Monday 30 October 2017

Otago Central Railway [34C]: Clyde Snapshots

As part of the public release of maps in stages for the Otago Central line, I have about 2 weeks to get maps of the section from Alexandra to Cromwell completed. The most complex section because of the large number of changes which need to be shown as snapshots on the maps is from Alexandra to the second Clyde terminus.  Rendering maps is a slow process because you always find mistakes which have to be corrected, and in the case of these snapshots, there is a fair amount of chopping and changing to get the right detail displayed.

By playing with filters and other mechanisms I can depict the changes fairly accurately by causing different features on the map to appear or disappear at will.

Here are the snapshots for the easternmost part of Clyde yard where the MOW had its depot during the Clyde Dam construction project.


The upper overlay shows where the main line originally ran for more than 70 years (suggested date 1977), while the lower tile shows the changes that happened when the new Clyde railhead was built and the main line was diverted (suggested date 1980).

There are five snapshots for the westernmost part of the Clyde yard as follows. These cover a 40 year period. (Please note that the aerial photography is the same for all, dated from 2013-2017, and is not dated the same as the map details)

In 1967 the railway ran in the same location that it had been for the preceding 60 years, and the area geographically east of it seen in the lower half of this picture was all open fields; it had not been developed for any particular purpose.
In 1968 the NZED (New Zealand Electricity Division, a government department responsible for electricity production) established a depot in Clyde. The original purpose was connected with the construction of a high voltage power line to the Tiwai Point Aluminium Smelter. However, the site remained in place for the duration of the Clyde Dam construction project and must have been used for works for this project also. NZED had staff housing located next to the depot site. The depot had its own railway siding off the Otago Central Railway.
 NZED's siding was closed and removed in the late 1970s when the new railhead and alteration of the railway was planned to take place at Clyde. A part of their site was taken for the new railway yard. They probably used the adjacent MOW siding when that site was opened for the Clyde Dam project. In 1979 the date of this snapshot, the main line to Cromwell had been deviated to allow the new highway to be built on the railway route, and the new alignment was temporarily connected to the old as shown at upper left.
In 1980 the new Clyde railhead was opened. The old line to Cromwell was disconnected and lifted.
After the Otago Central Railway was closed the Clyde yard was eventually handed over to DOC as part of the rail trail. This map shows how the site is used at the present day. A pedestrian/cycle  underpass has been installed under the main highway in the last couple of years.