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Why are ROVs needed?
One of the obvious reasons why remotely controlled vehicles
were put into use was to reduce the risk that undersea divers
were sometime exposed to. The risk faced underwater is not just
from underwater animals but also from situations like running
short of oxygen, encountering explosive or radioactive debris
and the like. Going too deep into the water could also prove
life threatening for the divers. However ROVs are not used only
in deep waters but also in shallow waters too. In deep waters
the main reasons that ROVs are pressed into use are - recovery
of wreckages of ships and aircraft, surveys of the ocean floor
for the purpose of research, for installing and carrying out
repair work of undersea telecommunication cables and use in off
shore oil and gas drilling projects. |
A tether cable ROV |
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How they work
The name Remotely
Operated does tell you that there is no operator sitting
inside the vehicle. Whoever is driving the vehicle stays
well out of water and is referred to as the pilot as he
does perform the task of ‘flying’ the ROV. The ROVs are
connected to a surface ship using an ‘umbilical cord’, a
cable that provides electrical power. The cable transmits
commands to the ROV and takes back the data retrieved by
the ROV. If the situation calls for, then an ROV is fitted
with mechanical arms for picking up objects from the ocean
floor. The ROVs are constructed specifically for a certain
task with features best suited to carry out the needed
functions. |
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The intense pressure experienced
underwater
When on the earth’s surface, although we do not realize it,
we are under a constant pressure exerted on us by the weight of
the atmosphere above us. An estimate puts this amount of
pressure at 14.7 pounds of force against every square inch. The
only time we are able to notice the existence of this pressure
is when it changes. This pressure change happens if you fly into
space and also if you dive deep down into sea. However it is
felt more intensely underwater. Estimates put the pressure
experienced at one mile underwater to be 2,300 pounds per square
inch. Not a very comfortable situation for a human being. So we
have ROVs to the rescue.
What makes the ROVs pressure
resistant?
ROVs are made using strong and solid pieces of metal. If a
piece is hollow then it is filled with a liquid to prevent its
getting crushed. Hollow pieces of metal that are used usually
have thick walls to make them pressure resistant.
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