of royal bells, and more so since they are the only set known to have left England. The bells are also known to have rung as the explorer James Cook set sail on the voyage in which he reached Australia. The bell tower The tower was designed by the local architects Hames Sharley. The 18 bells have a combined weight of about and, when rung, exert considerable forces on the support structure. To achieve the required rigidity, the six-story bell chamber was made with reinforced concrete cast in situ. The bell chamber was designed by the structural engineering firm Arup. Soundproof louvres and doors are used