The Salvation Hunters (1925)

A hopelessly hopeful drifter, a bitter young woman, and a helpless child live on the docks, spending their days in poverty and listless wandering. Overhead, a dredge hauls up mud and trash from the nearby seabed-- the same mud and trash from the day before. They finally decide to leave for the city to seek fulfillment, only to encounter further privation, destitution, temptation.