How is lifting capacity calculated?

You may need to find the Crane Capacity index for the load chart. To calculate the crane capacity index, use this formula: (Average (radius x max (lifting height x capacity))) / 100.

What is the difference between lifting beam and spreader beam?

The main difference between the two types of lifting devices is the types of forces that are applied to the beam. Lifting beam – Any beam where the load being lifted puts a bending stress in the beam. Spreader beam – Any beam where the load being lifted mainly puts a compressive stress in the beam.

What is a load spreader?

Material used to distribute the weight of a load over a given area to avoid exceeding designed stress.

How to design a spreader beam for lifting?

TheNavalArch has its own app for spreader beam design which performs all the checks diligently and can be used to either design a new spreader or check the suitability of an existing one for any lifting operation. Please do spend some time exploring it through the link below.

What are the calculations for a lifting beam?

Depending on the features of the lifting beam, additional calculations for connections (bolts, pins and welds) are specified to determine suitable sizing and spacing of each. Calculations for fatigue are also specified in the standard, dependent on the service class of the bar and bar geometry.

How is a spreader bar lifting device designed?

(a-iv) Design of eye bracket for out-of plane buckling – FAILURE MODE – 4 (as per David T. Ricker [2]) (b) Design of weld joint of the eye-bracket with the spreader beam for shear strength (50% of the allowable stress is governing)

How is the allowable compressive stress of a spreader calculated?

The allowable compressive stress is calculated in accordance with AISC ASD, Sec E2 by calculating the slenderness ratio (KL/r) of the spreader, and the factor Cc which depends on the material properties of the spreader.