United States
Hong KongPersonal fall arrest system numbers
Maximum arresting force 1,800 pounds with a body harness, maximum free fall 6 feet, maximum deceleration distance 3.5 feet, and anchorage strength 5,000 pounds per employee.
- All at 29 CFR 1926.502(d).
On this page4 sections
Four numbers in one provision, and questions routinely give you three and ask for the fourth.
The four
| Requirement | Figure |
|---|---|
| Maximum arresting force, body harness | 1,800 pounds |
| Maximum free fall distance | 6 feet |
| Maximum deceleration distance | 3.5 feet |
| Anchorage strength per employee | 5,000 pounds |
All at 29 CFR 1926.502(d), so one tab covers all four.
Why the numbers are what they are
Eighteen hundred pounds is roughly what a body can absorb without serious internal injury. A body belt, which concentrates force at the waist, is not permitted as part of a personal fall arrest system for that reason.
Six feet of free fall plus three and a half of deceleration is where the total fall distance calculation starts.
Free fall plus deceleration plus harness stretch plus a safety margin, measured from the anchorage. A worker at eight feet with a six-foot lanyard hits the ground before the system arrests them, and that is the scenario questions describe.
The anchorage figure
Five thousand pounds per employee attached, or a system designed by a qualified person with a safety factor of at least two.
Note the alternative. It is not five thousand pounds or nothing, and the alternative requires a qualified person specifically.
Inspection
Before each use, and any component subjected to an arrest is removed from service. A harness that has caught a fall does not go back on the rack.
Common questions
What is the maximum arresting force?
1,800 pounds with a body harness, under 29 CFR 1926.502(d)(16).
What is the maximum free fall distance?
6 feet, with a maximum deceleration distance of 3.5 feet.
What anchorage strength is required?
5,000 pounds per employee, or a system designed by a qualified person with a safety factor of at least two.
Why is a body belt not permitted?
It concentrates arresting force at the waist. A body harness distributes it, which is why the 1,800 pound limit is stated for harnesses.
What happens to equipment after a fall?
Any component subjected to an arrest is removed from service.