PASMA Environmental Considerations 1 — Questions and Answers
Question 1: At what Beaufort scale wind force should work on a tower scaffold cease?
- Force 2 (light breeze)
- Force 4 (moderate breeze, 13-17 mph) (Correct answer)
- Force 7 (near gale)
- Force 10 (storm)
Correct answer: Force 4 (moderate breeze, 13-17 mph)
PASMA recommends ceasing work on tower scaffolds at Beaufort Force 4 (moderate breeze, 13-17 mph), when small branches begin to move and dust and paper are raised. Tower scaffolds are lightweight and have large surface areas making them particularly wind-sensitive.
Question 2: What are the signs of Beaufort Force 4 wind that would trigger stopping work on a tower?
- Trees being uprooted
- Small branches move, dust and loose paper are raised, small waves on inland waters (Correct answer)
- Complete calm with no air movement
- Chimney pots and roof tiles being blown off
Correct answer: Small branches move, dust and loose paper are raised, small waves on inland waters
Beaufort Force 4 indicators include: small branches moving, dust and loose paper being raised from the ground, and small waves forming on inland waters. These are observable conditions that operatives can use to judge when to stop work.
Question 3: How does rain affect the safety of working on a tower scaffold?
- Rain has no effect on tower safety
- Rain creates slip hazards on platforms and ladders, reduces visibility, and can make components slippery and harder to grip (Correct answer)
- Rain improves stability by adding weight
- Rain only affects wooden towers
Correct answer: Rain creates slip hazards on platforms and ladders, reduces visibility, and can make components slippery and harder to grip
Rain makes aluminium platforms, ladder rungs, and components slippery, increasing the risk of slips and falls. It reduces visibility, makes tools harder to grip, and can obscure defects during inspection. Work may need to be suspended in heavy rain.
Question 4: What precautions should be taken when using a tower scaffold in freezing conditions?
- No special precautions are needed in the cold
- Check for ice on platforms, rungs, and components; apply grit to platforms; ensure operatives wear appropriate clothing and gloves without losing grip (Correct answer)
- Work faster to stay warm
- Only use the tower before sunrise
Correct answer: Check for ice on platforms, rungs, and components; apply grit to platforms; ensure operatives wear appropriate clothing and gloves without losing grip
Freezing conditions create ice on platforms, rungs, and handholds, dramatically increasing slip risk. Frost can also weaken components over time. Platforms must be de-iced and gritted. Operatives need warm clothing but must maintain dexterity and grip.
Question 5: What is the risk of using a tower scaffold in direct strong sunlight?
- No risks from sunlight
- Heat exhaustion and dehydration of operatives, thermal expansion of metal components, and glare affecting vision (Correct answer)
- Sunlight strengthens the aluminium
- UV light sanitises the tower
Correct answer: Heat exhaustion and dehydration of operatives, thermal expansion of metal components, and glare affecting vision
Strong sunlight can cause heat exhaustion and dehydration (especially at height where there is no shade). Metal components become hot to touch. Glare can impair vision and depth perception. Adequate water, sun protection, and rest breaks must be provided.
Question 6: What should be done with a tower scaffold if a storm is forecast overnight?
- Leave it as it is — it will be fine
- Dismantle it or reduce it to minimum height, secure all loose items, and consider tying the tower to a fixed structure (Correct answer)
- Move it to the centre of the car park
- Cover it with a tarpaulin
Correct answer: Dismantle it or reduce it to minimum height, secure all loose items, and consider tying the tower to a fixed structure
If a storm is forecast, the tower should be dismantled if possible, or reduced to minimum height. All loose items (boards, tools, materials) must be removed. If dismantling is not possible, consider tying the tower to a permanent structure and deploying all stabilisers.
PASMA Environmental Considerations 1
At what Beaufort scale wind force should work on a tower scaffold cease?