Although the Otago Central Railway had few changes in alignment, roads around it were realigned many times. One of the more interesting changes is just north of Wedderburn where the map dated from 1939 confirms that the highway was then located directly south of the railway rather than north today. As part of the highway the overbridge with railway number 66a was constructed and still exists on the route today although now bypassed. The highway realignment eliminated this bridge and a level crossing, the level crossing was very close to the railway summit of 630 metres which is the highest point on the whole of the Otago Central Railway.
The Wedderburn map (an extract from an NZGS map of 1939). http://natlib.govt.nz/records/21237571 The section of highway realigned is in the upper section of the map where the highway crosses the railway next to the words “F.McCarthy” and then crosses again further up near “P.Darling”. But whether the latter (northernmost) crossing was on an overbridge at the time the map was drawn has yet to be determined as the alignment shown actually resembles the current alignment with a level crossing due west of where the bridge actually is.
My map showing the entire section and the old and current highway routes. Bridge No.66a clearly is shown, along with the present alignment of the road to miss the overbridge entirely. Since the bridge number indicates it was not original, it is possible that where the road goes today, due west over the overbridge, may also be the original route that the road followed, or close to it, at a level crossing. Central Otago District Council’s bridge inventory lists the bridge as “[bridge no.] 108 [ward] MANIOTOTO [roadway] OLD SH DOWN FROM COAL PIT ROAD [waterway] RAILWAY” implying this may still be a public road. An interesting point is the extra land set aside at the summit which suggests provision may have been made for a summit siding.
![WedderburnN-Br66 WedderburnN-Br66](https://i0.wp.com/lh3.googleusercontent.com/-My9y3CBZagE/VVf6PcovjqI/AAAAAAACXD0/pBkLpf97ph8/WedderburnN-Br66_thumb%25255B1%25255D.jpg?resize=964%2C662)
UPDATE: I received information today including photos of the bridge and the information is that it appears to have been installed in 1950. Clearly at this time the realignment of the highway was still some years away. Whether this part of the highway was ever sealed is another question naturally, as it is not in a sealed condition today. The deck of the bridge as it now stands does not show any sealing. The way the bridge was installed is not commensurate with the needs of a high speed highway, as with the sharp bends it has been done in the cheapest possible way to make the shortest bridge, but as the line where the bridge goes over is in a cutting, the cutting may have caused visibility problems for traffic approaching the crossing. It does appear that the bridge is in private ownership along with the road today. Also it seems more likely the black line route marked would be where the railway went prior to the bridge, as this is clearly marked out in survey boundaries and on private land it would be unlikely to be formally surveyed. The location of the crossing would have been chosen to improve visibility being well clear of the cutting which can be seen on the above map and at right angles to get the best view overall. The use of the different areas of road isn’t so clear as of today but there may be still some use of the bridge but as we can see the old level crossing route is very clear and indicates it likely is still being used also.