Eighty Guests, One Socket: A Go/No-Go Decision at 18:40
The Grade 12 class at a school outside Keetmanshoop is staging its SBA practical project in a converted classroom at 19:00. Eighty guests are expected. The technical plan: a hired 5,5 kVA generator outside the window, its cable running across the walkway to the entrance; four extension leads daisy-chained from the single wall socket to feed two LED parcans, a laptop and a small PA; the parcans clamped to a T-bar on a desk-stand tripod and angled over the audience; a backdrop of donated bedsheets nailed to the fibreboard ceiling above the makeshift stage; the fire door opens inward, is held by stacked chairs and propped with a brick. The first-aid kit is in the office; the teacher with the key left at 16:00. One performer, Anna, has asthma and left her inhaler at home. It rained at 17:00 and the floor near the door is still wet. At 18:40 the audience begins arriving and the generator will not start on the first pull.
1. Identify the five most serious hazards and rank them by risk, explaining the ranking method.
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Method: risk = likelihood of harm × severity of harm, with severity weighted by the number of people exposed and by whether children are involved. Rank by residual risk after existing (inadequate) controls, not by how alarming the hazard sounds.
- Blocked, inward-opening fire exit. Severity: fatal in a panic; likelihood: moderate but rising with 80 people in a room with one usable door. Highest risk because it is unrecoverable - no second chance once smoke or a crush starts. Stacked chairs plus a brick is not a control; it is a deliberate defeat of one.
- Electrical daisy-chain from one socket to four leads. Overload, overheating, and a trip hazard in a dark room; the single socket is not designed for PA inrush plus lighting. Severity: fire and shock; likelihood: high once the generator fails and the load transfers or someone improvises.
- Generator cable across the walkway in the dark, after rain. Trip and electrocution risk, wet ground, audience arriving. Likelihood high, severity high.
- Lighting tripod with parcans over the audience. Unclamped desk stand, top-heavy, cables as a trip line - a falling fixture onto heads. Likelihood moderate, severity serious (head injury, burns).
- Asthmatic performer without an inhaler, plus first-aid kit locked away with no keyholder. Severity: potentially fatal asthma attack; likelihood: low but non-zero, and the response capacity is currently zero.
Bedsheets nailed to fibreboard are a real but lower-ranked risk here (they are not near a heat source if the parcans are LED and correctly distanced), which shows why ranking matters: not everything alarming is the top priority.
2. Give the controls you would apply in the 80 minutes available, using the hierarchy of controls.
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Hierarchy: eliminate → substitute → engineering → administrative → PPE. Cheapest and most reliable first.
Eliminate. Move the performance to a larger, safer space if one is open and lit - the school hall or covered courtyard. If that is impossible, cut the audience to capacity and remove the stacked chairs entirely. Cancel the lighting effect: a piece does not need parcans.
Substitute. Replace the generator with mains power if any circuit can safely carry the PA alone; run sound only, no lighting. Replace the bedsheet backdrop with a plain wall - remove the nails and the fabric over the audience's heads.
Engineering / physical controls. Fire door: clear the chairs, remove the brick, and station a named Grade 11 learner at the door as a steward for the whole show; a propped door that opens inward must be kept clear. Cables: gaffer-tape the generator lead down or reroute it away from the walkway; if it must cross, use a mat and light it. Electrical: one lead per appliance, uncoil the drums fully, no daisy-chaining, plug into different circuits where possible. If the tripod stays, sandbag or weight the base and tape the cable.
Administrative. A two-minute briefing to the audience naming the exits; a fire warden with a torch; the first-aid kit fetched or a backup kit assembled (gloves, gauze, plasters) and a named first-aider.
PPE / personal. Anna's inhaler: phone home, or send someone to fetch it, or move her to a non-performing role. She does not go on without it.
3. The principal says 'the parents are already here, just start'. Make and justify your go/no-go decision, and say what you would put in writing afterwards.
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Decision: no-go at 19:00 as planned. Delay up to 30 minutes and start only if the fire exit is clear, the electrical load is reduced to sound only, and the walkway cable is secured. If those three cannot be met by 19:30, the show does not happen in that room tonight - announce a short excerpt in the courtyard or reschedule.
Justification to the principal (say it in these terms). 'The audience is here, which is exactly why I cannot start: eighty people in a room with one blocked inward-opening door and improvised mains is a decision I cannot defend if anything goes wrong. Thirty minutes of embarrassment now is cheaper than one ambulance. Give me half an hour and we open with a reduced technical plan - no lighting effect, sound only.'
Note the framing: delay and reduce, not cancel - it gives the principal a face-saving option and gets the safest achievable show.
In writing afterwards (same night):
- A dated risk-assessment note listing each hazard, the control applied, who was responsible, and the time.
- The decision, who made it, and who was informed - including that the principal was told and what was agreed.
- Anna's inhaler status and the outcome.
- Any near-miss (e.g. the wet floor, the failed generator) reported to the school's safety officer and to whoever hired the generator.
Responsibility: the teacher in charge holds the duty of care during a school activity; the principal carries overall accountability for the venue and the event. 'The parents are here' is a social pressure, not a risk control, and a written record is what protects both staff and learners if the same shortcuts are proposed next year.