Harbour Bridge repairs begin today

An urgent $45 million programme to strengthen the outer clip-on lanes on the Auckland Harbour Bridge begins today.

About 760 tonnes of steel will be welded and bolted on to the box girders - the two sets of two clip-on lanes on either side of the bridge - over the next two-and-a-half years.

Last year the Herald on Sunday revealed engineering reports for Transit said the bridge was at risk of "catastrophic failure" from heavy traffic loads on certain parts of the span. The upgrade has been fast-tracked because the risk of damage can "no longer be accepted".

Heavy trucks were banned from the clip-on lanes and live video monitoring was introduced to stop long queues and prevent further wear and tear.

Work begins on the northbound clip-on today and will run through to Christmas.

It will close the two outside lanes from 9pm until the early morning, Saturday to Thursday.

The Curran St on-ramp will also be closed at these times.