Ngauranga 17, photographed in 2004, about two years after it ceased to be a part of the network. This is an example of a switchlock used in double-line territory and in yards.

I do not know why this switchlock has one head but single-line devices (right) have two heads.

Access to switchlock was from SH2 slip road. Photo taken in 2004.

Switchlock 33A on the Gracefield Branch. This switchlock ceased to function as such in the mid-1990s, after a fire at Woburn Station destroyed the panel. However train crews still open the door and operate the lock, although I assume that there is no longer an electric release. This is an example of a single line switchlock.

Photo taken in 2005 from the bow-string bridge.