Mobile Cranes No. 1 – Questions & Solutions
The load radius as shown on the capacity chart is the distance from the
center of rotation to the centerline of the vertical host line with:
Correct Ans - The rated load suspended.
If the jib angle to ground is changed from 50 degrees to 40 degrees, this
would affect the capacity of the crane how? Correct Ans - Capacity
will decrease.
Load capacity charts are based on 75% of tipping for crawler cranes
without out riggers. For wheel mounted cranes, using outriggers fully
extended, capacities are based on what percentage of tipping? Correct
Ans - 85%
The operators should exercise extreme caution when lifting loads from the
water mainly because: Correct Ans - The load on the crane will
increase as an object leaves the water.
On the upper works Correct Ans - On the carrier.
When working on soft soil with poor bearing support: Correct Ans -
Use matting to distribute crane's weight over a larger area.
The best way to determine the weight of a load to be lifted is to:
Correct Ans - Have a certified load weight and add in the weight of all
rigging.
When a situation arises that will not permit outriggers to be set at
positions that correspond to the locations established by the
manufacturer's load rating charts, the crane manufacturer shall be
consulted to determine if any capacity reductions, special operation
procedures, or limitations are required. If required information is not
available from the manufacturer, whom shall be consulted? Correct Ans
- Qualified person.
When performing a pick and carry operation using a crawler crane, the
load should be positioned: Correct Ans - Over the front.
, A thick dark line running across the load chart means that the load listings:
Correct Ans - Above the lines are limited by structural factors.
Dynamic motion such as swinging with a load can cause what change in the
crane operation? Correct Ans - Increased load radius.
The dead end of the wire rope above the wedge socket must extend a
minimum of 6 times the rope diameter or: Correct Ans - 6 inches.
A work area chart is used to: Correct Ans - Identify capacity
changes due to operational quadrants.
Which of the following 3 sling hitches is listed in order from the strongest
to the weakest? Correct Ans - Basket, Vertical, Chocker.
An anti-2-block damage of prevention system will: Correct Ans -
Prevent any crane movements that will cause a 2-block condition.
The minimum distance for safety between the swing radius of the counter
weight and any obstacle is: Correct Ans - 2 Feet.
What is the best source of information for determining boom tip height?
Correct Ans - Working range diagram
Attachments or extra counter weights not approved by the manufacturer
should not be attached to the rear of the crane because: Correct Ans -
They may cause a backward stability problem.
The first thing an operator should do before traveling under a low pipe
rack is: Correct Ans - Post a signal person to check clearance.
The only time the outrigger beams should be less than fully extended is
when: Correct Ans - The load chart indicates that this is allowed.
The boom angle indicator shows boom angle and reference to the capacity
chart: Correct Ans - Is used along with boom length to determine
radius.
The load radius as shown on the capacity chart is the distance from the
center of rotation to the centerline of the vertical host line with:
Correct Ans - The rated load suspended.
If the jib angle to ground is changed from 50 degrees to 40 degrees, this
would affect the capacity of the crane how? Correct Ans - Capacity
will decrease.
Load capacity charts are based on 75% of tipping for crawler cranes
without out riggers. For wheel mounted cranes, using outriggers fully
extended, capacities are based on what percentage of tipping? Correct
Ans - 85%
The operators should exercise extreme caution when lifting loads from the
water mainly because: Correct Ans - The load on the crane will
increase as an object leaves the water.
On the upper works Correct Ans - On the carrier.
When working on soft soil with poor bearing support: Correct Ans -
Use matting to distribute crane's weight over a larger area.
The best way to determine the weight of a load to be lifted is to:
Correct Ans - Have a certified load weight and add in the weight of all
rigging.
When a situation arises that will not permit outriggers to be set at
positions that correspond to the locations established by the
manufacturer's load rating charts, the crane manufacturer shall be
consulted to determine if any capacity reductions, special operation
procedures, or limitations are required. If required information is not
available from the manufacturer, whom shall be consulted? Correct Ans
- Qualified person.
When performing a pick and carry operation using a crawler crane, the
load should be positioned: Correct Ans - Over the front.
, A thick dark line running across the load chart means that the load listings:
Correct Ans - Above the lines are limited by structural factors.
Dynamic motion such as swinging with a load can cause what change in the
crane operation? Correct Ans - Increased load radius.
The dead end of the wire rope above the wedge socket must extend a
minimum of 6 times the rope diameter or: Correct Ans - 6 inches.
A work area chart is used to: Correct Ans - Identify capacity
changes due to operational quadrants.
Which of the following 3 sling hitches is listed in order from the strongest
to the weakest? Correct Ans - Basket, Vertical, Chocker.
An anti-2-block damage of prevention system will: Correct Ans -
Prevent any crane movements that will cause a 2-block condition.
The minimum distance for safety between the swing radius of the counter
weight and any obstacle is: Correct Ans - 2 Feet.
What is the best source of information for determining boom tip height?
Correct Ans - Working range diagram
Attachments or extra counter weights not approved by the manufacturer
should not be attached to the rear of the crane because: Correct Ans -
They may cause a backward stability problem.
The first thing an operator should do before traveling under a low pipe
rack is: Correct Ans - Post a signal person to check clearance.
The only time the outrigger beams should be less than fully extended is
when: Correct Ans - The load chart indicates that this is allowed.
The boom angle indicator shows boom angle and reference to the capacity
chart: Correct Ans - Is used along with boom length to determine
radius.
