A 103-year-old bridge serving Dannevirke has been found to be in much worse condition than previously thought.
By Rebecca Hogan for Local Democracy Reporting
The Rawhiti Bridge at the southern end of Dannevirke will close to heavy vehicles and face a speed limit of 30km from Wednesday after tests found parts of the bridge in a state of “substantial deterioration”.
The Tararua District Council announced Monday that routine testing in June and more recent detailed investigations revealed the bridge was in “significantly poorer condition” than expected due to age-related deterioration within the structure and supporting beams.
Andrew Desmond network manager for Tararua Alliance acknowledged it was a last minute change for commuters, but he said engineers say the route should be restricted to light vehicles “as soon as practical”.
He said tests showed accelerated cracking and low concrete strength in some parts of the bridge, putting it at risk from trucks, heavy commercial vehicles and heavy haulage units.
Restrictions were intended to slow further deterioration while a long-term solution was investigated and Tararua Alliance prepared a business case for funding from NZTA.
Less than a month ago, the council placed a similar 10km speed and weight limit on a 97-year-old bridge after investigations found Tararua’s Alfredton Bridge couldn’t hold more than 3.5 tonnes.
Rawhiti Street and bridge is a popular alternative route to Dannevirke’s main street.
Typically, the bridge has around 970 vehicles cross it each day – roughly 70 of those were estimated to be heavy vehicles which will now have to follow an alternate route.
Temporary electronic signs notifying drivers of these changes would be installed at both ends of the bridge by this Wednesday before permanent measures were put in place by the council.
– LDR is local body journalism co-funded by RNZ and NZ On Air.