Two phrases get used as if they mean the same thing - but they protect workers in completely different ways. Choose the wrong one and the harness becomes part of the injury, not part of the rescue.
The one-line difference
- Fall restraint stops the worker reaching the edge in the first place.
- Fall arrest catches the worker after they have already gone over.
Restraint prevents. Arrest catches. The Irish hierarchy of control - the same one in our safe work at height techniques guide - puts restraint above arrest every single time.
Fall restraint in detail
A restraint system is a harness, a fixed-length lanyard, and a properly rated anchor point positioned so the worker physically cannot reach the unprotected edge. The lanyard is shorter than the distance from the anchor to the edge. There is no fall, so there is no shock load, no rescue, no suspension trauma.
Typical kit: full body harness EN 361, fixed-length restraint lanyard EN 358 / EN 354, anchor point EN 795 type A or B, all of it inspected and tagged.
Fall arrest in detail
Fall arrest assumes a fall will happen and limits the consequences. The system uses a shock-absorbing lanyard or a self-retracting lifeline (SRL) that engages within milliseconds. The arrest force on the body is capped at 6 kN (around 600 kg of pull) - enough to bruise, not enough to kill if everything is set up correctly.
Typical kit: full body harness EN 361, energy-absorbing lanyard EN 355 or SRL EN 360, anchor point EN 795, and a verified fall clearance below the worker.
Fall clearance - the calculation everyone gets wrong
For a fall arrest system to actually save a life, there must be enough free space below the worker for the system to deploy without hitting the ground. The calculation:
- Length of lanyard (e.g. 2.0 m)
- + Energy absorber deployment (up to 1.75 m)
- + Worker height suspended (1.8 m)
- + Safety margin (1.0 m)
- = roughly 6.5 m clearance for a 2-metre lanyard
If your gantry is 5 metres up, a 2-metre fall arrest lanyard does not save you. Either restraint, an SRL with much shorter deployment, or a different work method.
When to use which
| Scenario | Choose | Why |
|---|---|---|
| Flat roof maintenance, edge 4m away | Restraint | Cheaper, no rescue plan needed, no shock load |
| Roof valley, no edge protection, working close to slope | Arrest with SRL | You will overshoot the edge, system must catch the fall |
| MEWP boom lift basket | Arrest, anchored inside basket | Catapult ejection is the risk |
| Window cleaner on rope access | Arrest with backup line | Rope access is by definition fall-arrested |
| Fragile roof skylight survey | Restraint AND crawl boards | Belt and braces, no margin for error |
Three Irish-specific gotchas
- Anchor points must be EN 795 certified. Tying onto a handrail, a vent pipe or a Velux frame is not legal and not safe.
- Harness inspection every 12 months by a competent person, plus pre-use checks every shift. The inspection log goes in the same file as your employer compliance pack.
- Rescue plan is part of the system. A worker hanging in a harness has 15-20 minutes before suspension trauma becomes life threatening. Plan the rescue before the work starts.
Training the system, not just the kit
Most fall arrest fatalities in Ireland are not equipment failures - they are wrong choices. The harness was right. The lanyard was right. The anchor was wrong, the clearance was wrong, or there was no rescue. Working at Heights Training drills the decision tree, not just the buckles. Take the Working at Heights Course online and your team will choose restraint, arrest or "neither, change the method" without thinking about it.
FAQs
Can the same harness be used for restraint and arrest?
An EN 361 full body harness covers both. The lanyard you connect to it is what makes it restraint or arrest.
Are positioning belts (EN 358) the same as restraint?
No. A positioning belt holds you in place at a work surface (linesman on a pole, for instance). It will not catch a fall on its own.
How often should anchor points be inspected?
Visual check before every use, formal inspection every 12 months, structural test every 5-10 years depending on type and exposure.
Train your team to choose the right system. The Working at Heights Course online walks through restraint, arrest, anchor selection, fall clearance and rescue. 45 minutes, instant Working at Heights Certificate.
