⠿ UAV INSPECTIONS
(^16) ⠿ MARINE MAINTENANCE TECHNOLOGY INTERNATIONAL | APRIL
inspect the underneath of the deck. Normally
that’s a difficult area to access and inspect.”
Until now, checking a flare stack meant
shutting down production. “A flare stack
typically has a large flame coming out of
it, so you can’t send someone up there to
inspect it,” says Buchan. “We can do our
inspection while the flare is online, and now
we can do it every six months to monitor
degradation of the stack.”
North Sea storm
Sky-futures also offers UAV inspections
to the offshore oil and gas industry. The
company’s recent experience shows
the more dramatic side of the business.
Following December storms in the North
Sea, it deployed an emergency inspection
team to a damaged access hatch on a flare
tower. The hatch posed a risk of falling onto
workers below due to the high winds and
poor weather. A helicopter had tried and
failed to get images of the hatch and there
was no chance of a second attempt.
The team landed on the platform on
Christmas Eve, with winds gusting above
65km/h (35kts) and a severe weather
pattern holding in the North Sea. Forecasts
suggested an upcoming weather lull with
winds dropping to 51km/h (28kts). Although
still above the company’s standard limit of
45km/h (24kts), revised risk assessments
allowed the team to fly.
Images captured from the drone
flight showed that crew safety required a
production shutdown until a further lull in
the weather allowed repairs to be made.
The company also supplies onshore and
offshore pre-shutdown UAV inspections
in the Middle East. The service increases
the safety and efficiency of maintenance
planning and reduces or eliminates the need
for personnel to work at height. It also gives
asset managers and turnaround managers
more time to order replacement parts and
better data to plan for maintenance work
required before shutdowns.
Defense research
At the other end of the spectrum, the USA’s
Defense Advanced Research Projects
Agency (DARPA) is working on autonomous
drones that are able to navigate their own
way around enclosed spaces. The program
aims to develop autonomous UAVs small
enough to fit through windows, to fly at
speeds up to 20m/s with no communication
to the operator and without GPS waypoints.
Their autonomy algorithms include sensing,
perception, planning and control. UAVs with
sophisticated sensing will allow drones to
avoid collisions and make surveys faster. \
ABOVE: A drone is launched from
the helicopter deck of an offshore
installation to inspect the gas flare
LEFT: Preparing a drone to inspect a
product tanker’s gas-free cargo hold
the company a shortlisting for this year’s
Offshore Achievement Awards, in the Safety
Innovations category.
Testing took place on board the Gryphon
FPSO, owned and operated by Maersk
Oil in the North Sea. Visual inspection of
cargo tanks is required to verify integrity
and class certification, and for damage
assessment. It is usually conducted by rope-
access technicians who inspect the tank
structure, focusing on areas of high stress
such as stiffeners, brackets, bracing, webs
and stringers.
Malcolm Connolly, Cyberhawk’s technical
director and founder, and part of the team
mobilized for this project, says that the
drone inspections reduce the human risk
factors of rope access, including working at
height for sustained periods and working
in confined spaces. The inspection
enabled Maersk to undertake a quick
and safe audit of the tank, identifying
and planning for any needed follow-up
contact-based inspections.
Cyberhawk’s two-man ROAV team
consisted of a pilot and an inspection
engineer. Inspection of critical
components of the tank took a day, rather
than the three to four days that would have
been needed for rope-access inspection.
Connolly says, “We have completed many
projects with Maersk Oil since first working
together in 2013. Both parties were keen
to develop an effective ROAV inspection
method for FPSO cargo oil tanks, as well
as for other tanks and storage vessels.
The successful completion of this project
has demonstrated that this technique is now
a possibi l it y.
“Not only have we removed one of
the greatest risks associated with tank
inspection – working at height – but we have
also highlighted the cost and time savings
achieved by ROAV inspection.”
Philip Buchan, commercial director for
Cyberhawk, says, “In the UK, the largest
number of industrial fatalities comes from
falls from heights. Our technique is reducing
the need for people to work at height.”
Buchan believes drone inspections
should not be left in the hands of hobbyists.
Two-man teams include a pilot for the UAV
and an engineer controlling the camera.
“The engineering half of the duo may have
been an inspector or may have been trained
by Cyberhawk after graduating,” he explains.
“Pilots might be hobbyists or may come from
a military background. At Cyberhawk they
go through four levels of training, with only
level-four pilots sent out to inspect assets
in complex harsh environments such as
offshore oil platforms.
“We can fly under the deck of an oil
platform, turn the camera and look up to