Block lifting and leap frogging are offshore lifting and logistics strategies designed to simplify equipment movement, reduce unnecessary handling and keep multi-platform projects moving.

In simple terms, block lifting means moving equipment as larger, prepared packages instead of breaking it down into many smaller individual pieces. Leap frogging takes a different approach to project logistics: it prepares lifting equipment at the next work location before the main equipment arrives.

Together, these methods can help reduce the number of lifts, equipment handling activities and waiting periods during complex offshore operations.

Offshore platforms often have limited deck space and existing cranes may not have the required lifting capacity, reach or hook height for a particular project. Temporary portable-modular cranes can provide the additional lifting capability required. Thunder Cranes describes its modular cranes as transportable in component pieces, rapidly assembled offshore and suitable for projects where existing platform lifting capacity is limited.

Consider an offshore equipment package that needs to be transported from a supply vessel to a platform. With a conventional approach, the equipment may need to be separated into numerous smaller components because the available crane cannot handle the complete package.

That means:

More components → More lifts → More handling → More installation time

With block lifting, larger equipment packages can be prepared for lifting as a single block or a smaller number of blocks, provided the crane capacity, structural capacity, rigging arrangement and lifting plan allow it.

The objective is straightforward:

Lift larger prepared packages instead of repeatedly lifting individual components.

This can simplify offshore logistics and reduce the amount of equipment handling required during installation.

Leap frogging addresses a different problem: waiting between platforms. Imagine an Hydraulic Workover Unit (HWU) finishing work on Platform A and then moving to Platform B.

If the same temporary crane has to move from Platform A to Platform B, the HWU may need to wait while the crane is dismantled, transported, rigged up, inspected and prepared for operation. With leap frogging, a second modular crane is installed and prepared on Platform B before the HWU leaves Platform A.

The sequence becomes:

Platform A → Work continues

Platform B → Second crane prepared

HWU moves → Platform B

Platform B → Work starts

The first crane can then be moved onward to Platform C.

Thunder Cranes’ example uses two TC90 modular cranes supporting HWU operations. One crane supports the HWU on Platform A while another is prepared on Platform B. Once the HWU moves, the first crane can then be redeployed to another platform.

The two techniques solve different parts of the offshore logistics problem.

Block lifting reduces handling.

Leap frogging reduces waiting.

For example, a multi-platform campaign may involve moving an HWU, RPU, CTU or other work package between several offshore platforms. Block lifting can help move larger equipment packages efficiently. Leap frogging can ensure the lifting capability at the destination platform is already prepared.

The result is a more coordinated project sequence:

PREPARE → LIFT AS A BLOCK → MOVE → RECEIVE → CONTINUE WORK → RE-DEPLOY

Thunder Cranes identifies these techniques as ways its modular cranes can improve logistics, reduce downtime and support faster equipment mobilisation.

Think about moving house. If you move every item individually, you make many trips.

Block lifting is like putting several items into one large, prepared box and moving the box in one trip. Now imagine you are moving between several houses.

Instead of taking the same equipment with you and setting it up after every move, you prepare the equipment at the next house before you arrive.

That is leap frogging.

One strategy reduces the number of handling activities.

The other reduces the waiting time between locations.

Offshore lifting is not only about the crane’s lifting capacity. Project efficiency also depends on how equipment is packaged, how it is moved and when lifting capability is available. By combining block lifting with leap-frogging logistics, Thunder Cranes can support clients in planning a more efficient movement of equipment across complex offshore campaigns.

The principle is simple:

Lift fewer times. Prepare the next location earlier. Keep the work moving.

Thunder Cranes provides portable-modular cranes, lift planning, engineering, operating crews and project support to help clients implement practical lifting solutions for restricted and challenging offshore environments.