Home' Work Boat World : October 2016 Contents A crew of one man
and one dog
Cutting-edge developments affecting the work boat world, By ANDREW BAIRD
The Bow Wave
Regular readers will know that I like to preach the wonders of
unmanned systems, be they surface vessels, subs or even
aircraft. They are undoubtedly the future for any of the “dull,
dirty and dangerous” jobs out there and it’s no surprise that
boffins around the world are investing heavily in the research.
Their introduction into industry is occurring slowly for a variety of
reasons, cost being the biggest factor and also because of uncertainty
when it comes to government regulation. Considering this it was
interesting to receive a press release from UK company ASV which
specialises in unmanned marine systems. One of their autonomous
surface vehicles (ASV) had recently completed a 2,275-nautical-mile
hydrographic survey in the Bering Sea off Alaska.
Working cooperatively with a survey ship from TerraSond that
also acted as the mothership, the two craft ran multibeam sonars
and simultaneously towed side scan so nars running a combined
total of 5,172 nautical miles of lines.
The drone covered approximately 130 nautical miles per day and
being only 5.5 metres long and with a draught of just 90cm, the ASV
was able to survey much closer to the shoreline than the mothership.
Although this voyage was more of a proof of concept type endeavour,
it certainly has proven the utility and value of the craft.
Each of the ASVs has an endurance of five days so it’s not
inconceivable to imagine a future survey vessel that carries a small
fleet of these craft, undertaking large scale surveys in a fraction of the
time of current survey methods. Whether or not the use of these
vessels can be expanded into the seismic survey industry will also be
interesting as the opportunity to carry streamers of hydrophones
further away from the pulse source could allow better definition of
stratigraphic boundaries. Using a second ship to carry the streamers
will be too costly but these ASVs could well fit the bill.
Survey ships already have special rules on the high seas with
regards to towed arrays and other vessels needing to keep clear so it
will be interesting to hear how industry reacts to these potential
new methods. Would other users of the navigational area prefer to
have a slightly larger parcel of the sea surface made an exclusion
zone, but for a much shorter time period, or stick with the current
process of a smaller exclusion zone for longer?
Six months in a leaky boat
The MicroTransat is a modern take on the famed Transat
(transatlantic) yacht race betwee n Plymouth, England and New
York, this time featuring autonomous vessels attempting to
complete the journey without suffering a catastrophic failure.
These craft are all sailing vessels with Dacron or other fabric sails
and are only a metre or two at most in length. Like many
university technology challenges, the craft are designed to meet
the goal and having a long life is not necessarily a consideration.
On the other side of the United States, however, is a small firm
that is designing autonomous sailing craft for long life spans.
Having just raised US$14 million, Saildrone of California is
producing four-metre-long outrigger style trimarans for long
endurance surface missions. Unlike their MicroTransat brethren,
these craft feature rigid wing-sails which are likely to survive strong
winds and waves far better than fabric sails.
With mission endurances of six to 12 mo nths, these craft are
capable of being equipped with a variety of instruments to measure
salinity, dissolved oxygen, CO2 and just about anything else that a
marine scientist could wish for, with an Iridium satellite
connection allowing frequent downloading of data to base.
It’s unlikely that we’ll see these sailing drones being used by the
hydrographic survey industry since being at the mercy of the winds is
unlikely to suit customers used to the prompt and predictable
schedules of powered craft. Onboard power supply would also be an
issue given the electrical requirements of modern sonars.
Given the porous quality of global bathymetry data within the
open ocean, these sail drones could be a potential solution to help
fill in the blanks. Unlike with a normal hydrographic survey that
requires constant sonar beams to create a high resolution map of
the sea floor, a fill-in-the-blanks type of mission only needs a
single ping once every nautical mile or so as it will dramatically
increase the resolution fro m the current level of tens of nautical
miles. Depending on availability of power and the electrical
requirements of the equipment, resolution could be adjusted.
... and at the other end of the price range
Readers might remember last year when I wrote about the
Trident remotely operated vessel (ROV) that was being promoted
through Kickstarter. Nearly 12 months later we get to see the
breakneck pace of technology in action as a remarkably similar
underwater drone is being marketed, again through Kickstarter, but
at around half the price. The Fathom Drone features a full HD
video camera that streams back to the operator’s tablet computer
via a 30-metre umbilical cable that connects to a WiFi buoy on the
surface of the water.
Three thrusters give the drone a top speed of three knots whilst
the built-in battery offers an hour of endurance. The whole unit is
pressure sealed and can handle depths of 45 metres, an extra 50
per cent margin compared to the length of the umbilical. If you
happen to run out of battery whilst using the craft, pick up the
WiFi buoy and start pulling in the umbilical.
The whole unit is compact and can be disassembled quickly for
transport with the entire system fitting into a small day pack. It’s a
little disappointing that there is no hot-swap option for the battery
so that you can have one battery charging whilst the other is
powering the drone but it’s not necessarily a deal breaker.
With prices in the region of US$500, the drone would be a low-
cost but handy addition to many marine operators. I can easily see
fish farms using them to inspect for dead stock or damaged cages
or even harbour security using them for hull inspections.
Visit www.fathomdrone.com for more info.
Any comments, or perhaps you’ve come across something interesting?
Feel free to conta ct me at the. bow.wave@gmail. co m
14 October 2016 WORK BOAT WORLD
An autonomus surface vehicle in action
14 BOW:Layout 1 12/9/16 3:58 PM Page 14
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