This marked up map is reproduced here thanks to Pierre-Noel Rietsch whose Camrail site provides information & photographs regarding the recent railway operations in Cameroon.
The pictures displayed in the attached gallery relate to a much earlier era in railway development here. These date back to the period around 1916 following the takeover of the then German colony by British & French forces. As no information was received with the glass negatives it is a matter of pure speculation as to what they depict. They were most likely taken by a British Army engineer as most relate to the repair of a bridge probably damaged during the conflict. As French forces captured the major part of Kamerun, this would suggest the locations are somewhere on the western line from Douala to Nsongkamba, a section of which had been opened in 1911.