Major Work Activity B - Performs hoisting calculations
Table of Contents
- Task B-3 Determines load weights
- Task B-4 Calculates crane capacity
- Task B-5 Performs rigging calculations
Task B-3 Determines load weights
Task descriptor
A mobile crane operator must be able to calculate accurately the load weight and centre of gravity of an object as it is vital to the safe operation of mobile cranes.
B-3.01-Identifies weight
| NL | NS | PE | NB | QC | ON | MB | SK | AB | BC | NT | YT | NU |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| yes | yes | NV | yes | NV | yes | yes | yes | yes | yes | NV | NV | NV |
| Reference Code | Performance Criteria | Evidence of Attainment |
|---|---|---|
| B-3.01.01P | determine weight of load to be lifted | weight of load to be lifted is determined according to unit weight of material to be lifted |
| B-3.01.02P | verify unit of measurement (metric or imperial) when missing or incorrect on source of load weight information | unit of measurement (metric or imperial) is verified when missing or incorrect on source of load weight information |
| B-3.01.03P | confirm weight of load to be lifted | it is verified that no adjustments, modifications or changes in conditions that may affect weight of load to be lifted have been made |
| B-3.01.04P | compare load calculations to sources of load weight information | load calculations are compared to sources of load weight information to confirm actual weight to be lifted |
Range of variables
- sources of load weight information include: bills of lading, stamped weights, engineered drawings, previous lift history, blueprints
| Reference Code | Learning Outcomes | Learning Objectives |
|---|---|---|
| B-3.01.01L | demonstrate knowledge of procedures used to identify weight of objects and basic shaped loads | define terminology associated with determining weight of objects and basic shaped loads |
| identify types of sources of load weight information | ||
| identify and apply formulas for conversion between imperial and metric systems | ||
| identify factors contributing to load weight |
Range of variables
- basic shaped loads include:cubes, cylinders, pyramid, rectangle, pipe
- sources of load weight information include: bills of lading, stamped weights, engineered drawings, previous lift history, blueprints
- factors contributing to load weight include: ice, water, mud, load frozen to ground, lifting in water, snow, crating, wind, incomplete demolition, friction, added components
B-3.02-Calculates weight
| NL | NS | PE | NB | QC | ON | MB | SK | AB | BC | NT | YT | NU |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| yes | yes | NV | yes | NV | yes | yes | yes | yes | yes | NV | NV | NV |
| Reference Code | Performance Criteria | Evidence of Attainment |
|---|---|---|
| B-3.02.01P | determine and apply formulas needed for object shape | formulas are determined and applied according to object shape |
| B-3.02.02P | perform calculation | calculation is performed according to formula |
Range of variables
- calculation is: volume times unit weight of material
| Reference Code | Learning Outcomes | Learning Objectives |
|---|---|---|
| B-3.02.01L | demonstrate knowledge of procedures used to calculate weight of objects and basic shaped loads | explain importance of determining weight of an object and basic shaped load and its relevance in lifting operations |
| identify factors contributing to load weight | ||
| describe procedures used to determine basic shaped loads | ||
| perform calculation and apply formula to calculate weight of objects and basic shaped loads | ||
| identify considerations used to determine weight of objects and basic shaped loads | ||
| B-3.02.02L | demonstrate knowledge of centre of gravity | describe conditions that affect centre of gravity |
| determine centre of gravity of objects | ||
| identify factors contributing to centre of gravity | ||
| perform calculations to determine centre of gravity in objects |
Range of variables
- basic shaped loads include:cubes, cylinders, pyramid, rectangle, pipe
- factors contributing to load weight include: ice, water, mud, load frozen to ground, lifting in water, snow, crating, wind, incomplete demolition, friction, added components
- calculation is: volume times unit weight of material
- considerations include: volume of object, weight of material
- factors contributing to centre of gravity include: shifting liquids,ice, water, mud, load frozen to ground, lifting in water, snow, crating, wind, incomplete demolition, friction, component distribution
Task B-4 Calculates crane capacity
Task descriptor
Mobile crane operators calculate crane capacities. This involves interpreting load charts, range diagrams and manufacturers’ specifications and instructions. Important considerations are radius and crane configuration.
B-4.01-Determines radius and crane configuration
| NL | NS | PE | NB | QC | ON | MB | SK | AB | BC | NT | YT | NU |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| yes | yes | NV | yes | NV | yes | yes | yes | yes | yes | NV | NV | NV |
| Reference Code | Performance Criteria | Evidence of Attainment |
|---|---|---|
| B-4.01.01P | measure horizontal distance from centre of rotation to centre of gravity of suspended load | horizontal distance from centre of rotation to centre of gravity of suspended load is measured |
| B-4.01.02P | use range diagram to determine boom length and jib/attachment offsets needed | range diagram is used to determine boom length and jib/attachment offsets needed to ensure radius and tip height can be achieved |
| B-4.01.03P | determine crane configurations | crane configurations are determined according to site and lift conditions, and manufacturers’ specifications and instructions |
| B-4.01.04P | determine main boom angle | main boom angle is determined according to range diagram, radius and operator aides |
| B-4.01.05P | determine jib/attachment angle | jib/attachment angle is determined according to range diagram, radius and operator aides |
Range of variables
- crane configurations include: counterweight, crawler, outrigger, boom, attachments
- manufacturers’ specifications and instructions include: load charts, configuration charts, hoist rope specifications, assembly/disassembly charts
| Reference Code | Learning Outcomes | Learning Objectives |
|---|---|---|
| B-4.01.01L | demonstrate knowledge of determining radius and crane configurations | define terminology associated with radius and crane configurations |
| identify methods used to measure radius | ||
| describe procedures used to determine crane configurations and main boom angle | ||
| identify manufacturers’ specifications and instructions | ||
| B-4.01.02L | demonstrate knowledge of regulatory requirements pertaining to crane configurations | identify codes, standards and regulations pertaining to radius and crane configurations |
Range of variables
- crane configurations include: counterweight, crawler, outrigger, boom, attachments
- methods used to measure radius include: measuring device, dry run
- manufacturers’ specifications and instructions include: load charts, configuration charts, hoist rope specifications, assembly/disassembly charts
- codes, standards and regulations include: CSA, OH&S, ASME
B-4.02-Interprets load charts
| NL | NS | PE | NB | QC | ON | MB | SK | AB | BC | NT | YT | NU |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| yes | yes | NV | yes | NV | yes | yes | yes | yes | yes | NV | NV | NV |
| Reference Code | Performance Criteria | Evidence of Attainment |
|---|---|---|
| B-4.02.01P | determine crane gross capacity | crane gross capacity is determined according to crane configurations and corresponding load charts |
| B-4.02.02P | refer to load charts for reductions of gross capacity | load charts are referred to for reductions of gross capacity |
| B-4.02.03P | calculate gross load and net capacity | gross load and net capacity are calculated |
| B-4.02.04P | locate warnings | warnings are located according to load charts, range diagrams and manufacturers’ notes |
| B-4.02.05P | de-rate crane gross capacity | crane gross capacity is de-rated using various site and regulatory restrictions, and manufacturers’ specifications |
Range of variables
- crane configurations include: counterweight, crawler, outrigger, boom, attachments
| Reference Code | Learning Outcomes | Learning Objectives |
|---|---|---|
| B-4.02.01L | demonstrate knowledge of load charts, their characteristics and applications | define terminology associated with load charts |
| identify components of load charts, and describe their characteristics and applications | ||
| B-4.02.02L | demonstrate knowledge of interpreting load charts | describe procedures used to interpret components of load charts required to plan lifts |
| identify factors that influence crane capacity in lifting operations and describe their impact | ||
| perform calculations to determine crane’s main boom configuration capacity | ||
| perform calculations to determine crane’s jib or extension configuration capacity | ||
| perform calculations to determine line pull, working load limit (WLL), minimum parts of line and size of hook block | ||
| perform calculations to determine maximum working radius | ||
| perform calculations to determine capacity deductions found in manufacturers’ notes |
Range of variables
- terminology includes: gross capacity, net capacity, gross load, net load, radius, boom length, angle
- components of load charts include: notes (factors affecting capacity), capacity charts, range diagram, technical data, parts of line, weights of deductions, quadrants of operation, crane configurations (on outriggers, on rubber, crawlers extended or retracted, counterweight, boom/jib), notes/technical data (line weight calculation/deduction), boom length and radius, boom deflection
- factors that influence crane capacity include: attachments, configurations, capacity deductions, duty cycle, manufacturers’ notes (wind, temperature), out of level, ground conditions
Task B-5 Performs rigging calculations
Task descriptor
Accurate rigging calculations are important for the proper selection and use of rigging and hardware to ensure safe hoisting operations.
B-5.01-Performs sling angle calculations
| NL | NS | PE | NB | QC | ON | MB | SK | AB | BC | NT | YT | NU |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| yes | yes | NV | yes | NV | yes | yes | yes | yes | yes | NV | NV | NV |
| Reference Code | Performance Criteria | Evidence of Attainment |
|---|---|---|
| B-5.01.01P | determine rigging capacity | rigging capacity is determined according to manufacturers’ identification tags, rigging guides and performing manual calculations |
| B-5.01.02P | calculate angle of each sling leg | angle of each sling leg is calculated to determine effect of angle on tension of sling and rigging hardware |
| B-5.01.03P | calculate equal sling leg tension | equal sling leg tension is calculated according to sling length and hook height |
| B-5.01.04P | calculate unequal sling leg tension | unequal sling leg tension is calculated according to location of centre of gravity, sling length and hook height |
| Reference Code | Learning Outcomes | Learning Objectives |
|---|---|---|
| B-5.01.01L | demonstrate knowledge of slings, hardware, sling configurations, their characteristics, applications and capacities | define terminology associated with slings and their hardware |
| identify hazards and describe safe work practices pertaining to slings | ||
| identify types of sling configurations, and describe their characteristics and applications | ||
| identify types of slings and their hardware, and describe their sizes, characteristics, applications and capacities | ||
| explain sling angles and their effect on sling capacities | ||
| B-5.01.02L | demonstrate knowledge of performing sling angle calculations | describe procedures used to determine sling angle |
| perform calculations to interpret load on slings used at an angle | ||
| describe procedures used to determine appropriate sling size for a given load | ||
| perform calculations using sling tension formulas | ||
| perform calculations using field formulas and sling angle charts | ||
| identify elements of lift data used to perform hoisting calculations | ||
| B-5.01.03L | demonstrate knowledge of regulatory requirements pertaining to rigging | identify codes, standards and regulations pertaining to rigging |
Range of variables
- hardware includes: shackles, lifting eyes, beams, rigging blocks
- types of sling configurations include: choker, basket, vertical, bridle
- types of slings include: steel, synthetic
- lift data includes: available rigging, pick points, load size, weight and centre of gravity
- codes, standards and regulations include: CSA, OH&S, ASME
B-5.02-Performs working load limit (WLL) calculations
| NL | NS | PE | NB | QC | ON | MB | SK | AB | BC | NT | YT | NU |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| yes | yes | NV | yes | NV | yes | yes | yes | yes | yes | NV | NV | NV |
| Reference Code | Performance Criteria | Evidence of Attainment |
|---|---|---|
| B-5.02.01P | determine factors that affect capacity of sling | factors that affect capacity of sling are determined |
| B-5.02.02P | interpret engineers’ and manufacturers’ specifications | engineers’ and manufacturers’ specifications are interpreted |
| B-5.02.03P | calculate rigging capacity and sling tension | rigging capacity and sling tension are calculated using formulas |
Range of variables
- factors include: choke, basket, vertical configuration, bridle configuration, D:d ratio, sharp edges, angle of choke
| Reference Code | Learning Outcomes | Learning Objectives |
|---|---|---|
| B-5.02.01L | demonstrate knowledge of WLL, their characteristics and applications | define terminology associated with WLL |
| identify and describe deduction factors that cause reduction in capacity to sling or wire rope | ||
| B-5.02.02L | demonstrate knowledge of performing WLL calculations | perform calculations to determine WLLs of slings |
| identify considerations used to determine WLLs |
Range of variables
- considerations include: manufacturers’ specifications, codes and standards, rigging applications