The following two case studies helped to support the development of Lloyd’s Register guidance notes for safe UAS inspections.
CASE STUDY: Flare tip inspection, resulting in speedy delivery of high-quality data and specialist analysis. Inspection completed for lower total cost than traditional manual inspection, despite a greater upfront investment.
Operation: Offshore installation, Liverpool Bay
Purpose: To set up a monitoring regime for the fixed structure asset Flare tip and boom inspection
Lloyd’s Register Project Manager Helen West said, “The UAS inspection delivered some key benefits to the client that a traditional inspection would not have done. A particular benefit is to minimise and even avoid the need for a shutdown planned or unplanned. With the application of UAS inspection, the technical inspection data received would be reviewed and reported by competent personnel report and an integrity assessment would outline areas of concern. So the UAS inspection included the specialist and data interpretation as well as the data collection. This is an addition to the service as the use of drones has evolved.”
Helen identified a number of additional benefits to the client. She said, “Although the correct paperwork needs to be used e.g. ISSOW, method statements, Risk Assessment Safety Procedures, the process was quick and easy to set up. This negated the need of putting men at risk to scale the flare-tip to confirm the condition of the flare tip and boom chords. The end product delivered was clear images, both video and stills and a permanent record. The UAS was able to cover large areas and provided as well as the inspection of the flare provided other benefits such as identifying potential dropped objects (PDO) which may have been difficult to spot. Crucially, the UAS facilitates the application of a screening tool that allows closer inspection of suspect areas and ongoing monitoring over a period of time to evaluate the rate of degradation. This enables operators to plan maintenance and repair in a planned and budgeted, structured way.”
In general, whilst there is significant upside to UAS inspections, there are also challenges to overcome. As Helen explained, “The UAS can capture very detailed data but it can’t carry out repairs which a team could. Similarly, it relies on experts to operate the kit, guide it to the right locations/suspect areas and identify further inspection requirements.”
Furthermore, whilst UAS inspection provides opportunities for economies when viewed as an end-to-end process, the upfront investment can be greater than with a traditional inspection. Helen said, “Operators are sometimes daunted by the initial layout but this needs to be carefully evaluated against the costs of a traditional inspection, as well as the safety of personnel. Whilst this is likely to vary between applications, it has been our experience that most operators continue to opt for UAS inspection. However, in the current climate, it is scrutinised as not essential for some tasks and a ‘nice to have’ so we have subsequently seen a decline of usage in the last 10 months.”
CASE STUDY: ‘Test and learn’ by Lloyd’s Register with Maersk Drilling, Keppel and Sky-Futures to investigate the safe and effective application of UAS inspection in offshore rig inspection
– Evaluate the UAS capabilities, safety and effectiveness in offshore rig inspection
– Investigate and improve inspections and reduce inspection costs
– Recommend areas and inform technology development roadmap
The scope was to assess the capabilities of UAS by conducting a series of test cases using an industry standard UAS service provider on a Jack-Up drilling rig owned by Maersk Drilling.
Test cases were devised based on Lloyd’s Register DROPS checklists and other cases created from typical Jack-Up inspection scenarios from Lloyd’s Register knowledge base.
Lloyd’s Register Senior Specialist Andy Frankland said: “The Jack-Up Rig had recently arrived in the shipyard for some upgrade work and was in the process of pre-loading dockside when the UAS project started. For this reason, it was decided to start the UAS test & learn by conducting an ‘inspection’ of the exterior of the hull, before continuing with under the helideck. Once the pre-load operation was completed, the jacking leg and derrick inspection would take place.”
1. Risk assessment, flight & work permit
2. Multi-party coordination
3. Toolbox talk and clarification of objectives
4. Equipment setup
5. Pre-flight checklist
6. FPV visuals and secondary views
7. Clear area for ground take off or hand launch; set emergency landing
8. On the spot, real-time general visual inspection
9. Battery endurance approximately 15 minutes per data collection flight
10. Off-site post-processing, hardware/software image enhancements
A range of learnings were captured, covering safety, regulatory, technical, data and operational issues, which input into the development of the Lloyd’s Register guidance notes for safe UAS inspections.