- In the event of co-lifting, the lifting must be calculated and the SJA must be performed.
- A lift-supervisor should always be appointed. The lift-supervisor must have a crane operator certificate (G1/G8)
- The lift-supervisor ensures that risks are assessed in advance, including the establishment of weights and, if applicable, the center of gravity.
- The lifting capacity of the cranes should be reduced by a minimum of 20%. Deviations from this must be documented in risk assessment and/or SJA
- If procedures or client requirements have other needs for further reduction to lifting capacity, this must be followed.
- Consider the design of the load and the impact of wind during a co-lift.
- Check the crane’s user manual as some crane manufacturers and crane types have clear exclusions on co-lifting.
Elements of risk assessment and SJA are:
- Weight of the load
- The center of gravity of the load
- Hookpoints
- The lifting capacity of the cranes with the current beam-support.
- Reduction factor
- Any angle of wire rope during the lifting operation (skew pull)
- Speeds
- Use of yoke etc.