Thursday, 2 April 2020

Wairarapa Line [3A]: Melling Branch / Western Hutt Section

"Western Hutt Section" covers the original route of the Wairarapa Line from Petone to Haywards on the west bank of the Hutt River. This is where the line was first opened in 1875. It remained the main line until 1954 when the Hutt Valley branch on the eastern side was extended through to Haywards and became the deviation from the original route, which was closed between Melling and Haywards, in 1954. There were various reasons for changing the route that included fewer maintenance problems (the original route was close to the Hutt River and subject to erosion from the water), more room available for stations and double tracking, and the greater population in the eastern side of the valley as new housing developments were made in the 1930s and 1940s that were more conveniently served by the new line on the same side of the river.

The original route was still able to be traced for a number of years after it closed but in about the 1970s, State Highway 2 was pushed through on the west bank and took over practically all of the rail corridor. Any that wasn't built on was landscaped out of existence. In reality the only segment that can be distinguished is a short piece at Haywards which is part of Benmore Crescent. At the same time as the line beyond Melling closed, Melling station was relocated to be more convenient to the new Melling Bridge which was part of river straightening works that would leave the old suspension bridge high and dry.


Current Melling station site in 1939. The ballast siding can be seen to the right.


Original Melling station site seen in 1957 with the platform and building still in place.




The junction at Haywards, with aerials from 1941, 1957 and 1970.

Wednesday, 1 April 2020

Wairarapa Line [0W]: Volume 6 Progress Update 23

Welcome to Volume 6 Progress Update 23. Over the past couple of days we've been working on the Rimutaka Incline Section from Kaitoke through to Featherston. We now have complete aerial photos from 1943 and some other bits to work with. This is a reasonably straightforward task to complete but does require a bit of time spent at Cross Creek to try to draw a reasonable tracing of the track layout.

Work is also continuing to make a set of 1957 maps for the Western Hutt Section. We had expected to have these a couple of days ago but there were some software issues due to the size these layers had to be scaled in the computer, because the originals are at 1:27000 and have to be scaled to match 0.1m pixel Linz aerial imagery. This meant that the original layer with 3.6 million pixels got scaled 14x in each direction and ended up with 6 billion pixels which the software found difficult to manage, so we have had to crop off all the bits we don't need, like the hills either side of the Hutt Valley etc. No impact on the maps but a lot of positive impact on our sanity being able to save the graphics file without it taking 10 hours or using 100 GB on the disk or crashing. (The only numbers that actually happened are 12 saves that crashed and lost all our work before we figured out the cropping)

The best bit after coming up with a more realistic schedule is having a better life balance even with everyone in the country being stuck at home during Covid 19 lockdown, plenty of time for other things without spending all day on these maps, it's still an important daily use of our time but not to the exclusion of everything else. Should have these WHS maps published today, and have the RHS part finished up to Featherston by the end of the week certainly, even with a bit of revision of the Upper Hutt to Mangaroa section and looking at the Featherston Army Camp siding. There is plenty of slack time when making mosaics because the bigger graphics project files take a couple of hours to save and that leaves time for other things.

According to the original schedule that left three days to finish from Featherston to Woodville that included creating mosaics of the three major stations (F-C-M) plus the Greytown Branch. More realistically that will take another week, and then we allow one more week to finish from Masterton to Woodville. In theory that is just Basic level revision of the remaining maps, but when we did Volume 5, we would look at aerial coverage of the major stations to see what detail we could pick out on the ground, and that did slow things a bit. But at any rate we expect this volume will be completed by the end of the present lockdown, so even if the country is still quarantined at the end of April, Volume 6 should be finalised and released by about April 21.

Monday, 30 March 2020

NZ Rail Maps Project Development Report [2020F]

In our last update we mentioned that we were considering relaxing the development schedule and allowing two years to complete the maps as expected. The key reason for this is that the level we are currently developing maps to will need longer than the current year to achieve, with the Intermediate level that we are working to.

This has naturally brought about the suggestion that we should work to release all 12 volumes to the Basic level as quickly as possible, and then push on with volume by volume completion to the next level.

However at this point we need to redefine the Basic, Intermediate and Comprehensive levels. In summary:
  • Basic is a set of diagram maps of the current and known historical rail corridors based on current aerial photography and other current sources.
  • Intermediate adds aerial maps, including georeferenced historical aerial photography, to the Basic level
  • Comprehensive adds a printable PDF volume to the Basic and Intermediate levels.
It's appropriate to change these because our priorities have changed. We now regard the online formats (diagrams and aerials) as being the highest priority and reaching the greatest number of users. The posts we made earlier this year defining these levels will therefore be republished.

Whilst the PDF volume format of the maps is still important to us, there are two facets of it that have to be considered for resourcing. The first is that the maps that are produceable in PDF form have to be a unique form factor just for those volumes. This means we have to generate a completely different set of diagrams from the ones that are on the web site. The second issue is simply that there is low demand for this format. Hence it is becoming the lowest priority overall and we now consider it to be the premium format that will take a lot longer to appear.

We are still very serious about completing the 12 volumes and bringing the overall project to a close. We anticipate staging that out over the next three years. The stages will be as follows:

  1. Completion of all 12 volumes to a Basic level will be undertaken serially after Volume 6 is released. This should only take about 2 months.
  2. Serial completion of individual volumes (after Volume 5 and Volume 5) to Intermediate level. This will continue much as it does now, but is now expected to take until the end of 2021.
  3. Complete the Comprehensive level, i.e PDF volume, in all 12 volumes over 2022.
 So for now we'll be pushing on with the Volume 6 Intermediate level, then we'll be switching to Basic level of the other 10 volumes. We will then go back to Intermediate level for those 10 volumes, and then Comprehensive level for all 12. This will ensure there is at least some maps available for all 12 volumes in the shortest possible time and then they are being progressively upgraded to the full level of coverage.