Advances in Flooded Tunnel Inspections by ROV

The remotely operated vehicle (ROV) was initially developed for inspection purposes and for monitoring of diver activities on offshore petroleum rigs. The ROV gradually replaced divers in many inspection scenarios and evolved primarily as an exploratory or inspection device that allowed access to environments considered too dangerous or expensive for manned intervention. Research in ocean sciences and particularly in military technology helped to drive ROV capabilities beyond mere visual observation to include tooling packages for light work such as scientific sampling and performance of specific tasks such as mine detection and disablement. More advanced sensor capabilities (such as sonar) were gradually incorporated, primarily for navigation. Concurrently, the petroleum industry steadily pushed the capabilities of work machines to new levels of performance. Today, some industrial centres such as Norway, have a `no man in the water' policy intended to maximise reliance on ROVs to promote diver safety and reduce direct and indirect (insurance) costs associated with dive operations. Many subsea installations are now designed exclusively for ROV maintenance using dedicated tooling packages. Pipe and telecommunications lines are routinely laid over thousands of kilometres using specialized trench-and-fill ROVs equipped with high power water jets for excavation and burial.