Load Charts and Capacity Calculations Flashcards
6 cards from real NCCCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Load Charts and Capacity Calculations flashcards as text
A crane load chart shows a rated capacity of 42,000 lbs at a 30-foot radius with a 60-foot boom. The rigging hardware (hook block, slings, and shackles) weighs 800 lbs. What is the maximum net load that can be safely lifted?
Answer: 41,200 lbs
The rigging hardware weight must be subtracted from the load chart rated capacity to determine the maximum net load. 42,000 - 800 = 41,200 lbs.
What does a dagger symbol (†) or asterisk (*) next to a rated capacity in a load chart typically indicate?
Answer: A footnote that imposes an additional condition or restriction on that capacity value
Symbols such as daggers or asterisks in load charts are footnote markers that reference additional conditions, restrictions, or special instructions that apply to that specific capacity value.
When planning a lift with a telescoping boom crane, why is it important to know the boom's actual extended length?
Answer: Boom length determines which column in the load chart provides the applicable rated capacities
In load charts for telescoping boom cranes, boom length is a primary variable that determines which column of capacities to use; different boom lengths have different rated capacities at the same working radius.
A crane is set up with outriggers partially extended. Which load chart table should the operator use?
Answer: The table specifically showing the actual partial extension percentage used
The operator must use the load chart table that specifically corresponds to the actual outrigger extension configuration used. Using the wrong table — particularly one showing higher capacities — is a serious safety violation.
What is 'chart capacity' versus 'structural capacity' in crane load chart terminology?
Answer: Chart capacity is the lower of structural limit and stability limit; structural capacity is the limit based on crane structure strength alone
Chart (rated) capacity represents the lower of structural or stability limits with required safety factors applied. Structural capacity refers specifically to limits imposed by the crane's structural components rather than its tipping stability.
If a load chart shows 'N/A' or a blank cell for a specific radius and boom length combination, what does this mean for the operator?
Answer: That combination is not permitted; the crane must not be operated at that radius with that boom length
A blank or N/A cell in a load chart means the crane must not be operated at that combination of radius and boom length — it falls outside the crane's design envelope.