MARINE MAINTENANCE TECHNOLOGY INTERNATIONAL | APRIL 2016 ⠿ 13A drone is launched from
an offshore platform to
inspect areas that are
difficult to accessCamera-equipped drones are now
much more widely available and
affordable, and by using them for
a first screening, we can identify
areas that require closer inspection
Cezary Galinski, manager of the DNV GL – maritime
classification’s flying squadduring its first five-year mandated dry
docking, renewal and overhaul.
DNV GL’s Gdansk-based classification
team used modified commercial drones
to visually check the condition of remote
structural components. “We have been
looking at ways we could help our customers
by accelerating the survey process,” says
Cezary Galinski, manager of the DNV GL- maritime classification’s flying squad
based in Gdansk, Poland. “Camera-equipped
drones are now much more widely available
and affordable, and by using them for a first
screening, we can identify areas that require
closer inspection quickly and without
extensive staging, which can be costly and
time-consuming.”
The tests used a camera-equipped drone
to visually evaluate structural components
through video streamed to a tablet. One
surveyor operated the drone, while a second
checked the video feed in real time. The
stream was also recorded for review and
documentation purposes.
“We used a modified off-the-shelf drone
for our tests,” explains Galinski. “Because
there are currently no commercially
available drones formally certified as
explosion-proof, we performed a risk
assessment. Of course, before the drone
operation started, we also ensured that the
cargo tank was gas-free and certified for
sa fe ent r y.”
The tests with the drone were carried
out inside one of the ship’s cargo tanks. The
drone was equipped with a high-definition
camera and its own lighting, and recorded
both HD video and still pictures. It was able
to access all parts of the tank, including
resting against the bulkhead while hovering.
“The drone demonstrated excellent
stability in a confined space, delivering
good-quality visual inspection material,”
according to a Remontowa shipyard
statement, adding that the experiments
provided a “promising outcome” and that
Remontowa is willing to proceed with
introducing the technology in commercial
operations in selected applications.
Vegar Rype, head of section hull and
materials for DNV GL in Norway, adds that
development is ongoing. “We don’t have all
the answers yet and we are still doing tests
with various drones and tanks. We have not
yet designed and built our own drones but
that will come, possibly with more than one
type for different areas.
“It is not a completely straightforward
operation yet. The drone and camera
settings need careful adjustment – the droneUAV INSPECTIONS (^) ⠿
F
or ships, the time and money
required for inspections are a major
part of survey expenses, not least of
which is the need to build staging
throughout holds and inaccessible places
to enable inspectors to visually inspect all
areas. Offshore, inspections of inaccessible
towers and booms are extremely difficult by
any other means.
Described as both ROAVs (remotely
operated aerial vehicles) or UAVs (unmanned
aerial vehicles), drone technology is nothing
new and classification societies are working
on trials to bring the technology into use
for visual inspection. Potential difficulties
include achieving the close distances
needed, providing enough light in the right
places, and simply maintaining control.
Operators also have to take note of the risk
of explosion in an enclosed space that may
contain flammable fumes should there be a
malfunction in a drone’s motor.
Polish trials
At a trial in Poland’s Remontowa shipyard,
DNV GL inspectors recently used drones
to inspect internal spaces in a 51,747dwt
chemical/product tanker. The CPO Japan,
owned by Germany’s Reederei Claus-Peter
Offen, was the subject for tests at Remontowa