Power Failure with Two Workers Aloft

1. Establish and hold contact. Confirm both workers are uninjured, their harnesses/lanyards are as required, and the cage gates are closed. Instruct them: stay in the cage, do not climb out, do not attempt to open a landing gate, do not jump. Tell them what you are doing and when you will next call.
2. Clear the area. Stop other work in the exclusion zone under and around the hoist. Nobody walks under the cage. Rope off the bottom landing.
3. Get the documents and the key. Manual from the site office, key from the supervisor - call the supervisor back to site now. Also get a second trained person to assist.
4. Establish the cause if it is quick and safe. Is it a site-wide outage or only the hoist circuit? Check the board from a safe distance only - no resetting (see next task).
5. Notify the PCBU, the hoist owner and, if the delay will be extended or anyone is at risk, the emergency services.
6. Prepare for controlled emergency lowering exactly as the manual specifies: two people, one at the controls, one spotting and communicating, exclusion zone held, and a stated wind limit beyond which you do not lower.
7. Log times and decisions as they happen - this becomes the incident record.

A tripped main is a symptom, not a nuisance. In rain, the likely candidates are water ingress into the control box or a landing station, a damaged cable, or an insulation/earth fault on the hoist circuit.

Risks of resetting:

• anyone touching the hoist or a landing gate can receive a shock from an energised faulty enclosure;
• a fault can arc and start a fire in the control panel or along a cable tray;
• if the brake releases as power returns, the cage can move unexpectedly with two people in it - an uncontrolled descent is the worst possible outcome of the whole incident.

Correct approach: isolate and lock out the hoist supply; have a licensed electrician test insulation resistance and locate the fault; repair, re-test, then re-energise with the machine clear of people. Nobody resets a breaker on a machine with people in the cage 'to see if it holds'. If the fault cannot be found and cleared before dark, plan the rescue on the basis that power is not coming back.

The decision depends on two things: the manual's wind limit for emergency lowering, and whether you have the key plus a genuinely competent person to do it. A manual descent relies on controlled brake release - with an overspeed/arrest device governing the descent - and it is not something to improvise in rising wind and rain at dusk.

• If the key arrives within ~30 minutes and the wind stays under the manual's limit, conduct the controlled lowering with the trained person at the controls, a second person spotting, the exclusion zone held and continuous voice contact. Lower to the bottom landing, get them out, and stand the machine down.
• If the wind is at or above the limit, or no competent person is available, do not lower. Keep them in the cage, brief them honestly, keep them warm, keep someone talking to them, and call emergency services for a height rescue while you still have light. Give them the hoist type, height, cage position, brake arrangement and site access.

Close-out afterwards:

• Isolate and lock off the main; tag out the control and bottom gate; cage at the bottom landing if it can be reached, gates closed and latched.
• Barricade the base and landings; nothing returns to service.
• Incident report and notification to the regulator - persons trapped/evacuated from height is a notifiable incident; preserve the scene and the logbook.
• Root causes to fix before the hoist runs again: no generator connection to the hoist, emergency-lowering instructions not at the machine, key custody on one person who leaves site, and no tested rescue plan for a power failure at height.