November 16, 2021
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A big part of the OE Attachments business is in the name: attachments. As highlighted in our Attachment Awareness Series, attachments can improve the overall operation and add versatility to your equipment.
These added benefits make it easy for customers to forget that adding attachments to a forklift vehicle impacts the capacity of the forklift, which is referred to as “Lost Load Capacity.”
What’s the big deal with apacity?
Many forklift operators may not have been trained to find and know their machine’s rated capacity before an attachment is installed or a load is picked up. Considering that weight/capacity-related forklift rollovers are the most common type of fatal forklift accident, it is imperative to understand the capacity of the forklift being operated as well as how that capacity is affected by the addition of an attachment. This is also known as the net capacity. For example, the weight of the vehicle will increase because of the weight of the attachment and that will cause the overall capacity available to the vehicle to decrease.
The forklift data plate, required by both the Occupational Safety and Health Association (OSHA) and the American National Standards Institute (ANSI), provides capacity information as well as other important information about the machine. You can see a great example of what a data plate for a forklift vehicle looks like and how to read one here.
OE Attachments includes data plates on all our as well.
This will provide essential information like the weight of the attachment, capacity of the attachment and center of gravity. These specifications are directly used in calculating the lost load capacity and net capacity after installation.
How to calculate Lost Load Capacity and determine Net Capacity
We want to be as informative as we can so, while we advise seeking professional consultation with understanding the capacity of your specific equipment, here is a general overview of how net capacity is calculated.
The formula for net capacity reads: [R(F+L) – W(D+H)] / (D+T+C)
Below is what each letter in the equation represents:
- R = Rated capacity (pounds)
- F = Distance from the front wheel centerline to the front of forks (inches)
- L = Distance from fork face to rated load center (inches)
- W = Attachment weight (pounds)
- D = Distance from the front wheel centerline to the carriage face (inches)
- H = Attachment horizontal center of gravity (inches)
- T = Distance from carriage face to the rear face of load (inches)
- C = Load center of gravity (inchecs)
Some of the numbers you need will not be on the data plate. They will have to be taken from attachment spec sheets or measured on your lift.
In a pinch, there are also online net capacity calculators that you can use for estimation as well.
Again, because of the potential safety repercussions from incorrect capacity calculations, we highly recommend seeking professional consultation for your specific equipment.
What attachments have you found have the biggest impact on net capacity? What questions do you still have? Let us know in the comments!
can provide you with specific dimensions and information on any of our forks and attachments.
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