What is the ruling on my current job as a crane operator at a port that deals with permissible and impermissible goods, given my ignorance of what the containers hold, and what is the ruling on my future job if I become able to distinguish containers of wine?

There is no problem with the questioner's work, and he is not required to investigate the contents of containers unless he knows that something forbidden is present. However, if he knows that a container carries alcohol, it is not permissible for him to carry it or unload it, because the Prophet, peace and blessings be upon him, cursed everyone who assisted with alcohol, and this includes its carrier. He said: "May Allah curse alcohol, its drinker, its server, its seller, its buyer, its presser, its extractor, its carrier, and the one to whom it is carried."