The two structures in this frame have no operational relationship. The railway serves the port; the cooling tower serves a reactor. They share a horizon because the left bank is flat and there is nothing between them to interrupt the view.
That is worth stating because a photograph puts things in a relationship whether or not one exists. Stacked in a single frame, a line of rails leading toward a tower reads as cause and effect.
What a cooling tower actually does
A hyperbolic tower is not a chimney. Nothing burned passes through it. It is a heat exchanger with no moving parts: warm water is sprayed in near the bottom, some of it evaporates, and the shape of the shell produces enough draught to pull air up through the falling water.
The plume is condensed vapour. On a cold evening it is dense and visible for kilometres; on a warm dry one the same tower looks switched off.
Twilight
Civil twilight is the half hour when the sky still carries colour but artificial light already reads. For flat industrial ground it is the only hour with modelling in it — at noon this landscape is a grey line under a grey sky.
The photographer made three pictures on this bank on the same February afternoon. This is the one with the rails in it.
