Mais oui, c'est un pont secteur...
An example of a pivoting turnplate which allows locos to switch to one of several tracks amongst the station headshunts. This arrangement is like a partial turntable but with an incomplete circle. The black box was for the operator and moved along with the track. Clearly there was not a lot of space to build beyond the end of the platforms here without building out over the harbour wall. The blue pillars and lintels demarcate the boundary between the railway area and the ferry quay (orange containers).
A shot showing a loco turning is available here: http://reseau3gg.centerblog.net/3696-un-pont-secteur-avec-une-bb-67400
Location: Boulogne Maritime
Original line: SNCF
Photographer: Charlie Niven
Contact photographer: Charlie Niven
Date: 07/09/1992
Image number: 74222