Four men working in an oil refinery, ca.1940

Photograph of four men working in an oil refinery, ca.1940. A man at center can be seen leaning over a round structure on the wooden floor. A second man is visible crouching on a platform behind and to the right of the structure, and is obscured by a few metal beams. A third man is visible on a raised platform towards the back left next to a rectangular machine reading, "Emsco", while a fourth man holds a rope to the left of him. The men can all be seen wearing hard hats, long sleeved shirts, and pants or overalls. A canopy can be seen in the background over a machine reading, "Caterpillar".