Lightning TARP template
A trigger action response plan (TARP) for lightning sets out what happens at each stage of a storm: the trigger, what people do, who does it and how everyone is told. Print this template or save it as a PDF, fill it in for your site, and work through it with your crews before storm season.
How to use it
- List the work areas that need their own distances, such as pits, the plant, the camp, blasting areas and crane lifts.
- Set a stop and a warning distance for each area from the time it takes to clear it. See choosing your distances below.
- Fill in the actions, the people responsible and how the message goes out at each level.
- Work through the plan with the people who will use it and their health and safety representatives, then brief every crew.
- Review it after each storm season, after any near miss, and whenever the work areas change.
Site details
| Site name | |
|---|---|
| Location (coordinates) | |
| Lightning information used (for example a detection service, an on-site detector or alarm) | |
| Person watching it whenever storms are forecast | |
| Backup if that information is unavailable | |
| Prepared by | |
| Approved by | |
| Date | |
| Next review |
Areas, distances and shelter
| Area | Stop distance (km) | Warning distance (km) | Time to clear (minutes) | Nearest safe shelter | Area supervisor |
|---|---|---|---|---|---|
Trigger levels
The actions below are examples to adapt. Cross out what does not apply and add your own in the notes underneath.
| Level | Trigger | Actions | Who | How people are told |
|---|---|---|---|---|
| Normal | No storm forecast for the shift and no strikes inside the warning distance | Check the storm outlook at pre-start. Everyone knows their nearest safe shelter. | ||
| Watch (optional) | Storms forecast during the shift | Brief crews at pre-start. Plan lifts, pours and blasts around the storm window. Check shelters and radios. | ||
| Caution | A strike inside the warning distance: ____ km | Prepare to stop. Make suspended loads and open work safe, start no new exposed tasks, and move people towards shelter. | ||
| Stop | A strike inside the stop distance: ____ km | Stop outdoor work and get everyone into safe shelter. Nobody on cranes, at height, on charged blast patterns or in the open. Follow the explosives procedure. | ||
| All-clear | ____ minutes (30 is common) with no strike inside the stop distance, or inside the warning distance to clear Caution | The supervisor confirms the all-clear, checks everyone is accounted for and restarts work area by area. |
Site-specific actions and exceptions
| Level | Area or task | Action | Who |
|---|---|---|---|
Choosing your distances
The warning distance has to give people enough time to finish safely and reach shelter before the stop distance is reached. Work it out from the slowest part of the operation:
- Time to clear. How long it takes to get a crew off a pit floor, bring a load down from a crane, or clear people from a charged blast pattern.
- How fast storms travel. A storm moving at 30 km/h covers 10 km in 20 minutes, so a warning distance only 10 km beyond the stop distance gives about 20 minutes, less if the storm is faster or grows overhead.
- Different areas, different distances. A blasting area with charged holes may need a much larger stop distance than a workshop with shelter next door.
Lumen Sites starts every site at 10 km to stop and 30 km for a warning, and each site can have its own. There is more on setting them in lightning stand-down alerts, and the lightning distance calculator covers counting from flash to thunder when there is nothing else to go on.
What counts as shelter
Safe: a substantial building with wiring and plumbing, or a fully enclosed hard-top vehicle or machine cab with the doors and windows shut.
Not safe: open-sided sheds and shade structures, tents, open vehicles and plant without an enclosed cab, and anywhere under a tree.
Sign-off
| Role | Name | Signature | Date |
|---|---|---|---|
| Prepared by | |||
| Consulted (workers and health and safety representatives) | |||
| Approved by |
This template is a starting point. Adapt it to your site with your own risk assessment, in consultation with your workers, and check it against the requirements of your regulator and your explosives and emergency procedures. It is not legal or safety advice.
Related: Heat stress TARP template · Lightning detection options · Cyclone season for remote sites