• You can use fixed ladders for climbing elevated structures, such as tanks, towers, and overhead traveling cranes, when their use is common practice in your industry.
• You can use winding stairways on tanks and similar round structures if the structure's diameter is at least five feet.
• You could use a spiral stairway as an exit route in a restricted area that lacks room for a conventional stairway.
• A stairway or fixed stairs is a series of steps and landings:
– Leading from one level or floor to another.
– Leading to platforms, pits, boiler rooms, crossovers, or around machinery, tanks, and other equipment.
– Used more or less continuously or routinely by employees or only occasionally by specific individuals.
– With three or more risers.
• A riser is the vertical part of the step at the back of a tread that rises to the front of the tread above.
• A tread is the horizontal part of the step. Tread width is the distance from the front of the tread to the back.