New Zealand has few significant historic ruins as a young country. One example is the Wilsons Cement Works ruins on the east side of Warkworth in the Mahurangi region of the Matakana Coast. From the Warkworth town centre, take Church Hill to Percy Street, then turn southeast onto Pulham Road and continue for around 1 km to the turnoff onto gravel Wilson Road. Follow this to the car park. It is a short walk to the fenced ruins through a grove of deciduous trees, with a water-filled limestone quarry on the southwest side and the Mahurangi River to the north. The Mahurangi Marina is also located by the river, with a boat access ramp. Several panels describing the history of the works are next to the marina.
It takes about 15 minutes to walk around the ruins, which are gradually becoming overgrown by bush. The exotic pine next to the largest chimney is a particular curiosity. There is a grassy reserve between the ruins and the quarry with picnic tables. You may find references online encouraging swimming in the quarry, but there are water quality warning signs, and it would be better to enjoy the view and take photos. As a quarry, it will be deep if you decide to go in.
The Wilson’s Cement Works dates back to the 1880s and was the first factory to commercially produce Portland cement in Australasia, and possibly the Southern Hemisphere. However, the production of lime preceded the works. John Southgate made hydraulic lime at the site of the works in the early 1850s. By 1857, Walter Combes and William Crush Daldy owned the site with a lime kiln, a hut, and a jetty.
In 1869, the property was purchased by Nathaniel Wilson. He read Henry Reid’s book, Science and Art of the Manufacture of Portland Cement, and he and his brothers established a company to make Portland cement. Early production was difficult due to the variability of the limestone. The quality was resolved by adding shells from the river, and later Clevedon, to increase the lime content. Initially, imported cement was preferred, but the public works programme in the late 1800s dramatically increased the demand for cement. By 1893, more boilers for the kilns were added to the works.
The Grafton Bridge in Auckland was one of the most notable structures built with Wilson’s cement. The bridge had the longest single concrete span in the world when it was completed in 1910. At the time, the company doubled the size of its plant, and the prominent 42-metre reinforced concrete chimney was added in 1916.
After WWI, the company merged with three others, and cement production was moved to Whangarei in 1924. The plant was finally closed in 1930, and most of the land was sold. In 2003, the site passed into public ownership. It is registered as a historic site with Heritage New Zealand.
