Truck cranes are one of the most useful additions contractors and business owners can add to a service truck body. How much they are able to lift is completely dependent on the type of crane, the size of the crane, and the max load rating specified by the manufacturer.
So… as you probably expected, there is no clear-cut answer to this question.
However, the purpose of this post is to explain how to properly read a truck crane manufacturer’s spec sheet to determine the max load of your crane in several different positions (this varies, depending upon the reach and angle of the crane.)
Max Load Rating
The max load rating on a crane will determine the maximum amount of weight that a crane can lift in a certain position AND at a certain angle.
This number is important to bear in mind, as it will determine the more practical applications your crane can be used for.
In most instances, the crane’s max load can be achieved with a very short extension in proximity to the truck body, requiring the truck body to be extremely close to the cargo or item you are intending to lift and move.
For more practical capacity ratings, you should direct your attention to the manufacturer spec manual that will give you far more insight into how much weight your service truck crane is able to lift.
Manufacturer Spec Sheets
The absolute best resource for determining the functional weight that your service truck crane can lift is the manufacturer capacity chart (typically located on a manufacturer spec sheet.)
The capacity chart will provide the maximum weight load that a truck crane can handle, specified with three different parameters: crane extension, crane angle, and weight capacity.
The crane extension refers to the actual height of the tip of the boom in relation to the base of the crane.
The crane angle will refer to the angle at which the crane is lifting the cargo or material.
The crane weight capacity will be the maximum load that the crane can handle at a certain extension and angle.
A simple formula to keep in mind when it comes to interpreting a capacity chart is angle + extension is the method of determining a load capacity for a truck crane.
Reading a Capacity Chart
In our example, the crane featured is a JOMAC STC-80 telescoping crane, with a maximum load capacity of 8000 lbs.
To achieve the 8,000 lbs load capacity, the crane must be at an 80 degree angle, with no extra extension (in this case, the boom will be raised 13 ft, without extension).
If the crane remains in the same 80 degree angle, but it is extended to 20 ft, the maximum weight capacity decreases from 8,000 lbs to 3,500 lbs.
As an additional example, let’s take the crane with no additional extension at a 45 degree angle.
We can look at the load capacity chart and determine that at 45 degrees, the crane is able to handle 5,000 lbs.
If we extend the crane to 12 ft reach at that same 45 degree angle, the weight capacity diminishes to 3,500 lbs.
A simple rule of thumb is the greater the horizontal reach of the crane, the less weight capacity it can handle.
Manufacturer Capacity Charts
It is important as a truck crane operator to have the manufacturer capacity chart available. Capacity charts are given with user safety and well-being in mind.
Aside from the safety aspect, you could run the risk of significantly damaging a truck crane if loaded with too much weight. That is a costly error, no doubt.
If you do not have a manufacturer capacity chart available, we suggest contacting the crane manufacturer to acquire one.
It will save you time, headache, and potential harm to have one available.
Always consult the capacity chart to ensure you are moving material safely and effectively.
