NCCCO Counterweight and Ballast Configuration 2

Question 1

What is the primary purpose of a crane's counterweight?

Accepted Answer

To offset the overturning moment created by the lifted load and boom weight, allowing the crane to lift heavier loads at greater radii without tipping

Answer

To add overall weight to the crane for better ground stability

Answer

To provide ballast for wind resistance during storms

Answer

To protect the crane's drive components from impact damage

Question 2

A mobile crane's load chart shows different capacities for standard counterweight and maximum counterweight configurations. When would a crane operator use the maximum counterweight?

Accepted Answer

When the planned lift exceeds the capacity shown in the standard counterweight chart, and the additional counterweight is necessary to achieve the required rated capacity for the load radius

Answer

When maximum counterweight is always used regardless of load requirements

Answer

Maximum counterweight is only used during transport, not during lifts

Answer

When the crane is operating on soft ground that cannot support heavy loads

Question 3

What is a superlift or SuperLift counterweight system on a large lattice boom crane, and what advantage does it provide?

Accepted Answer

A superlift is an additional removable counterweight mounted on a separate trailing car or mast behind the crane that dramatically increases the counterbalancing moment, enabling much higher rated capacities for heavy lifts

Answer

A superlift is a safety device that lifts the counterweight off the ground during transport

Answer

Superlift refers to the crane's ability to lift loads heavier than its standard capacity

Answer

A superlift is the name for the maximum hydraulic pressure setting on the crane's hoist

Question 4

What happens to a crane's rated lifting capacity if the counterweight is installed in a different amount than specified in the load chart being used?

Accepted Answer

Using a different counterweight amount than specified in the load chart makes that load chart inapplicable — the operator must use the load chart that matches the actual counterweight installed, or not perform the lift

Answer

Rated capacity automatically adjusts to match whatever counterweight is installed

Answer

Counterweight variations of less than 10% have no effect on rated capacity

Answer

Adding more counterweight than specified in the chart always increases the rated capacity

Question 5

During crane setup on a sloped surface, the crane is leveled using its outrigger cylinders. How does leveling affect the counterweight's effectiveness?

Accepted Answer

Proper leveling ensures the counterweight's stabilizing moment is applied as designed in the load chart. A tilted crane shifts the counterweight's effective position and changes the stability calculation

Answer

Leveling has no effect on counterweight — it is a fixed weight regardless of slope

Answer

A sloped crane requires removal of counterweight to maintain balance

Answer

Counterweight effectiveness increases when the crane is tilted toward the load

Question 6

What safety precaution must be taken when a crane's counterweight is being installed or removed?

Accepted Answer

All non-essential personnel must be kept clear of the crane during counterweight installation or removal, and a qualified maintenance person or operator must supervise the operation following manufacturer procedures

Answer

Only the operator needs to be present; no other personnel are required nearby

Answer

Counterweight installation requires no special precautions beyond normal crane setup

Answer

The crane must be in motion (running) during counterweight changes to prevent hydraulic lock