Polar Tankers: Drone inspections reduce risk, save time and improve safety


This is one in a series of articles about how ConocoPhillips global business units around the globe are using drones to safeguard personnel and property, minimize environmental impact and cut costs.


by Jan Hester, photography by Patrick Currey

Around the globe, ConocoPhillips business units are using unmanned aerial vehicles (UAV), or drones, to change the way they do business. In the process, they’re saving time and money while reducing risks to the company’s people and property.

Man smiling on deck of ship
Engineering Superintendent John Strebel, project lead for the drone inspection program

The traditional method of inspecting a vessel’s crude oil cargo tank is to stage (scaffold) the internal structure and have surveyors and technicians perform a visual survey and take thickness measurements. This method was adopted to meet American Bureau of Shipping (ABS) and U.S. Coast Guard (USCG) close-up inspection requirements. Associated risks to people and property include damaging tank coatings, dropping objects to the tank floor and working at height in confined spaces.

Infographic

In May 2018, ConocoPhillips’ wholly owned subsidiary Polar Tankers successfully completed a series of inspections on the Polar Discovery using a UAV — a first for ConocoPhillips. A team headed by Engineering Superintendent John Strebel worked with ABS and UAV contractor Cyberhawk Innovations to develop an alternative inspection process for performing a full-class inspection of 12 cargo, two slop and five ballast tanks.

Completing mandatory inspections using UAV technology was an industry first for a U.S. flagged vessel and satisfied both ABS and USCG regulatory requirements for U.S.-flagged vessels operating in Alaskan waters.

UAVs can reduce the need for people to work at height and in confined spaces, enabling a safe first audit of the tank so that further inspection and maintenance can be prioritized.

women in white jumpsuit ascending stairway
Ascending to the vessel’s deck via a long gangway
montage of caged drone photos
CLOCKWISE FROM TOP LEFT:  the interior of a crude storage tank with fresh air pumped from the surface through the blue tube for ventilation; Malcolm Connolly, Cyberhawk founder and technical manager, with the Flyability ELIOS; the protective cage enables the ELIOS to sustain collisions from all sides while the optical and thermal sensors enable it to roll and bounce off obstructions without damaging either the drone or the tank structure; one pilot guides the aircraft from a console while a second provides guidance and controls the remote camera.

The typical time required to stage — set up and remove the scaffolding — and complete the inspection is roughly seven days per tank.

“Using the UAV, it took 16 days to inspect 19 of the ships’ tanks,” said Strebel. “Staging operations delay other scheduled work from taking place, and reducing staging requirements helps mitigate asset and equipment damage.”

Man on deck of ship
Third Mate Isaac Mitchell explains the maintenance work being performed on the ship. All safety, cargo loading and discharge systems are being inspected and overhauled.

Having successfully completed the proof of concept to demonstrate to both ABS and USCG that the UAV was an effective option for tank inspections, the Polar Tankers team was ready to move forward.

In September 2018, Cyberhawk used three UAVs — a DJI Mavic, a Flyability Elios and a new prototype – to inspect 14 cargo and five ballast tanks on the Polar Resolution at the Sembcorp shipyard in Singapore. The improved onboard lighting of the Mavic, coupled with the enhanced features of the prototype, reduced lighting requirements, cutting tank preparation time in half. The new drone features better camera views than the others. It performed so well that it was used for the entire survey, allowing two drones to be flown simultaneously by the Cyberhawk pilots.

group photo
Polar Resolution crew at Singapore shipyard, 2018

“Both pilots were highly capable, and we increased efficiency while decreasing inspection time by operating two drones simultaneously,” Strebel said.

4 men in jumpsuits smiling
Third Engineer Lee Payne (second from right) with the shipyard electrical shop team

During the Polar Resolution project, Strebel and Cyberhawk trialed a purpose-built drone to attempt to accurately measure the thickness of a tank’s structure.

“The initial trials went well. We obtained thickness readings with the prototype and were able to accurately gauge six out of six areas of the tank’s bulkhead. During the process, we highlighted some areas for improvement in designing the next survey,” Strebel said.

The inspection team also successfully flew the drone remotely from the ship’s main deck directly into the cargo tank.

Engineer smiling with key in hand
Third Engineer Jose Gonzalez performs switchboard maintenance.

“Although this is not allowed for purposes of regulatory inspections,” Strebel said, “it has huge potential for maintenance and voyage repair opportunities.”

For the first time during the Polar Resolution inspection, the team used a drone to fly a 36-inch cargo pipeline.

“We normally have an individual crawl the pipeline to look for erosion, damaged valves and overall condition, but we wanted to see if a drone could achieve these goals,” Strebel said. “The results were excellent, providing good clarity for general inspection purposes.”

The drone entered the pipeline from the access hatch in the cargo tank, eliminating the need for pilots to enter the pipeline to control the UAV. Signal strength was consistently strong, allowing both bottom line (horizontal) and cargo drop (vertical) inspections.

Tanker in harbor
 Freshly painted and ready for her journey back to the U.S. West Coast

While the first inspection of the Polar Discovery served as a proof of concept, the Polar Resolution program was one of repeatability, fine tuning processes for efficiency and pushing the boundaries.

Next up is the Polar Enterprise, in April 2019. Because it’s the youngest ship in the fleet, there are fewer inspection requirements. But next August the Polar Adventure will be required to undergo comprehensive tank inspections similar to the Polar Resolution and Polar Discovery.

In a field where UAV technology changes at warp speed, who knows what the next twelve months will bring for the Polar Tankers drone inspection program?