By Dariusz Roseger, EnerMech
Offshore engineering innovation is increasingly being driven by the need to balance operational efficiency with safety, sustainability and cost.
In the North Sea, where many assets are approaching the later stages of operational life, lifting operations present a particular challenge. Platform cranes are critical to daily logistics and any reduction in performance or operator confidence can have serious implications for both safety and efficiency.
This case study outlines how a crane control issue was resolved by EnerMech on a North Sea platform through a targeted engineering approach that focused on simplicity, operator familiarity and risk reduction.
As part of a crane control system upgrade, the original safe load indicator was replaced with a package intended to integrate the monitoring system. Following the upgrade, operators reported degraded performance and inconsistent system responses, particularly during boat lifts where precision and reliability are essential. Confidence in the crane was diminished, leading to its restriction to essential lifts under operational risk assessments. These limitations strained routine operations, prompting the operator to seek a solution that could restore functionality and safety without a full system redesign.
Development and testing process
A front-end engineering design (FEED) study was carried out to determine the best way forward. The system needed to be reliable, maintainable and familiar to the operators that used it daily. A decision was made to reinstate the original hydraulic-over-hydraulic control philosophy, well understood by crane operators, but enhanced with modern materials and open software to ensure long-term maintainability.
A Siemens programmable logic controller was selected for its reliability and straightforward configuration and to enable full internal ownership of diagnostics and future support. The system was designed so it could be replicated across other assets facing similar challenges.
Risk management was central to the development process. Before being installed offshore, the system was extensively tested in a controlled onshore environment. A bespoke test rig was built to simulate crane operations and replicate hydraulic and electrical interfaces mirroring offshore conditions to validate integration, control response and functionality before deployment. The approach reduced offshore commissioning time and increased operator confidence, ensuring that when the crane returned to service, system performance was already well understood.
A full drive chain and control system replacement would have required significant downtime and carried a higher risk of integration difficulties. Instead, a fit-for-purpose intervention was chosen, allowing the existing crane structure to be retained while addressing its weaknesses. A MIPEG X rated capacity indicator system was incorporated to deliver accurate load monitoring and enhanced safety functions in line with EN13852-1 and EN ISO 13849-1 standards. This targeted approach provided a future-proofed solution without the disruption and expense of a full redesign.
