OSHA Scaffold Safety Quiz — 29 CFR 1926.450-454 Practice Questions — Page 4 of 4
Free OSHA 30-Hour Construction scaffold safety practice test with 40 realistic scenarios. Covers supported scaffolds, suspended scaffolds, aerial lifts, platform construction, guardrails, and competent person inspection with 29 CFR 1926 Subpart L references. (Page 4 of 4)
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Q31/ 40
At a stadium renovation, a catenary scaffold (a platform supported by two parallel horizontal wire ropes, with the platform suspended between them) is used for ceiling work 80 feet above the arena floor. The platform is accessed by a rope ladder dropped from the catwalk. What additional fall protection is required for workers on the catenary scaffold?
✅ Correct Answer: B
1926.451(g)(1)(ii): employees on catenary scaffolds must be protected by a personal fall arrest system. 1926.451(g)(1)(vii): PFAS used on suspended scaffolds must be attached to an independent vertical lifeline. Catenary scaffolds are particularly susceptible to dynamic movement — the horizontal wire ropes can oscillate, and the platform can swing or tilt. Platform guardrails alone may not prevent ejection during unexpected movement. The independent vertical lifeline (separate from the catenary support ropes) provides continuous fall protection regardless of platform movement.
Q32/ 40
A baker scaffold (narrow mobile scaffold, approximately 2 feet × 6 feet platform) is being moved by a worker who is still on the platform — the worker 'surfs' the scaffold by pushing off a wall and riding it to the next location. The platform is at 12 feet height. What violations exist?
✅ Correct Answer: B
1926.452(w)(2): employees shall not be allowed to ride on scaffolds unless the surface is within 3 degrees of level, free of pits and obstructions, the height-to-base ratio is 2:1 or less, and outriggers are installed (if used). 1926.452(w)(5): the force necessary to move the scaffold shall be applied as close to the base as possible. A narrow baker scaffold at 12 feet height with a 2-foot base width has a 6:1 height-to-base ratio — far exceeding the 2:1 limit for riding. Additionally, 'surfing' involves the worker's body weight shifting, which can cause the scaffold to tip.
Q33/ 40
A scaffold is erected in a high-wind area. Weather forecast predicts 35 mph sustained winds with 50 mph gusts. The scaffold manufacturer specifies a maximum wind speed of 25 mph for erected scaffolds. Workers are scheduled for exterior stucco work at height 40 feet. What must the competent person do?
✅ Correct Answer: B
1926.451(f)(12): scaffolds shall not be used during storms or high winds unless a competent person determines it is safe. The manufacturer's 25 mph limit is binding. Wind force is proportional to the square of velocity — 35 mph wind exerts nearly double the force of 25 mph. At 40 feet height, wind speed is higher than ground level measurement. Additionally, the scaffold may be carrying materials (stucco) that increase the sail area. The scaffold should be secured or dismantled before winds reach the limit. The General Duty Clause also requires the employer to protect workers from recognized hazards.
Q34/ 40
Workers install a bracket scaffold by inserting two metal brackets into wall openings and laying planks across them. The brackets are designed to support 500 lbs each. One bracket is inserted into a deteriorated brick pocket that has loose mortar. The competent person approved the installation without inspecting the wall condition. When loaded, the bracket pulls out of the wall. What should have been done?
✅ Correct Answer: B
1926.452(k)(5): brackets for bracket scaffolds shall be seated securely on the supporting surface, and the supporting surface shall be capable of supporting the intended load. The competent person's inspection under 1926.451(f)(3) must include the supporting structure, not just the scaffold components. Deteriorated brick with loose mortar cannot provide the friction and bearing capacity needed for the bracket. A 500-lb rated bracket inserted into a weak wall pocket is only as strong as the wall itself. The employer must evaluate the entire load path from scaffold to ground.
Q35/ 40
A scaffold erector uses scaffold components from three different manufacturers on a single frame scaffold. The frames interlock (the pins fit) but the locking mechanisms are different designs. The competent person says 'if it fits, it's fine.' What does OSHA require?
✅ Correct Answer: B
1926.451(d)(1): scaffold components manufactured by different manufacturers shall not be intermixed unless the components fit together without force and the scaffold's structural integrity is maintained by the user. The competent person must make an affirmative determination of compatibility, not just assume that fitting pins equals structural compatibility. Different locking mechanisms (wedge locks, gravity pins, snap pins, etc.) may not engage properly with different frame dimples or slots, potentially releasing under dynamic load. If there is any doubt, the manufacturer should be consulted or components should not be mixed.
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Q36/ 40
A worker on a float scaffold (a single plank suspended by two ropes from above, used for light-duty tasks like caulking) at 40 feet height is not wearing fall protection. The scaffold is the worker's only support. Is this compliant?
✅ Correct Answer: B
1926.451(g)(1)(ii): employees on float scaffolds shall be protected by a personal fall arrest system. The PFAS must be attached to an independent lifeline (separate from the scaffold support ropes — 1926.451(g)(1)(vii)). A float scaffold is essentially a single plank hanging from two ropes — if either rope support fails, the plank drops. Without an independent PFAS, the worker has no backup. Float scaffolds are inherently unstable (they can tilt, rotate, and swing), making an independent fall arrest system essential for worker survival.
Q37/ 40
After a scaffold is erected, the competent person inspects it and finds that the platform planks overhang the end supports by 14 inches. The platform is 7 feet long between supports. Is the overhang acceptable?
✅ Correct Answer: B
1926.451(b)(6): on supported scaffolds, the ends of each platform must overhang the centerline of the support between 6 and 12 inches, unless the platform is designed to cantilever loads or is secured to prevent movement. At 14 inches, a worker stepping near the end of the plank could cause it to teeter (the plank becomes a lever with the support as fulcrum). The 6-12 inch range ensures adequate bearing on the support while limiting the cantilever effect. The plank should be replaced with a shorter one or the support spacing adjusted.
Q38/ 40
A mast climber (mast climbing work platform) is being used for masonry work on a 6-story building. The platform rises along a vertical mast tied to the building. Workers are loading bricks onto the platform from a forklift at ground level, and the platform is being raised with workers aboard. What must be verified during operation?
✅ Correct Answer: B
1926.451(c)(2)(v): mast climbers shall be tied to the building at intervals specified by the manufacturer. 1926.451(a)(6): scaffolds must not be loaded beyond capacity. 1926.451(f)(3): inspection before each shift. 1926.451(g)(1)(vii): guardrails required. 1926.451(h)(1): toeboards. Additionally, mast climbers must have operational emergency descent systems and limit switches. No one should be beneath the platform during raising/lowering (struck-by hazard). The operator must be trained and competent. Mast climbers are classified as scaffolds under Subpart L, not elevators.
Q39/ 40
During disassembly of a 60-foot high frame scaffold, the crew starts removing tie-ins from the top down. After removing the top two sets of ties, the 40-foot remaining scaffold section is freestanding at 40 feet with a 5-foot base — an 8:1 height-to-base ratio. A wind gust of 20 mph causes the scaffold to sway noticeably. What should have been done?
✅ Correct Answer: B
1926.451(f)(7): scaffolds shall be dismantled in a systematic manner. While the standard doesn't explicitly mandate maintaining tie-ins during dismantling, the General Duty Clause and the structural requirement of 1926.451(c)(1) (4:1 height-to-base ratio with ties) apply during ALL phases including disassembly. A freestanding scaffold at 8:1 is unstable. Disassembly should be planned so that ties closest to the remaining working level are removed last, or temporary guys are installed. The swaying is a warning sign of incipient collapse.
Q40/ 40
A worker on a supported scaffold at 18 feet height is using a PFAS with a 6-foot shock-absorbing lanyard anchored to the scaffold frame at foot level. The scaffold is fully guarded. The worker falls — the anchor is at foot level on the scaffold frame. What is the concern with anchoring to the scaffold frame?
✅ Correct Answer: B
1926.502(d)(15) requires anchorages to be capable of supporting 5,000 lbs. 1926.451(g)(1)(vii): PFAS may be anchored to the scaffold structure ONLY if the scaffold is capable of supporting the fall arrest loads. A scaffold frame is designed for vertical loads — a horizontal 5,000-lb shock load from a falling worker can pull the scaffold sideways. If the scaffold is not adequately tied to the building, it can tip over. Additionally, foot-level anchoring increases free fall distance. The competent person must verify the scaffold (including its ties) can resist the fall arrest forces in the direction they'll be applied.