What you need to know about crane safe load indicators

Safe load indicator is a device that indicates if the load lifted by a crane is within the safety range or not. Safe load indicators are not a new invention. They have been in use for over 50 years; although it has undergone considerable technological changes over time and today we have quite a sophisticated yet user-friendly system in use. It is not only used to alert for maximum weight exceeded but is also for weighing, measuring loads, load testing, load measuring and control cable tension. Certain crane safe load indicators even automatically lock the machinery if the load lifted by the crane exceeds that safety range.

So how do crane safe load indicators work? They work through measurement of load moment. Load moment is a term commonly used in physics and engineering. It is calculated as the product of force and moment arm. Now, this might be a bit technical for those who are not well versed with engineering. We use the example of cranes to understand this fully. So to explain there are three important things to understand.

  • Reference Point – is the point at which the crane rotates.
  • Force – the force is measured vertically based on the center of gravity of the load.
  • Moment Arm – is the horizontal distance between the force and reference point.

The reason we defined there is to understand load moment. Load moment which is the product of moment arm and force is of critical importance to crane operators. There is quite a lot of engineering to understand behind this but thankfully we do not need to get into it. Safe load Indicators have replaced the need for cranes operators to make calculations or rely on gut instinct.

Crane safe load indicator devices operate through microprocessors that are connected to the sensor located on the different parts of the cranes. It is not a simple weight and warms indicator. In fact, the safe load indicator is a sophisticated device that uses the angle, weight and ground radius of the crane. In the cabin of the crane, the operator has access to the displays of all the sensors placed on the crane.

Safe load indicators come for different types of cranes including crawler cranes, hydraulic cranes, port cranes, rail cranes, tower cranes, telescopic cranes, and boom cranes. Safe load indicators help crane operators by providing critical information that the operator requires to make a decision regarding the lifting of the weight.

Crane Safe Load Indicators have multiple alert options such as:

  1. To alert for maximum angle exceeded – this helps the crane operator whether the load is in danger of falling or not to go beyond that angle.
  2. To alert for maximum load – of course, this is the basic purpose of the crane safe load indicators.
  3. To alert for maximum radium exceeded – so the crane’s operator knows that the load might be at risk of falling if it is raised any further.
  4. To alert for maximum wind speed exceeded – so the crane operator can make appropriate speed and height adjustments.

There are many advantages of using safe load indicator – from cost reductions and better control to safety.

Heavy Equipment Manufacturing:

During manufacturing of heavy equipment, crane safe load indicators are increasingly used as hanging scales. This prevents the need for the manufactured products to continuously move back and forth to truck-based scales for weighing. This helps reduces manufacturing time, and is more productive.

Advanced Stock Management:

Stock control and stock management have also become quite easy, thanks to safe load indicators that are attached to low height industrial cranes. Movement of stock for weighing purposes is reduced thus reducing a time taken to manage stock and also reducing wastage that we caused during moving of stock.

Minimized Truck Overloading:

Since goods containers are being weighed automatically through safe load indicators when they are hanging on the crane, it helps in avoiding overloading of trucks.

High-Temperature Sites:

In high-temperature applications, a hanging crane scale is very useful. Because the Safe load indicator devices work as wireless weight scales.

Ship Manufacturing Sites:

Crane safe load indicators are not only used at shipyards to move and dock containers. In fact, they are also used at ship manufacturing sites where each section of the ship needs to be weighted for stability and density. By keeping each part through the crane safe load indicator, ship manufacturing companies know the exact weight of the ship upon completion.

Cable Tension Tests:

Crane safe load indicators are used to test cable tension for high tension overhead electricity cables by using as a dynamometers load cell.

Meeting safety legislation:

Safe load indicators prevent overloading and help in abiding by safety regulations set under industrial rules and regulations.

Use in Marine Industry:

Crane safe load indicators are also extensively used in the marine industry. They are used to measure the force felt by underwater fishing nets using electric dynamometer’s.

Another benefit of crane safe load indicator is to ensure that marine vessels are not overloaded. They are particularly helpful in weighing, loading and unloading fuel. Overloading of fuel is extremely risky and dangerous for both the vessels as well as the sea. If the fuel spills, it could be disastrous for aquatic life.


Crane safe load indicators are a very useful invention and serve many purposes across industries. The benefits of safe load indicators are widespread. They are not only minimizing loss of material and equipment but also minimize loss of lives for workers who are working in close proximity to load lifting cranes.