A city railway bridge will be dismantled brick by brick and replaced after more than a year of disruption.

The structure in Long John Hill was inspected by engineers for Network Rail in May 2015 and the road underneath was closed to allow for maintenance work.

A three-week closure became six weeks and then 16 months – with the road and footpath now due to re-open on September 30, 2016.

The bridge, which was built in 1850, has been shored up in the interim so trains on the Norwich to London Liverpool Street line can continue to use it.

It will be dismantled and removed in August, with a new bridge put in place over three days.

A Network Rail spokesman said: 'Network Rail always intended to replace this very old bridge, but further deterioration has meant that it is being replaced sooner than originally planned to ensure the safety of everyone who uses it.

'At the moment extra support is in place so that it can be used safely before it is replaced over the August bank holiday weekend.

'Work of this nature means that there will be disruption to train services and passengers should check before they travel that weekend.'

The road was previously due to be closed until late November, but work has been brought forward by two months.

While the new bridge should be completed by August 31, the road will not open until a month later while post-installation work is completed.

The section of the road affected is between the A1054 Martineau Lane junction and the A146 Barrett Road junction.

It is understood that the process has taken so long as engineers had to work on designs for the bridge's reconstruction while the bridge deck replacement was

being worked on at a separate site.