Under-running cranes are a particular kind of equipment anchored to above structures such as roofs of warehouses, hangars or other metallic structures.
Under-running cranes can be provided with oversails (which allow to operate on a larger surface) or with mechanised oversails (which, apart from further increasing the available surface, permit load transfers between adjacent buildings).
Typical places of application of under-running cranes are aeronautic or naval hangars.