Basic Crane Limitations – Tool Box Talks
BASIC CRANE SET UP
- A cranes capacity is different over the Sides than it is over the Front or Rear.
- There is a difference in capacity if outriggers are extended. Fully Extend Outriggers (unless
charts have ratings for other settings).
- Pads 3 times the size of the floats.
- Wheels Off the ground (just enough for clearance).
- Barricade the entire swing radius and ensure NOBODY is within the swing radius while in use.
- Increasing the radius generally reduces the total capacity
- Is the angle of the boom to the horizontal.
- Booming up reduces radius, increases boom angle, and generally increases capacity. Booming
down increases radius, decreases boom angle, and generally decreases capacity.
- A condition when the ball or load block comes in contact with the sheaves at the tip.
- This could cause the rope to break causing dynamic unloading which will drop the load and
damage the crane.
- Dynamic loading can dramatically effect the stability of the crane and is typically caused by rapidly
accelerating or stopping a load.
- Typically cause by not having the tip of the crane over the load when trying to hoist or when there is a rapid
start or stop of the swing.
- This can cause sever structural damage to the boom and eventually cause failure of the crane boom.
EFFECTS OF WIND
From the Back
- Effect of wind on the load increases the load radius and reduces capacity.
Forward stability is the critical consideration when the wind is from behind the
- It has same effect as adding load to the hook.
From the Front
- Effect of the wind on the load reacts at the boom tip by creating a backward tipping load.
- Backward stability is the critical factor when the wind is from the front, particularly when the boom
is at or approaching maximum boom angle.
From the Side
- Boom Strength is most affected when the wind is from the side.
SAFETY REMINDERS – RIG IT RIGHT THE FIRST TIME-EVERYTIME!