Scaffolding Works NC II flashcards
Scaffolding Works NC II · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Fall-arrest anchor height
- A personal fall-arrest lanyard should be anchored at or above shoulder level so the free-fall distance stays short and the deceleration device can arrest the fall safely.
- Guardrail height requirement
- A toprail is fitted between 0.9 m and 1.15 m above the platform, with a midrail at about half that height and toe boards at least 150 mm high.
- Toe board purpose
- Toe boards at least 150 mm high along platform edges prevent tools, materials, and debris from being kicked or blown off and striking workers below.
- Electrical clearance rule
- Keep scaffolds and long materials at least 3.0 m clear of energized lines up to 50 kV, and increase the distance for higher voltages unless the line is de-energized and locked out.
- Manual handling limit
- One person should not lift more than roughly 25 kg at waist height; use two-person lifts, hoists, or rope-and-pulley systems for heavier scaffold components.
- Suspension trauma risk
- A worker left hanging in a harness after a fall can lose consciousness within minutes, so the rescue plan must allow retrieval almost immediately, not after a long wait.
- Coupler torque value
- Right-angle and swivel couplers are tightened to the manufacturer's specified torque, commonly about 40 to 50 N·m, and checked periodically with a torque wrench.
- Scaffold tube dimensions
- Common steel scaffold tube has an outside diameter of 48.3 mm with a wall thickness of 3.2 mm or 4.0 mm; reject tubes that are bent, cracked, or badly corroded.
- Inspection tag color code
- A green tag means the component or scaffold has been inspected and is safe to use; a red tag means defective or unsafe and the item must be quarantined.
- Wire rope discard criterion
- A wire rope sling is removed from service when broken wires reach about 10 percent of the total wires in one lay, or when there is distortion or severe corrosion.
- Sole board specification
- Sole boards under scaffold standards are at least 35 mm thick and 220 mm wide, laid flat on firm ground to spread the load and prevent settlement.
- Plank defect rejection
- Reject scaffold planks that have splits through the thickness, rot, large loose knots, or heavy warping, because these defects reduce the plank's load-carrying capacity.
- RCD protection for tools
- Portable electric tools on site must be protected by a residual current device and have undamaged cords and guards; damaged tools are tagged and removed from service.
- Standard bay dimensions
- For tube-and-coupler independent scaffolds, bay length is typically 1.8 to 2.1 m, lift height about 2.0 m, and platform width at least 0.6 m.
- Tie pattern 2:2
- A common tie pattern for independent scaffolds ties every alternate standard at every alternate lift, but the design drawing always governs the actual pattern.
- Scaffold load classes
- Light duty allows up to 150 kg per bay, medium duty up to 250 kg per bay, and heavy duty up to 450 kg per bay; classes must not be mixed without design approval.
- Base jack function
- Adjustable base jacks sit on sole boards under each standard to level the scaffold and spread the load, and must be checked for bearing on firm ground.
- Façade brace angle
- Façade bracing is fixed at roughly 45 to 60 degrees in both directions and must never be removed to create access; ledger bracing is added at alternate lifts.
- Plumb tolerance for standards
- Scaffold standards must be plumb within 1 in 500, and joints in standards are staggered so no more than one joint occurs at the same level in one standard.
- Platform plank gap limit
- Planks are laid with gaps no greater than 25 mm, butt-jointed over a transom with each end supported, and secured so they cannot move or lift.
- Ladder extension above landing
- An access ladder must extend at least 1.0 m above the landing platform and be secured against displacement; climbing on braces is prohibited.
- Free-standing height limit
- An untied tube-and-coupler scaffold is generally limited to about four times its minimum base dimension in height before ties to the structure are required.
- Coupler position rule
- Couplers are fitted with the bolt on the outside and kept at least 150 mm from the end of a tube so the tube end is not crushed or split.
- Inspection interval
- A scaffold in use is inspected before first use, after alteration or bad weather, and at intervals not exceeding seven days, with each inspection recorded and tagged.
- Handover certificate content
- The handover certificate records the scaffold location, dimensions, load class, inspection date, inspector's name, and a statement that it is safe to use.
- Dismantling sequence
- Dismantle top down: remove platforms and guardrails first, then transoms, ledgers, ties, and finally standards, lowering components by rope and never dropping them.
- Exclusion zone before dismantling
- Before dismantling, barricade the area below, post warning signs, and confirm no one is working underneath, because falling tubes and couplers can be fatal.
- Post-weather re-inspection
- A scaffold struck by high wind, heavy rain, or a vehicle, or one that has been partly dismantled, is treated as new and must be re-inspected before further use.
- Toolbox talk record
- A toolbox talk record captures the topic, date, hazards discussed, and the names and signatures of attendees, and is kept on site for audit purposes.
- Scaffold register purpose
- The scaffold register links each scaffold to its tag number, erection date, inspection dates, and responsible person so its status can be verified at any time.
- Crane hand signal stop
- A raised hand with the palm facing the operator means stop; only the designated banksman should give signals when the operator's view is blocked.
- Standard count formula
- For a straight run, the number of standards equals the number of bays plus one, and ledger length per lift equals bay length multiplied by the number of bays.
- Load per bay calculation
- Divide the total mass of persons, tools, and materials by the number of bays, then compare the result with the rated class of 150, 250, or 450 kg per bay.