Six concrete pier support seven spans. Towards the center, the boxes arch upwards,...

[narrator] Six concrete pier support seven spans. Towards the center, the boxes arch upwards, creating a more than 650 foot wide, 130 foot high channel for shipping. Construction began in 1955. At the time, it was New Zealand's largest infrastructure project ever It took 1000 workers
four years to complete the mammoth structure, using more than 40,000 tons
of concrete and nearly 6000 tons of stee [narrator] When it opened, the four lane bridge was the North Island's longest crossing, and it was quickly put to work. It became pretty much
the only main road that links the north
of New Zealand with the south of New Zealan [narrator] But within a decade, it was clear New Zealand's largest bridg wasn't big enough. The initial amount of traffic
going over the bridge was about 10, 15,000 vehicles
per day, which was substantial