In 1925 Oban was located on the Minnedosa–Saskatoon–Edmonton CPR branch line between Castlewood, and Naseby. The CPR was intersected by the CNRGTP West. Oban was located on the CNR between Biggar and Palo. Oban was also a part of the Porter Subdivision, CNR between Lett and Biggar.
Oban tower was a requirement for the Grand Trunk Pacific Railway when it wanted to cross the existing CPR rail tracks. (The Canadian Northern Railway was amalgamated with the Grand Trunk Railway by the Dominion Government to form the Canadian National Railways in 1919.) Oban tower consisted of a 16-frame interlocking machine. There were levers attached to pipes and cranks which controlled semaphore signals and train derails. If an approaching train did not react to the signals at the crossing, the derails were utilized, causing a minor accident and averting a major collision. The signals would be operated 1,750 feet (530 m) and 1,200 feet (370 m) along the railway track. At 55 feet (17 m) the derail would be set if the train could not stop before the intersection.
There have been 8,800 miles (14,200 km) railway track in the province of Saskatchewan. Rail companies were intersected 58 times at level crossings. Some of these were railway lines crossing municipal street car rail lines. There were 36 Saskatchewan crossings which were controlled by mechanical interlocking machines between the early 1900s and 1990.
Title A Harvest of Memories: Oban, Neola, Avalon, Elwell, Monarch, Louvain, Kensmith, Twin Hill, Fairmount, Vanceview, Gagenville, Curths Hill, Castlewood, Whiteshore, Wilson Lake / [editor: Isla Solanik] or the North Biggar history
Published Biggar, Sask.: North Biggar History Book Committee, 1986