Rejuvenation of the heritage Makatote rail viaduct

Structural Designer

Opus International Consultants

Client Name

KiwiRail

Location

New Zealand

PRINCIPAL CONTRACTOR: TBS Farnsworth

ARCHITECT: Heritage New Zealand

PROJECT MANAGEMENT AND CONTRACT ADMINISTRATION: 41 South

INDEPENDENT COATING INSPECTOR: Pacific Corrosion Consultants

PROJECT DESCRIPTION

Makatote rail viaduct is located in the North Island of New Zealand. It is one of the tallest railway viaducts in the country and holds significant heritage value for its elegance and the technology used at the time of construction (circa 1908). The viaduct began to suffer from corrosion, which subsequently led to section losses of steel elements. With an additional desire to upgrade the viaduct to the future load requirements of KiwiRail, the viaduct was refurbished and strengthened to extend its life for another 50 years.

Judge's comment:

The Makatote viaduct was built between 1905 and 1908 and carries the North Island Main Trunk Railway over the Makatote River. It is one of the tallest viaducts in New Zealand, and is much admired for its elegance and for the technological skill of its construction; it is listed as a Category 1 Structure.

The viaduct is made of steel and had been suffering from deterioration of the paint coating which was over 50 years old; there was serious corrosion in some of the steel members. There was also a need to upgrade the viaduct for the heavier loads required by KiwiRail. One option might have been to demolish and rebuild, but in view of its historic importance it was decided to strengthen the existing structure.

This was done in as inconspicuous a way as possible, so that the quality of the original design was not lost. This was a fine piece of meticulous work maintaining a splendid piece of engineering now over a hundred years old.