In today's update, we can report we have finally completed the historical map mosaics for the section of the Main South Line from Woolston to Waltham, after splitting the Gimp project into two parts to deal with persistent crashes caused by project file size. The last section to be added this morning was the historical coverage of the section for the year 2000, which is the most recent aerial photography available from Retrolens.
The historical eras covered in these mosaics of the Main South line are 1940s, 1950s, 1960s, 1970s, 1980s, 1990s and 2000s, with Linz aerial photography available after 2000. NZR official station surveys cover from Opawa to Waltham in 1970, Woolston in 1974, and Woolston to Waltham in 1981. NZR corridor survey is available from 1984, but only for Waltham; for some reason, an entire run (B) is missing from this survey. The rest of the coverage is general for Christchurch and of a lower quality and only the NZR surveys in general will be able to fill in the historical data for the section.
To back up the map data, this week we also have commenced three half-days of research at Christchurch Archives at the rate of one half-day per week for the Christchurch Station, which includes Waltham. We are prepared to carry out the more intensive scale of research just for Christchurch, and do not intend to spend any significant amount of time on the other stations, each of which would have less than one half-day spent on them. In each half-day session we would typically expect to view and copy content from around 40 files, and the time scale of one half-day per week is governed by limits on the rate at which Archives can produce and issue the files for our research. The main purpose of this research is to obtain additional map information about the locations and track layouts of sidings and time limitations mean we are not able to take in general historical research of the areas concerned, even though much of the information about Christchurch in the 1980s and 1990s is very interesting, being an era we lived through and had extensive knowledge of from a personal perspective.
At the moment our focus is going more into producing all of the mosaics as quickly as possible for Greater Christchurch, and less into drawing actual maps, and that is why we are publishing project diary updates lately rather than map coverage of the areas. This is driven by the needs of Christchurch Transport Blog for map tiles for project work, being a higher priority than NZ Rail Maps at present. Once all of the Greater Christchurch map tiles have been completed, then NZ Rail Maps can go back into map development around the country according to its existing goals. This of course also means the original project schedule for NZ Rail Maps that we outlined for 2019 will not be kept. We estimate at the moment it may take for the rest of 2019 to be able to complete the Christchurch Transport Blog map tiles, and therefore will have to rearrange our goals.
This will mean the overall schedule for completing the bulk of the NZ Rail Maps project work for all of New Zealand will be altered. Against that, having increased resources has improved our efficiency considerably this week and will speed up the mosaic production.
Tile extraction for Woolston to Waltham will start early next week, so expect to see some actual historical mappables displayed in the next update. Mosaic production is shifting to the Middleton to Hornby section of the Main South Line, the Lyttelton to Heathcote section of the Main South Line (including Ferrymead) and the Bryndwr to Ashley section of the Main North Line which as far as possible will be worked on more or less simultaneously, as is now easier to achieve with the resourcing improvements.