Restraint or Arrest? Fall Protection on an Array-Covered Roof

Correct answer: C) Use the adjustable lanyard from a roof anchor, set short enough that they cannot physically reach the edge

Fall restraint and fall arrest are two different systems that happen to share a harness. Restraint keeps you from reaching the place you could fall from, so the fall never happens. Arrest lets the fall happen and catches you partway through it. When the work can be done from a position you can tether short of the hazard, restraint is the better arrangement, and this scenario was built so that it can be: the box is three metres back from the edge, so a lanyard set short still reaches the work.

Choosing arrest here means accepting everything that comes with being caught. You take the arresting forces, you need enough clear space below for the system to do its job, and you need somebody to get you down quickly afterwards, which on a roof means a rescue plan and not just a phone call. None of that is required if you simply cannot get to the edge.

The O&M point is the array itself. On a bare roof, an arrested fall drops into open air. On a roof covered in modules on ballasted racking, the space a falling body would swing through is full of glass, rails and ballast blocks, and the aisle you are standing in is narrow enough that a pendulum swing has somewhere to go and something to hit. This is a hazard that the crew who built the roof did not work around, because they were installing that hardware rather than moving among it. Every service visit for the next twenty years happens on a roof where arrest has been made worse and restraint has been made more attractive.

Why the other options are wrong

A) Clip the lanyard to the module racking, which is the most substantial structure within reach of the work

Substantial is not the same as rated, and this is one of the most common field habits worth unlearning. Ballasted racking is engineered to hold modules against wind uplift while resting on the roof membrane. It is not designed, tested or certified to take the shock load of an arrested fall, and a ballasted system is specifically the kind that is meant to be able to shift rather than resist a large point load. Anchorage is a rated function, and the fact that something feels solid when you pull on it tells you nothing about what it does with a falling body attached.

B) Use the shock-absorbing lanyard from the nearest roof anchor, so that a fall from the edge would be arrested

This is a real fall protection system correctly assembled, and it is still the second-best answer here, which is what makes it worth thinking about. Arrest is what you reach for when the work genuinely has to happen at the edge and restraint is therefore impossible. That is not this job. Selecting arrest when restraint would do means choosing to be caught over choosing not to fall, and on this particular roof it means choosing to swing through the array.

D) Use the shock-absorbing lanyard at full length and work kneeling, keeping their weight back from the edge

Body position is not a fall protection system. Working kneeling and staying back from the edge is a sensible habit and it depends entirely on the technician's attention holding for the whole task, which is the definition of a control that fails when someone is tired, startled or concentrating on the work in front of them. Meanwhile the lanyard at full length still permits reaching the edge, so the equipment on the harness is not making up the difference. Compare this with option C, where the same harness and the same anchor are arranged so that no amount of inattention gets you over the side.

References

• NABCEP OMAT JTA v.2026.5 — Domain 1, Task 5.A: "Protection systems (e.g., harness, personal fall arrest systems, guardrails, scaffolding, skylight guards)"
• NABCEP OMAT JTA v.2026.5 — Domain 1, Task 3.A names OSHA and NFPA as the safety regulations in scope. OSHA recognises both restraint and arrest, and requires anchorages used for fall arrest to be rated for that purpose. No anchorage load figures or clearance distances are quoted here; the JTA does not test numeric thresholds.