Tuesday 21 February 2017

Otago Central Railway [9]: Wedderburn-Auripo

Here's some features of the line between Wedderburn and Auripo. I have rushed ahead with marking mileposts up to 102 M and features and have yet to draw layouts of Oturehua, Ida Valley and Auripo stations.


Bridge 65 (Wedderburn) and Bridge 66 (highway overbridge). There have been two bridges at the latter site. The present bridge dates from 1966 (according to the DOC notes).



In an earlier post I wrote at length about the highway realignment between the 88 and 90 milepegs. The old highway route had a level crossing of the railway just before it reached the route summit of 618 metres above sea level. The railway then crossed the 45th parallel for the first time.

At some time before the highway realignment took place, a second overbridge, No.66a, was added near the 89 mile peg. The date being uncertain. I previously stated this could have been 1950 but now I have the chainage charts I see the entry recorded for this date simply states the clearance under the bridge. Additional research would be needed to clarify the installation date. I also have no idea when the highway was realigned but I am guessing it could have been in the late 1950s or early 1960s. Prior to installing the overbridge the highway crossed on the level just north of the bridge site.



Bridge 66a as seen from track level and road level respectively. The first photo is by Gerald Hyland. As was common in an earlier era, the bridge was placed at a right angle to the tracks in order to make it as short as possible, creating an S bend in the road.


At 92 miles just north of Oturehua a ballast siding was located with an engine shed for a time.


This ballast siding between Oturehua and Ida Valley at 95 miles has been marked previously on maps by me.


At 102 miles this is believed to be one of four alignment changes on the line. The others being at Wingatui (junction curve), Prices Creek (bridge replacement), and Clyde (new station site). Dangerfield and Emerson mentions an unstable hillside near Auripo (101 M) where a small deviation was later required. When I travelled on the line in 1989 a subsidence at this point dating from the 1950s was mentioned in the commentary given by George Emerson. The chainage charts show at this location only a continuous right hand curve, not the R-L-R curvature of the later route. It would appear the hillside subsided at this point and the bypass track built to get around the collapsed embankment became the permanent route.