Benefits of Real-Time 3D Imaging - Subsea UK

Innovation in Underwater
Construction:
Benefits of Real-Time 3D Imaging
Stephen Auld
Managing Director
CodaOctopus Products Ltd.
Subsea 2010 Conference
10 th of February 2010

Programme
• Introduction to the Echoscope 3D Sonar
• Innovative Techniques for Breakwater Construction
• Wind Farm Installations using a real-time 3D sonar
• ROV Operations for enhanced spatial awareness

Echoscope 3D Imaging Sonar
• World’s first real-time high resolution
3D (or 4D) sonar
• Generates over 16,000 beams per
acoustic transmission (ping)
• Beam spacing along and across track of
0.39˚ with standard 375 kHz projector
• Ping rate up to 12 Hz, with each ping
being a true 3D dataset
• Each beam contains unique X,Y,Z and
Intensity value

Real-Time 3D Operation

Real-Time Imagery

Innovation in Breakwater Construction
• The Ras Laffan Port Expansion Project – expanding the
existing LNG port at Ras Laffan to become the largest one
in the world
• The scope of the expansion works was 20 million m 3 of
dredging, 27 million m 3 reclamation, two 10 km
breakwaters, and two 6 km causeways
• The outer end of the northern breakwater was to be
armoured with over 37,000 Accropodes, of the 3, 4 and 5
m 3 sizes.

Accropode Placement
• Accropodes are single layer concrete armour units
• Produced in a range of sizes, the ones in this project were
3 – 5 m 3
• Accropodes must be placed according to a set of rules that
govern their density and the orientation of each block
with regard to the adjacent blocks
• With active dredging activity in the area, they must be
positioned and oriented accurately in near zero-visibility
conditions

Accropode Placement – the problem

Accropode Placement – the solution
• To avoid having to man-handle these concrete blocks
underwater, RLNBC developed a hydraulic rotator to allow
crane operators to manipulate the Accropode orientation
• This allows the operator to move the block, but he still
cannot see it
• Video cameras were attached in various positions but the
low visibility conditions meant that they were not
effective

Accropode Placement – the solution
• An Echoscope 3D Sonar was installed in January 2008 for
the first time to view the Accropode
• It immediately gave the crane operator a view of the block
that was far in advance of what had previously been
possible
• RLNBC started working with the Echoscope on the project,
while CodaOctopus went to work optimising the system
for their application

Echoscope Imagery – raw data

Development of Construction Monitoring System
• Accropodes TM are regular shapes (variable size)
• Identify and track blocks based on 3D spatial sonar
data using a real-time geometrical algorithm
• Thereby allow operator to easily identify the block
when it is only partially imaged
• Chart of area can be viewed, with target block
positions and current target position
• Database of ‘as-laid’ positions and orientations can
be generated

Echoscope Imagery – fully referenced

Not just placing blocks …

Results
• Peter van Gelderen from Van Oord presented a
paper to the Institute of Civil Engineers at the
‘Coasts, Marine Structures and Breakwaters’
conference, presenting this innovative new approach
• The results were quite clear
• The Echoscope allowed them to operate efficiently
without the constant intervention of divers
• The incremental improvements in the software
enhanced the crane operators ability to use the
software, increasing efficiency further

Echoscope Imagery – inspecting
structures post-placement

Offshore Wind Farm Installation

Wind Farm Construction

Enhancement of Subsea Spatial Awareness
ROV Application using single ping view

Enhancement of Subsea Spatial Awareness
ROV Application using multi-ping aided data

New High Frequency Sonar
610 kHz with 25 x 25 viewing volume

ROV Monitoring from DP Vessel
viewing the global subsea scene

Thank you
Stephen Auld
Managing Director
CodaOctopus Products Ltd.
Subsea 2010 Conference
10 th of February 2010