Application · Lifting
Measuring the load at each point of a crane's rope
In brief
Crane safety starts with one question: can the crane and its rigging carry the load? Load cells measure the force the load puts on each critical point along the rope: above the hook, in the hook block, below the hook and at the dead end. The measured load includes the weight of the rope itself, which is large on big lifts.
- 4
- locations along the rope: above the hook, below the hook, hook block, dead end
In the load block
The load block, or hook block, is where the rope meets the load. It is the assembly that forms the hook of the crane: trunnions, sheave pins and swivels. Load cells measure the forces applied to the block.
Below the hook
Below-the-hook devices do the lifting and depend on the application: shackles, magnets, canisters, beams. A load cell measures the force applied to the device itself.
At the dead end of the rope, load cells serve anti-two-block (A2B) systems, wedge sockets and line riders.
Above the hook
Above the hook are the mechanisms that move the hook, and the load, vertically and laterally.
| Drums | The rope is wound around them to lower or raise the load. |
|---|---|
| Sheaves | The pulleys that guide the rope and reduce its wear. |
| Trolley | It moves the rope laterally, along the length of the crane. |
What you get
The force at each instrumented point of the rope and the rigging, during the lift. When no catalog load cell fits the pin or the shackle, the part itself can be strain gaged and calibrated.
Frequent questions
Where are load cells fitted on a crane?
At four locations along the rope: above the hook, in the hook block, below the hook and at the dead end of the rope. They measure the force the load puts on each of these points.
What is a load cell at the dead end of a crane rope used for?
At the dead end of the rope, load cells serve anti-two-block (A2B) systems, wedge sockets and line riders.
Does the weight of the rope count in the load on a crane?
Yes. The load on the crane includes the weight of the rope itself, which is large on big operations.
What if no standard load cell fits the sheave pin or the shackle?
The part itself can be strain gaged and calibrated. The pin or the shackle then acts as the load cell.
Similar applications
All applications-
Towing Pintle hitch forces The three forces between towing vehicle and trailer, recorded in real towing situations. -
Rig Force and moment load platform Net forces and net moments on a system, calculated from four three-axis load cells. -
Component Engine mount loads The three forces each mount passes to the frame during start-up, acceleration and gear shifts.