Approved AC-ROV operator Allied Marine Logistics (London, England) recently carried out the world's first internal inspection of a crude oil offloading marine hose system offshore West Africa. The one man operated AC-ROV was deployed and recovered from the rescue zone of an Anchor Handling Tug Supply vessel in 1m seas with a 1kt current.
Allied Managing Director, Mr Andrew Lang, explained: "The AC-ROV is the only ROV capable of completing this inspection. It is small and agile enough to fly into a 12-24in flexible bonded rubber hose string. The systems cube shape and vectored thruster design gives it the ideal profile for this kind of ingress work. The alternative to in-situ hose bore inspection is to decommission the hose system periodically which is far more costly, reduces the availability of the terminal and runs the risk of damaging the hoses due to the additional handling."
An external inspection of the hoses was also performed checking for loose bolts, third party impact damage, abrasion, kinking, leak detection devices and other early signs of deterioration. The internal and external inspections were completed within 2 working days with no down time.
Meanwhile in the North Sea, Ocean Frontier Services Ltd (OFS) have successful completed the inspection of J-tubes for a wind-farm operator using an AC-ROV hired from Allied Marine Logistics. The internals of the J-tubes were visually inspected with checks being made for evidence of sediment flooding. OFS Managing Director, Bernd Ocic, says: "The smaller AC-ROV was able to enter inside the J-tubes with an internal diameter of 350 mm which is something our larger vehicles were unable to do. The AC-ROV may be small but its robustness and mobility takes it into unexpected places."