Free Red Seal Ironworker (Generalist) (420B) Practice Test

Answer: A. More than 3 m

Ontario's construction regulation requires fall protection where a worker could fall more than 3 m. Lower thresholds apply in special cases, for example a fall of more than 1.2 m from a wheelbarrow route or any fall into operating machinery, water or a hazardous substance.

Check it: O. Reg. 213/91 s. 26

Answer: B. To stop a flame travelling back into the hose, regulator or cylinder

A flashback arrestor stops a flame front from moving back up the hose toward the regulator and cylinder. Check valves, a separate component, stop reverse gas flow; many arrestors combine both functions.

Check it: CSA W117.2

Answer: D. About 393 kg

Volume = 2.0 m x 1.0 m x 0.025 m = 0.05 m³. Mass = 0.05 x 7850 = 392.5 kg, about 393 kg. Converting all dimensions to metres first avoids errors.

Check it: Formula: mass = volume x density

Answer: B. To prevent slips and trips, and to stop material from falling to lower levels

Housekeeping prevents tripping hazards at height and stops loose material from falling or being kicked off the edge onto workers below.

Check it: NOA Block A – organizes work

Answer: B. About 2310 kg

Each leg carries half the load divided by the sine of the angle from horizontal: (4000 / 2) / sin 60° = 2000 / 0.866 = 2309 kg. The steeper the legs, the closer the tension gets to half the load.

Check it: Sling angle formula; CSA Z150 / ASME B30.9 sling angle factors

Answer: C. Six strands with about 19 wires per strand

The first number is the number of strands and the second is the (nominal) number of wires per strand. More, smaller wires (e.g. 6x36) give more flexibility; fewer, larger wires resist abrasion better.

Check it: Wire rope nomenclature

Answer: C. Missing or illegible identification tag

Synthetic slings must be removed if the tag is missing or unreadable, and for cuts, holes, tears, broken stitching, burns, melting, chemical damage, embedded particles or exposed red warning yarns.

Check it: ASME B30.9 synthetic sling removal criteria

Answer: A. About 20 kN

When the line turns 180°, both parts pull in the same direction, so the block and its anchor see twice the line pull. At 90° the load is about 1.41 times the line pull.

Check it: Snatch block load factors

Answer: C. Movement or tilting of the load can shift weight onto one crane

If one crane hoists faster or the load tilts, the load shifts toward one crane. Plans calculate each crane's share at the worst position and allow a margin below chart capacity.

Check it: CSA Z150 (multiple crane lifts)

Answer: B. About 429 kg

Cross-section area = π/4 x (0.300² - 0.280²) = π/4 x 0.0116 = 0.00911 m². Volume = 0.00911 x 6 = 0.0547 m³. Mass = 0.0547 x 7850 = 429 kg.

Check it: Formula: volume of a hollow cylinder

Answer: D. CSA Z150

CSA Z150 is the safety code on mobile cranes. CSA Z248 covers tower cranes, CSA B167 overhead travelling cranes, hoists and monorails, and CSA W59 welded steel construction.

Check it: CSA Z150

Answer: C. The manufacturer's erection manual and the engineered erection plan

Tower crane erection follows the manufacturer's instructions and an engineered plan for the site (foundation, ties, sequence, torques). CSA Z248 requires competent supervision and inspection.

Check it: CSA Z248

Answer: B. A disassembly plan, an adequate assist crane and suitable wind and site conditions

Dismantling reverses the erection sequence under a planned procedure, often with a mobile crane. The assist crane must reach the heaviest components at the required radius, and wind limits apply.

Check it: CSA Z248

Answer: C. 1.570 kg/m

CSA G30.18 lists 15M as 16.0 mm nominal diameter, 200 mm² area and 1.570 kg/m. 10M is 0.785 kg/m, 20M 2.355 kg/m and 25M 3.925 kg/m.

Check it: CSA G30.18 (bar sizes)

Answer: A. Precast concrete blocks (dobies) or supports with sand plates

On soil, wire chairs sink in. Precast concrete blocks or chairs with plates spread the load and maintain cover. Wood is not left in concrete because it rots and wicks moisture.

Check it: RSIC Manual (bar supports)

Answer: D. 30

Distance between end bars = 12,000 - 400 = 11,600 mm. Spaces = 11,600 / 400 = 29. Bars = 29 + 1 = 30.

Check it: Bar spacing calculation

Answer: D. So concrete and aggregate can flow between bars and fully surround them

Minimum clear spacing (related to bar size and aggregate size) lets concrete consolidate around bars. Congested reinforcement can cause honeycombing and voids.

Check it: CSA A23.1 (spacing)

Answer: C. Off the ground on dunnage, sorted by mark, and protected as required

Storing bars on dunnage keeps them clean and accessible. Sorting by mark speeds placing. Coated bars may need covering from UV.

Check it: RSIC handling and storage

Answer: A. Pre-tensioning stresses strands before casting; post-tensioning stresses tendons afterward

In pre-tensioning (usually in a precast plant) strands are tensioned between abutments, concrete is cast, and the strands are released once it reaches strength. In post-tensioning, tendons in sheathing or ducts are stressed after the concrete has gained the required strength.

Check it: NOA Block E – places pre-stressed/post-tensioning systems

Answer: B. So the gauge pressure accurately represents the force in the tendon

Jacks and gauges are calibrated as a pair; the calibration chart converts gauge pressure to force. Uncalibrated equipment can overstress or understress tendons.

Check it: PTI stressing practice

Answer: D. CSA S16

CSA S16 (Design of steel structures) includes requirements for fabrication and erection of structural steel, including bolting, tolerances and temporary bracing. Welding follows CSA W59.

Check it: CSA S16

Answer: C. No, they must not be reused or retightened after full pretensioning

Pretensioning stretches high-strength bolts. A490 bolts and galvanized A325 bolts must not be reused. Black A325 bolts may be reused only if approved.

Check it: CSA S16; RCSC specification

Answer: A. Panels of lumber layers glued at right angles, used as walls and floors

CLT is an engineered wood panel of crosswise layers. Ironworkers on mass timber projects install panels and steel connections, using the manufacturer's lifting systems.

Check it: Mass timber construction

Answer: D. Bolt the splice plates to hold alignment, then plumb and finish

Splice plates are bolted to hold the upper column in alignment. After plumbing, splices are fully bolted or welded as detailed.

Check it: Erection practice

Answer: A. To show the order in which members are erected for stability

Erection sequence drawings show the order and stages, making sure each stage is stable before the next.

Check it: Erection planning

Answer: A. A non-load-bearing exterior wall hung from the structure

Curtain walls carry their own weight and wind loads to the structure through anchors but do not support floors. Ironworkers often install them.

Check it: Building terminology

Answer: D. To allow slight adjustment of the anchor bolt position

Sleeves around anchor bolts let the bolt move slightly to align with the machine's holes before grouting.

Check it: Machinery installation practice

Answer: B. Holes too close to an edge can tear out under load

CSA S16 sets minimum edge distances so the steel between the hole and the edge can carry bearing forces without tearing. Field holes must respect these distances.

Check it: CSA S16 (edge distance)

Answer: B. Determine how removal will affect stability and follow an engineered removal sequence

Removing members changes load paths. A demolition or removal plan (often engineered) sets the sequence, shoring and rigging so remaining members stay stable.

Check it: NOA Block G – dismantles and removes components; O. Reg. 213/91 (demolition)

Answer: A. Isolating and decommissioning it before rigging and removal

Equipment is decommissioned: utilities and energy isolated, fluids drained and connections removed before rigging.

Check it: NOA Block G – dismantles and removes components