Saturday 31 August 2019

Project Diary 2019-08-31

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.

Thursday 29 August 2019

Project Diary 2019-08-29

This week work is still continuing on the historical map tiles for Waltham, Linwood, Opawa and Woolston. We have gained some additional resources this week to enable us to speed up the tile production work, so we are also simultaneously working on tile production for Middleton to Hornby section of the Main South Line, and the Bryndwr to Ashley section of the Main North Line. So the production of these tiles should be able to be sped up noticeably, as part of the reason for it being slow is the inherent slowness Gimp has when working with very large mosaic projects. Some of these cover a canvas surface having a working area of 3.5 billion pixels (3,500,000,000) and around 100 layers in total. The Woolston-Waltham project is now completed and tile extraction will be commencing and could be completed tomorrow but will probably have to be deferred for a couple of days due to other commitments, and we have had numerous Gimp crashes, so it has been slowed down a lot from what we expected last week.

The issue with a city like Christchurch or any main centre is you are looking at an entire section of a corridor, rather than a number of individual stations along it. Because there are sidings and stuff all the way along that corridor that you want to document, and that is certainly the case for the Main South Line from Woolston to Islington in particular, and on the Hornby Industrial Line as far as Prebbleton. It is not quite the same on the Main North Line which has historically much less industrial development. So that dictates Gimp projects that cover large areas. We could split these into multiple smaller projects but then there is too much problems with overlapping at the edges of these projects because those edges all have to line up when the tiles are put together in Qgis, and the historical aerial photos boundaries don't neatly end on a tile boundary. So a smaller number of larger projects is definitely the way to go, but we have had a few instances of having to split some of them up when they got too large. For example Addington to Ashley started off as one project, but then Addington and Riccarton got combined into another project with Christchurch and it ended up too large to put the rest of the MNL suburban area into it, so Bryndwr to Ashley is what it has ended up as. Same with Lyttelton to Waltham originally being one project that now has Lyttelton and Heathcote in one file and Woolston to Waltham in another. And so on. 

The extra resources mean the time Gimp wastes on saving large projects, which can actually take several hours to complete, can be used to work on another project at the same time. So in fact today we really were working on three at the same time at one stage because the first one was being saved. After completing the progress on the second one, it too was saved, and while that was happening, we worked on the third. Another time saving measure is to use Cubic interpolation for unified transforms instead of LoHalo. My hunch is that Cubic is a lot faster than LoHalo and makes very little difference to the quality of practically any layer we throw at it.

Thursday 22 August 2019

Project Diary 2019-08-22

Since last week's diary report we have continued working on the maps for the Christchurch area. Putting together all the aerial photos can take a while to complete but we now have complete historical aerial photo tiles for Christchurch, Addington and Riccarton, and have started working on ones for Waltham, Linwood, Opawa and Woolston. These ones should be ready in a couple of days. Then after that we still have, as far as Greater Christchurch goes, to look at Lyttelton, Heathcote, Middleton, Sockburn, Hornby, Islington, Weedons and Rolleston on the MSL; Prebbleton and Lincoln on the Hornby Line; and Bryndwr, Papanui, Styx, Belfast, Chaneys, Stewarts Gully, Kainga, Kaiapoi, Flaxton, Southbrook and Rangiora on the MNL, to complete all of the stuff for GC.

Research has shifted to the GC area as well. After a break from the Midland Line work is starting with Christchurch Station which will take about 3 weeks to complete with over 100 files to view. The plan is to look at every station within the GC area in order to be able to fully detail the maps being drawn of the area.

Tuesday 13 August 2019

Project Diary 2019-08-12

This week we have switched back to the Christchurch area maps due to the impeding local government elections. We are currently working with several candidates and preparing material in order to assist some of their campaigns, in association with Christchurch Transport Blog.

Because of this the Midland Line work has temporarily halted, although research at the local branch of Archives New Zealand has continued. We estimate approximately two more days of research at Archives will be sufficient to complete the Midland Line maps, but are unsure exactly when these maps will actually be ready.

We are taking the time to complete more of the historical maps of Christchurch as well as some of the other stuff we are doing so I have pulled up a number of Gimp projects and revised them as necessary to keep them within reasonable file sizes. For the Main North Line it is now split into one project that covers Addington and Riccarton along with Christchurch (from MSL) and a second one covering from Bryndwr to Ashley, previously it was all one project from Addington to Ashley. 

For the Main South Line we have Lyttelton to Heathcote including Ferrymead in a project, then from Woolston to Waltham, then from Middleton to Hornby, and then from Islington to Rolleston. The reason Christchurch was put in with Addington going north to Riccarton was because we had Addington in two projects, one for the MNL and one for the MSL, which was an unwarranted duplication.The one we haven't started on really is Hornby to Lincoln, and it's likely we will take Hornby out of the MSL Gimp projects at this point and put it into the one for the Hornby Industrial Line.

It's timely to comment briefly about maps of local government boundaries. Linz Data Services does not have this type of map in the list of layers that can be downloaded through their site on Koordinates. However, Statistics New Zealand, another Government department, does have them through its Datafinder site, also hosted on Koordinates. As a result we have taken the opportunity to download six layers together: Maori Constituency 2019, Constituency 2019, Community Board 2019, Regional Council 2019, Territorial Authority 2019 and Ward 2019. This information is needed in order to discover the boundaries of each of the wards for the Regional Council elections and in so doing, be able to assist certain candidates in the wards of the transport related issues in their constituency.

Saturday 10 August 2019

MSL Branches [17A]: Bluff Island Harbour

This week we took a little side trip to have a look at Bluff with the NZR aerial photos from 1972-3 covering the island harbour as well as the land based station yard. Like many ports, Bluff once had extensive shipside trackwork on the wharves that is no longer needed in this era of containerisation. As a result their rail network is much less extensive than formerly, aided by the shift to road transport and traffic being railed between Southland and other regions' ports to suit shipping patterns.

 Starting off with our usual pair of overview maps showing how things have changed over a 40-plus year period.

Our first maps are the island harbour. We don't know much about this structure, when it was built or for what purpose. Most ports have a series of wharves that jut out from and at right angles to, the shoreline. The "Island" is very unusual in NZ, and made for an interesting and unique rail layout. The westernmost tip as you can see was notable for the railway engine turning triangle, which is now gone.

Going east along the island, we get into one of the wharves, with a storage shed and attendant sidings. Ship-side sidings were very common on NZ wharves once, but have mostly disappeared since containerisation made it unnecessary to directly unload to railway wagons. Often times tracks are still in place on parts of wharves, but here there is just a single siding still connected and usable.

 More into the middle of the island is the main railway storage area. However the large yard with its multiple sidings has been largely reduced to the main line and a couple of tracks.

The south-eastern part of the island had several wharves along with their numerous tracks. Scissors crossings and other complex track structures such as double slips were commonly seen on wharves back in the day in order to fit as much track space as possible into a cramped layout. These days all but gone with just a couple of tracks across the whole area.

We can now have a look at the main railway station and yard at Bluff. The curve taking the main line across the bridge to the island harbour is to the left. Even in the 1970s there were few sidings in this area. The island section became the main line a long time ago and the Bluff township area a siding off it.

A little further east we come to the main railyards and some industrial sidings. These days practically everything is gone. 

Here we can see a shore-based wharf and a couple of industrial premises served by wagon turntables. These were once a popular way of getting into premises with a track and space saving layout, but fell from favour as longer and heavier wagons became more prevalent. The wharf was very interesting as there were no fewer than three separate tracks crossing between it and the shore, two of which can be seen in the black and white historical map. This was a necessity to connect up all the tracks in the tight space available, but these days, with no shipside tracks needed, the connecting lines and even some of the bridging has gone.

 Closeup views of the two sets of private sidings connected by wagon turntables. In the first photo we can see another track coming out of the front of one of the premises (far left) that appears to have been disconnected. The right hand premises in the same map is interesting as it was connected directly without a turntable.

Lastly we can see the end of the line where it went down to the tank farm and simply stopped adjacent to what was then the famed Fluteys Paua House. This area is known as "Bluff Township Siding".

Friday 2 August 2019

Project Development Report [2019K]

This brief report is to update progress for 2019 so far as the year is now more than half over.

At the start of this year work was happening on the MNPL line which continued until the end of January and then work was switched onto the Main North Line, followed by the Kinleith Branch, North Auckland Line, then parts of the Main South Line around Dunedin. Then we had a look at Hamilton on the NIMT, followed by a significant chunk of the MSL within Canterbury. The next section to be looked at was the Cromwell Gorge.

At the start of June, work was begun on the Christchurch specific project in conjunction with some of the other areas that we support, and the Midland Line work was started towards the end of that month. Since then, work has alternated between Christchurch and the Midland Line.

It seems a good move right now to push ahead to complete Volume 9 for the Midland Line over the month of August, alternating with the Christchurch specific project as necessary. 

In terms of the overall project and its goal to have all 12 volumes completed at a basic level by the end of this year, that hasn't really fired, however neither has the alternative preference of completing any volume at all. We are now substituting an alternative schedule, which is to prioritise the South Island volumes of which we have six, to be completed first at whatever level seems appropriate, which will be more than basic. This includes revising Volume 7, the Nelson Section, with inline yard layouts and other detail using the aerial photography we previously obtained, which was put into an appendix at the end of the most recent edition of the printed volume.

However it is possible to work on the North Island maps by using WMTS to pull in live aerial layers of any area without the extensive work that is needed to download map layers for offline use, so using this to complete any area of the North Island to the Basic level that we proposed could make it happen a lot faster than has been the case to date. 

The priorities have shifted from first completing all of the maps to the Basic level in 2019, to completing as much as possible of the South Island at intermediate or comprehensive level before completing the Basic maps in the rest of the country. Some intermediate or comprehensive work of the North Island will continue throughout next year, especially for the Palmerston North Gisborne Line. Basic maps for North Island areas will also continue this year but we can't say how complete that will be by the end of 2019 at this stage.

Midland Line [0E]: Volume 9 Progress Report 5

This is a brief update on progress with Volume 9. Currently we have completed the route alignment as far as Otira and the details of the Otira yard tracks are being drawn in. A decision has been made to use the available aerial photography we have as far as Kotuku to draw layouts of all stations for which the photographs cover west of Otira.

Route alignment which consists of drawing tracks and station markers is one stage of the mapwork and the second stage after that is to put in bridges, tunnels and milepost markers where applicable. We expect to push on with route alignment towards Stillwater, Greymouth, Hokitika and Ross, although the last section is mostly done already, so there isn't a lot to be done in that respect.

Visits to Archives New Zealand over past and coming weeks will fill in in the details of the major yards of Stillwater, Greymouth, Hokitika and Ross in lieu of any available aerial photography. We hope this should enable Volume 9 to be completed by the end of August.

 The location of Bealey Bridge is an interesting question. Working Timetables and Kiwirail maps place it on the eastern end of the bridge as shown to the right corresponding to 68 miles 45 chains. However NZR file information shows the placement of the passenger stop at the western end of the bridge corresponding to 69 miles.

The other question is the location of Bealey Quarry and at this stage we are not confident of being able to determine that with our current level of research.
 Apart from the ballast siding at Waimakariri Bridge there was also one at Cora Lynn for a period probably around the 1940s which is likely to be the one with wagons in it shown above. This was not a source of high quality ballast and was only used for emergencies.
Another location where ballast was taken along the Midland Line was Sawmill Stream at approximately the location shown above. Probably this dates from the construction days and only one reference to it from 1923 has been found so far.