OSHA ship ladder requirements are set out in 29 CFR 1910.25(e) for the stair itself, 1910.25(b) for general stairway rules, and 29 CFR 1910.28 and 1910.29 for handrails and stair rail systems. A ship stair must sit at a slope of 50 to 70 degrees, have open risers, treads at least 4 inches deep and 18 inches wide, a vertical rise of 6.5 to 12 inches between treads, handrails on both sides, landings at top and bottom, and load capacity of at least five times the anticipated live load with a 1,000-pound minimum concentrated load. It is also only permitted where a standard stairway will not fit.
When a Ship Stair Is Allowed at All
Under 29 CFR 1910.25(b)(8), an employer may install spiral, ship, or alternating tread-type stairs only when standard stairs are not feasible for the location.1Occupational Safety and Health Administration. 1910.25 – Stairways The burden of proof sits with the employer. Cost and convenience do not qualify; the justification has to rest on physical space or structural constraints, which is why ship stairs typically appear in tight mechanical rooms, mezzanine access points, and rooftop equipment platforms. Once the feasibility test is met, the general stairway rules in 1910.25(b) apply on top of the ship stair-specific rules in 1910.25(e).
Slope, Tread, and Riser Dimensions
Slope is the defining spec. A ship stair must be installed at 50 to 70 degrees from horizontal.2eCFR. 29 CFR 1910.25 – Stairways Anything shallower or steeper falls outside the regulation.
The dimensional requirements under 1910.25(e)(1) through (e)(4) are:
- Vertical rise between consecutive tread surfaces of 6.5 to 12 inches, kept uniform along the full length of the stair.
- Tread depth of at least 4 inches, measured front to back on the stepping surface.
- Tread width of at least 18 inches.
- Open risers. Closed risers are not permitted on a ship stair.
Uniform riser height matters as much as the range itself. Inconsistent spacing between treads creates a tripping hazard because a worker’s stride anticipates the same step each time.2eCFR. 29 CFR 1910.25 – Stairways
Load Capacity and Manufacturer Instructions
Ship stairs inherit the general stairway load standard: each stair must support at least five times the normal anticipated live load, and in no case less than a concentrated load of 1,000 pounds applied at any single point.1Occupational Safety and Health Administration. 1910.25 – Stairways
Under 1910.25(b)(9), the stair also has to be installed, used, and maintained according to the manufacturer’s instructions.1Occupational Safety and Health Administration. 1910.25 – Stairways If the manufacturer specifies a maximum load rating, corrosion-resistant coatings, or fastener torque values, deviating from those instructions is a compliance failure even when the stair otherwise meets every dimensional requirement.
Handrails and Stair Rail Systems
Handrails are required on both sides of every ship stair under 29 CFR 1910.28(b)(11)(iii).3Occupational Safety and Health Administration. 1910.28 – Duty to Have Fall Protection and Falling Object Protection There is no exception for narrow or low-traffic installations.
Under 29 CFR 1910.29(f), handrail height must be 30 to 38 inches, measured from the leading edge of the tread to the top of the handrail. Clearance between the handrail and any wall or object must be at least 2.25 inches so a worker can wrap a full grip around the rail.4eCFR. 29 CFR 1910.29 – Fall Protection Systems and Falling Object Protection Criteria and Practices
Handrails and stair rail top rails must withstand at least 200 pounds of force applied in any downward or outward direction within 2 inches of any point along the top edge.4eCFR. 29 CFR 1910.29 – Fall Protection Systems and Falling Object Protection Criteria and Practices If the rail bends, breaks, or pulls away from its mounting at that load, the installation fails.
Stair Rail Height and the Two-Rail Problem
OSHA distinguishes handrails, which workers grip, from stair rail systems, which are the barriers preventing a fall off the open side. For stair rail systems installed on or after January 17, 2017, the top rail must be at least 42 inches high measured from the leading edge of the tread. Systems installed before that date need only 30 inches.5Occupational Safety and Health Administration. Heights of Handrail and Stair Rail Systems
The top rail can double as the handrail only if its height is between 36 and 38 inches and it meets all handrail grip and clearance requirements.4eCFR. 29 CFR 1910.29 – Fall Protection Systems and Falling Object Protection Criteria and Practices Most newer installations use a 42-inch stair rail, which is too tall to grip. In that case a separate handrail at 30 to 38 inches is required in addition to the stair rail. Two rails, not one.
Landings and Door Clearance
A landing is required at the top and the bottom of every ship stair. Each landing must be at least as wide as the stair and at least 30 inches deep in the direction of travel.1Occupational Safety and Health Administration. 1910.25 – Stairways
When a door or gate opens onto the landing, its swing cannot reduce the usable depth below 22 inches for platforms installed on or after January 17, 2017, or below 20 inches for platforms installed before that date.1Occupational Safety and Health Administration. 1910.25 – Stairways
Clear Width
OSHA measures stair width between vertical barriers such as stair rails, guardrails, and walls, not between handrails, and handrails protruding into that space are not counted as obstructions. The general minimum clear width is 22 inches between barriers.6Occupational Safety and Health Administration. Stairway Width The ship stair tread minimum of 18 inches under 1910.25(e)(4) applies to the stepping surface, and the general clear-width rules in 1910.25(b) and (c) apply to the overall installation.2eCFR. 29 CFR 1910.25 – Stairways
Training Workers Who Use the Stair
Under 29 CFR 1910.30, every employee exposed to fall hazards must be trained by a qualified person before working in the area. Training must cover the nature of the fall hazards, how to recognize them, and procedures for minimizing them. If workers use personal fall protection equipment on or around the stair, training also has to address hook-up, anchoring, and tie-off.7eCFR. 29 CFR 1910.30 – Training Requirements
Retraining is required when workplace changes make earlier training outdated, when fall protection equipment changes, or when a worker shows they no longer understand safe use. Training must also be delivered in a form the employee understands, which matters in multilingual workplaces.7eCFR. 29 CFR 1910.30 – Training Requirements
Maintenance and Inspection
OSHA does not publish a standalone defect list for pulling a ship stair out of service. Instead, 1910.25(b)(9) ties maintenance to the manufacturer’s instructions.1Occupational Safety and Health Administration. 1910.25 – Stairways Whatever the manufacturer specifies for inspection intervals, bolt-torque checks, recoating, or replacement thresholds becomes enforceable through that provision. Keep the installation and maintenance manual accessible near the equipment; losing the documentation does not eliminate the obligation.
Penalties for Noncompliance
Ship stair violations fall under OSHA’s general enforcement framework. As of January 2025, the maximum penalty for a serious violation is $16,550 per instance, and OSHA adjusts penalty amounts annually for inflation.8Occupational Safety and Health Administration. OSHA Penalties Willful or repeated violations carry significantly higher maximums. Each individual deficiency on a single stair can be cited separately, so a missing handrail, an out-of-range slope, and undersized treads on the same installation can produce three citations rather than one.