Once part of what was New Zealand’s largest commercial flax industry when they were completed in 1917-18, the concrete remains of the Tane Hemp Company Limited Suspension Bridge and Flaxmill is now a prominent landmark on the Manawatu River at Opiki.

One of New Zealand’s earliest export products, during the opening decades of the twentieth century flax fibre made a key contribution to the national economy. There were many flax growing regions, but the Manawatu and Horowhenua were notable from the 1860s. In particular, the Makerua Swamp stretching between Linton and Shannon was an important centre, and its production peaked during World War One making it New Zealand’s largest commercial flax production area.

Members of the prominent local flax industry families, the Seiferts and Akers, combined forces with other investors in 1915 to form the Tane Hemp Company Limited. Access to the local railway station was problematic, so roads through the swamp, and means of crossing the Manawatu River, were soon devised. This included the company’s significant investment in a suspension bridge, designed by the prolific Pahiatua bridge builder, Joseph Dawson. The company also upgraded its mill facilities in 1918 with a replacement concrete chimney for its steam engine exhaust. However, a devastating flax disease compounded the post-war slump in demand, and by the early 1920s the Tane mill had closed, like the majority of its local counterparts. These mills were then demolished and the swamp drained to create farmland. The suspension bridge passed into sole Akers family ownership, and soon a toll began to be charged to contribute to the structure’s maintenance. In 1969 a replacement state highway bridge was constructed and the decking of the suspension bridge was removed.

The mill and bridge remains are located on a pastoral flood plain. The structures consist of concrete bridge towers, with suspension wires and hangers dangling between, and the nearby concrete flaxmill chimney, which is approximately 20 metres high, and a boiler pad at its base. These structures no longer have a functional purpose, but have been left as monuments to the local flax industry.
The Tane Hemp Company Limited Suspension Bridge and Flaxmill Remains have special significance for their ability to represent New Zealand’s flax production industry, which was of particular importance to the national economy in the early twentieth century. These are landmark structures that are the only substantive vestiges of a formerly defining regional industry. The structures are significant representative examples of the industry because they are located in what was New Zealand’s largest commercial flax production area, they were built during the industry’s boom period, and because they are now the most intact structures that remain of the industry in what was once the country’s centre for flax production. The suspension bridge retains special historical and technological value as a rare surviving example of Dawson’s work, a relatively early use of reinforced concrete in a New Zealand bridge, and because it was one of the largest bridge main spans ever constructed in New Zealand. After the collapse of the flax industry, the bridge gained distinction as the only privately owned toll bridge in this country’s highway network.