NDT Trends: Uncovering the Untold Narrative of Titan Submersible

July 2023 | Issue 76
Uncovering the Untold Narrative of
Titan

Submersible

Innovation
Stingray - Your Subsea
Inspection Companion
DRS Magnetic Crawler
The Stingray is a low-profile, ‘high
strength’ magnetic scanner used for…
Insights
Decoding NDT Engineers
Exploring the Role and Specializations of
NDT Engineers in Subsea Inspections
To begin, the term "engineer" appears to
have become…
Expert T
alk
Innovation Beneath the Waves
Lizard NDE's Journey in Revolutionary
Subsea Inspection Technology
Paul, as the Director of Lizard NDE, we're
eager to learn about your company's...
Article
Unleashing the Power of
Remotely Operated Vehicles in
Subsea Component Inspections
Remotely Operated Vehicles, or ROVs
were developed in the 1960s to retrieve
underwater missiles, mines, and other…
Cover Story
Uncovering the Untold
Narrative of Titan Submersible
Submersibles have played a vital role in
deep-sea exploration. Their use…
Product Spotlight
Dive into the Future
Cygnus Underwater Gauge - Unleashing
Astonishing Transformation
Last month at Seawork and IMX
exhibitions, Cygnus offered an exclusive
introduction to…
Case Study
Exploring the Depths
SPECTA , TSC Subsea’s latest technology,
identifies what lies beneath
Subsea Pulsed Eddy Current Testing
Array…

Kaddy B
Editor
Dive into the Depths
Dear readers,

Prepare for an emotional odyssey, awakening curiosity about hidden wonders
beneath the waves.
We bring you the captivating cover story covering the Titan Submersible Fiasco.
However, as we unveil the details of the Titan Submersible's tragic journey, we
must also reflect on the lessons learned and the implications for future sub-sea
expeditions. Through this cautionary tale, we gain a deeper understanding of the
risks involved in pushing the limits of exploration and the crucial role of NDT
Engineers in ensuring the safety and reliability of underwater vehicles.
Feel the exhilaration of exploration as we reveal the remarkable advancements
that redefine the realm of sub-sea inspections. Witness the astonishing
transformation brought by the Cygnus Underwater Gauge, empowering
inspectors with unprecedented accuracy and efficiency. Discover the
revolutionary technology of SPECTA, developed by TSC Sub-sea, as it uncovers
the hidden secrets of the depths, illuminating what lies beneath and safeguarding
the integrity of sub-sea structures.
So, embrace the emotions, the wonders, and the undeniable beauty that awaits
us below the surface.
Join us on social media
www.onestopndt.com
LinkedIn -@OSNDT Instagram -one_stop_ndt Facebook -@One Stop NDT
Twitter -OneStopNDT Youtube -@onestopndt3281

Paul Bentley
Director at Lizard
NDE Ltd
Joshua de
Monbrun
CEng | Technical
Authority at
MISTRAS Group, Inc.
Grant Hosie
Principal Subsea and
Pipeline Engineer at
SEA
Chiemela Victor
Amaechi
PhD Researcher/
Associate Lecturer at
Lancaster University
Ahmed Reda
Under-graduate
Refining &
Petrochemical
Engineer | Aspen
Certified User in
Aspen HYSYS
Editor-in-chief
Santosh Gavankar
Marketing Director
Ravindra Warang
Design
Designer
Bhavesh Sawant
Editorial
Copyeditor
Abhishek Sawant
Researcher
Sakshi Shriyan
Sales & Marketing
Corporate Communications
Govind W
A heartfelt thank you to all the contributors for
their valuable contributions to this month's edition

The Main Reason
of Titan Implosion
and Its
Seaworthiness
When assessing the "seaworthiness" of a marine vessel,
the experts essentially evaluate its suitability for the
intended purpose, its operational safety, and its
compliance with environmental protection measures. In
the case of the Titan, being fit for purpose means having
the capability to launch safely from a surface-based
mothership, operate autonomously at depths of
approximately 4,000 meters corresponding to the Titanic
shipwreck, and resurface for recovery by the mothership
after a dive lasting several hours.
One day after the United States Coast Guard officially
confirmed the implosion of the missing Titan submersible,
officials then faced the daunting task of navigating. The
Communicat
ion was lost
during dive
off Canada's
coast after 1
hr 45 mins.
www.onestopndt.com | July 2023 | Issue 76 05

submersible, which was operated by the private US
company OceanGate Expeditions, had embarked on a
mission to explore the wreckage of the Titanic from 1912.
Ongoing Suspicions on Safety Overhauls Raised
about the Sub
The tragic implosion of the Titan submersible has raised
concerns regarding the vessel's potential for disaster due
to its unconventional design and the creator's refusal to
undergo independent checks, which are standard in the
industry. According to U.S. Coast Guard Rear Adm. John
Mauger, all five individuals aboard the Titan lost their lives
when the submersible was crushed near the renowned
Titanic wreckage. The incident marked the conclusion of a
large-scale international search.
Ensuring safety during operation entails the absence of
equipment damage & the prevention of harm to
passengers, ensuring their well-being and avoiding any
potential injuries or worse. Moreover, protecting the
environment means that the submersible should not cause
any significant adverse impact on its surroundings, such as
pollution or disturbance to the ecosystem. However, it's
important to note that this ideal scenario exists in theory.
Deep-sea submersibles operate in a challenging and
unforgiving environment, where unforeseen
circumstances can occur.
The Titan, measuring 22 feet (6.7 meters) in length and
weighing 23,000 pounds (10,432 kilograms), had a larger
internal volume than its counterparts. However, even with
a maximum capacity of five seated individuals, the
increased size meant that it faced higher external pressure.
Jasper Graham-Jones, an associate professor of
mechanical and marine engineering at the University of
Plymouth in the United Kingdom, explained that
elongating the cabin space in a submersible leads to
increased pressure loads in the midsections.
Ad

NDT: Safran
Engineering
Services
banks on its
software suite
Safran Nacelles' Burnley site is synonymous with the manufacture of nacelle
systems and thrust reversers. In recent years, the site had been primarily
associated with the Airbus A330, but is now embarking on new programmes
such as the Airbus A320neo and Comac C919.
LEAP engine fan blades, fixed internal structure panels for
their nacelles, internal landing gear pistons... these items
all have one thing in common: their quality is inspected and
assessed using NDT, for which Safran Engineering Services
has developed the SMV2 software suite. The development
prospects are promising.
Non-destructive testing: a technique for the
future.
NDT is a technique used to inspect & assess the quality of
materials, components or structures, while preserving
their integrity. It uses a variety of methods & technologies
to detect defects such as cracks, porosities, inclusions,
dimensional variations and other potential imperfections
in the materials. Safran uses this type of technology to
inspect metal and composite parts, including large-scale
components.
The Group therefore called on internal and external
expertise to develop high-performance non-destructive
testing tools. One of the most ambitious, enabling the
inspection of fixed internal nacelle structure panels, is
based on an infrared thermography inspection method
using a flash and a thermal camera.
Safran Engineering Services has been involved in the
research phases of these projects from the outset, and it
has developed a software suite, a veritable toolbox that
can be adapted to different testing projects.
The SMV2 software suite
This software suite, known as SMV2, has been designed for
the Group’s various use cases, from the different
acquisition methods - thermography, tomography,
radiography and digital cameras - to the geometric
specificities of each part & the types of peculiarities to be
investigated. The Human-Machine Interfaces (HMIs) have

This is an
innovative method.
Others use digital
tomography, 2D
digital radiography
or visual inspection
with high-definition
digital cameras
Marc Garas
Application Software Service Manager

Safran Engineering Services
been the subject of extensive ergonomic research to help
inspectors in their work.
Integrated into a robotized cell, the software suite
performs multiple functions. “In the case of nacelle parts, it
communicates with the robotized cell and controls the
infra-red camera built into the cell, as well as the flash
which heats the surface of the part. It allows images to be
analyzed by an operator to detect any defects. It
supervises the entire process in real time, and stores
information in a database which can then be used by data
scientists or production managers,” continues Marc Garas.
An inspection report, which is used to validate the part, can
then be generated automatically.
“We must also aim to constantly improve the software’s
algorithms, in close collaboration with Safran Tech, to
obtain the best detection & characterization performance,
reduce the system’s learning time, and continue to work on
simplified ergonomics that facilitate analysis.”
To facilitate the deployment of NDT projects within Safran,
an initial consortium agreement was signed at the Paris Air
Show between Safran Engineering Services, Axiome and
Groupe ADF (LATESYS), manufacturers of the robotized
cell & integrators. “This agreement demonstrates Safran’s
confidence in our product, which is part of the
digitalization of the Group’s processes, which is known as
Manufacturing 4.0. Whether in maintenance, repair or
operations (MRO), the potential applications to be
addressed are enormous. This will enable us, by 2024, to
provide a global, high-performance, tailor-made NDT
solution, with a robotized cell and secure integrated
software suite, within the Group and even beyond -– in
short, a major step towards digital continuity!” concludes
Marc Garas.

Stingray
Magnetic Crawler
- Your Subsea
Companion with
DRS Inspection
Technology
The Stingray is a low-profile, ‘high strength’ magnetic
scanner used for subsea inspection of pipelines and
structures such as caissons/conductors. It weighs a mere
6.5kg in water (10kg in air). The scanner is fully
manoeuvrable using a joystick and conducts automated
scanning as set by the topside operator.
When deployed
the Stingray
harnesses its
power supply
and data
communication
feeds from the
host ROV,
making it a very
versatile
system.
- Sonomatic

The scanner has a short umbilical, enabling deployment in
a number of challenging locations, such as inside a jacket
structure to conduct structural weld inspections. The
scanner is suitable for inspection of pipelines that are 6”
and above and can be utilised for various different
applications such as TOFD/PA/UT/ACFM /DRS.
The Technology used for Stingray
In a recent application, the system was deployed with
both conventional ultrasonics, and a bespoke technology
called Dynamic Response Spectroscopy (DRS), an
innovative ultrasonic inspection technique for corrosion
mapping through challenging coatings such as Neoprene,
Polypropylene/Polyethylene, GSPU, Composite Wrap
repairs, and Thermotite.
A custom DRS probe mounted on the Stingray scanner,
rasters across the coating surface to construct a map of
the underlying steel thickness. The probe is positioned
several millimetres above the inspection surface, and
ultrasound is transmitted through the seawater and
coating.
The probe excites the steel with a range of low ultrasonic
frequencies and the steel responds, vibrating at natural
frequencies related to its thickness and the local variation
in thickness. Using advanced signal processing algorithms,
these frequencies are extracted from the returning signals
and used to determine the steel thickness at each
location. A corrosion map is constructed using the
frequency content of multiple A-scans.
Where delamination type flaws exist in the coating, the
signals cannot travel into the steel. DRS can identify
disbondment or delamination of the coating.
Conventional UT offers accurate measurements of steel
thickness based on reflections using high frequencies (5 –
10 MHz) signals and speed, distance, & time calculations.
However, many coatings attenuate high-frequency signals
rendering conventional UT often not possible.
DRS, however, uses lower-frequency ultrasound to make
accurate measurements of steel WT as low frequencies
penetrate coatings more easily. Low frequencies cause
the steel to vibrate at its natural frequencies (usually < 1
MHz) and these vibration frequencies are used to
calculate steel WT.
Steel WT measurement accuracy is typically ±0.5 mm
(80% tolerance).
WT variations of <1 mm can be measured.
Steel WT measurement accuracy is typically ±0.5 mm
(80% tolerance).
Max steel WT = 22 mm (currently). However ongoing
validation for 58 mm thick steel with 3-4 mm internal
cladding.
Min measurable steel WT = 3 mm (coating dependent)
Applications of the product in the industry
One particular application required external inspection of
a deepwater subsea pipeline. The challenge was that the
pipeline had a 5mm 3-Layer Polypropylene (3LPP)
external coating, and an injection moulded polyurethane
(IMPU) coating (9 mm thick) over the field joint locations,
which also required inspection. The coating was not to be
removed.
Onshore ‘blind’ validation trials were conducted on a
client provided sample with numerous internal machined
holes at varying depths/diameters to represent

differing levels of corrosion that were anticipated to be
found in the pipeline. DRS located 56, out of 60 machined
defects.
On successful completion of the onshore validations, an
offshore campaign commenced. In a bid to support the
clients’ needs to further reduce their carbon footprint,
and increased productivity, 2 scanners were deployed
simultaneously, one collecting data on the 3LPP, and the
2nd scanner inspecting through the IMPU coatings at the
field joints.
F Benefits of Stingray to the industry and NDT
professionals
There are several key benefits the Stingray scanner and
DRS offer the industry:
{ Lightweight for use with smaller Observation/
inspection class ROV’s
{ Live data collection
{ Strong magnetic adhesion for use on thicker coatings
{ Ability to conduct cleaning and deploy several
techniques simultaneously.
DRS provided a solution for the client to inspect the
pipeline, without having to consider the need to remove
the external coating, resulting in a lower carbon footprint,
due to fewer resources required offshore.
W
e strive to lead
the way with innovative
solutions, encouraging
positive challenges and
change. So, we are
pleased to see the
progression of our
subsea equipment
continually being
adapted to support our
clients.

The Ultimate go-to-market strategy
For this job, a client we had worked for previously,
reached out to us as they were impressed with the service
Sonomatic provided on that project. They asked if we had
the capacity to support this new project and conduct
onshore validations. One of our core values is quality, we
strive for continuous improvement to exceed
expectations and to be known for excellence in
everything we do. Practicing this on every project helps
to build a good and lasting impression on our clients.
In recent years, we have also updated our marketing
materials and website to help build our brand presence
and credibility, using the platform to educate new, old,
and prospective clients about our business, technology, &
services to reach and form a good impression on them.
History of the company
Sonomatic specialises in the design, development, and
application of Non-Destructive Testing (NDT) inspections.
Since the company’s formation in the 1980s, we have
combined these NDT processes with cutting-edge
integrity engineering capabilities to provide fully
integrated inspection packages that directly meet the
client’s needs. We bring innovative bespoke inspection
solutions to the market through in-house development of
equipment, software, and robotics.
Sonomatic resides as the global market leader for ROV-
deployed subsea inspection and Non-Intrusive Inspection
(NII) technologies. Our team is committed to providing
accurate, proactive inspection and engineering solutions
that enable clients to make informed decisions crucial to
the safe continued operation of mature assets and to
manage the integrity of newly constructed ones.
Other innovative products
We have developed and adapted multiple technologies
and techniques over the years. One example includes
Sonomatic adapting existing subsea inspection
equipment (MAG-Rover), to enable simultaneous water
jet cleaning and ultrasonic PA data collection on a subsea
structure. A new challenge for Sonomatic with an intense
development process due to vessel operational
timeframes. We completed the task in hand, successfully
with all stakeholders very satisfied with the outcome.
Visit Now

Decoding NDT
Engineers
Joshua de Monbrun, CEng
Technical Authority – MISTRAS Group, Inc.
Subsea Engineer & ASNT Level III
ABSTRACT
The phrase "NDE/NDT Engineer" is becoming more
common across all sectors of our industry, with little
overlap in description. The goal of this presentation is to
describe what an NDT Engineer is, emphasize the
educational and experience backgrounds required to
become an NDT Engineer, and then go into detail about
specializing as a Subsea NDT Engineer. Most current
definitions of an NDE Engineer are a combination of an
engineer and a qualified NDT Level III, or are misapplied
to jobs such as an NDT Level II Technician in some
situations. This document intends to not only describe
what or who an NDT Engineer is, but also to outline the
roles and responsibilities of such, as well as the minimal
educational and experience qualifications, as well as
advanced subsea industry specialty areas in which an
NDE Engineer can specialize.
Keywords: NDT, engineer, undersea, inspection, asset
integrity, subsea, commercial diving, ROV are some of the
terms used.
TECHNICAL INTRODUCTION
What exactly is a Subsea NDT Engineer?
To begin, the term "engineer" appears to have become
abused in the industry in recent years. As such, an
"engineer" can be a person who operates a train, works on
ship engines, designs software or programs computers,
connects networks or operates a broadcast, and now also
providing custodial services. The majority of these
occupations are technical positions that do not necessitate
a formal, validated degree in a typical engineering
discipline. For the purposes of this paper, engineers, as
practitioners of engineering, are professionals who invent,
design, analyze, build, & test machines, systems,
structures, & materials to meet objectives & requirements
while considering practicality, regulation, safety, and cost
constraints. In addition, we will take into account
graduation from an accredited engineering program, as
well as membership and accreditation with a recognized
engineering council.
It is someone who has a BSc or higher in Engineering (or a
Science related to engineering), has significant inspection
experience with offshore oil and gas and other maritime
infrastructure, is proficient in most NDT methods and
techniques while also being a subject matter expert in
more than one, is accredited by an engineering council and
is a member of an internationally recognized organization
such as the American Society of Non-Destructive Testing
(ASNT), the British Institute of Non-Destructive Testing
(BINDT), the Engineering Council (EC), the National
Decoding NDT
Engineers
Joshua de Monbrun, CEng
Technical Authority – MISTRAS Group, Inc.
Subsea Engineer & ASNT Level III
ABSTRACT
The phrase "NDE/NDT Engineer" is becoming more
common across all sectors of our industry, with little
overlap in description. The goal of this presentation is to
describe what an NDT Engineer is, emphasize the
educational and experience backgrounds required to
become an NDT Engineer, and then go into detail about
specializing as a Subsea NDT Engineer. Most current
definitions of an NDE Engineer are a combination of an
engineer and a qualified NDT Level III, or are misapplied
to jobs such as an NDT Level II Technician in some
situations. This document intends to not only describe
what or who an NDT Engineer is, but also to outline the
roles and responsibilities of such, as well as the minimal
educational and experience qualifications, as well as
advanced subsea industry specialty areas in which an
NDE Engineer can specialize.
Keywords: NDT, engineer, undersea, inspection, asset
integrity, subsea, commercial diving, ROV are some of the
terms used.
TECHNICAL INTRODUCTION
To begin, the term "engineer" appears to have become
abused in the industry in recent years. As such, an
"engineer" can be a person who operates a train, works on
ship engines, designs software or programs computers,
connects networks or operates a broadcast, and now also
providing custodial services. The majority of these
occupations are technical positions that do not necessitate
a formal, validated degree in a typical engineering
discipline. For the purposes of this paper, engineers, as
practitioners of engineering, are professionals who invent,
design, analyze, build, & test machines, systems,
structures, & materials to meet objectives & requirements
while considering practicality, regulation, safety, and cost
constraints. In addition, we will take into account
graduation from an accredited engineering program, as
well as membership and accreditation with a recognized
engineering council.

Society of Professional Engineers (NSPE), the American
Council of Engineering Companies (ACEC), the Order of
the Engineer (OE), the American Society of Mechanical
Engineers (ASME), or the American Society of Civil
Engineers (ASCE).
Occupational Understanding
In addition to the above fundamental technical
knowledge, years of experience and "Occupational
Knowledge" are required as a basis for becoming an NDT
Engineer. This means that an NDT Engineer cannot
simply graduate from a university. It necessitates a blend
of formal education and on-the-job training.
This practical field experience will include extensive
knowledge and familiarity with topside and underwater
systems, procedures, damage mechanisms, inspection
techniques, and deployment vehicles. Deployment
vehicles are merely a means of transporting the tools
required to complete a task to the region of interest.
Commercial divers, remotely operated vehicles (ROVs),
and autonomous vehicles are examples of underwater
deployment vehicles. It is not necessary to have formal
training as a commercial diver or even a ROV pilot,
although it certainly helps! A formal education in material
properties, electronic principles, mathematics, chemistry,
and corrosion analysis, as well as technical project
management, should be required of the Subsea NDT
Engineer. Experience and training in Advanced NDT
methods such as Electromagnetic T
esting, Ultrasonic
T
esting, Acoustic Emission, Cathodic Protection
systems,Computed & Digital Radiography, Guided Wave,
and Pipe Inspection Gauge systems (ILI; in-line-inspection)
are necessary. Professional certificates such as NDT Level
III from the American Society of Non-Destructive T
esting
(ASNT) or PCN Level III from the British Institute of Non-
Destructive T
esting (BINDT) will be required. A Subsea
NDT Engineer must also be well-versed in regulatory and
international standards requirements imposed by
organizations such as the American Society of Mechanical
Engineers (ASME), the American Petroleum Institute (API),
the International Organization for Standardization (ISO),
the American Welding Society (AWS), Det Norske Veritas
(DNV GL), and others. Professional certifications in
welding and pipeline inspection from these organizations
are also highly desirable.
An NDT Engineer's job includes knowing both engineering
tasks as well as having technical NDT training, on-the-job
experience (OJT), and certification. Certification is a
documented attestation to one's practical qualifications. A
NDT Engineer's primary responsibilities include the
interaction of NDT with other engineering activities, the
implications of failure, and the contribution of NDT to
asset management and life extension. Most system
engineers understand why and where their components
must be inspected, but not necessarily "how" the
inspection should take place or the best potential
technique to apply to find the damage mechanisms of
interest. That's where the Subject Matter Expert (SME)
comes in, and as a fully educated and qualified NDT
T
echnician, you should know how to examine a component
properly, but not necessarily why. NDT Engineers are able
to bridge the gap between being a competent engineer and
a subject matter expert. They can use design procedures,
such as material selection, to fulfill NDT and construction
requirements, as well as undertake root cause analysis,
fracture mechanics, and failure analysis, and learn from
experience (LFE).

Acquiring experience is essential, but so is putting that
experience to use. An NDT Engineer must critically apply
knowledge of concepts, principles, and theories of
developing technology relevant to the interdisciplinary
fields of NDT. An NDT Engineer must have advanced skills
in NDT methods substantiating their lead competency role
within the subsea sector, but also be able to work in ALL
sectors, such as aerospace, nuclear, etc. Analyze
engineering challenges by selecting and using
mathematical and theoretical data to deliver appropriate
NDT solutions while keeping the complete inspection cycle
in mind. Finally, apply engineering knowledge to the
development, operation, maintenance, and advancement
of NDT technology.
APPLICATIONS
Topside/Inland
Yes, Subsea NDT Engineers also work topside. The great
bulk of education, training, and practical experience is
gained on land before being adapted for use in underwater
or subsea conditions. We know that most of the
technology we use in the field of NDT, notably the
Ultrasonic and Radiographic methods, initially emerged
and were utilized by the medical field before being
appropriated and adapted for use in the industrial
applications we are more familiar with. The same is true
about these technologies being further modified for usage
in underwater environments. Most assets in subsea or
underwater environments have or are linked to topside
components in some way, so complete inspections require
the use of both topside and underwater techniques.
Offshore platforms, ships, barges, risers, pipes, bridges,
docks, berths, above ground storage tanks, water towers,
water intake facilities, amusement parks, hydroelectric
dams, and, yes, nuclear reactor pools. The list is endless.
Most importantly, one must first understand the
technologies and techniques available to them on the
surface before attempting to employ them effectively in a
more confined and less accessible environment. The
majority of underwater work occurs in uncomfortable
environments, with little to no visibility, rather than in nice,
clear, warm, tropical locales. A Subsea NDT Engineer must
be skilled both above and below the waterline.
Offshore
When thinking of NDT inspection of subsea or underwater
assets, offshore oil platforms and pipelines appear to be
the first things that come to mind. It is a massive industry,
with the Gulf of Mexico alone accounting for more than
80% of all billable underwater commercial diving hours
worldwide. The inspections covered by it are not your
standard NDT methods. Yes, there are many Visual and
Ultrasonic Thickness measurements being performed, as
well as underwater Magnetic Particle inspections
(although ACFM is taking over), but in these remote
locations, particularly in low-visibility or difficult-to-access
environments, Advanced NDT methods are gradually
taking over. This is also true for the usage of ROVs, where
technology is being deployed to eliminate the human
aspect, not only for enhanced trust in data collecting, but
also for reduced human exposure to risky conditions.
Technology is advancing quickly these days, so we are
seeing an increase in the use of Advanced NDT techniques
used underwater such as Automated Ultrasonic Testing
(AUT), Shear wave and Phased Array Ultrasonic (PAUT) for
full volumetric weld inspections as well as corrosion
mapping or crack detection and sizing, Electromagnetic
Testing techniques such as Pulsed Eddy Current (PEC) and
Alternating Current Field Measurement (ACFM),
Computed and Digital Radiography (CR/DR), Cathodic
Protection and potential readings (CP), Computed and
Digital Radiography (CR/DR), just to name a few.
IMPROVEMENTS IN THE SUBSEA SECTOR
Over the last few decades, there has been a rising need to
change the "status quo" of how underwater or subsea

assets have been inspected. Underwater assets are "out of
sight, and out of mind" for most industries. This is not
always the case, but it was for manyyears. Today, we can
see that a shift has begun. Unfortunately, this drive is
fuelled in part by large disasters that frequently make
headlines. However, we will not go into depth about those
here.
Subseaassets,bydefinition,operateinamoreinvasiveand
hostileenvironment,andtheirfailurecanhavea
substantialimpactnotjustonacompany'sbottomline,but
alsoontheenvironmentinwhichtheyoperate. Thiswould
naturallyleadtomorefrequentmonitoringofthoseassets,
astheirfailureismorecostly. Becausetheseassetsareina
morehazardousenvironment,onewouldassumethatsuch
inspectionswouldrequireamorecompetentand
experiencedspecialist. Thisisnotalwaysthecase;infact,
mostoftheseinspectionsareassignedtocommercial
divingorganizations,whosendouta"jack-of-all-trades"
divertocarryoutwhateverNDTtasktheOwnerrequests.
Normally,noonewouldhandanultrasonicthicknessscope
toarockclimberandhavethemclimbuptheirflaretower
totakeUTthicknessreadingsonapipeline. Notwithout
thenecessarytraining,documentedexperiencehours,
validatedqualifications,andcurrentcertifications. In
contrast,theindustryshouldnotputaUTscopeinthe
handsofadivertodothesamethingunderwater. Diving,
ROVpiloting,andropeaccesscertificationsarenot
qualificationsthatenableeffectiveinspections. Theyare
simplyvehiclesthattransportthequalifiedandcertified
inspectortothelocationofthework. Inspectionscarried
outinthismannerarefrequentlyinsufficient,anddonot
providethetypeofqualitydatarequiredtoaccurately
assessasystem'scurrentcondition. Unfortunately,a
cultureandhistoryofallowingdiverswithminimalorno
NDTtrainingtoconductunderwaterinspectionshas
developedovertheyears,withoutholdingthemtothe
samequalificationandcertificationpracticesrequiredfor
thesameinspectionofatopsideasset. Assubsea
inspections are more difficult to execute, they are always
in a "confined space" (underwater), on components whose
failure would be catastrophic, wouldn't it seem logical to
require inspections by specialists who are proficient in the
use of those techniques and technologies?
Figure1:DiverwithUTTscopeandA-Scan.
Case Study:
Thisisasimpleexample,chosensinceithasproventobe
themostcommonlyabusedthepast40years. Mostcodes
statethatultrasonicthicknessmeasurementscannotbe
acceptedbyaunitthatonlyhasadigitalthickness
readout,butmustbeperformedwitheitheraflaw
detectororamachinecapableofproducinganultrasonic
A-Scaninadditiontoadigitalreadout(Figure1).
However,untilrecently,thetechnologyavailableforhand-
held,underwaterUTthicknessscopeswasdesignedtobe
confinedtoadigitalthicknessdisplay(Figure2). Froma
fundamentalstandpoint,thisneedmakesperfectsense,as
allinterpretationandsizingmustoccurfromtheA-Scan
dataandinterpretingthewaveform. Wehavenomeansof
knowingifthedigitalthicknessreadingisaccurateand
reproduciblewithoutanA-Scandisplay.Isthisreadingthe
IDconnectedremainingwallthicknessofthematerialora
mid-wallinclusionorlamination?Themajorityofasset
ownerswouldalsorelyonthecontractorprovidingthe
servicetoensurethattheindividualsoperatingthe
www.onestopndt.com | July2023|Issue76 18

equipment were properly trained and certified. Routinely,
this meant simply familiarizing themselves with the UT
system, perhaps with a short training course, rather than a
full-fledged internal company NDT program complete with
written practice, procedures, training, written certification
exams, practical demonstrations, etc., proctored by a
qualified NDT Level III. Other times, they may invite a
topside NDT technician to wave a wand over the diver,
magically transforming them into a "NDT Trainee," and
then walking them through manipulating the tool while on
site. In this way, the actual certified technician can observe
the diver on a video monitor, directing them through the
inspection procedures, and then sign off on a "job well
done". No owner/operator would tolerate such activity on
any of their topside assets, so why has it been tolerated for
so long underwater?
Figure 2: Diver employing solely the UTT digital readout.
CHANGE-MAKING ORGANIZATIONS
There are no ASNT or BINDT/PCN guidelines or
recommendations for underwater NDT inspection
personnel training & certification at this time. The
Certification Scheme for Weldment Inspection Personnel
(CSWIP) is the only organization that currently offers
training and certification. Underwater training for Diver
Inspectors (3.1u, 3.2u), ROV Inspectors (3.3u), &
Underwater Inspection Controllers (3.4u) is included in
these schemes. Although this is a good start, these courses
only cover the practical use of standard NDT methods such
as visual/tactile, ultrasonic thickness, magnetic
particle,video/still photography, and cathodic potential
readings. Unfortunately, these are not recognized NDT
certifications the same as our topside counterparts are
required. The transition is underway, & numerous
companies are now requiring individuals with these
qualifications to perform asset inspections. This pattern
will continue, as will the demand for more qualified
underwater inspection personnel with advanced
inspection training & experience, who hold internationally
recognized professional certificates, preferably from a
central certification scheme of some kind.
Over the last few years, there have also been more
reference guides written and used in an attempt to develop
norms for specific sectors of the industry. In 1999, the
International Institute of Welding (TIIW) issued a paper
titled "Non-Destructive Examination of Underwater
Welded Steel Structures" (1).
Despite its simplicity, the information was able to
introduce people to the idea that many classic NDT
methods may be utilized underwater for the examination
of welded steel structures. Many additional papers have
since been released with updated information and
technologies that we see being used today. To mention a
few, "Subsea Pipeline Integrity and Risk Management" (2),
"Subsea Inspection Controller" (3), and "Image-Based
Damage Assessment for Underwater Inspections" (4).
Aside from privately published guidelines or internal
procedures drafted by subject matter experts, institutions
such as the American Society of Civil Engineers have
begun to issue publications such as their "Waterfront
Facilities Inspection and Assessment" (5).
CONCLUSION
So, why are specialized NDT engineers required? The

expected answer in today's world is always "SAFETY"! Yes,
safety is a factor, but as with most industries, it all boils
down to the economic benefits. Hire one individual who
can perform the duties of multiple individuals. NDT
Engineers bridge the gap between what has to be done and
knowing the most feasible and cost-effective approaches
to accomplish what's required. Because of their technical
understanding of codes and regulations, as well as their
experience and competence in advanced inspection
technologies and techniques, NDT Engineers can impact
greater production output with decreased program costs.
Overall inspection durations are reduced by using the most
appropriate and efficient inspection techniques to collect
the most relevant data. As a result, probability of detection
and the data's dependability and usability improve.
Integrating all of the above will boost not only safety but
also revenue. More efficient "bottom-time" = maximized
"bottom-line"!
REFERENCES
Davey, V S, 1999, Non-destructive Examination of
Underwater Welded Steel Structures, Cambridge,
England: Abington
Bai, Yong and Qiang, 2014, “Subsea Pipeline Assessment
for Underwater Inspections,” Gulf Publishing
Clancy, A, 2017. “Subsea Inspection Controller”,
#inspector2U
O’Byrne, M, 2018, “Image-Based Damage Assessment for
Underwater Inspections”, CRC Press
Waterfront Inspection Task Committee, 2015,
“Waterfront Facilities Inspection and Assessment”,
American Society of Civil Engineers
expected answer in today's world is always "SAFETY"! Yes,
safety is a factor, but as with most industries, it all boils
down to the economic benefits. Hire one individual who
can perform the duties of multiple individuals. NDT
Engineers bridge the gap between what has to be done and
knowing the most feasible and cost-effective approaches
to accomplish what's required. Because of their technical
understanding of codes and regulations, as well as their
experience and competence in advanced inspection
technologies and techniques, NDT Engineers can impact
greater production output with decreased program costs.
Overall inspection durations are reduced by using the most
appropriate and efficient inspection techniques to collect
the most relevant data. As a result, probability of detection
and the data's dependability and usability improve.
Integrating all of the above will boost not only safety but
also revenue. More efficient "bottom-time" = maximized
"bottom-line"!
REFERENCES
Davey, V S, 1999, Non-destructive Examination of
Underwater Welded Steel Structures, Cambridge,
England: Abington
Bai, Yong and Qiang, 2014, “Subsea Pipeline Assessment
for Underwater Inspections,” Gulf Publishing
Clancy, A, 2017. “Subsea Inspection Controller”,
#inspector2U
O’Byrne, M, 2018, “Image-Based Damage Assessment for
Underwater Inspections”, CRC Press
Waterfront Inspection Task Committee, 2015,
“Waterfront Facilities Inspection and Assessment”,
American Society of Civil Engineers
Ad

Paul Bentley
Director - Lizard NDE Ltd
Lizard NDE's
Journey in
Revolutionary
Subsea
Inspection
Technology
Innovation Beneath
the Waves
? Paul, as the Director of Lizard NDE,
we're eager to learn about your
company's fascinating involvement in
subsea inspection technology. Could
you walk us through the pivotal
moments or breakthroughs that have
shaped your journey?
Thank you for inviting me. It really has
been quite a journey. Lizard
technology had become directed
towards topside operations, rail &
infrastructure in particular, for many
years and following company
restructure decided to re-enter the
subsea arena after invitation from
Aker Solutions & Oceanscan of
Norway and Oceaneering to
participate in projects for robotic
inspection. These were my first
projects where I was both fully
responsible from design through to
delivery & applying the Lizard
technology to, what was for me at
least as my background was nearly all
topside until this point, an entirely
new arena of subsea & all the
challenges involved with such a
difficult environment. The result was
the Lizard LP180SR 12 channel
subsea array for nodal joints & the
LP184SR high lift off flat array for flat
plate and they both performed
perfectly, far exceeding the
expectations required. That was when
we knew as a company that we should
seriously re-visit what was the original
home of the Lizard innovation, the
subsea market, & apply the knowledge
we had gleaned over the many
preceding years of topside
development towards this new
direction. In fact, many of our recent
topside innovations have been the
direct result of our developments
towards offshore applications so the
new approach has really benefited us.
One of our strengths is that the Lizard
technology has always had the
advantage of both Bx & Bz responses
in impedance format, giving the user a
secondary data output that as well as
a detection & advanced analysis data-
stream in itself also provides for lift
off (distance of sensor to conductive
piece) and therefore position
understanding of the array during
operation. Lizard’s breakthrough
moment was to better incorporate

that output to enable the array to
transmit what is essentially distance
feedback to the operator &
manipulation controller. By providing
this output the robotic probe sweep
can be far easier controlled than by
camera’s alone, giving an almost zero
latency out-put per Bx sensor and full
control of each array sensor response
down to an individual level if required.
LP100S – Quad Array (4Bx/4Bz) Handheld Weld
Probe
There are some
extremely interesting
and innovative
solutions coming soon,
I’ll make sure your
readers have the
exclusive when the
timing is correct!
In addition, our decision to work
together with Oceanscan of Aberdeen
to enable the rental of Lizard products
for the first time in the UK has been
another major step. That plus our
continued works with Dr Alessandro
Demma of Xcel Inspection, here we
have been extremely successful in the
continuing evolution of the Lizard
methodology and resulting products.
? Additionally, why do you believe
subsea inspection technology plays a
crucial role in the broader industry
landscape?
It is vital that the subsea inspection
technology keeps pace with the
requirements of the industry as assets
worldwide reach operational life.
Early detection of what may initially
be unnoticeable events using
traditional NDT methods could
prevent expensive failure in the
future. In today’s environment it is
vital that existing assets are properly
maintained to enable the needed
worldwide supply, especially with
many reaching or exceeding original
operational life.
In addition, as I have already
mentioned, the offshore industry
requirements drive innovation that
can be applied for other sectors.
? What are the key challenges
associated with subsea inspections,
and how does Lizard NDE address
them through its advanced NDT
technologies?
If something can go wrong offshore, it
generally does! To list all of the
operational challenges associated
with offshore works would take an
extremely long answer! We try to
mitigate as much as we can, all subsea
arrays being triple insulated from
seawater ingress for example. Of
course, the main advantage is we
ensure the Lizard array does not
require physical contact with the
contact piece to operate, therefore
highly reducing the chance of wear
and damage to the array face. The
Lizard Dive system uses and ultra-low
AC power and as such is far safer than
DC with an instant alert for power/
comms failures (another subsea
regular occurrence) although the
Lizard Dive can also be battery
powered in such an event.
Lizard M8XL Topside System with LP184T in
carriage mount
Other examples of offshore support is
the issuance via download of
replacement Lizard software for our
customers with no additional fee or
license cost. Use of the software for
subsea or topside operations is
virtually the same, allowing users to
easily transfer to differing
applications as needed. In addition, for
many offshore operations deep water
functionality is not required, for this
instance we enable the topside Lizard
M8XL to operate a probe senor
extension cable of up to 200M in
length to allow for subsea data

collection through the topside unit,
vastly extending the range of
inspection capabilities with the simple
inclusion of a cable and subsea Lizard
probe type.
As an even simpler example, due to
the connectivity of the Lizard M8XL,
the user can operate many standard
eddy current probe types for many ET
based tasks & even Conductivity
Measurement as an option within a
drop down menu of the software. Our
approach is to make the Lizard the go
to for electromagnetic based tasks, an
electro-magnetic toolbox approach if
you will.
? Could you highlight some of the
innovative subsea inspection
technologies developed by Lizard
NDE and how they have improved the
efficiency and accuracy of
inspections?
We work closely with our clients to
design the array with the intended
application in mind from day rom the
outset we must understand the
application itself (geometry, material
type, thickness coating, physical
hindrances & tolerances to name just a
few) and the restrictions imposed by
the manipulation and deployment
method. Each case can be wildly
different and it’s with this knowledge
we can begin to approach the senor
design requirement and work with our
client to find the most suitable array
type & a working operational
procedure of use. We use can then
liaise with the client at every step to
ensure the array configuration will be
correct according to the manipulation
requirements, with 3D printed mock
ups used to guarantee agreement of
final design specification. It is by
working in such close collaboration
with our clients, partners and friends
that we have learnt so much along our
journey, I must here say thank you to
all on the LP180SR, LP184SR, and
LP170SR projects, again I’m sure I’m
under confidentiality somewhere but
you know who you are!
The LP180SR and LP184 are perhaps
our best recent examples of the Lizard
innovation towards offshore and how
we approach the task differently to
others. Both probe types utilise the
Lizard Field Gradient Imaging sensor
technology which has proved
incredibly effective in real world
operations for speed & accuracy of
detection plus ease of use. Complex
geometries are catered for by the
LP180SR, having 6 independent
sensor pairs of Bx & Bz fitted to 3
flanks of the array face. By angling the
array to the weld or structure the
array operates 4 of these 6 pairs,
software selectable, to address the
geometric variability of the piece
without requirement to turn the array
manipulation system 180 degrees.
Data collection speed can be varied &
later corrected for in simple software,
reducing the difficulties once again of
the manipulation system
requirements & making life far easier
for the operator. Knowing for certain
that the region you have just
inspected has actually been correctly
addressed ensures a far more
confident & relaxed inspection
environment for all involved.
LP180SRInUse–OceantechManipulationSystem
The brother of the LP180SR, the
LP184SR, is designed as a flat array,
designed to operate at a great
distance from the conductive piece,
such as to enable the inspection of a
weld cap in a floor plate in a single
pass. Again, due to the FGI technology
employed the contact of field to the
conductive piece can be monitored
and as such enabling a very quick and
confident inspection with zero contact
of the array. Many customers have
found that the FGI output can replace
cameras & associated lighting & power
requirements from crawler use of the
Lizard technology and when combined
with the FGI C-Scan Colour Imaging
Mode within the Lizard software
results in extremely quick & confident
inspection of many applications.
Again, remember that Lizard is
providing Bx and Bz as a pure
impedance output which can be
altered both physically (drop down
www.onestopndt.com | July 2023 |Issue 76 24

frequency and gain change) and via
software (Lizard Adjustment menu).
Therefore, all responses can be
tailored, per channel, to differing
output configurations with respective
sensitivities and various display
modes. That is an incredibly powerful
‘all in one’ and again displays our
‘electromagnetic toolbox’ approach.
? How does Lizard NDE's subsea
inspection technology contribute to
enhancing the safety and integrity of
underwater structures and
equipment?
By increasing the level of Field
Coupling (Lift Off), our technology is
capable of ensuring that most
standard structures can be catered for
without coating removal. That is a
huge benefit for many operations, the
complete non-invasiveness of the
Lizard. No couplant or similar is
required and so the Lizard is
incredibly environmentally friendly.
Lizard Dive – 2023 Small Housing Version
A simple example is that we use nickel
metal hydride (NiMH) batteries for
our Lizard products rather than
lithium, a safer alternative and easy to
transport offshore.
Of course, the powerful Lizard Sizing
software is extremely good at data
analysis, allowing for length and depth
interpretation using the easy to use
Sizing menu. Since we have the pure
impedance of each event and full
control of each of these outputs
throughout the suite Lizard can make
a far clear assessment of each and
every event. The output from Lizard
campaigns & close monitoring of
known events over time have allowed
many clients to investigate and
resolve say, design flaws with a whole
swathe of clear information.
Our innovations towards ROV based
diver-less campaigns are also a good
example of how Lizard is helping to
reduce the risk to human personal
through the requirements of offshore
data acquisition at depth or other
dangerous locations. ROV’s & robots
are very unlikely to replace divers in
the wider sense however enabling a
robot activity that can stay at depth
for longer duration yet still accurately
acquire the required scan collection
activity is a real step forward.
? Can you share some success stories
or case studies where Lizard NDE's
subsea inspection technology made a
significant impact on the operational
performance or maintenance
strategies of clients?
Our works with Bluestream Offshore
in the Netherlands is a true example of
our collaboration approach with our
clients, a great success story for all
involved. Here we worked together to
provide an array in line with the
requirements of the Bluestream
Gobiesox Subsea Manipulation
system, a truly remarkable innovation
that utilises downward thrust to
maintain grip and deployment of the
array without the requirement of
magnets.
The resulting LP170SR array (our
latest subsea array type) provides for
a 7 channel pair of Bx/Bz, again
switchable like the LP180SR. Housed
in a very small enclosure, the LP170SR
is the perfect fit to the Gobiesox.
Original Gobiesox with LP170SR Lizard Array
Fitted
? What are the major advancements
or trends you foresee in subsea
inspection using NDT in the near
future?
Increase in crawler innovations,
smaller, smarter and more responsive
manipulation systems. I’ve seen some
great examples out there of clever
innovations in the robotic
manipulation and control that only a
few years ago would have been nigh
on impossible. I also see the increased
use of offshore ROV based campaigns
being run from onshore operations

sites via internet and more than likely
AI having some involvement
somewhere!
? How does Lizard NDE ensure the
reliability and quality of data
obtained through subsea inspections,
and how is this data utilized by clients
to make informed decisions?
Each Lizard data file contains the
individual Gain responses of each Bx
and Bz channel, plus visual read out of
interrogating field to conductive piece
and timestamped as a basic function
of the Lizard software. Our proven
procedure ensures reference data is
collected in addition such that
comparison of data output against
known piece is always available, with
data packets being incredibly small
and easily shareable to others for
further action or comment for
example. The powerful sizing tool
within Lizard allows clients to monitor
events for example, returning to
known stress points at measure
growth (or not) of known events and
by extension enabling clients to
understand the causes of failure such
that sometimes a very small
engineering change can then address.
Actually, Lizard has a long history of
supporting the offshore industry with
our technology, one of our highlights
was the extension of the lifetime of
HMS Fearless for the UK Ministry of
Defence (now finally decommissioned
so I can tell you!). There the Lizard
technology was influential in an
extension for some 5 years past
operational life following Lizards work
for corrosion monitoring and
detection of the fuel tanks where steel
plate had been corroded by a
biological agent within the diesel fuel.
There are many many examples I could
share with you however it’s highly
likely I’m under a confidentiality
agreement but at least I can share this
example!
? Could you discuss the role of
automation and robotics in subsea
inspection, and how Lizard NDE
incorporates these technologies to
enhance inspection capabilities?
We mostly receive requests for tools
for inspection of locations where
human intervention would be nigh on
impossible and as such these assets
now requiring inspection will always
need clever innovations to achieve the
required confidence of operation.
Therefore it is very common for us to
have to work within very tight
tolerances and in very close contact
with our clients to ensure the best
outcome of the application. In addition
there is a large move towards use of
ROV’s or other automated means of
data collection where accurate scan
acquisition is paramount, a task that is
simple for a human diver’s hand is
incredibly difficult to replicate by a
robot, at depth, however I am still
surprised at just how good the recent
innovations in crawler and
manipulation control has become in
such a short time and Lizard are
absolutely committed to keeping pace
with our own innovations and helping
our clients world wide.
REVOLVER
Select the appropriate band size, snap the
scanner on the pipe, and scan away!
www.autsolutions.net
Ad

Fundamentals
of NDT for
Subsea and
Off-shore
Introduction
The vast expanse of oceans & seas, where subsea &
offshore structures stand tall, is also the grounds of the
battle between man-made ingenuity & the unyielding
forces of nature in marine environments. Structures like oil
rigs, pipelines, & underwater cables, are exposed to various
environmental factors that can harm their integrity.
The consequences faced by operating in the dynamic &
ruthless realm of marine environments are severe &
factors like extreme weather events, seabed conditions,
corrosion, wave and current forces, & subsea geohazards
can cause failure or damage to these structures.
Failure or damage of such structures may cause major oil
spills, interruption of energy supplies, contamination of
the environment, and risk to human health and life.
The need for increased safety measures, environmental
preservation, or stricter regulations was realized as
recently as 2010. The phenomenon that caused it was the
blowout in the Deepwater Horizon rig, induced by the
failure of its safety systems, which also included the failure
of the blowout preventer (BOP).
Months-Long
Oil Released!
Deepwater
Horizon Spill,
Known as the
Macondo Blowout,
Ravaged the Sea
The Deepwater Horizon spill, also called the Macondo
blowout, released oil into the sea for approximately a
period of three months. Multiple fire containment and
remedial efforts were made, however, the rig collapsed
into the Gulf of Mexico.
This incident caused around 4.9 million barrels of crude oil
to be released into the Gulf, causing harm to the marine life
and animal life that depended on the water source. This
also affected the livelihoods of fishermen and the coaster
community and affected tourism in the region.
This event also highlighted the dire need to employ
thorough inspection and maintenance of subsea and
offshore vehicles & infrastructure. NDT caught on as a
crucial methodology to evaluate the condition of the
components or infrastructures under study and aided in
identifying potential points of failure or defects.
Fundamentals
www.onestopndt.com | July 2023|Issue 76 30

The tragic implosion of the Titan submersible built by the
American company OceanGate in the North Atlantic
Ocean on 18th June 2023, is a testament to the necessity
of responsible testing and quality control practices in
industries. Numerous safety concerns were dismissed by
CEO Mr. Stockton Rush, who asserted that emphasizing
safety impedes innovation. As a result of his disregard for
safety and testing procedures, Mr. Rush met his untimely
demise in the submersible disaster.
TYPES OF NDT METHODS FOR SUBSEA AND
OFFSHORE APPLICATIONS
Some of the key Non-destructive testing methods
employed in subsea and offshore applications are:
c Visual Inspection (VI)
c Liquid Penetrant Testing (LPT)
c Radiographic Testing (RT)
c Ultrasonic Testing (UT)
c Eddy Current Testing (ECT)
The selection of Non-destructive testing methods depends
on the properties of the material under inspection, the
accessibility of the test area, and the type of defect being
targeted for detection.
(Image credits: ndtinspect.com)
ADVANTAGES AND LIMITATIONS OF NDT
TECHNIQUES IN SUBSEA AND OFFSHORE
APPLICATIONS
The advantages of NDT techniques in subsea and offshore
applications are as follows:

c NDT methods do not cause damage to the subject
under test; hence they can be used to test subsea and
offshore components and structures without affecting
their integrity or operability.
c NDT methods can obtain data on potential defects,
flaws, and degradation in structures, pipelines, and
equipment, consequently contributing to the overall
safety of subsea and offshore applications. Premature
detection of defects enables timely remedial actions
and reduces the probability of accidents, damage to the
environment, and loss of revenue due to downtime.
c NDT techniques can provide economical solutions for
maintenance and inspection programs for subsea and
offshore applications. Identification of areas of concern
can enable industries to resources and efforts towards
vital elements. This reduces unnecessary maintenance
and repair processes.
c NDT permits meticulous analyses of large sections or
lengths of subsea pipelines and structures. Advanced
techniques like PAUT and GWT, enable faster data
acquisition and provide data on defects and
deformities.
c NDT techniques are versatile and apply to a variety of
materials that include metals, composites, and non-
metals. This versatility permits the inspection of a
variety of test subjects.
The disadvantages of NDT techniques in subsea and
offshore applications are as follows:
c Smaller or hidden defects are often hard to detect using
NDT. The sensitivity of the method and operators’
knowledge and skill can affect the detection
capabilities. This may lead to errors or
misinterpretation of defects.
c NDT methods require skilled and trained operators.
Operating the equipment, acquiring data, and making
correct inferences are of utmost priority.

Some NDT techniques require specific surface
conditions (e.g., Ultrasonic Testing) to obtain optimal
results. Subsea and offshore environments may cause
corrosion and marine growth on test subjects, and prior
surface preparation may be required to conduct tests.
Equipment limitations hinder the testing process.
Depth restrictions, Inaccessibility, and Environmental
factors contribute to the ability of the test apparatus
to operate.
Skilled interpretation of results is essential to
determine the extent and significance of damage on
test subjects, as well as remedial actions. Test outcomes
may vary between operators, leading to inconsistencies
in data.
It is imperative to consider the advantages and
disadvantages of NDT methods while implementing them
in subsea and offshore applications. Thorough
comprehension, planning, and training are essential to
maximize the benefits of Non-destructive testing.
APPLICATIONS OF NDT METHODS IN SUBSEA
AND OFFSHORE INDUSTRIES
Non-destructive testing has numerous applications in the
subsea and offshore industries. Non-destructive testing
methods are employed to gauge the quality, safety, and
structural integrity of subsea and offshore equipment,
components, and structures.
Some key applications of NDT methods in subsea and
offshore industries include:
Subsea pipelines: NDT techniques like Magnetic
Particle Inspection (MPI) and ultrasonic testing are
used to assess subsea pipelines for the presence of
defects and corrosion. These methods can also be used
to check the pipeline wall thickness. Potential leaks and
failures can be anticipated using these methods.
Subsea risers: Subsea risers connect subsea wellheads
to the surface facilities. Methods like Ultrasonic Testing
(UT), Visual Inspection (VI), etc. are used to check for
any defects, deterioration, or cracks. This helps
evaluate any potential risks to the risers’ integrity.
Subsea structures: Subsea structures (e.g., platform
jackets or subsea manifolds) are often inspected using
techniques like Visual Inspection (VI) and Acoustic
Emission Testing (AET). These assessments aid with the
detection of fatigue cracks, damage, or corrosion that
may cause failure in the structural integrity of such
structures.
Blowout preventers (BOP): BOPs are safety devices
that help control oil and gas well blowouts. BOP
components (e.g., shear rams and hydraulic systems)
are assessed using techniques like Ultrasonic Testing
(UT) and Radiographic Testing (RT).
Weld Inspection: NDT techniques such as Magnetic
Particle Testing (MPT), Ultrasonic Testing (UT), and
Radiographic Testing (RT) are used to test for weld
defects such as cracks, porosity, or insufficient fusion.
Welds in subsea pipelines, offshore platforms, and
structural components.
Detecting corrosion: Corrosion-related deterioration
may be tested using NDT techniques such as Ultrasonic
Testing (UT), Radiographic Testing (RT), and visual
inspection (VI). Subsea and offshore industries depend
on NDT techniques to evaluate the state of corrosion in
structures, equipment, and pipelines.
Thickness Measurement: Electromagnetic Testing

techniques such as Eddy Current T
esting (ECT) & Eddy
Current Array T
esting (ECA) aid in the thickness
measurement of structural components, pipelines, and
vessels. Apart from the structural integrity, thickness
measurement helps gauge the thinning due to
corrosion or erosion and helps assess the lifetime of
the subject.
Material Composition: The quality and properties of
materials used in offshore and subsea applications can
be evaluated using NDT methods like Ultrasonic T
esting
(UT), Radiographic T
esting (RT), and Magnetic Particle
T
esting (MPT). This helps verify the materials’
adherence to the industry specification, standards, and
regulatory requirements.
Condition Monitoring: NDT methods like Acoustic
Emission T
esting (AET) AND Vibration Analysis are
used to analyze the acoustic or vibration signals
emitted from the structure under inspection. This
ensures the detection of degradation, deformities, and
defects, ensuring thorough maintenance and
prevention of structural failure.
Offshore Platform Inspection: The structural integrity,
presence of weld defects, corrosion, etc. of an offshore
platform are detected using NDT techniques like Visual
Inspection (VI), Magnetic Particle T
esting (MPT),
Radiographic T
esting (RT), and Ultrasonic T
esting (UT).
Regulatory requirements, test subject characteristics,
working environment, and other factors play an important
role in the testing procedures, frequency, and modus
operandi. NDT methods have great potential in the subsea
and offshore industry and are critical to their smooth
operation.
EMERGING TECHNOLOGIES IN NDT FOR
SUBSEA AND OFFSHORE
T
echnological advancements have led to an evolution in
the field of Non-destructive T
esting. Efficient and accurate
testing methodologies are of priority to meet modern-day
technological demands.
Some of the emerging techniques in Non-destructive
testing for subsea and offshore industries are:
Phased Array Ultrasonic T
esting (PAUT): Phased Array
Ultrasonic T
esting uses multiple transducers to induce
and receive ultrasonic waves. The transducer elements
can be controlled and their properties like amplitude
etc. can be adjusted to electronically scan a component
or structure. PAUT can be used to inspect weld defects,
pipelines, & other vital elements in a subsea & offshore
structure.
Digital Radiography: This technique employs the use of
digital detectors instead of radiographic films to obtain
X-ray and Gamma-ray images. Difficult-to-access areas
in subsea & offshore structures can be tested using this
NDT method as it provides real-time image
manipulation & analysis, faster image acquisition, &
sharper images.
Eddy Current Array T
esting (ECA): Eddy Current Array
T
esting is an advanced method of Eddy Current T
esting
that can be used on conductive materials to check for
surface and near-surface defects. ECA uses an array of
sensors to provide a quick and thorough inspection of
non-ferromagnetic elements of subsea and offshore
structures and components.
Remote Visual Inspection (RVI): This method uses
remotely operated cameras and robotic mechanisms to

inspect hard-to-access areas. RVI can conduct visual
inspections using mobility mechanisms, lighting, and
advanced cameras to assess subsea structures,
equipment, and pipelines.
; Time-of-flight Diffraction (TOFD): This NDT method
utilized diffracted signals to detect defects in welds and
other elements. This method provides depth sizing and
imaging, making it an efficient choice to assess welds in
subsea and offshore structures and elements.
; Guide Wave Testing (GWT): GWT employs the use of
low-frequency guided ultrasonic waves to evaluate long
lengths of structures or pipelines from a single access
point. This method is useful in detecting variations in
wall thickness along the length of the test subject,
corrosion, and erosion. The test area covered from a
single access point is large in the case of GWT, hence
making it a viable testing option for large-scale
structures and machinery.
; Artificial Intelligence and Machine Learning: Artificial
Intelligence and Machine Learning are being used to
automate NDT testing processes using data analysis,
predictive analytics, and pattern recognition. The
transition of the field of NDT into Industry 4.0 uses
such techniques to enable efficient evaluations in
subsea and offshore environments.
The future of NDT is bright and illustrated with newer
technologies that provide improvements in speed,
accuracy, inspection, and data analysis which help ensure
the longevity and safety of essential components and
structures in the offshore and subsea industry.
CONCLUSION
The fundamental concepts of NDT, which include
techniques like Ultrasonic Testing, Radiographic Testing,
Visual Inspection, & Magnetic Particle Testing provide a
deeper perspective into the state of offshore and subsea .
equipment & their reaction to their environment with time
Detection of defects, anomalies and degradation using
NDT methodologies ensures timely maintenance, repair,
and replacement of damaged or vital elements. This
safeguards industries from untoward incidents and
hazards to human life.
The domain of Non-destructive testing methods is ever
expanding due its to demand and relevance to modern
engineering, and methods like Phased Array Ultrasonic
Testing, Guide Wave Testing, and Radiographic Testing
provide vital data on a large variety of subjects, which
helps elevate the quality of human engineering
capabilities.
The amalgamation of Artificial Intelligence and Machine
Learning with NDT technology has kick-started the
possibility of automated operations and testing. Efficient
maintenance strategies can be planned with these
methods, which in turn increases their reliability.
Researchers, industries, and governing bodies need to
collaborate to keep up with NDT methods with the
constant evolution of the subsea and offshore industries.
Non-destructive testing is a vital element of risk
mitigation, quality assurance, and asset integrity
management. By efficiently utilizing the principles of Non-
destructive testing and newer technology, we can navigate
the complex challenges of subsea and offshore operations
and build a culture of safety, reliability, and responsibility
towards the environment.

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Unleashing the Power of
Remotely Operated Vehicles
(ROVs) in Subsea Component
Inspections
Introduction
Remotely Operated Vehicles, or ROVs were developed in
the 1960s to retrieve underwater missiles, mines, and
other naval weapons. ROVs have hence become a
successful tool for various industries and are often used in
deep-sea research, retrieval, and rescue missions.
Similar technology, operated by Jean-Louis Michel and
Robert Ballard aboard the French research vehicle RV Le
Suroît, named Argo/Jason was used in the hunt for the
RMS Titanic debris that sunk after a collision with an
iceberg on its doomed maiden voyage. Argo is a remotely
operated deep-sea vehicle, that used SONARs and cameras
to map out the ocean floor and locate the position of the
test subjects. The Argo is towed behind a ship that
transports the ROV to the search location and has a two-
body ROV called Jason, developed by the Woods Hole
Oceanographic Institution (WHOI). Former prototypes of
the ROV named Jason Jr. (1991), Hercules (2021), and
Argus (2021) were lost at sea, however, Jason managed to
recover the latter two ROVs as they were less than 200
miles away from its location.
ROVs bridge the gap between human ability and the forces
of nature, enabling researchers, engineers, and those
curious in accessing otherwise inaccessible locations of
experimentation and research, further broadening
mankind’s perspective of the world we operate in.
The Evolution of Subsea Component
Inspections
ROVs are generally used in subsea component inspection
in various industries like oil and gas, offshore renewable
energy, underwater research, and marine salvage
operations. Quality testing and structural health
assessments of subsea infrastructure depend heavily on
the abilities of ROVs.
Image of a Remotely Operated Vehicle (Image credits: ScienceDirect.com)

The evolution of subsea components has been accelerated
by the rapid advancements in technology, industry
demands, and the need to operate in increasingly
challenging subsea terrain. Significant developments in
materials, design, manufacturing techniques, and
monitoring systems for subsea technology and
infrastructure over the past few decades have further
expedited the process.
Some notable aspects of the evolution of subsea
components are:
G Advancements in material science have led to the
utilization of more resilient materials, which can
withstand the unforgiving conditions in deep-sea,
including high pressures, corrosive seawater, and
extreme temperatures. Carbon steel which was the
traditionally preferred material has now been replaced
or supplemented by corrosion-resistant alloys (CRAs)
which include stainless steel, nickel-based alloys, etc.
Coatings such as epoxy or polyethylene are also
applied to protect the material from corrosion.
G Structural analysis techniques like finite element
analysis (FEM) have helped evolve the design of subsea
components to ensure structural integrity and
optimized designs for various loading conditions.
Components are designed to withstand extreme
external pressures, internal stress, and various
external factors. Rigorous testing procedures such as
pressure and fatigue testing are also carried out to
assess their performance.
G Robust and watertight connections in challenging
subsea environments are ensured with the use of
specialized connectors and hydraulic couplings.
Sealings and connector systems have undergone
massive improvements with the use of elastomeric
materials, metal-to-metal seals, and composite gaskets
to ensure long-term sealing integrity.
G The evolution of subsea components has also led to
advancements in intervention and maintenance
techniques. ROVs and Autonomous Underwater
Vehicles (AUVs) are extensively used for inspections,
repairs, and maintenance activities on subsea
infrastructure. This has greatly improved the
accessibility and serviceability of subsea components,
reducing the need for expensive and laborious
interventions.
G Subsea control systems have also evolved with the
facilitation of remote monitoring and control
components. This technology enables operators to
remotely operate valves, actuators, and other subsea
equipment. Advances in control systems have led to the
development of subsea control modules, umbilicals, and
master control stations that improve their efficiency
and reliability.
G Instrumentation and monitoring systems in the deep
sea have become progressively sophisticated. Sensors
and data acquisition systems monitor different
parameters, including pressure, temperature, flow
rates, corrosion rates, and structural integrity.
Continuous monitoring and early detection of potential
issues are now possible because of real-time data
transmission and communication systems. These
features enhance safety and operational efficiency.
The evolution of subsea components has been focused on
increasing their durability, reliability, and performance in
demanding subsea environments. The development of
material sciences and materials, advanced designs,
augmented sealing systems, enhanced control systems,
and monitoring technologies have significantly
contributed to the safe and efficient operation of subsea
infrastructure.
Continuous improvement drives the evolution of subsea
components, focusing on sustainability, cost-effectiveness,
and environmental consciousness.

ROVs in Action: Examining Subsea Components
Thorough inspection, assessment, and analysis of various
elements of underwater infrastructure are imperative in
the examination of subsea components. This ensures their
integrity, performance, and adherence to safety and
regulatory standards.
(Image credits: wevolver.com)
Examining subsea components includes the following
aspects:
t Visual inspection is the primary method for examining
subsea components. ROVs are primarily used in this
process and are equipped with cameras to capture
real-time visual footage of the components. The visual
feed hence obtained helps the operator to identify any
signs of damage, corrosion, leaks, etc. High-definition
cameras and lighting systems aid in providing clear
visibility in the deep-sea environment for better
footage.
t Non-destructive techniques are preferred for a
detailed assessment of the structural integrity of
subsea components and to detect hidden defects
present. Non-destructive testing methods commonly
used for deep sea applications include Ultrasonic
testing, Magnetic particle testing, Radiographic testing,
and Eddy current testing. These methods enable the
assessment of critical parameters such as wall
thickness, material properties, and the presence of
cracks or deformities.
t Subsea components are susceptible to corrosion due to
the corrosive nature of seawater. Monitoring the
corrosion in subsea components involves studying the
corrosion rate, extent, and potential impact on the
component’s structural integrity. A variety of methods
like corrosion coupons, corrosion probes, and cathodic
protection systems are employed to monitor and
mitigate corrosion risks.
t Integrity assessments are conducted to determine the
fitness of subsea components for service. The
component’s design, structure, operational history, and
maintenance records are analyzed in an integrity
assessment. The analysis may also include testing
stress and fatigue levels, gauging the remaining life of
the components, & determining repair or replacement
requirements.
t Subsea components undergo testing to ensure their
applicability in the harsh subsea work environment.
This is done by evaluating the mechanical properties,
corrosion resistance, and fatigue behaviour of the
material used. Material testing methods such as tensile
tests, hardness tests, and chemical analyses are
employed to analyze the material’s performance and
adherence to industry codes.
t The data generated during the analysis of subsea
components (inspection reports, NDT results, and
environmental parameters) is vast & data analysis
techniques such as statistical analysis and trend
monitoring are used to identify patterns, defects, &
potential problem areas. A report is hence prepared,
summarizing the inferences & providing
recommendations for further actions such as
maintenance and repair.

" Compliance with industry codes and standards is
critical during the assessment of the structural
integrity of subsea components. Organizations like the
American Petroleum Institute (API), International
Organization for Standardization (ISO), and relevant
government organizations provide guidelines and
criteria to adhere to for the employment of subsea
equipment, their testing, and maintenance.
Verification of the compliance of these subsea components
requires the amalgamation of visual inspections, non-
destructive testing, integrity assessments, material
testing, and data analysis. These examination activities aid
in the assessment of the condition, operational abilities,
and safety of the components, enabling informed decision-
making regarding maintenance, repairs, and asset
management in subsea environments.
(Image credits: wevolver.com)
Overcoming Challenges and Advancements
The exponential growth in the use of Remotely Operated
Vehicles has significantly aided the exploration and
inspection of the challenges in underwater environments.
The technology used in ROVs has been developed after
numerous losses and challenges and has greatly benefitted
from technological growth, hence enhancing the abilities of
ROVs, and broadening their range of applications.
Some key breakthroughs in the use of ROVs are as follows:
" Developments in pressure-resistant housings, buoyant
materials, and thruster technology have permitted
ROVs to access and operate deeper in the ocean,
accessing thousands of meters below what was earlier
possible. Access to these regions is practically
impossible for human divers due to the pressure and
temperature changes. An improved understanding of
the ocean, due to the benefits of ROVs has made deep-
sea exploration, offshore energy development, and
subsea infrastructure a reality for modern engineering.
" Former versions of ROVs were limited in power and
endurance, as they relied on surface power and were
connected via a tether. Advancements in battery
technology and the use of hybrid power systems have
significantly increased the duration of operation of
modern ROVs. This reduces the issue of recharging and
obtaining power from surface vessels repeatedly and
enables longer missions.
" Progress in thruster design, control algorithms, and
feedback systems have improved the responsiveness
and stability of ROVs. Advanced navigation and
positioning technology such as Doppler velocity logs,
inertial navigation, and acoustic positioning systems,
has improved the accuracy and reliability of ROV
operations.
" Underwater communication technology has been
upgraded in present times with the use of acoustic
modems and fiber-optic solutions. The reliability and
rate of data transfer have significantly improved.
Operators receive high-resolution visual feed, sensor
data, and control commands in real-time, facilitating
efficient decision-making and remote access.
" Manipulator’s arms are often installed on ROVs to
enable them to perform tasks such as the operation of
valves, collection of samples, and deployment of tools.
Progress in robotics has created improved manipulator

arm designs and dexterity. Control systems are also
progressing in terms of their effectiveness and
accuracy. Newer ROVs can perform more nuanced and
complex tasks, eliminating the need to risk human life
in hazardous working environments.
D Modern ROVs are also equipped with autonomous
abilities and artificial intelligence (AI) to perform
autonomous tasks and further reduce human
intervention. AI algorithms aid the ROV in avoiding
obstructions, planning its path of motion, and enabling
autonomous inspection processes. This reduces the
workload of an operator and increases the efficiency of
a mission. The complexity of operations can be
increased in this regard.
These challenges and advancements in the operation,
testing, and design of ROVs have made them efficient tools
for multiple industries, and progress in technologies
continues to enhance the versatility of ROVs in
underwater operations.
ROVs: Enablers of Cost Efficiency and Risk
Mitigation
ROVs have emerged as a facilitator of cost efficiency and
risk mitigation in a variety of industries. Some ways that
ROVs promote cost efficiency and risk mitigation are:
D The offshore oil and gas industry, renewable energy,
and underwater infrastructure industries use ROVs in
multiple applications. They can carry out visual
inspections, data collection, and conduct non-
destructive tests while eliminating the need for human
interference and risk to human life. Inspection costs are
hence lowered, and hazardous working conditions can
be avoided.
D Unlike human beings, ROVs can operate without the
limitations that are caused by human physiology and
they do not need to take breaks or get fatigued. This
not only improves productivity but also the efficiency
of the operations.
D Accessibility is a major benefit provided using ROVs.
They can access challenging environments enabling
inspections, testing, repair, etc in such conditions.
D ROVs can be equipped with data collection equipment
like sensors, cameras, etc. This data can be crucial for
risk assessment, optimization, and decision-making.
They also transmit data back to the control center for
remote access to data and processes.
D Rescue and salvage missions, like that of the implosion
of the Titan submersible, are often assisted by ROVs to
map the ocean and help locate debris or other objects.
ROVs were also used in prior expeditions to the original
Titanic wreckage, aiding in the study of the remains of
the ship. Their mobility and ability to potentially
manipulate and recover objects provide better access
to search sites and provide crucial data to operators.
The cost efficiency and abilities of ROVs make them
indispensable for multiple applications and their risk
mitigation capabilities have saved millions of dollars and
multiple human lives.
Conclusion
The world of Remotely Operated Vehicles is captivating,
and its capabilities evoke amazement at the potential for
noteworthy discoveries. ROVs are a testament to the
capabilities of modern technology that transcend human
limitations, allowing us to venture into unfamiliar
territories and unravel the mysteries that lie beneath. It is
evidence of human resourcefulness and our unending
pursuit of knowledge.
Mankind will continue to be fascinated by the wealth of
data that ROVs bring forth as they propel us onward in our
relentless pursuit of knowledge and comprehension.

Uncovering the
Untold Narrative
of Titan
Submersible
Submersibles have played a vital role in deep-sea
exploration. Their use has enabled us to make
extraordinary revelations, such as that of the Titanic
wreckage. Having met its unfortunate end in 1912, the
remains of the legendary ship had remained undiscovered
for around 70 years before submersibles made it possible
for mankind to venture deeper into the abyss of the ocean.
Representation of the Cyclops 1, produced by OceanGate (Image credit:
https://washington.edu/news/2013/10/08/uw-local-company-building-
innovative-deep-sea-manned-submarine/)
Submersibles have created opportunities to unravel the
mysteries of the deep, dark, and cold oceans. The Titanic
wreckage has been frequented by researchers, scientists,
and enthusiasts since the successful journey of DSV Alvin.
DSV stands for deep submergence vehicle, and its
expeditions to the wreckage site provided crucial data and
documentation of the condition and wear of the remnants
of the ship on the ocean floor.
OceanGate Inc. is a private organization, specializing in
oceanic exploration and manned submersible technology.
The company owns a fleet of manually operated
submersibles that permit deep-sea exploration and are
often utilized for marine research, environmental studies,
deep-sea or underwater inspections, and the exploration
of historically significant shipwrecks.
OceanGate Inc. recently made headlines in the news for
the unforeseen implosion of its submersible, Titan,
formerly called Cyclops 2, which led to the demise of the
five passengers onboard, including the CEO of the
organization, Stockton Rush.
Overview of the Titan Submarine and its
Purpose
The Titan submersible was a remarkable submersible
developed and engineered by OceanGate Inc. in
conjunction with NASA, Boeing, and the University of
Washington. This was the world’s only carbon-fiber
submersible that could carry five people to depths of 4000
meters (13,123feet). Specifically used in deep-sea
exploration, the Titan played a significant role in the annual
Titanic expeditions for surveying the wreck of the RMS
Titanic.
One of the distinctive attributes of the Titan was its ability
to carry a larger crew, allowing for the participation of
multiple mission specialists, scientists, and content experts
to embark on a rare and memorable deep-ocean diving
experience.
www.onestopndt.com | July 2023|Issue 76 43

The Titan debuted in 2018, displaying cutting-edge
technology and employing advanced materials, such as
carbon fiber, resulting in a lighter weight than other deep-
diving submersibles. This approach to its construction
permitted a more spacious and comfortable interior, that
enhanced the overall diving experience for its passengers.
The Titan submersible was furnished with high-tech
lighting and SONAR navigation systems. It was also
equipped with 4K video and photography gear, mounted
both internally and externally. The interiors were said to
have sufficient space for extra monitoring, inspection, and
data collection equipment. This facilitated direct
observation, inspection, and exploration of the deep
recesses of the sea.
The salient features of the Titan build and design, as
specified by the specification sheet issued by OceanGate
Inc. include the following:
¥ The dimensions of the Titan submersible spanned 22ft
x 9.2ft x 8.3 ft, offering restricted room to the
passengers. The crew would include one pilot and up to
four crew members.
¥ Weighing 9,525 kgs or 21,000 lbs, the Titan could carry
a payload of up to 685 kgs or 1,510 lbs and has a speed
of 3 knots.
¥ The propulsion of the submersible was powered by four
1002 series electric thrusters made by Innerspace
Corporation. This included two vertical and two
horizontal thrusters.
¥ The life support provided by the Titan submersible
could last for 96 hours for a crew of five members.
¥ The navigation technology included the BlueView 2D
SONAR, built by Teledyne Marine, as well as the
Teledyne 6000m RDI phased array Pioneer Doppler
Velocity Log (DVL), with XRT extended tracking and
Ultra-Short Baseline (USBL)internal navigation
systems (INS).
¥ The lighting systems consisted of four LEDSealites
manufactured by DeepSea Power and Light that
provide a total output of 40,000 Lumens.
www.onestopndt.com | July 2023 |Issue 76 44

The Titan was fitted with a 380-mm acrylic viewport,
said to be double that of any competing submersible,
providing unparalleled views to the passengers.
The visual data collection mechanism involved the use
of the Rayfin Subsea 4K camera (produced by SubC
imaging) and three axis-cameras.
The Titan submersible was also equipped with the
ULS-500 PRO, produced by 2G Robotics, which is a laser
scanner that can help provide information for high-
tolerance subsea metrology, damage detection and
assessment, installation repair and maintenance, and as-
built surveying.
(Image credit: https://www.usatoday.com/story/graphics/2023/06/21/titanic-
submarine-missing-titan-submersible/70340478007/)
Despite the numerous technical redundancies in place,
catastrophes can seldom be prevented when faced with
unforeseen environmental and logistical variables that
may have yet to be accounted for. To understand and
solidify measures to prevent incidents such as the
implosion of the Titan submersible, there should be a
chronological evaluation of the events which led to the
subsequent implosion is imperative.
Detailed timeline of the incident, from initial
reports to the implosion
The series of events that led to the catastrophic implosion
are speculated to be as follows:
Mission 1: Scheduled for May 11-19th, 2023, was
unsuccessful due to poor weather conditions.
Mission 2: Scheduled for May 20-28th, 2023, was also
A dive attempt was made on 23rd May 2023 but failed
due to technical issues with the launch platform.
Mission 3: Scheduled for May 29-June 6th, 2023, but to
no success as the test dive had to be aborted due to
computer systems troubles and poor weather
conditions.
Mission 4: Scheduled for June 7-15th, 2023, was
Mission 5: Scheduled for June 16-24th, 2023.
The dive was attempted on 18th June 2023.
8:00 ET- Titan is scheduled to start descent but was
delayed.
12:00- Titan dive began.
13:45- Communication was lost between Titan and
the Polar Prince, the Titan’s support vessel.
Acoustic anomaly is detected by the US Navy
15:00- The Titan was expected to resurface,
however, it failed to appear.
17:40- The Coast Guard was notified of the delay by
the Polar Prince.
By June 19th, search and rescue missions were
operational, and planes and ships from the USA and
Canada were scouting the area for signs of the Titan. It
was announced that the submersible may be left with
approximately 70-96 hours of oxygen.
June 20th- France joined the search efforts by
deploying the Atalante, a deep-sea diving vessel.
The Canadian Lockheed P-3 Orion aircraft detected
sounds over a period.

The sounds were said to have been detected at 30-
minute intervals.
Many international ships, underwater vessels, and
aircraft joined the mission.
June 21st- A unified command of the US Coast Guard,
Canadian Coast Guard, US Navy, and OceanGate set
out to handle the search.
It was announced that the Canadian P-3 aircraft
detected noises underwater and ROVs were being
utilized to scope the area. The data obtained was
sent to the US Navy for analysis.
June 22nd- As per, US Coast Guard estimates, the
oxygen in the submersible was expected to run out.
A debris field containing pieces of the submersible
was found near the Titanic wreckage in the North
Atlantic Ocean.
The debris field indicated the loss of the pressure
chamber and there was evidence of an implosion.
The crew of the missing Titanic submersible was hence
believed to be dead.
Explanation of the implosion of the Titan
submersible
The destruction of the Titan submersible was said to have
been caused by a ‘catastrophic implosion’
. This would entail
destruction under tremendous power and swiftness,
considering the immense water pressure of the ocean
floor.
The wreckage of the Titanic rests approximately 12,400 ft
deep on the seabed of the North Atlantic. While the
atmospheric pressure at sea level is about 14.7 psi, the
water pressure at the Titanic's location reaches an
immense 6,000 psi (equivalent to 400 atmospheres).
It is postulated that the implosion was caused due to a
defect in the hull. In such a scenario, the Titan would have
A thorough analysis of the debris retrieved will be the only
way to confirm the cause of the unfortunate incident,
shining a light on the reason for the failure of the vehicle.
Many questions had been raised before the incident,
regarding the safety of the Titan submersible. The carbon
fiber composite cylinder, consisting of titanium end caps
was a matter of concern to many experts. The external
pressure of the working environment of the Titan was
bound to deteriorate the integrity of the vessel with every
dive.
(Image credit: https://www.scientificamerican.com/article/what-safety-
features-should-subs-titan-be-equipped-with/)
Carbon-fiber composites are stiffer and less elastic than
Titanium, which can adapt to pressure forces by shrinking.
The differences in materials may have caused a loss of
integrity, causing delamination of the composite material.
Delamination may result in the separation of the layers of
reinforcement.
The delamination of the composite may have led to defect
formation, causing an instant failure and subsequent
implosion due to the high environmental pressures. The
newer design and hull material exacerbated the need for
extensive testing.
It was also revealed that the submersible had not followed
certain safety codes and had not undergone certification.
Experts in the industry had issued warnings to OceanGate

about the safety of the vehicle, which was disregarded by
the organization.
How NDT could have prevented the incident
Ocean Gate’s former Director of Marine Operations, David
Lochridge filed an OSHA complaint in 2018, stating that
the testing of the hull was insufficient to determine the
defects and deformities present. He noted that this
inadequate testing could potentially cause a disaster.
Lochridge emphasized the use of Non-destructive testing
methods, calling them critical in ensuring a stable and safe
vehicle for the safety of the crew onboard. Lochridge was
Multiple experts and ex-passengers of the Titan
submersible raised concerns about its safety. Despite
these concerns, OceanGate proceeded to transport
passengers without addressing the importance of
comprehensive non-destructive testing and analysis for a
vital vehicle such as the Titan submersible. Regrettably, the
passengers remained unaware of the company's
negligence in this regard.
By omitting NDT in the manufacturing process of a
submersible, the chances of undetected defects rise,
leading to compromised structural integrity and
substantial risks to the submersible's safety, performance,
and longevity.
NDT methods that are commonly used in the production
and assessment of submersibles include:
Ê Visual Inspection
Ê Ultrasonic T
esting
Ê Magnetic Particle T
esting
Ê Dye Penetrant T
esting
Ê Radiographic T
esting
Ê Eddy Current T
esting
Ê Pressure T
esting
Advanced NDT methods like Phased Array Ultrasonic
T
esting, Pulsed Thermography, Laser Shearography, etc.
may also be employed to detect hidden flaws or material
defects that may negatively impact the submersibles'
integrity.
Implementing responsible engineering practices, such as
thorough and timely inspections, non-destructive testing,
pressure testing of components, functionality and
performance testing, and validation of design
modifications, can enhance the future of deep-sea vehicles
and reduce the likelihood of a similar incident happening
again.
Engineering Lessons Learned
The Titan submersible may have been one of the most
significant engineering failures of 2023, but it taught us
some sombre but vital lessons to pay heed to in the
future:
Ê The implosion of the Titan submersible emphasizes the
need to give precedence to the safety and execution of
reliable risk-management methods. The field of deep-
sea research and engineering is laden with hazards,
hence, stringent safety measures, meticulous and
timely inspection of equipment, and emergency plans
need to be ensured.
Ê Equipment and vehicles used in harsh environments
need to undergo precise engineering design, testing,
and manufacturing. Detailed testing, using destructive
and non-destructive testing methods should be carried
out at various points of the design and manufacturing
process to ensure their reliability in extreme operating
conditions.
Ê Kaizen or continuous improvement should be
implemented, and notes should be taken from failures.
Failure assessment and investigations should be
conducted to gather data from the Titan’s debris to
improve equipment, safety considerations, and
operating procedures for future missions.

Prompt emergency response in the event of such
incidents should be pre-determined. Incidents such as
the Titan implosion highlight the limitations in
technology, communication systems, and accessibility.
Emergency measures should be well planned to curb
losses and potentially avoid disasters of this magnitude.
The implosion of the Titan submersible underscores the
need to improve cooperation between researchers,
engineers, deep-sea industries, and various other
experts. Sharing the lessons learned from failures,
technology, and optimal approaches can lead to
collective growth and consequentially overall progress
in deep-sea exploration.
The fatal implosion of the Titan submersible has raised
important questions about the reliability and future of
deep-sea vehicles. The need for regulations and adherence
to safety codes and design principles such as that of the US
Navy known as SUBSAFE were highlighted.
Conclusion
The fatal implosion of the Titan submersible has raised
important questions about the reliability and future of
deep-sea vehicles. The need for regulations and adherence
to safety codes and design principles such as that of the US
Navy known as SUBSAFE were highlighted.
In the aftermath of the Titan submersible disaster, the
lessons learned will reverberate through time. This
incident will remind us of the significance of safety,
effective information exchange, oversight, and
advancement of technology.
(Image credit: https://www.ndtv.com/world-news/titan-submersible-what-is-a-
catastrophic-implosion-likely-cause-of-titan-subs-destruction-4145349)
Emphasis has been made on the need to avoid bypassing
standards and compromising safety due to the
apprehension of hindering innovation. OceanGate could
have evaded this tragically unfortunate event by paying
heed to the concerns of the multiple experts, engineers,
and employees who raised concerns about the design,
safety, and operation of the Titan submersible.
Armed with this knowledge, we can ensure that future
calamities of this nature are averted. This wisdom secures
the safety of those who traverse the oceans and seas.
The past must be honoured by paving the way for a future
where every voyage comes with a promise of the welfare
and security of all.

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NDT Trends: Uncovering the Untold Narrative of Titan Submersible

NDT Trends: Uncovering the Untold Narrative of Titan Submersible

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