Page 534 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition
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19.7 Subsea interface standards 531
ROT Suspended from Winch
FIGURE 19.29
Dual downline ROT being nudged into position by vehicle.
Cage
ROV nudges ROT into place
Well Head
Pioneer
ROT
vehicle) can be suspended from the deployment vessel of opportunity and surface-operated/powered, allowing the vehicle more maneuvering capability to precisely position the tool as well as provide more power to the tool (since the power is surface-supplied). This allows separation of the lift from the vehicle to a surface lift (downline), thus providing a much higher lifting capability. The CCO tool is defined within the standard along with guidelines for design and operation (including launch/catch assist design) as well as tool interface considerations plus ROV nudging techniques for the tool.
19.7.5 Tool skid
Tool skiddeployed CCO designs are also addressed within the standard, defining guidelines for subsea CCO, such as control pods and chokes. This type of intervention configuration is similar to dual downline ROT operation but requires the delicacy requirement of decoupling of the surface vessel heave from the intervention tool. As such, the CCO tool is mounted to (typically) an under- slung tooling skid (mounted to the vehicle frame beneath the vehicle).
