433A rigging and hoisting practice questions.

Five free practice questions on rigging and hoisting: block B of the Red Seal 433A Industrial Mechanic Millwright exam, about 17 of its 135 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.

01The questions

1. Procedural · Performs hoist/lift and move

   A pump must be lowered by mobile crane into a pit at a water treatment plant. The operator cannot see the pit or the rigger in it at any point in the lift. How should communication be handled?

   1. The rigger shouts up from the pit
   2. Send signals by text message from the pit
   3. The operator lowers slowly until the load feels landed
   4. Two-way radio on a dedicated channel; stop if contact is lost
   Show the answer

   D. Correct. The RSOS requires an alternate communication method when there is no direct line of sight, and lists two-way radio first. The signaller and operator use a channel nobody else is on, the signaller talks continuously during movement (for example 'lower... lower... lower... stop'), and any loss of communication means the operator stops immediately and holds.

   Why not the others

   A. Shouting is drowned by the crane and plant noise and cannot be confirmed heard. It is not an acceptable method where sight is lost.

   B. Texting is not continuous, has no confirmation and takes the operator's eyes off the controls. Voice radio or a relayed signaller, per site rules, is used.

   C. Feeling for the bottom means the operator is moving a load into a space with a person in it, blind. Every movement must be directed.

2. Procedural · Selects rigging equipment

   A millwright must estimate the working load limit of a 19 mm (3/4 in) 6 × 19 wire rope for a vertical pull, using the formula sheet's WLL of a 6 × 19 wire rope = diameter² × 8. What result does the formula give?

   1. 4080 kg (4.5 tons)
   2. 5440 kg (6 tons)
   3. 2040 kg (2.25 tons)
   4. 2720 kg (3 tons)
   Show the answer

   A. Correct. Diameter in inches: 0.75² = 0.5625; × 8 = 4.5 tons. The formula assumes the diameter is entered in inches and gives the answer in tons (2 000 lb), so 4.5 tons is about 4 080 kg. It is a rule-of-thumb for 6 × 19 rope only; the actual WLL used on the job is the manufacturer's rating for that rope and termination.

   Why not the others

   B. This forgot to square the diameter (0.75 × 8 = 6). Squaring is what makes the rating grow quickly with size: doubling the diameter quadruples the WLL.

   C. This multiplies the squared diameter by 4 instead of 8 (0.5625 × 4). The sheet's constant for 6 × 19 rope is 8.

   D. This is what the formula returns for a 5/8 in rope (0.625² × 8 = 3.1). The formula takes the full nominal diameter of the rope actually being used, in inches, not a radius and not the next size down.

3. Procedural · Sets up rigging, hoisting/lifting and moving equipment

   A mobile crane is being set up on a compacted gravel laydown area at a mine to lift a 6 000 kg (13 200 lb) motor. How should the outriggers be set before the lift?

   1. Leave the tires on the ground to share the load
   2. Extend only the outriggers on the load side
   3. Set the floats directly on the gravel to save time
   4. Fully extended per the chart, floats on mats, crane level
   Show the answer

   D. Correct. The RSOS requires the lift to be prepared using floats under outriggers and cribbing. Outriggers are extended to the position the load chart was read for (charts change with partial extension), floats sit on mats or cribbing sized to spread the load to what the ground can bear, and the crane is levelled within the manufacturer's tolerance so the load moment is not thrown off by an out-of-level slew.

   Why not the others

   A. Unless the chart specifically gives on-rubber capacities, tires sharing the load make the crane's reaction uncertain and the outrigger setting invalid.

   B. The counterweight side must be supported too; the crane swings, and a partially set crane is unstable through part of its rotation.

   C. Compacted gravel can still punch under a float under peak load. Mats or cribbing reduce the bearing pressure; skipping them is how outriggers sink mid-lift.

4. Procedural · Secures area

   A mobile crane will lift a 3 000 kg (6 600 lb) conveyor drive over a walkway in a pulp mill yard. Which area must be barricaded and tagged before the lift starts?

   1. Only the ground directly under the pick point
   2. The crane's outrigger positions
   3. The entire mill yard for the day
   4. The load path and the crane's full swing radius
   Show the answer

   D. Correct. The RSOS requires the lift radius to be determined and secured with barricades and tape, and the location of personnel confirmed. The zone covers the whole path the load will travel, the area under it, and the crane's swing including the counterweight tail swing, which can crush a person against a wall or structure.

   Why not the others

   A. The load travels from pick to set-down, and the hazard follows it. Barricading a single spot leaves the rest of the path and the crane's swing open to foot traffic.

   B. Outrigger pads mark where the crane stands, not where the hazard is. People are struck by the load or the rotating counterweight, not by a stationary float.

   C. Over-barricading blocks work that is nowhere near the lift and tends to get ignored. The zone is sized to the actual lift radius and route, with a permit where site rules require one.

5. Procedural · Maintains rigging, hoisting/lifting and moving equipment

   A millwright suspects the hook on an overhead crane's block has been tip-loaded and may have opened. How is a hook checked for excessive throat opening during inspection?

   1. Compare it by eye with another hook of the same size
   2. Check that the safety latch still closes
   3. Measure the throat opening against the manufacturer's dimension
   4. Load-test it with the next lift and watch for movement
   Show the answer

   C. Correct. The throat is measured between the manufacturer's marked points, or tip to shank, and compared with the original dimension or the baseline recorded when the hook was new. Published limits differ, so the manufacturer's criteria govern: ASME B30.10 removes a hook for a throat increase over 5 %, not to exceed 6 mm (1/4 in), or for any visible bend or twist out of the plane of the unbent hook. A hook past the limit is removed; it is never bent back, heated or welded.

   Why not the others

   A. Opening from tip loading can be a few millimetres and still exceed the limit; the eye cannot resolve it and the comparison hook may itself be stretched.

   B. A latch can close on a hook that has opened well past its limit; the latch check is necessary but does not measure the throat.

   D. Using a suspect hook on a real load is exactly the risk inspection exists to prevent. A hook that fails a measurement never goes back on the block.

02Answer key

03What block B covers

This block covers planning and carrying out lifts and machinery moves. It includes estimating load weight and centre of gravity, sling angles and working load limits, wire rope, chain and synthetic slings, shackles, eyebolts and wire rope clips, chain hoists, toe jacks and skates, mobile and overhead crane load charts, hand signals and radio, barricades and power-line limits, and rigging inspection.

The Red Seal Occupational Standard names this block “Performs rigging, hoisting/lifting and moving”. It carries 12.6% of the exam, about 17 of the 135 questions, split across two tasks. The share column is each task's weight within the block, as the standard publishes it.

04What the questions turn on

Sling angle and leg load

Use the formula sheet: length divided by height, times the load, divided by the number of legs, counting no more than three. At 30 degrees to the horizontal, each leg of a two-leg bridle carries the full weight of the load.

The weakest part governs

A rigging assembly may lift only what its lowest-rated component allows, whether that is the sling, shackle, hook or eyebolt. Only a shoulder eyebolt, seated flat and square, may take an angled pull, and its rating drops with the angle.

Know the real load

The lift weight includes the rigging hardware, added components and anything still inside, such as slurry left in a pump casing. In a bridle with legs of different lengths, the leg nearer the centre of gravity carries the larger share.

Wire rope clips

Clips needed equal 3 x rope diameter in inches plus 1, rounded up, so a 3/4 in rope takes four. The saddle sits on the live end and the U-bolt on the dead end, and the nuts are re-torqued after the first loading.

05The other blocks

The 433A exam has six blocks. Each has its own page of free questions:

The 433A Industrial Mechanic Millwright practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.