The bascule bridge is being delivered by BAM Construct UK Farrans Construction Joint Venture for Norfolk County Council and it is due to open to the public this summer.
Each leaf measures 45m by 24m. They have been installed during a 72-hour river possession, with the east leaf lifted into place first in a nine-hour operation.
Each leaf weighs 700t and a further 500t of concrete per leaf is poured to create the counterweight. When both leaves are up there will be 50m of navigable channel between the two bascule chambers.
The bridge, also known as the Third River Crossing, is being built over the River Yare. It is one of two opening bridges under construction in the East Anglia region (link opens in new tab).