Monday, 27 June 2016

MSL Part 5, Onehunga, Palmerston North

Well now that I have checked to see what aerial coverage exists in Canterbury Maps I have been fortunate to discover full coverage of Rakaia in 1974. I am now considering mapping the rail yards as the quality of this is very good. Burnham and Rolleston were also well covered in the same run of aerial photography. There is actually still a lot of work to do with the aerial coverage around the Christchurch area. At the moment I am still continuing to work my way south and not actually sure when I will do these areas.

There has been a lot of debate today about the Onehunga Branch because of the dropping of a proposed extension to Auckland Airport. This brings into focus the truncation of the branch when it ceased to be a freight line to the port. I will have a look at historic Auckland aerial photography to see if there is enough to draw the full Onehunga Port yard as quite a lot of tracks are still visible on the wharves there.

With a bit more work some aerial footage of Palmerston North in 1945 has also turned up and shows quite a bit of detail of the old central railway route so that is another thing to look forward to in future.

Sunday, 5 June 2016

Wairarapa Line Maps Completed, MSL Next

Well after a few days work I have completed maps of the Wairarapa Line. There are 95 individual maps covering roughly 170 km of line. The scale varies from 1:2222 to 1:3333 for the Wellington-Speedys Crossing section (55 km) which has a lot more detail in it as it includes all of the suburban stations, branches and deviations that occurred along the Hutt Valley and Rimutakas route. This 55 km takes more than two thirds of all the maps. From Featherston to Woodville the map scale is reduced to 1:9999 with only two exceptions - the realignment of the track at Bridge 80, around the 99 km peg, at 1:2490 and the Woodville map at 1:6666. One important change in the data layout of the maps which was taken (aside from the earlier reclassification of milepegs as "stations") has been to combine bridges and tunnels into a single table. The reason for this which is particularly relevant for the Wairarapa Line is that subways under the track tend to be classified as bridges by Kiwirail even though we have used a tunnel (subway) symbol for them and thus put them in as tunnels. So they will use the subway symbol but will have a B series number on the map. I intend to implement this change in all of the NZ projects (6 for the whole country) but will not be rushing them all through as I did with the milepegs change. One useful thing done with the milepegs change was to implement the new styles as global styles so that they are at least accessible across every project instead of having to duplicate the style changes in 6 projects.

One detail omitted from the Wellington maps has been the ferry terminals with their linkspans which are classified as bridges by Kiwirail. This detail will have to be left until a future time, such as when the NIMT gets done.

My attention has now turned to the Main South Line from Christchurch to Invercargill. This will take in a number of stations in Christchurch where I have previously drawn historical yard layouts from the Canterbury Maps footage. When I changed the maps data layout in a major way last year and combined a lot of separate tables together, unfortunately a lot of the job of pulling the yard layouts into the new tables was not completed for some reason. Consequently this is one of the jobs that now has to be done because this data is notably absent from the maps and should not be. For example in Lyttelton where the MSL starts, I put together the maps only in March last year and all the data was in the maps that were published on the Flickr site, yet I have still not imported it into the new data tables. And Lyttelton is far from being the only station in the Christchurch suburban area where this is the case. In fact I am sure in all the yards that will be the case. The new tables were created in which to store the historic yard layouts but the data still has to be put in. So this one is actually quite a big task which is going to take several weeks to complete.

The major reason that is now emerging for the mess is that the version of Qgis that I used at the time would not paste table data properly and often filled in nulls for a lot of columns in the data tables. This means I am having to painstakingly transcribe some of the pasted data. And this also explains why some of the pastes required have not already been done. They were left until now, at which point the Qgis problem has largely been fixed. After a lot of work pulling together data from a lot of tables I have managed to pull the Lyttelton yard maps together except for the current yard which has eluded me and may have to be put back in from an original source, hopefully I have it already drawn in KML. 

Then finally it will be back onto the Otago Central as I have let that one slide since last year. Part of the reason is I have had a lot of personal stuff to deal with this year, but it has been worth waiting to get the chainage charts that I have just received.

UPDATE: Well I managed to find everything I needed for Lyttelton eventually after scrabbling around for a few more "old" data tables. And then I started marking out the details heading towards Heathcote. Once getting the map done as far as Heathcote, again some details had to be picked up from old tables and put into the current table structure. I have now got to Woolston but in the main these old details are just buildings/structures and siding locations as it seems some of the track data for stations other than Lyttelton was completed previously in the new data structure. Things have been a little slow lately but with new commitments in some other areas I will have to accept that there will be a lesser pace during term time. One good thing earlier this year was finding a suitable software package to automatically sync the project's Google Drive as Google does not produce its own client for Linux. This required a small license fee to purchase (OverGrive) but it seems to be doing a proper job.