Due to the ready availability of aerial photography at affordable prices I am intending to make use of a lot of the available imagery from Archives New Zealand in order to update various maps and the first map apart from the ones drawn for Christchurch (using the Canterbury Maps aerials) will be the Otago Central Railway which is Volume 17 of the NZ Rail Maps published volumes. As time goes on it will be possible to use aerial photography to document a lot of currently unknown information about various features of closed and open railway lines in New Zealand and therefore make an immeasurable contribution to our growing historical knowledge of these lines.
At the present time I am obtaining aerial photography for the Cromwell Gorge and as seen in recent posts have completed drawing a layout of the Cromwell railway station from 1962 and when I have all the photos in about three or four weeks will be in a position to update the maps for that entire section of line from Clyde to Cromwell. This is particularly notable in that the Cromwell Gorge is the only section of railway line in New Zealand to have been buried under a hydro lake and because of this it is one of the few lines we cannot trace the route of at ground level today.
Once the Cromwell Gorge section is completed the next stage will be to obtain aerial photography for every station yard and other notable features on the rest of the line (the current rail trail) and then update the rest of the maps back to Wingatui. This process will therefore take probably the rest of this year to complete.
From that point on aerial photography will be used where of value to document other branch lines for which I have limited information and particularly yard layouts and other notable aspects of these lines. Therefore other volumes produced to date will be updated as found useful from time to time. An example is the Ngatapa Branch and the legendary three tunnels that are supposed to have been dug at the top end of this line. Probably with at least a few branches where the route is not well known by me then aerials may be used to cover significant sections of the routes. My expectation is that following the completion of Volume 17, the next volume to be worked on will be Volume 10 which covers the Wairarapa Line as this will include full coverage of all the closed routes including the Rimutaka Incline and its approaches and the other realignments within the area. Then the next after that will probably be Volume 9 which is the NIMT from Marton to Wellington, because it incorporates the old WMR line which is of considerable interest to me.