- Part Number:1917
- Part Number Title:Marine Terminals
- Subpart:1917 Subpart F
- Subpart Title:Terminal Facilities
- Standard Number:
- Title:Spiral stairways.
- GPO Source:
Definition. "Spiral stairway" means one with closed circular form, uniform sector-shaped treads and a supporting column.
Requirements. Spiral stairways shall meet the following requirements:
Stairways shall conform to the minimum dimensions of Figure F-1;
Spiral Stairway - Minimum Dimensions
|A (half-tread width)||B|
|Normal use by employees||11 inches (27.94 cm)||6 inches (15.24 cm).|
|Limited access||9 inches (22.86 cm)||5 inches (12.7 cm).|
Stairway risers shall be uniform and shall range from 6 1⁄2 to 10 1⁄2 inches (16.5 to 26.67 cm) in height;
Minimum loading capability shall be 100 pounds per square foot (4.79kN), and minimum tread center concentrated loading shall be 300 pounds (1334 N);
Railings shall conform to the requirements of § 1917.112(c)(1). If balusters are used, there shall be a minimum of one per tread. Handrails shall be a minimum of 1 1⁄4 inches (3.18 cm) in outside diameter; and
Maintenance. Spiral stairways shall be maintained in safe condition.
[48 FR 30909, July 5, 1983; 62 FR 40141, July 25, 1997; 65 FR 40942, June 30, 2000]