the Raurimu Spiral

The most famous railway engineering work in New Zealand is the spiral at Raurimu on the North Island Main Trunk, from the first decade of the 20th century which, like all other similar works in the world, was built to achieve acceptable gradients when the altitude change in a short 'line of sight' distance is steep, by increasing the distance the line travels, through twists, turns and a few tunnels.

Some New Zealand enthusiasts consider it the most spectacular in the world, when in reality there are several others in various countries which are more impressive.  We will make future posts about these.