Wairarapa Line [1A]: Rimutaka Deviation [1A]: Upper Hutt-Maymorn

So here is our first article specifically about the Wairarapa Line main line route. There is a lot to this route, and articles that we write about it will not follow a sequence corresponding to the geographical sequence of the line itself. This is because this corridor has had so many different parts to it and some of these have already been blogged about under different names. But we will use series and subseries numbering to distinguish between the different parts of the route. For this first article we are documenting the new section of railway that was constructed from 1948 to 1955 and generally known as the “Rimutaka Deviation”, being in general focused around the Remutaka Rail Tunnel through the Remutaka Mountains.

There is probably a whole story all by itself to be written about the Remutaka Tunnel
project because Cameron only has a chapter about it at the end of the
book. The tunnel itself was mostly bored by an American/NZ private
consortium, but the work was started by the NZ government’s Public Works
Department, which built many of the railways in this country, and we
can speculate that the change of government in 1949 probably saw a
desire by the new National Party administration to contract out the work, because PWD in
fact did drive almost a kilometre of the tunnel itself until the
contract was signed in 1951 with the private consortium (Morris Knudsen
and Downers), that completed the project. Apart from the tunnel there
was other work like the formation, the shorter Maoribank Tunnel and
bridging, and Cameron is unclear as to who actually constructed these
additional works, noting only that in February 1955, the two tunnels,
formation and piers of four bridges were handed over to NZR at that
Our aerial photos for this section, beyond Upper Hutt Station, are mostly from the dates 1943, 1951 and 1957. The 1943 showing the route before any deviation work was undertaken, 1951 during the construction, and 1957 after. By  mere coincidence, the 1951 aerial photos come from Survey 570, which was flown on 7 May 1951, the day on which the contract was signed for the private construction of the Rimutaka Tunnel. The work of the tunnel construction being taken over by the private consortium in June the same year. 
The following are a few randomly chosen maps. There is a lot of stuff for interest in this area because of the development of the Rimutaka Deviation.

At 34.5 km on the Rimutaka Deviation just past Upper Hutt. The bridge B35B at the end of Cruickshanks Road provides convenient public access to the historical area and tunnel. To the right we can see the probable site of Cruickshanks first sawmill. However this would be much harder to pinpoint since 1955 as earthworks for the new embankment are likely to have destroyed any historical traces.

Up between 35.5 and 36 km we can see in the 1957 aerial, at the end of Moeraki Road, a large flat area. This was very probably a work site for driving the Maoribank Tunnel, which is just around the next curve out of sight on the right of this picture.

Maoribank Tunnel under construction in 1951 with the formation works underway.

Bridge 37 approaches being formed just north of Maoribank Tunnel. This bridge crosses the Mangaroa River.

Overview of the Maymorn area, 1943, 1951 and 1957, showing the changes made for the tunnel and deviation construction. The housing area at the south side (along Old School Rd) remained in place for another 10-15 years or so after the deviation was finished. Old School Rd follows the access siding that was built to connect Maymorn with the existing line from Upper Hutt. The siding was used to bring in materials into Maymorn by rail, but it had not been constructed at the time the 1951 aerial was taken, and its route is only apparent in the 1957 map.

Maymorn shortly after the deviation opened is seen in the 1957 aerial photo above. A culvert has been installed under the railway tracks at the south end as seen to the left

When Maymorn was first opened it had a crossing loop and two passenger platforms, as seen in the 1980 aerial map above. This was at a time when there were more passenger services on the Wairarapa Line than is the case today. Over time, the loop and second passenger platform were taken out of service. In recent years Greater Wellington Regional Council has taken a look at extending suburban passenger services from Wellington beyond Upper Hutt as far as Maymorn, including the possibility of extending the electric overhead. The Government agreed to reinstate the Maymorn crossing loop in January 2020 but the second platform site was previously leased to the Rimutaka Incline Railway and the platform itself has been dug away. GWRC or Kiwirail should be cancelling the lease for that part of the Maymorn yard to allow for future reinstatement of the second platform for suburban trains.