Notice that the bollards go off into the distance in a straight line. This section of dock would thus appear to be straight.
Notice that, beyond the crane, the rail on concrete curves abruptly to the left. That curve looks unusually abrupt for a dockside crane. And to no obvious point.
Notice also that the distance between rails 1 and 3 is very similar to the distance between rails 2 and 4.
Notice also what appear to be tie plates under rail 2 only. Narrow gage cars would be unlikely to be more needful of tie plates than the standard gage cars. Especially under one rail only.
For now, I will go with a track being added to lessen the distance between rail cars and ships so that crane loading is to better advantage.