Saturday, 29 July 2017

Otago Central Railway [34A]: Clyde 1977

As noted in my previous post this aerial photo holds a crucial piece of detail regarding to the Clyde railway station dating from March 1977. I have had previous scans done of photos from the same aerial survey, partly to look for the NZED siding. Now it seems the location of this siding was near the MOW sidings that were installed for the Clyde Dam project. This aerial photo at hi res has been ordered from Archives NZ and I hope to take a look at it next week, it is really the final piece of the puzzle in terms of writing the article. This week has been pretty slack in terms of any sort of writing so next week I will have to wind things up again pretty hard to make sure I meet the deadline.

Friday, 28 July 2017

Otago Central Railway [34]: Clyde Sidings

Well just a quick note really. Work is continuing in progress on the Otago Central with a lot of writing and various last minute changes to maps to ensure they are properly up to date.

Clyde from 1969 to 1978 had an NZED depot which was accessed by a siding with the points facing the original Clyde station.

With the advent of the Clyde Dam project the depot was taken over by the Ministry of Works and the tracks rearranged.

I have enquired for one last aerial photo. This is Survey 5073 Run G Photo 10 that covers the footprint area shown in green above. The aim is to confirm the above details. As time is running short to complete the map of Clyde I hope just this one photo will confirm the site and track layout for the NZED depot as it then was.

Friday, 14 July 2017

Otago Central Railway [31F]: Alexandra aerial photos 2

Well in OCR[32] I posted the footprints of three aerial photos of Alexandra. I have now purchased these photos for $110 and received them today.

The yard at Alexandra was comparable with Clyde or Cromwell in view of the type of facilities that were needed in order to service the commercial requirements of the local community and there is a lot in the photos that I have not seen documented anywhere else. This is quite typical of the focus that the NZ Rail Maps project has been able to bring to the history of this and other railway lines in accessing different historical material that has not been widely used in the past to fill in lesser known information about the railways.

Whilst I won't publish the photos at this stage the kind of information I am able to fill in incorporates all the yard details and will enable the track layouts and buildings to be marked out in exactly the right places instead of being somewhat guessed. The main additional detail to be added is the sidings at the oil company depots and other premises. These depots still existed at the time the aerials were taken whereas I had originally thought they may have been removed by 1983 so it seems that the general loss of freight to road transport was relatively slow to kick in given that road transport started to take over from the mid 1970s. It may be that the sidings were still in place but disused by this time.

The article is progressing well, there will be a short delay for me to update the maps over the next couple of days then back into it to get the writing finished so that the first part of the article is ready for publication on time.

Tuesday, 11 July 2017

ProjectDev: Ensuring correct distances on maps

When it comes to rail maps, we have things like stations that have distances associated with them, and marking the correct distances is a pretty important facet of designing maps.

When the Quail Atlas came out in the third and fourth editions, it was metricated from the first two editions which were produced in the pre-metric era and had imperial distances shown. I would guess most of the imperial data came from earlier working timetables (two in particular were re-released by NZRLS for the North and South Island dating from the early 1950s and are important reference works that I may yet want to access for the maps other than Otago Central). 

The metric Quails apparently chose to convert all the imperial distances to kilometres which is something I disagree with most strongly. I don't believe they were obliged to convert all maps to the metric measurements and this brought with it other issues. Basically the imperial distances are a kind of "namespace" if you like. That particular namespace was defined by the process by which these measurements were obtained and the era in which that occurred. It is extremely possible that every railway line has its own distance measurement namespace and that there may in fact be several different distance measurement namespaces for any particular line.

What is important to recognise is that the measurement namespaces for a line like the Otago Central were obtained by separate measurement processes and the problem with simply converting the imperial distances from another namespace to the metric distances risks confusing these distances with the metric measurement namespace that NZR obtained for all of their lines that were open at the time of metrication in 1974. The metric measurements were probably obtained by track evaluation car whereas some of the imperial measurements came from hand measurement of the lines as they were built (chain pegs and mileposts were installed as each section of line was constructed). The reason that the metric measurements often differ from metricated imperial measurements is that inaccuracies in the earlier measurements could occur and that lines were also improved, deviated and curves straightened or eased changing the actual length of the line.

It's important to recognise that the measurements from one namespace therefore will often differ from the measurements in another namespace that have been metricated (as is the case in the Quail Atlas for all lines and stations that closed before metrication). The metrication of NZR also resulted in all existing bridges and tunnels being renumbered into new namespaces which has created similar problems with the potential for confusion and duplication of numbers across the different (imperial and metric) namespaces.

Essentially it is my desire to have the correct distances marked and to ensure there is a clear understanding and avoid confusion the following policy has been adopted:
  • All metric distances are those which can be obtained from an official NZR / KRL working timetable. 
  • Where a metric distance cannot be obtained from the above sources, the distance is displayed in imperial measurements (decimal miles).
Where I am having to use the Quail Atlas as a reference source I am converting metric measurements back to imperial, for the present. But I hope to get copies of the working timetables that NZRLS produced in order to have the correct distances shown in imperial units and also some that the Quail atlas is missing (possibly stations that closed before the NZRLS's working timetable reprints were released).

The Otago Central maps have mileposts marked from the chainage charts. There has never been any intention to metricate the milepost markings as the actual km posts on the ground are unlikely to align with positions obtained from converting a position on a chainage chart (for example, 161 km = 100 miles 5 chains).

Now a footnote to the last post: Unfortunate issues with the latest master of Qgis 2.99 means I can't use it for map editing and I have had to revert to an older version running on my Windows computer. Just to make things even harder there are networking issues with my mainpc running Xubuntu 17.10 that means none of the virtual machines that I could run on it can connect to the shared volume on it. But the Windows computer can. So at the moment I am trying to determine with the Xubuntu developers why this networking issue exists. It's taken a couple of days I didn't really have to get an older build of 2.99 running on the Windows computer to ensure I have something that actually works for all the rest of the map work I am going to do until the project finishes at the end of the year.

Well I have now sorted the networking issue but still have to use the Windows computer along with an older development master running on a Linux computer because of various issues. But we will get there.

Main North Line [3]: Clarence

I'm going to go a bit out of sequence here and put Clarence into the mix while also talking about some other things. I had to reinstall the computer that I do the maps on (it was updated to Xubuntu 17.10 which is actually a beta version), this let me update Qgis 2.99 to the latest master so it is all looking pretty good all round except for new bugs that seem to creep in but I do still have 2.14.10 running on Windows. No VMs seem to be able to network to the new installation and I can't be bothered trying to fix the issue as Windows 10 is OK with networking to this computer. Considering the short life of the entire project it is not worth the hassle. For the same sort of reason I had a look at the Nelson-Marlborough project section of NZ Rail Maps and instead of doing a whole lot of work to update that project to the current standard, I have just rolled the data into a bigger CanterburyWestland section that is now CanterburyWestlandNelsonMarlborough. So there are two sections for the whole South Island and three for the North Island instead of three each. The NM section was pretty small anyway as it only had about 100 km of the MNL and the Nelson line in it. So that just makes it real easy dealing with the MNL with the aerial photographs from the earthquake. At the moment I am just transferring data into the new CWNM section so it is all integrated properly. 

The issue in a Xubuntu component that caused long decimal values with a lot of extra zeroes in them to be displayed for distances of stations and milepegs is gone so that's great as well. But the digitising is worse in this new version and for me so tricky compared to 313ec55 that I am installing that version onto the mediapc so I can keep using it to finish the digitising without mucking around as I just don't have the time to muck around with everything needing to be finished by the end of the year. 

Another thing that has happened is that National Archives replied to my query about aerial photos of Alexandra and I have placed the order with them to have these scanned for my use so hopefully I should get these in a couple of weeks. This will probably not hold up the work still going on to finish revising the first part of the article which I have to make a priority to finish this week so I will have to drop the MNL work for a bit until I get the Otago Central stuff pushed along some more. So these aerials of Alexandra will probably not turn up in time to be useful for the OC part 1 but will inform the online maps which is a separate stage.

A construction photo of the Clarence River railway bridge c.1940. Although some sources claim Clarence used a combined bridge before this period, this was actually the first time the railway crossed the Clarence River. The old highway bridge was a kilometre upstream of where the railway bridge was built and there would have been some sharp curves to get the railway to it as well as running alongside a cliff face on the south side and adding several km in length to the railway route must have all been factors in deciding to locate the bridge where it is today.

What's really worth posting about is this is the first train to cross the Clarence River in eight months. This means trains can now go from Picton almost all the way to Kaikoura. Maybe they can actually go all the way to Kaikoura. You can see scaffolding around most of the piers; this suggests the repair work was concerned with the attachment of the bridge trusses to the piers. What we can also see is the bridge pier that has been underpinned on the right; this more or less means the extent of flood induced scouring in the riverbed has been so much that several piers have had new bases put around them to secure them.

 The whole bridge.

The south end and you can see quite a few underpinned piers here in this river channel which must be the main river channel of the Clarence River at this bridge with four piers underpinned in the water and a few more up out of the water by the looks of it.

Friday, 7 July 2017

Main North Line [2]: Ferniehurst-Claverley

Last post we had a look at Parnassus as the first station within the ambit of the aerial photography that we have as a result of the earthquake in November 2016. There are two main goals to be served by making use of that aerial photography: mapping out all railway features in greater detail, and documenting some of the damage caused by the earthquake. By the time these maps are published the MNL should be open again. Whilst I could use Linz aerials to document the entire line I will not have time to remap any other parts of the MNL so it will just have to do as far as the whole maps project goes.

As we go north from Parnassus I have found this realignment of the MNL between the 137 and 138 km pegs. This was done like much of the other realignment works found on many lines, on the basis of land boundaries on a curve being further out than the current alignment of the railway. Having previously identified many other realignments, particularly several between Nonoti and Phoebe, this is a new one between Parnassus and Ferniehurst.

The curve and gradient diagram for this area says that these two curves as they are today have a radius of 240 metres each. The originals may have been as sharp as 150 metres radius (I don't have any corroboration of this) and would have therefore had a fairly significant limit on train speeds.

From there the next major point of interest is the Hawkswood Bridge. The original structure here was a single lane overbridge. The current overbridge (like many these days a large steel culvert with earth fill embankment over the top) was constructed as part of a highway realignment project in 1999 or 2001. The overbridge sustained significant damage in the quake and repairs have only just been completed at the time of writing.

See this post on Enzed Transport about the highway re-alignments in the area.

 This photo shows the section of highway that was bypassed. This area is still a local road into the settlement of Hawkswood. The highway was winding, narrow and steep at this location.

The next thing north is Ferniehurst at 143.27 km. It used to be much closer to the highway than is the case today because another realignment knocked out some more sharp curves, probably at around the same timeframe as Hawkswood. In this case part of the former highway has been dug up and ploughed into farmland, which is much more commonly seen today than would have been the case in the past, in fact the Resource Management Act probably makes NZTA obligated to remove former roads off the face of the earth. Unlike Parnassus, Ferniehurst stayed open to the public until 1988. It is 10 km north of Parnassus. Spotswood is the station 4 km south of Parnassus that closed in 1978, and Mina a further 10 km south of Spotswood. Mina stayed open to freight until 1987 (the Coastal Pacific still stopped for passengers for a few more years after this). So from the period of closing Spotswood and Parnassus, freight in the area must have been expected to be handled by Mina and Ferniehurst. I would say by 1987 it was pretty clear that the railways wasn't going to hang on to a lot of freight in these small rural areas and the Booz Allen Hamilton report was being implemented in force so there were a lot less stations staying open. Subsequently Rangiora became the first freight centre south of Kaikoura. Mina stayed as a loop, as did Spotswood, Parnassus and Ferniehurst, but with the further rationalisation of service facilities, only Spotswood and Ferniehurst are loops today. 

Ferniehurst also has an old siding still in place as do many of these stations, with the points still in place off the loop.
In this case the siding track which is still in the ground is covered by ballast for loading, so the track has been disused many years and it would seem ballast trains are loaded in the loop, although this blocks out the loop for freight train crossings during loading. Just north of Ferniehurst is Bridge 89 crossing the Conway River.

This is Bridge 90 which is the next one north from the Conway River. It is about halfway between 148 and 149 km. You can see obvious damage at the approaches. The bridge itself was badly damaged and was completely demolished and replaced by a temporary bridge, a permanent bridge is to be built in future.

Hundalee, the next station north at 152.05 km, dates from 1943 with the push through the middle to finish the MNL during WW2, and was closed to traffic in 1981. The station building stayed on the ground until the early 1990s when it was sold and relocated to Waikari to become the terminus of the Weka Pass Railway. Their other station building, at Waipara (named Glenmark) came from Mina in the mid 1980s. The highway between Ferniehurst and Hundalee used to be really twisty but has been straightened out with the realignments around 20 years ago at places called Glen Colwyn and Siberia Ford. Hundalee is where the highway crosses the Conway River (that the railway crossed at Ferniehurst) so that between the two stations the railway and highway are on opposite sites of the river. I remember the Conway River highway bridge being replaced in the mid 1980s. At Hundalee the highway and railway split and they follow completely different routes north and don't meet again until Oaro.

Next station up is Claverley at 157.75 km. This is actually the first point north of Christchurch where the Main North Line runs along the coast. This was the route chosen to put the railway north of Parnassus because the construction was expected to be cheaper and easier than the inland route (which even today is pretty challenging as is clear from some of the repairs needed on the Inland Highway). 

Claverley is another station that dates from the 1940s and had a quiet life until closing to public traffic in 1981 but was retained as a loop. There is again a former disused siding here still buried in the dirt.

One of the daftest ideas I heard from some railfans not long after the quakes was that the Waiau Branch would need to be reopened to Waiau because the present MNL route was likely to be abandoned and the railway constructed through the same inland route as what used to be Highway 70 to Kaikoura. This was never going to happen because SH1 runs alongside the MNL for much of the way and the reconstruction costs would be shared in many places. And the inland route north of Waiau would be very expensive to construct. For the Waiau Branch the Weka Pass section was the most expensive form of construction with the many cuttings and embankments, then the country from there to Waiau was pretty easy but then north of Waiau it is all very hilly and would be very expensive to build. History is clear that the Waiau Branch was one of the routes that was considered to take the MNL north but like all the other ideas (including the Mendip Hills section) it was ultimately obsoleted in favour of the present route. The line to Parnassus which finished in 1912 was actually built as the Cheviot Branch. But obviously by that time it had been decided to make it the main line north because, probably, the inland route north of Waiau was going to have too many problems. So there was never ever going to be any likelihood the Waiau Branch would ever be re opened as the MNL in the future, it is well over 100 years since that decision was taken, as in reality, most of the damage south of Kaikoura is confined to a relatively small stretch of route between Claverley and Puketa.

Bridge 95 and Tunnel 1. There was a bit of damage at Bridge 95 that needed to be repaired, I don't recall the details right now.

Bridge 96 is the famous Okarahia Viaduct. The machinery at the south end was already there before the quakes and was removing the side of a cutting that has given a lot of trouble from slipping. There has been no information suggesting any problems with the viaduct itself; it was probably designed to withstand quakes as this became a focus in the 1940s and the bridge at Kopuawhara on the Gisborne Line, which has similar piers but also has an arch that is not present at Okarahia, was also designed with quake resistance in view.

Thursday, 6 July 2017

Main North Line [1]: Parnassus

While I am still revising the article on the Otago Central Railway, actual mapping work has come to a halt on the section Cromwell-Oturehua because all the work that is needed to inform the article writing has been completed. The exception to this is Alexandra, where I am waiting to hear from Archives New Zealand about the three aerial photos referred to in a previous article. Whilst that is happening (or not) for mapping I am tidying up the maps elsewhere in the country because the whole mapping project has to be finished by the end of the year, not just the Otago Central.

So the specific significance of Parnassus to Ward is the aerial photo coverage that was taken after the earthquake last November and because it is of such a high resolution it is great for revising the maps because there are always issues like the length and placement of bridges for example as they aren't always correct in the Linz data service layers that I use for much of the map data. And also I need to put in distances for some of the stations.

Another thing that will be put into the maps is to trace the major slips that have happened from the earthquakes onto the maps. Whether there will be more aerial photography to enable tracing the changes to road and rail routes before I reach deadline remains to be seen.

So I am juggling the MNL maps in between sessions of working on the Otago Central article and checking the maps of that line as well as a few things still need to be put into those maps but I am just getting some variation away from the Otago Central for a bit of variety to alleviate boredom in this part of the project.

I am really not sorry to be finishing the maps as, although I have really enjoyed it and could keep it going forever, it is time to move on to new things in my life that will have a more meaningful longer term impact and involve a lot more people than could ever be the case with such a niche interest as railways let alone railway maps.

Now let's have a look at Parnassus. Because an aerial photo was available from 1972 and with the aid of the Linz aerial photography I have drawn in a basic station layout in the maps that are included in this post.

Parnassus was at exactly 133.0 km. Because of that, the map doesn't have the 133 km peg marked separately as would usually be the case. It used to be possible to still see things at the site which had some track remaining in place (sidings) even though the main part of the station closed in 1981, it was kept as a crossing loop for some time afterwards but I don't know exactly when the loop was finally taken up. I remember a visit there in 1986 as the sidings had bullhead rail in them and I have a vague recollection we may have found a turntable pit (Parnassus was a railhead for many years, from 1912 until about 1940 when the MNL extensions north resumed).  1940 was also about the time a new rail bridge was put in across the Waiau River just south of Parnassus reverting the combined bridge to road-only usage, in which role it continued until a new highway bridge was opened about 1980. At that same time as part of that project SH1 was bypassed around Parnassus and an overbridge just north of the township replaced a level crossing. Since the closure of the station however the local government of the area have had a local road put across the railway line going close to the station site probably also affecting some of the remains of the station. However there are a number of traces if you know where to look and these are documented in the maps and photos, including the bufferstop of the siding and the bridge in the yard.

 South of Parnassus, the approach onto the old combined bridge. This was opened 1912.
 Combined bridge which was used used by both road and rail traffic until about 1940 when the new rail bridge was built just alongside. The bridge was then used only by road traffic until about 1980 when the highway was moved onto the new bridge at the bottom of the map. In its latter years traffic lights were fitted on the old single lane bridge and weight restrictions meant heavy vehicles had to travel via the inland route through Waikari, Culverden and Waiau, using the Leader Road to rejoin SH1 just north of Parnassus.
 Coming off the north side of the old bridge. The highway carried on at the western side of the bridge as it ran through the middle of Parnassus originally.
 Coming into Parnassus from the south. The best location I can come up with for the turntable pit, would be just south of where the road originally curved in to meet the railway station (where the word CLOSED appears at lower right).

 The main station facilities are all visible in this photo. The bridge had a double width section for the main and loop which is still fully in place, and a separate section for the siding which still has the abutments in place but the span removed.
 North end of the yard showing where the buffer stop is still visible, and where also the line originally was intended to go inland via the Mendip Hills.
 Showing the overbridge at this location. Since this was not built until after 1980 it seems oddly convenient it was able to be numbered as Bridge 84.

 A small scale map showing the entire Mendip section. This was never operated as the formation works and bridge were never finished. There is still a lot of formation work that is visible even today virtually 100 years later.
Whites Aviation view of the station yard in 1972.

At 134 km, 1 km north of Parnassus station, there used to be this level crossing over the railway. This was probably closed when the highway went through. Although the highway improvements were bundled in with the new bridge across the Waiau River, the overbridge was finished about a year after the Waiau bridge, so this crossing probably stayed in use until then.

Part of the interest factor at Parnassus is also that the MNL was originally expected to go further inland from where it does now and some formation work and abutments for a bridge across the Leader River was done going north from there. The remnants of that construction including the south side bridge abutment can still be found today. Part of the reason for the delays going north was finding the correct route. Here we can see where the inland going route went off to the left, passing behind the school.

Two photos taken from the Leader Road where the inland route formation works crossed this road. The first photo shows a cutting through a river terrace, the second shows the embankment going onto the bridge that was to cross the Leader River. If one was to walk along that embankment the concrete bridge abutment and the first pier would be found still in the riverbed as illustrated on the aerial photo below.

 Station as seen as a 2016 aerial photo.
 Bridge in Parnassus yard as seen from the railway yard side. the abutments for the siding clearly visible.
 Bridge seen from the other side, i.e. the old roadway inboard of the present highway.
 Site of the old station. The station building was at the side of the road and the goods shed was just opposite it.
Auckland Weekly News photo of the Waiau River bridge under construction in 1911.

Christchurch City Libraries photo of the Waiau River bridge under construction in 1910.

Photo from the A P Godber collection of the ghost bridge at the Leader River on the proposed inland route, with the big cutting clearly visible in the background. About 1917.

Sunday, 2 July 2017

Otago Central Railway [31E]: Article Part 1 / Alexandra aerial photos

Well as you can see it has been a couple of weeks since posting, I have been busy talking to people and looking at a few things.

I am seriously having a look at whether to get some more aerial photos to update the knowledge I have of Alexandra yard, but this will just be to get the maps finished. It won't affect the writing of an  article which is due to be completed within the next week because that won't necessarily include all the maps.

Survey no. 5073 dates from 1977 and is at a scale of 1:7800 which is about as good as it gets. However more digging has found me Survey no. 8194 produced in 1983 and with only three photos total that just happen to cover the railway yard, which makes me think it was a survey produced specifically for NZR. The scale on these is 1:4300 which is even better. According to Archives NZ it should cost $70 total for all three to be scanned at high resolution which is a pretty good deal.

Meanwhile the article continues and it will be fully completed in the first part as the higher priority because there is a deadline to meet and the layout has to be finalised after completing the text. So I am aiming on finishing that this week. The maps may have a little revision but not a lot because the article has to be finished no matter what.