NCCCO Load Charts and Capacity Calculations 2

Question 1

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?

Accepted Answer

41,200 lbs

Answer

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.

Question 2

What does a dagger symbol (†) or asterisk (*) next to a rated capacity in a load chart typically indicate?

Accepted Answer

A footnote that imposes an additional condition or restriction on that capacity value

Answer

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.

Question 3

When planning a lift with a telescoping boom crane, why is it important to know the boom's actual extended length?

Accepted Answer

Boom length determines which column in the load chart provides the applicable rated capacities

Answer

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.

Question 4

A crane is set up with outriggers partially extended. Which load chart table should the operator use?

Accepted Answer

The table specifically showing the actual partial extension percentage used

Answer

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.

Question 5

What is 'chart capacity' versus 'structural capacity' in crane load chart terminology?

Accepted Answer

Chart capacity is the lower of structural limit and stability limit; structural capacity is the limit based on crane structure strength alone

Answer

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.

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO Load Charts and Capacity Calculations 2