Short plan length stair flight - has longitudinal split with treads in half flights staggered

摘要

The stairway (1) is subdivided longitudinally into two adjacent half flights (1, 2) whose treads (4) are staggered. The treads (4) and the risers (5) of each half flight (2, 3) are identical and are respectively equal to and double the corresponding dimensions of a normal stairway. A conventional step (4a, 4b) i.e. with half the riser (5) generally used on the half-flights is located at the foot of one half flight (3) and at the head of its neighbour (2). Successive flights may be perpendicular to one another in plan.