Grafton Bridge

Grafton Bridge
Coordinates	36°51′33.88″S 174°45′54.95″E / 36.8594111°S 174.7652639°E / -36.8594111; 174.7652639Coordinates: 36°51′33.88″S 174°45′54.95″E / 36.8594111°S 174.7652639°E / -36.8594111; 174.7652639
Carries	Buses, Motor vehicles, pedestrians and bicycles
Crosses	Grafton Gully
Locale	Auckland, New Zealand
Characteristics
Design	Deck arch bridge
Material	Reinforced concrete
Total length	97.5 m (320 ft)
Height	25.6 m (84 ft)
Number of spans	1
Clearance below	43.3 m (142 ft)
History
Engineering design by	Robert Forbes Moore Karl Rosegger Agster
Constructed by	Ferro-Concrete Company of Australasia
Construction begin	1908
Construction end	1910
Opened	28 April 1910 (1910-04-28)
Heritage New Zealand - Category I
Designated	23 June 1983
Reference no.	16
Grafton Bridge Location of bridge in Auckland, New Zealand

Grafton Bridge is a road bridge spanning Grafton Gully in Auckland, New Zealand. Built of reinforced concrete in 1910, it connects the Auckland CBD and Karangahape Road with Grafton. It spans about 97.6 metres (320 feet), rises 25.6 metres (84 feet) above the abutments to a height of around 43 metres (142 feet) over the gully.

The bridge is listed by Heritage New Zealand and on the IPENZ Engineering Heritage Register. In a 2006 poll of 600 alumni of the University of Auckland School of Engineering, the bridge was third in the list of New Zealand engineering achievements, after Manapouri Power Station and Black Magic.

Since 2009 the bridge has formed a core part of the Central Connector public transport route between the CBD and Newmarket, and is closed to private vehicles during the day.

Designed by engineers R. F. Moore and Karl Rosegger Agster for the Ferro-Concrete Company of Australasia, the bridge's completion was supervised by the city's engineer, W. E. Bush. The bridge was built between 1908 and 1910 and was the third to cross Grafton Gully. The first, built in 1884, was a cable-stay pedestrian bridge from the bottom of St Martins Lane to Bridge Street in Grafton (the current bridge connects Karangahape Road and Grafton Road). Designed by the City Engineer Edward Anderson, the first bridge proved to be comparatively unstable, at least towards the end of its life when it would appear that maintenance was not kept up. By the time it was approaching 20 years old, police were stationed at each end after rugby matches to ensure rowdy crowds did not cause it to wobble alarmingly by jumping or stamping on it.

In 1904, a report showed it was not only beyond repair but that it was lucky it hadn't collapsed. It was immediately closed and supplemented by a temporary bridge of quite simple design at the bottom of the gully. The old disused bridge stood until 1906. Discussions within Council over the design of a new permanent bridge dragged on for years, requiring a rebuild of the temporary bridge and the construction of long flights of wooden steps from St Martins Lane and Bridge Street to make pedestrian access easier. There was conflict over whether any new bridge should be another pedestrian bridge or one that would take vehicle traffic as well. Eventually the decision to build a road bridge was taken.