SMSTS Equipment and Tools Knowledge 3 — Questions and Answers
Question 1: Hand-arm vibration syndrome (HAVS) is caused by prolonged use of vibrating tools. Which tool category typically presents the greatest risk?
- Electric screwdrivers used intermittently
- Petrol-powered concrete breakers used daily (Correct answer)
- Battery-operated drills used for less than 30 minutes per day
- Cordless hot-glue guns
Correct answer: Petrol-powered concrete breakers used daily
Petrol-powered concrete breakers produce high-magnitude vibration and are used for extended periods, maximizing HAVS exposure.
Question 2: Under the Control of Vibration at Work Regulations 2005, what is the daily Exposure Action Value (EAV) for hand-arm vibration?
- 2.5 m/s² (Correct answer)
- 5.0 m/s²
- 10.0 m/s²
- 15.0 m/s²
Correct answer: 2.5 m/s²
The EAV for hand-arm vibration is 2.5 m/s² A(8), above which employers must take action to reduce exposure.
Question 3: A grinder disc shatters during use. Which of the following would most likely have prevented this?
- Storing the disc in a heated environment overnight
- Checking the disc's maximum RPM matches or exceeds the grinder's no-load speed (Correct answer)
- Using a larger guard to catch fragments
- Reducing the air pressure supply to the grinder
Correct answer: Checking the disc's maximum RPM matches or exceeds the grinder's no-load speed
Using a disc with a maximum RPM lower than the grinder's speed causes over-spinning, leading to disc failure and fragmentation.
Question 4: What is the function of a residual current device (RCD) on a construction site?
- It reduces the supply voltage to 110 V
- It disconnects the circuit within milliseconds if a fault current is detected (Correct answer)
- It prevents tools from overheating during sustained use
- It records energy consumption for billing purposes
Correct answer: It disconnects the circuit within milliseconds if a fault current is detected
An RCD detects current imbalance caused by earth faults and disconnects power in milliseconds, preventing electrocution.
Question 5: A forklift truck is to be used on a public road to move materials between two site compounds. What is required?
- A banksman must walk alongside at all times
- The vehicle must be road registered, insured, and the driver must hold a valid driving licence (Correct answer)
- The forks must be fully raised during road travel
- A site manager must accompany the driver in a separate vehicle
Correct answer: The vehicle must be road registered, insured, and the driver must hold a valid driving licence
Using a forklift on a public road requires road registration, insurance, and a valid driving licence as it becomes a road vehicle under the Road Traffic Act.
Question 6: Which PPE is specifically required when using a disc cutter to cut concrete or masonry?
- Chemical-resistant gloves
- Face shield, hearing protection, and respiratory protection against silica dust (Correct answer)
- Anti-static footwear only
- High-visibility vest and hard hat only
Correct answer: Face shield, hearing protection, and respiratory protection against silica dust
Disc cutting of concrete generates high noise levels, sparks, and respirable crystalline silica dust, requiring face, hearing, and respiratory protection.
Question 7: When must a lifting plan be reviewed and updated before a crane lift proceeds?
- Only if the crane model changes
- When site conditions, loads, or environmental factors change significantly from those in the original plan (Correct answer)
- At the start of each calendar month
- After every 10 lifts
Correct answer: When site conditions, loads, or environmental factors change significantly from those in the original plan
A lifting plan must be reviewed whenever changed conditions—such as ground conditions, load weight, or weather—differ materially from the plan's assumptions.
SMSTS Equipment and Tools Knowledge 3
Hand-arm vibration syndrome (HAVS) is caused by prolonged use of vibrating tools.
Which tool category typically presents the greatest risk?