Wednesday, 23 August 2017

MSL Palmerston-Dunedin [1]: Palmerston-Waikouaiti

This series on the Main South Line is being republished after having been taken off the blog last year. At that time it was necessary to vet all of the previous content and this process is still happening with some 250 posts to check as time permits. I have elected to republish with the current rather than previous dates.

A curve realignment at the 333 km peg, between Goodwood and Tumai.

From Tumai to Waikouaiti a highway deviation of 3.5 km was opened in 2007. At Tumai, the highway used to cross the railway on a narrow twisting overbridge dating from many years ago (before the 1940s). It was an accident black spot due to the geometry with a steep blind approach from the Tumai end going around a 55 km/h curve onto the bridge itself as it went over the top of a cutting. The approach from the other side was relatively easy by comparison. There has been a trend in recent years to straighten out a lot of older overbridges that have sharp curves because when many were built, as recently as the 1940s, it was the trend to have them at right angles to the track wherever possible with sharp approach curvature. Other examples of late including at Waianakarua (Sharpes Bend), Elevation (Picton) and Waipukurau have been replaced with new bridges on more favourable alignments. In this case it was determined bypassing the bridge (which remains as a local road into Waikouaiti from the north) achieved another desired outcome of eliminating a highway level crossing of the railway at Waikouaiti. 

Tumai (closed 1954) with the old highway route over Bridge 197 just north of the 326 km peg.

Other end of the highway project at Waikouaiti with the closed crossing (now open only to pedestrians) and also showing the location of the old railway station in the township.

Waikouaiti railway station as seen in 1964. It was closed to all traffic in 1986. There was a second railway station in the township, Beach Street, which closed in 1978. (Whites Aviation)