Crane capacity is typically stated in one of two ways:
Foot*Pounds / Overturning Moment - typically used when describing Pedestal cranes.
The Foot*Pound rating is independent of the Maximum Lifting Capacity of the winch itself.
For example: the ET10KX is rated for 10,800 ft*lbs. The Maximum Lifting Capacity of the winch is 3,200 lbs (using snatch block to provide 2 part line).
- or -
Maximum Lifting Capacity - typically used when describing Mast cranes
For example, the CT2004FB is rated for 2,000 lbs. It is able to handle 2,000 lbs a maximum of 3 feet from the center of rotation, making it a 6,000 ft*lb crane.
How to determine Foot*Pounds (Overturning Moment)
a) Determine the WEIGHT of the load to be picked up.
b) Determine the DISTANCE from the Center of Crane Rotation to the spot where the load is to be picked up.
c) FOOT*POUNDS = DISTANCE x WEIGHT
Example #1: 2000 lb WEIGHT to be picked up at 10 feet = 20,000 ft*lbs
Venturo crane to be used = ET25KX or HT25KX
Example #2: 1000 lb WEIGHT to be picked up at 20 feet = 20,000 ft*lbs
Venturo crane to be used = ET25KX or HT25KX
Note that in both examples, the required Foot*Pounds was the same. It is important to determine the greatest Foot*Pounds requirement (“worst case scenario”) when selecting your crane capacity.
When considering a Ferrari Knuckle-Boom (Articulating) Crane:
To convert Foot*Pounds to Meter*Tonnes, divide by 7,260.
7,260 ft*lbs = 1 meter*tonne
In most cases the Foot*Pounds calculation will dictate the model of crane to be used, the GVW of the truck, and the type of body.
This page is courtesy of Venturo Cranes. See more at http://www.venturo.com/
