The mechanical journey of a bright yellow lifting gantry known as "Dennis", across the skyline of Auckland's Northwestern motorway has come to an end.

The gantry has placed the last of 277 super heavyweight concrete beams into position on the Great North Road Interchange that straddles State Highway 16 at Waterview.

Work has now began deconstructing the gantry, which has been a feature of the New Zealand Transport Agency's Waterview Connection project for the past 2 1/2 years, according to acting highway manager Mieszko Iwaskow.

"Dennis finished as it began - a faultless and precise performance combining engineering muscle and innovation to construct the interchange," Mr Iwaskow said.


The gantry has been sold by the Well-Connected Alliance, which is constructing the interchange and tunnels for NZTA.

The last super tee beam has been lowered into position at the western tip of ramp 4 - the interchange ramp that will carry Waterview tunnel traffic on to the westbound lanes of the Northwestern motorway.

The interchange will connect the Northwestern motorway with the Waterview tunnels and the Southwestern motorway in early 2017.

The gantry was designed and built in Italy for the Waterview project. It was named Dennis to commemorate a project worker who died of cancer.

Dennis fetched and lifted concrete beams weighing up to 69 tonnes and up to 36 metres long, and then lowered them into place between the 55 columns or piers supporting the interchange. The beams are the foundations for the roads that will now be laid on top.

"Dennis has played an important role in the construction of the huge Waterview project that will bring big changes to the way people travel around the city," Mr Iwaskow said.

When it opens next year, the Waterview Connection completes the Government's $2.4 billion Western Ring Route - a 48km-long alternative motorway route around Auckland which reduces dependence on State Highway 1, especially through the central business district and over the Auckland Harbour Bridge.