The Canterbury Association survey of Christchurch in 1850 laid out the nascent town in a grid, bisected only by diagonals providing access to the port of Lyttelton and the northern hinterland. Disrupting the regularity of this street pattern however were the sinuous curves of the Avon River. These proved a serious impediment to travel within the city, and necessitated the prompt construction of a series of bridges. Initially simple structures, by the 1880s the majority of these inner city bridges had been replaced in permanent materials. With their fine cast iron railings, they contribute much to the townscape and character of Christchurch. A timber road bridge was erected around 1873 to cross the Avon adjacent to the Provincial Government Buildings on Armagh St. In February 1883 the City Surveyor Charles Walkden reported serious decay of the fabric, and was instructed to prepare plans for a new bridge. The tender of Grieg and Hunter for £1, 390 (exclusive of cement, approach roads and paths) was accepted in June of that year. Six months later the bridge was complete. It opened to the public on December 11, 1883. William Grieg (1836-1911) was born in Rothesay in Scotland. Arriving in Christchurch in 1860, he worked on the Lyttelton Railway Tunnel before taking the contract for the Bank of Australasia. After working as a builder for eight years, Grieg farmed at Ashley for a period. He returned to Christchurch in 1876 and went into partnership with John Hunter. The buildings they erected together included the Boys and Girls High Schools, Supreme Court, part of Sunnyside Asylum, and Ballantynes. Grieg retired in 1893, but returned to building in 1904 in partnership with his sons. Surveyor and engineer Charles Walkden (1824-1908) had worked in Austria and Denmark for a number of years before arriving in Christchurch in 1871. In 1874 he was appointed City Surveyor to the City Council, a position he held for 22 years. During this time, Walkden was responsible for building or rebuilding many of the bridges in central Christchurch. He retired in 1896 on an allowance of £375 p.a.