Work at height · Equipment-specific inputs
Check fall-clearance inputs against the actual equipment method
Add the clearance components specified by your selected fall-arrest system and compare the sum with available clearance.
By HSECalc · Published
Check that this method fits your task
Use only with manufacturer instructions that specify this additive method and the same reference surface. Not a universal lanyard or self-retracting lifeline calculator. No equipment values are assumed.
Choose your inputs and work through the steps
- Find the current instructions for every component and confirm that they support this additive worksheet. If they require a different chart or method, use that instead.
- Enter every applicable allowance on one reference-surface basis. Measure available clearance to the first obstruction from that same basis.
- Add the terms once, compare with available clearance and retain the product references. Stop and revise the assessment if there is a shortfall or uncertain input.
Required clearance = free fall + deceleration + harness/body allowance + other allowances + safety margin. Difference = available clearance − required clearance.
A worked example
Illustrative values explain the tool; they are not prescribed inputs for your work.
- Illustrative allowances: 1.8 + 1.2 + 0.5 + 0.3 + 1.0 = 4.8 m required.
- Available clearance is 4.0 m on the same fictional reference basis.
- 4.0 − 4.8 = −0.8 m: an entered shortfall of 0.8 m, not approval to use the system.
Read the result and decide what needs checking
The example values below are invented to demonstrate addition. They do not specify any product’s free-fall distance, arrest distance or margin.
A surplus does not approve a fall-arrest system. Swing fall, anchorage, compatibility, position, obstacles and rescue require separate checks under the equipment instructions.
Common questions
Can I use this with any SRL?
No. Many systems require product-specific charts or different geometry. Use that method directly when it differs from this worksheet.
Does surplus clearance mean safe?
No. It only compares the values entered. Swing fall, anchor position, equipment compatibility, obstacles and rescue still need checking.
Which surface do I measure from?
Use the reference surface defined in your selected equipment instructions for every term and available clearance; do not mix anchor-level and working-surface methods.
References and scope notes
Use the current official guidance and the instructions for your actual equipment. HSECalc is independent; a reference is not an endorsement. Read how we use methods and sources or report a correction.