Such doors, often with a hoisting beam above, are also seen on older telephone central office buildings in the U.S., for the same reason: they made it easier fo

Such doors, often with a hoisting beam above, are also seen on older telephone central office buildings in the U.S., for the same reason: they made it easier for Western Electric to install full-height (11′ 6″) distributing frames and other large equipment on upper floors.