Milk-shake: Fonterra builds earthquake-proof dairy plant

Fonterra has opened a unique whole milk drying plant at its site on New Zealand’s North Island, reinforced to withstand the tremors of an earthquake.

Built by GEA, the facility is among the largest in the world with a capacity of 15 tons of milk per hour, and took just two years to complete. The plant in Pahiatua, 20km from Palmerston North, lies on an earthquake fault line and has been designed to withstand a 1/2500-year event without damage. It is believed to be the first plant of its kind in the world to be built this way, German-headquartered GEA said.

The small town of Pahiatua was last hit by 7.6 magnitude quake in 1934. However, in all other respects the plant is ideally located for the dairy farms it serves, avoiding the need for tankers to traverse the Manawatu Gorge, which can be dangerous in bad weather.

Building a plant in the middle of New Zealand’s earthquake zone requires special precautions, GEA continued. In an effort to speed up the process, and keep costs down, it was agreed not to design a new facility that would withstand tremors but to build a copy of the company’s Darfield 1 dryer, but with base isolation that would allow the building to move should a quake hit. As well as providing all the processing equipment, GEA was also contracted as a consortium to provide the building work for the project with its partner, Ebert Construction. There are only a handful of other buildings in New Zealand that are protected in this way including the parliament building in Wellington and the country’s national museum.

The whole plant weighs upwards of 20,000 tons, including its 40-metre-high drying tower, all of which sits on 50 triple friction pendulum bearings that will allow the whole construction to move up to 900mm in any lateral direction in the event of a quake. Each 1.4m square bearing weighs 2.7 tons and has a Teflon center to reduce friction.

Gary Reynolds, GEA’s project manager, said: “All these plants are difficult because of their sheer size, but this was similar to many plants we have built in New Zealand.

“Our goal was to change the way construction was done in New Zealand. We brought the whole team together in a ‘community’ in which GEA and Fonterra work side-by-side. There had to be absolute cooperation between us, the client and the builder. There was some steep learning but if we had a problem we just talked it through and found a solution together. It is a very refreshing approach. If we had a disagreement we’d get it out in the open and deal with it.”