Well after my last post back in the beginning of the year, things did slow down a bit. A fair amount of mapping work did get done, but not as much as I expected. But I have worked on a lot of different things since then.
Currently I am focusing on the Springburn Branch because Canterbury Maps turns out to have good coverage from 1956 of a part of it (unfortunately not all of it) but enough to cover Mount Somers to Springburn with the existing layout data we already have from the NZMRG. In other words I can use their diagrams in combination with the aerial photos to draw actual layouts to scale etc.
This past weekend things have slowed down a bit due to changing my main computer over to Linux (Mint 17.3). But right now I am back up to speed with all the software installed that I need for this task because Qgis and some other packages all run on Linux and a lot of the other stuff just happens in web browsers anyway.
Here is a screendump of Qgis 2.14 running on Linux
The only issue with migration has been changes in paths, as the file path structure was not copied exactly the same from the old computer. I was able to open the project in a text editor and bulk replace the changed paths to 189 layers otherwise it would have been a lot of fun to have to browse to all the layers' new locations to find them in the GUI.
We can accurately size and place buildings from the aerial photo which is a big improvement on the previous schematic from NZMRG that was not to scale. The purply coloured lines and shapes still have to be put into the right places to produce the finished result.
Here is the aerial photo the above were traced from. This is a 1956 image from Canterbury Maps.
There is some additional detail not present in the Canterbury Maps image that was traced from a track diagram from the 1930s. What is interesting about this 1956 image is that four houses could still be seen even though the engine depot apparently was closed in the 1930s as far as I know. It appears only train crew were based at Springburn which must have been a flag station with no actual stationmaster. It is somewhat odd that Mt Somers did not draw the extra facilities but I guess Springburn was the obvious location at the end of the line for engine servicing, but did not have enough traffic to be attended.
Here is a part of the track layout diagram referred to.