The TC15 Stiff Leg (portable-modular crane) was selected as the most cost-effective and efficient solution to assist our client with lifting a Knock-Out-Pot (KOP) at an offshore platform in Malaysia. The KOP was lifted from the vessel to the platform and the installation completed safely and successfully within a timely manner.


Case Summary

The objective of the lifting operations on this offshore platform was the lifting of a Knock-Out-Pot (KOP) and its support structure from a supply vessel and onto the platform’s main deck.   KOP’s are widely used in the oil and gas industry for separating components of a vapour-liquid mixture. The KOP total weight was 8.4T.
Many jacket platforms offshore have minimal existing fixed crane capacities, and in this case a platform jib crane with a SWL of 2T.   This was insufficient for the task which required lifting capacity for a load of 8.4T and 40ft boom radius to reach the installation area.

While a crane barge or other vessel crane can carry out this lifting task, this would be expensive and the equivalent of using a canon to kill a mosquito. By far the most cost-effective and efficient solution would be to deploy a portable-modular crane with a lifting capacity suited to the task.

Prior to performing the project, a site inspection was conducted by a Thunder Cranes supervisor and engineer to verify the proposed rig up locations and to identify any requirement for the rig up activities including obstructions on the rig up area and requirement for load testing.

Following the site inspection we proposed the stiff leg crane model TC15 with 40ft boom length to perform the lifting activities.  The TC15 being the right-size and right price for the job.

TC15 was deployed to the site by a supply vessel and the platform jib crane on the platform was used to lift TC15 components from the supply boat to the platform main deck. TC15 components were then skidded to the proposed rig up location and the rig up completed within 24 hours.

The crane base beam and outrigger beam were placed on the structural beam on the main deck and secured by using sandwich clamp, and a crane load test as per API RP 2D was done to prove the connection integrity of the crane to the platform beam.  The load test was witnessed by a 3rd party load test inspector. Lifting of KOP was then carried out upon completion of the load test.


  • Site Inspection, Site Visit Report and Proposal
  • Equipment & Personnel Mobilisation to Platform
  • Crane Rig Up & Load Test on Platform
  • Crane Operating – Lifting & Installation of KOP
  • Crane Rig Down, Demob & Transfer Onshore


Thunder Cranes’ expertise in the provision of offshore modular rental cranes allowed us to assist our client with the most cost-effective, and efficient lifting solutions to lift the KOP from the supply boat to the platform main deck for installation.   The project was safely and successfully completed within a timely manner with the TC15 stiff leg crane.

  • Lifting Solution for KOP installation
  • Installation location
  • Space constraints
Our Service
  • Offshore Rental Crane TC15
  • Crane Operators
  • Detailed Planning & Preparation
  • Cost effective, efficient lifting solutions
  • Right-sized for the project
  • South China Sea