In a tandem lift operation involving two cranes, Crane A is rated for 75 tonnes and Crane B for 50 tonnes. The total load to be lifted is 80 tonnes. According to good practice for tandem lifts, which statement regarding load distribution is correct?

Question: In a tandem lift operation involving two cranes, Crane A is rated for 75 tonnes and Crane B for 50 tonnes. The total load to be lifted is 80 tonnes. According to good practice for tandem lifts, which statement regarding load distribution is correct?

Answer options:

• Crane A should lift 50 tonnes, and Crane B should lift 30 tonnes.
• Crane A should lift no more than 60 tonnes, and Crane B no more than 40 tonnes, to ensure both operate below 80% of their capacity. ✅ Each crane should ideally share the load equally at 40 tonnes each, if feasible.
• The stronger crane (Crane A) should lift as much as possible, up to its capacity, with Crane B handling the remainder.

Correct answer: Each crane should ideally share the load equally at 40 tonnes each, if feasible.

Explanation: In an ideal tandem lift, the load should be distributed as evenly as possible to minimize stress on either crane and simplify the lift. If even distribution is not possible due to the load's centre of gravity, load share must be calculated, and each crane must remain within its capacity and typically below a specific percentage (e.g., 75-80%) of its rated capacity for tandem lifts. Option B incorrectly allocates load based on a predefined percentage rather than an objective for even distribution. Option D is unsafe as it could overload Crane A or lead to difficult dynamic forces.