Thursday, 25 April 2013

Port Chalmers-Dunedin-Mosgiel [3]

This is basically the “Dunedin Suburban Area”, which is the extent of coverage of suburban passenger transport in the Dunedin area. This is a three part article incorporating 33 maps which were originally produced at 1:2000 scale. N.B. Due to some vagaries of Blogger the maps get resized to a smaller scale so I can’t really help by saying what the actual scale is that you will see in the maps following.


Heading up through Green Island the Walton Park or Green Island branch went south off the main line, north/east of the station. The original route dating from 1874 when the line opened was deviated as part of the duplication works, although it’s not too obvious why such a large deviation was needed. Possibly the original junction was too close to Carnfort Street bridge, which I assume replaced a crossing, and perhaps also embankment construction was needed. Another possibility is that the later route already existed as a siding and in any case, perhaps it was just easier to make a new connection rather than lift the line up on the embankment like was done with the main line. I understand the latter route was kept as a siding after the rest of the line closed, and it got its own subway when the motorway was put through, which is still there today. As at other stations the main line was deviated through Green Island, this being an easier method of construction where there was enough space to deviate the main line. Where space was more confined, the original route was used with the tracks being lifted up in stages. The actual works carried out at Green Island were to “raise the dip” by which means the grade was levelled out.


Coming through Abbotsford there was again a main line deviation along with the duplication works. The Fernhill branch can be seen at the upper left of the map. The main works needed in the regrading of Abbotsford in 1911 were to lower the station yard by 18 feet (approx 5 metres).


Further south/west of Abbotsford can be seen a tramway at right angles to the track that apparently served a coal mine.


At lower right of this map is the Abbots Creek bridge. This bridge had to be raised in the duplication and the two sides were alternately lifted in stages with the abutments being extended, until the required height was reached (the embankments being built up in the same way and the bridges raised to match each embankment raising stage). The disused duplicate bridge at this location is still in place. Towards the middle/left of the map can be seen the original route leading to the original Chain Hills tunnel.


Here we see the tracks entering the two tunnels. The new Wingatui tunnel is about twice the length of the old Chain Hills tunnel. Below we see the tracks coming out at the south/west ends of the tunnels. The Chain Hills tunnel still exists today. The new double track tunnel was rather difficult to build costing 3 1/2 times as much per lineal yard as the Caversham Tunnel due to the nature of the ground that was encountered in building it. On reflection the conditions at Caversham were unusually good compared to a more typical experience of most railway tunnels in NZ, that Wingatui would tend to represent.


The site of Wingatui Station was changed to be closer to Dunedin and is directly adjacent to the tunnel portal.


Approaching Mosgiel the junction with the Outram Branch is encountered. Mosgiel (below) is the end of the double track section from Dunedin.


Port Chalmers-Dunedin-Mosgiel [2]

This is basically the “Dunedin Suburban Area”, which is the extent of coverage of suburban passenger transport in the Dunedin area. This is a three part article incorporating 33 maps which were originally produced at 1:2000 scale. N.B. Due to some vagaries of Blogger the maps get resized to a smaller scale so I can’t really help by saying what the actual scale is that you will see in the maps following.


Just north/east of Dunedin there is this interesting deviation that involved a station called Pelichet Bay (see the third map, below).


Because of the construction of Forsyth Barr Stadium at Awatea St, the powers that be decided they wanted to push State Highway 88 through on a new route alongside the main line. This involved ripping up a number of railway sidings so that part of the rail corridor could be stolen for the highway.


Here we can see the site of Pelichet Bay station at the corner of Frederick St and Anzac Ave (approximate location). There in fact was a bay there at the time the railway was originally built; the line was deviated onto a causeway in the 1920s, unlike the other bays north of Dunedin this one was completely filled in, in fact the land on both sides was reclaimed so the shoreline has moved out a lot.


The doubling project of 1908-1914 between Dunedin and Mosgiel involved a lot of work to improve the gradients and eliminate level crossings. The work more or less starts about where the Dunedin Loco sidings come off at the left; the main line was raised up on an embankment at 1 in 100 to take it over Andersons Bay Road which was the first crossing removed. The dashed line to the right is approximately where the main line would have run originally. The DP & Ocean Beach Railway ended up going under the main line and the segment as far as Strathallan St is still in place today. The embankment was built up by constructing trestling, which was then buried, an old-school method of constructing embankments used around NZ before the advent of heavy earthmoving machinery.


The Andersons Bay Rd bridge still carries double tracks today but the extent of double track now reaches only a short distance to the south/west of this bridge. The original site of Kensington Station near King Edward Street, on the level, was replaced by a new station on the embankment at the north side of the new King Edward St bridge. The station had only pedestrian access, gained by a stairway entered through the bridge abutment rising between the twin tracks to the island platform. One side of the bridge was removed at the singling of the line and it has since been rebuilt with new abutments. A siding crossing Wilkie Road just south/west of King Edward Street bridge was probably removed when the line was raised, if not before. Just to the south/west is the current siding into the Hillside Engineering site. Wilkie Road Bridge has also been singled but retains its dual track abutments.


As the line came around the back of Carisbrook Stadium, this is about where the extent of the raising from Dunedin Station ended. My research found an old photo that shows there has always been a railway bridge over South Road. There have been not one, but in fact two, deviations of the line between Murrayfield St and Caversham Station. In 1910 the duplication work required a new double track replacement of the Caversham Tunnel at a lower level. A deviation was put in to take the railway line down to this lower level. This new section of double track remained in use until the 1980s. It was then that a proposal to build a new motorway through Caversham was put into effect. Up until that time the main traffic route was via South Road which was well clear of the tracks. In order to make room for the motorway a new single track railway embankment was constructed from Murrayfield St to Caversham so that the old route could be taken over by the motorway. This required a new railway bridge over South Road. The map above therefore properly shows this new section as always being single track. Due to the motorway construction, no trace can be found today of Caversham Station with its island platform, nor of the original 1874 railway route. The new railway route of the 1980s did bring one benefit and that was curve easing, the previous curve had a speed limit of 60 km/h, the realignment considerably eased what was quite a spectacular S bend at this location. The 1910 route on the other hand was first started in 1907, but was not finished until after the new tunnel had been built, due to a lot of unstable ground in the area causing many problems with the construction.


Continuing south/west from Caversham we can see how the railway and the motorway bisected Caversham. There were six north/south aligned streets that all got bridges to replace level crossings when the new line was opened in 1910. The advent of the motorway resulted in all of the streets except Barnes Drive being closed, and given new names on the true north side. The bridges were all removed except at Barnes Drive, and at Goodall Street (between Catherine Street and Asquith Street) where it is still used for access to a footbridge over the motorway. Before there was a motorway, South Road came along to Caversham Place and crossed over the railway line on a massive bridge that is still in place today, although now on a dead end. Just south/west of this bridge the present day Caversham Tunnel is encountered. This is constructed through sandstone and is completely unlined except at the portals. This is a very wet tunnel and at the time of completion was discharging more than 60,000 litres of water a day, which was piped to Hillside.


Continuing to the south/west are the two Caversham tunnels. The portal of the original is now below the motorway which at the time of the recent reconstruction (2009-10) was carried directly over the top of it, when formerly it was to the side of it. The tunnel remains accessible and has in recent years been used by the DCC Waterworks department to carry water and sewerage reticulation. The approach to the north/east portal is made through a deep sandstone cutting and there used to be a footbridge over the top at the end of Lindsay Road (off Rockyside Terrace) but this was removed in the recent motorway works.


The original tunnel came out below Kaikorai Valley Road which crossed over the top of it. Since closure of the 1874 route the overbridge was removed, but a culvert was put underneath the road to carry waterworks pipes. The railway bridge over a stream just to the south/west of the road is gone but a road bridge was built parallel to it to give access into the old fertiliser works site. Sidings shown on the map at the old Cattleyards station are those which existed in about 1964, all of the industries at the site now being closed. The current Caversham tunnel exits into a cutting just to the north/east of Kaikorai Valley Road. The line then passes through the former site of Burnside station.

Port Chalmers–Dunedin-Mosgiel [1]

This is basically the “Dunedin Suburban Area”, which is the extent of coverage of suburban passenger transport in the Dunedin area. This is a three part article incorporating 33 maps which were originally produced at 1:2000 scale. N.B. Due to some vagaries of Blogger the maps get resized to a smaller scale so I can’t really help by saying what the actual scale is that you will see in the maps following.


Port Chalmers showing the wharf and freight terminal sidings and the tunnel.


Heading down to Sawyers Bay, a curve easement can be seen to the left. This work was done about three years ago.


Sawyers Bay station and continuing south, the eponymous tunnel (double track width).


Between Sawyers Bay and Dunedin are numerous realignments of the original railway route, which followed the shoreline of various bays. These were bypassed by causeways which were built to accommodate double tracks. However the last of these (Blanket Bay) was never completed as a double track section and the tunnel has subsequently been used to accommodate the single main line and the Sawyers Bay station loop. There was also a tunnel in the original shoreline route which was demolished to make way for a realignment of the highway.


The completed double track section to the north reached to St Leonards and was singled again in the 1980s.



South of Ravensbourne is Dunedin’s only remaining double track mainline section.

Saturday, 20 April 2013

Maimai Siding

Maimai (~50 km) is a small locality on the Stillwater Ngakawau Line, near Reefton (~62 km). It is divided from the latter by the Reefton Saddle. Suttons Mill operated at some past time to the north of Maimai with a bush tramway. Maimai is just before a 70 degree bend in both the railway and State Highway 7 which are parallel at this point. Just downline from Maimai is the bridge crossing the Mawheraiti (Little Grey) River. Maimai is the last location before Reefton that is in the valley of the Mawheraiti River, therefore the last bit of flat land before a train has to climb the Reefton Saddle, pass through the Tawhai Tunnel and descend again to Reefton.
Birchfield Coal established an opencast coal mine at Giles Creek in 1984 and the operation has developed to produce 500,000 tonnes of annual output. The mine is situated in the Rotokohu Coal Measures at an altitude of about 200 metres on an escarpment directly overlooking the Inangahua River Valley. Due to the topography and lack of bridges across the Inangahua River, road access to Giles Creek Mine runs on a north south alignment, towards Maimai, rather than heading east towards Reefton (or more correctly, Cronadun). From Maimai, the route goes north for the first ~7.5 km on the sealed Maimai Road. Reaching the turnoff to the mine, the road climbs steadily through forest to reach the mine after about another 7 km. All of the mine’s output is trucked via Maimai as there is no other road access. Here is an area map of the country between the Mawheraiti and Inangahua Rivers.
Due to the proximity of the railway line to Maimai and the desire to rail coal for customers, a loading facility has been established at Maimai, consisting initially of a loading bank made out of old highsider wagons (similar to the loading bank at Waimangaroa for Denniston coal traffic that closed in the mid 1990s) with a single ended siding. The map below shows the layout.
Fonterra has contracted to bring coal from Maimai by rail to its new dairy factory at Darfield. The siding is now being redeveloped and may have a different final layout to that shown above.
Maimai is one of numerous locations on the Stillwater Ngakawau Line and Midland Line and their branches where coal is or has been historically loaded for customers. Some of the other locations for coal loading include Stillwater, Rapahoe, Dunollie, Rewanui, Reefton, Westport, Rahui, Cascade, Waimangaroa, Conns Creek, Ngakawau, Granity, Summerlea, Seddonville, Mokihinui Mine, Ikamatua,  Ngahere, Blackball, Brunner. As of today, active locations include Ngakawau, Reefton, Maimai and Stillwater, while Rapahoe may be mothballed due to closure of the Spring Creek Mine (except for other possible Solid Energy production such as at Strongman or future new production at Rewanui). Sergeants Hill is proposed as a loading point by Bathurst Mining which is establishing new opencast production at Denniston.
Acknowledgements to the Newzealandlocomotives group for contributions.

Saturday, 13 April 2013

The five faces of Paeroa Junction

Well the previous article said there were only four. But things got more complex because there were two different bridges across the river between the junction and Paeroa town. So here are five faces of Paeroa Junction.
N.B. The parts that were operational at each image are in red, parts in black did not exist or operate at the time.
In 1898, the railway from Frankton to Paeroa opened. A single track wooden bridge was used to cross the Ohinemuri River south of the town. The railway station was a little north of this bridge.
In 1905, the branch line to Waikino was opened. This needed a curved track towards the east which had a set of junction points just to the south of the bridge. The signals over this set of points were controlled by a signalbox and ground frame at Paeroa station.
In 1925, stopbanks were constructed along the banks of the Ohinemuri River. This meant the railway bridge had to be raised about 8 feet (2.5 metres). This made the gradient from Paeroa railway station to the bridge severe, so that it was decided to move the station 1 km further north to ease out the gradient. Therefore it was also decided to move the junction of the two lines to the north side of the river. This meant the new bridge had to be built for two tracks, and it was opened in 1926. The track from Frankton was on the west side of the bridge, and the track to Waikino was on the east side of the bridge. The new bridge was constructed of steel girders replacing the wooden Howe Truss original. Within two years the East Coast Main Trunk was completed. All through trains had to go into Paeroa and were then reversed to continue their journey. This did not matter much as steam engines had to be serviced at the locomotive depot, and an extra engine could be attached at Paeroa for trains heading to the east if it was needed. Because of the loss of the passenger station just to the north of the bridges, the new flag halt of Paeroa Township was opened in 1932 at the location of the old station. Only one platform and shelter were provided so that passengers could only board trains travelling on one of the tracks.
In 1959, traffic on the line was increasing because of the output of timber processing plants at Kawerau and Kinleith, which had been built earlier the same decade. At the same time, dieselisation of the ECMT meant that the locomotive servicing stop at Paeroa was not as essential any more. It was decided to shift the junction of the two lines south again, by opening a new station at Paeroa South. A deviation in the eastward route was made to make room for the new railway yard at this location. The direct link from Frankton to Paeroa was removed and all trains to or from the Thames Branch had to reverse at Paeroa South. ECMT trains had a direct connection to Frankton via the new south curve and saved about 5 km in distance and also in time by being able to run straight through instead of reversing. Paeroa Township station was closed, while Paeroa became a station only on the Thames Branch. The second track and bridge between Paeroa South and Paeroa were no longer needed and were removed.
In 1978, the Kaimai Tunnel opened. This resulted in the closure of the railway between Paeroa South and Katikati and it was lifted about five years later. In order to continue with the Thames Branch, which was now extended by 43 km back to Morrinsville, the new ECMT junction, the direct link north to south needed to be reinstated. This was installed as the new curved route shown rather than the more direct link of 1898 to the west. Some say that the original formation had been built on in the intervening 19 years, while others suggest the curved route needed less new track laid and reused the existing level crossing of SH26. Paeroa South station was closed, and most of the track to Apata was eventually lifted, except for the section now owned by the Goldfields Railway between Waihi and Waikino. The track between Apata and Katikati stayed open for several years after 1978 but a railfreight terminal proposal at Katikati came to nothing.
The sixth face (not illustrated) happened after 1995 when the Thames Branch closed. All track and most structures on the branch were removed beyond Waitoa. Railfans can still trace some of the site of the junction and branch today. The most notable remnants on the entire former ECMT route and Thames Branch today are
  • The Te Aroha railway station building preserved at its original site.
  • The bridge just to the south of Te Aroha.
  • The Thames railway station at its original site.
  • The Karangahake Tunnel which is part of a public walkway, along with the old railway bridge at the east end.
  • The station at Athenree which was relocated to the nearby site of Athenree Historic Homestead.
  • The Paeroa station which was taken to Waikino as part of the Goldfields heritage railway project.
  • The Waihi station on its original site as part of the Goldfields heritage railway project.
  • A culvert just east of Waihi where the railway crossed over a tramway
  • Between Katikati and Apata some of the larger bridges are still in place, used to carry power lines.

Monday, 1 April 2013

The four faces of Paeroa

With my change of focus today to mapping part of the old ECMT route I got to Paeroa and then started drawing up the notorious junction triangle at the south end. This story is well known but I will repeat it here with these four images.
In all of the images, the red lines are the ones that were in use at the time. The black ones are shown for interest but did not actually exist or were in use at the time. As you will see this was not a triangle as we would ordinarily know it since there were not three legs in use at any one time.
Paeroa in 1898. The Thames Branch had reached Paeroa from the south, and the red route went north to Paeroa and south towards Frankton. A pretty straightforward layout.
Paeroa in 1905. A branch to Waikino (which later became the ECMT) had started to be constructed. Therefore a connecting curve was added so that trains could run from Paeroa to the east.
Paeroa in 1959. In conjunction with the dieselisation of the line, the direct link curve to the ECMT was added. As the direct link to Paeroa from the south was closed, a new junction station called Paeroa South was added, which required a realignment of the approaches to it. All trains for the Thames Branch would now have to reverse or be shunted at Paeroa South.
Paeroa in 1978. The ECMT along with Paeroa South station was closed. The direct link from Frankton to Paeroa was reinstated, albeit on a new alignment because the original route had been sold and built on.
Work will continue on this in the coming week heading out to find the Pokeno-Paeroa deviation proposal of the 1930s (formation was constructed, but never completed). This is well covered on several NZMS 1 maps almost all the way through. This is where you can begin to wonder why it was that this route was never actually completed, certainly most if not all of the formation was surveyed and a lot of work done on it. Info received indicates the work was started 1938 but it was never finished. In hindsight this only moved the junction of the ECMT further to the north and did not address the problems of the difficult Paeroa-Apata section which was addressed by building the Kaimai Tunnel. Post war efforts focused on the latter and the Pokeno-Paeroa cutoff line was abandoned and forgotten.