Marine Energy Component
Analysis - Case Study
July 2016
ORE Catapult
PN78-SRT-001-Case Study
Document History
Field
Detail
Report Title
Marine Energy Component Analysis
Report Sub-Title
Case Study
Client
ORE Catapult
Status
Rev 0
Project Reference
PN78
Document Reference
PN78-SRT-001
Author Revision Status
Revision Date
Prepared by
Checked by
Draft 1
07/04/16
CL
EB
Draft for client
review
Draft 2
24/04/16
CL
EB
Incorporated client
feedback
Draft 3
20/6/16
CL
EB
Final comments
Marine Energy Component Analysis Case Study
Issue: Rev 0
Approved by
Revision History
2
ORE Catapult
PN78-SRT-001-Case Study
ORE Catapult Revision Status
Revision Date
Reviewed by
Rev 0
Gordon
Stewart
12/7/26
Checked by
Vicky Coy
Approved by
Revision History
Chris Hill
ORE Catapult
review and
acceptance
Disclaimer: The information contained in this report is for general information and is provided by
EMEC. Whilst we endeavour to keep the information up to date and correct, neither ORE
Catapult nor EMEC make any representations or warranties of any kind, express, or implied
about the completeness, accuracy or reliability of the information and related graphics. Any
reliance you place on this information is at your own risk and in no event shall ORE Catapult or
EMEC be held liable for any loss, damage including without limitation indirect or consequential
damage or any loss or damage whatsoever arising from reliance on same.
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Contents
1
Background............................................................................................................. 5
2
Scope of Work ........................................................................................................ 5
3
Analysis Results ..................................................................................................... 8
4
Conclusions and Recommendations .................................................................. 15
5
References ............................................................................................................ 17
Appendix 1
AFRC Proposed Taxonomy Structure ............................................... 19
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List of Tables
Table 1 Commonly reported component failures by failure mode (AFRC, 2015; EMEC,
2015)............................................................................................................................... 6
Table 2 Identified components for undergoing analysis .................................................. 7
Table 3 Bolt class 12.9 steel analysis results.................................................................. 8
Table 4 Bolt analysis results ........................................................................................... 9
Table 5 Tubular composite bearing analysis results ..................................................... 10
Table 6 Fibre optic communications cable analysis results .......................................... 11
Table 7 Pod sensor cable analysis results .................................................................... 12
Table 8 Marine shackle analysis results ....................................................................... 13
Table 9 Bolt analysis results ......................................................................................... 14
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1 Background
The Offshore Renewable Energy Catapult (ORE Catapult) and The European Marine Energy
Centre (EMEC), are working together, and pooling their first-hand testing experience to tackle a
key technology challenge facing the marine energy industry; component failures and their
impact on device reliability and survivability.
Due to the difficulties in access inherent in wave and tidal energy, component failures contribute
to high operational and maintenance costs within the industry and must be reduced for the wave
and tidal energy sector to improve reliability and survivability (Thies et al., 2015; Weller et al.,
2015). Using off-the-shelf components tends to be the most cost efficient option for the wave
and tidal energy industry in the short term, as bespoke design and manufacture is costly,
provided that these components can cope with the challenges associated with the highly
energetic marine environment. However, in reality, these components have often been
designed for use in quite different environments without the loads and conditions faced in high
energy highly oxygenated sea states.
In 2013, EMEC assessed the demand for an analytical testing service, and looked into the
expertise available for component investigation, undertaking two initial case studies with the
High Value Manufacturing Catapult. Both these case studies were successful, and EMEC
received a formal request from developers to extend this activity over a longer trial period, with
a view to developing a wider programme looking at technical challenges relating to component
survivability.
To address this request it was agreed that a dataset of component failures and analysis results
were required to be developed. To build a dataset which can be used to address this challenge
a pilot test programme in association with the Advance Forming Research Centre (AFRC) and
Brunel University ETC Investigations was setup to undertake analysis of a variety of component
parts to identify the failure mode.
2 Scope of Work
An online survey was conducted with industry at the start of the project to provide details of the
components that they wished to see included in the pilot analysis. Further to this, a knowledge
exchange workshop was held to bring together developers, component manufacturers and
technical experts to explore the issues encountered when using the various components and
materials. The workshop provided a vehicle to share realised experiences relating to failure
issues occurring in components during real-sea testing (EMEC, 2015; ARFC, 2015). The
following table summarises the common component failure modes experienced by marine
renewable energy developers during real-sea testing. See Appendix 1 for the taxonomy
structure proposed by the AFRC.
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Failure
Mode
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Commonly Reported Component Failures



Design





Fabrication
and
assembly



Manufacture





Material





Unexpected
service
conditions






Design failures due to manufacture input during design stage.
Direct current pump for high pressure use: designed to be operated for only 5 minutes
per 60 minutes of device operation. Specified component not able to function to level
required, therefor limiting what electricity could be produced when device in operation.
Bolts: requiring higher specification for actual use in operation (also Unexpected Service
Conditions).
Bearing component failure resulting from understanding of pre-conceived application
and service environment, rather than on verified data.
Hydraulic pump seals wearing faster than expected, resulted in a burnt out cylinder
pump.
Thermal cycling of components, designed for inappropriate service conditions, e.g.
designed under air pressure, not sea-pressure (also Unexpected Service Conditions).
Anode failure (incorrect choice of material during design stage).
Couplings between generator & motor, passed workshop testing programme but
following assembly for use, discovered it was not robust enough for operational use.
Kinked cables, as a result of poor handling by installation vessel during laying
(assembly).
Split pipe protector not staying in place due to method of fabrication or how it was
assembled on to pipe components (also Unexpected Service Conditions issues).
Prototype versions of products, where the flange was manufactured with seals not
properly in place.
Incorrectly welded component made assembly difficult.
Poorly welded components, meant that components could not be used and had to be
scrapped.
Kevlar tether broke during testing.
Shackles – bolt assembly not manufactured to same specification as other parts of
component, resulting in failure due to corrosion.
Time pressure to move to commercial operations, resulted in inappropriate material
selection being made.
Material specification for bolts (part of brake calliper set-up) was insufficient to withstand
operational use, resulting in the bolts shearing.
Unexpected wear on coatings of components, resulting in failure to withstand
environmental conditions.
High G failures in bearings.
Pitting corrosion of surface of components.
Low voltage electrical connections corroded resulting in shortened life expectancy
(around 3 months).
Mooring components - vibrations causing wear and abrasion.
Accelerated corrosion in shallow water from high O2 concentration
Break in fibre optic cable
Hydraulic valve failures.
Unexpected contamination of 6” check valves leading to failure in service.
Failure of electrical components (poor power quality, burn-out).
Table 1 Commonly reported component failures by failure mode (AFRC, 2015; EMEC, 2015)
The second phase of the project was to investigate a number of the identified components, to
establish the appropriate analytical processes, and develop relationships with relevant analytical
laboratories (ARFC and Brunel University) to take the investigation forward. The project
encompassed components from a range of devices at different Technology Readiness Levels
(TRLs). Five components were identified as the most appropriate to undergo analysis are
outlined in Table 2.
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It should be noted that EMEC had previously conducted investigations into a marine shackle
and bolt which failed during real sea testing. Information regarding these components is also
supplied in Table 2.
Component
Type
Brake caliper bolt
Class 12.9
steel
Use
Testing Period
Used in brake caliper assembly
within offshore operating
No sea testing carried out
equipment for tidal energy device
Not specified
Bolt (assumed
but assumed
Not specified but assumed use in
brake caliper)
class 12.9
brake caliper
No sea testing carried out
steel
Tubular
Bearing
composite
bearing
Fibre optic cable
Fitted to main body of tidal energy
device
Fibre optic
Part of the fibre optic
core of subsea
communication system for tidal
cable
energy device
2 months’ sea testing at EMEC
8 months’ sea testing at EMEC
Triple steel
wire armoured
Sensor cable
outer with a
Power and fibre optic
core
communications cable for
comprising 4 x
integrated environmental
4mm2 copper
monitoring platform installed at
conductors
EMEC tidal site
Approximately 3 years’ sea testing
at EMEC
and 8 fibres
Shackle
Bolts
5kg ‘S-5’ tool
Not specified but assumed use on
steel shackle
wave energy device
Steel bolt M16
Attachment bolts used on wave
grade 8.8
energy device
2-3 weeks’ sea testing at EMEC
2-3 weeks’ sea testing at EMEC
Table 2 Identified components for undergoing analysis
For the purpose of the component analysis project, the analysis included investigation into
material selection and metallurgy. Manufacturing methods were also examined and
opportunities for conducting component evaluation were identified. In addition, EMEC
conducted initial case studies to assess the demand for this investigative activity, together with
the availability of expertise for component investigation.
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Analysis Results
The following tables summarise the analysis methodologies, findings and conclusions of the
component testing conducted by AFRC and Brunel University:
Failed component: Brake
caliper bolt (Class 12.9 steel
grade)
Fault: Bolt sheared 24 hours after torques
Failure analysis method:
 Removal of corrosion products from bolt surface

Scanning electron microscopy (SEM) to produce SEM fractographs

ASTM E8 standard tensile specimens machined from new bolts; tensile tests conducted at varying
temperatures
Nature of failure:
 Evidence of intergranular cracking

Base tensile strength of material consistent with class 12.9 steel; no deleterious effects caused by reduced
temperature
Findings:
 Fractured bolt revealed clear evidence of intergranular fracture, suggesting a possible influence of corrosion on
the final failure.

Presence of dimpling features indicate a ductile failure propagating through the non-corroded sections of the
bolt.

Presence of sulphide inclusions may have aided the crack propagation.

No effect of sub-zero temperature exposure on the strength of class 12.9 grade material.
Conclusions:
 Due to speed of failure it is unlikely that fatigue would be the cause of the failure.

Combination of factors likely to be cause. Intergranular failure, linked to pre-exiting corrosion attack of both
material, which may have been triggered by local stress raising effects caused by the threads on the bolt.
Failure mode: Material
It is recommended that the existing bolt material should have protective corrosion resistant coating. A more
corrosion-resistant grade can be selected for the bolt material. Increasing the safety factor through increasing bolt
diameter may also considered.
Table 3 Bolt class 12.9 steel analysis results
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Failed component: Bolt (steel)
Fault: Surface oxidation throughout screw and
fracture on head
Failure analysis method:
 Imaging as received using a Zeiss Supra FEG-SEM

Chemical analysis
Nature of failure:
 Bolt shows surface oxidation throughout the screw and fracture on the head.
Findings:
 Indication of a non-homogenous surface with scratches and pits.

Chemical evaluation of the surface indicated the presence of areas where the zinc is oxidised, the
galvanisation is lost, and iron is exposed.

Layer of homogeneity on left- hand side of fracture and strong oxidation in area of fracture; strong enrichment
of phosphorus corresponding to the fracture.

Stronger chemical inhomogeneity visible further along fracture; parallel to fractures are also lines of enrichment
of oxygen creating a series of layers of weakness along fracture itself
Conclusions:
 Location and direction of crack unusual and not due to tensile stress (would produce transverse crack);
possible cause was overtightening of bolt using Allen key. May be pre-existing crack introduced during
manufacture; may be forged or result of a defect in material (e.g. rolling inclusion in original metal blank)

Also has typical light surface damage and contamination from handling. Fracture may be following a grain
boundary; not expected unless bolt had been heat treated, causing a weakness along a prior-austenite grain
boundary.
Failure Mode: Fabrication & Assembly/Material
Table 4 Bolt analysis results
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Failed component: Tubular
Composite Bearing
Fault: Showing signs of higher loading than
predicted. Worn areas present.
Failure analysis method:
 Surface roughness measurements of worn and unworn areas

Silicon putty applied to worn and unworn areas of casing to create replicas for surface roughness
measurements (procedure carried out due to size of bearing casing)

Used a non-contact optical measurement system – Alicona InfiniteFocus
Nature of failure:
 Unworn area characterised by matrix structure (inherent in composite material) (average roughness Ra = 512μm)

Worn areas consisted of smooth zones (as a result of heavily deteriorated zones) (maximum roughness Ra =
150μm)
Findings:
 Surface roughness (Ra) of the worn area revealed a uniformly distributed woven cloth type texture with Ra
values in the range of 5-12μm (upper zones) and 6-8μm (central zones). The Rz values were in the range of
35-60μm.

The surface roughness (Ra) for the worn area was twice that for the unworn area with Rz values 3 times higher
at to 150μm amplitude.

The worn areas are surrounded by regions with a finer surface roughness (Ra ~2μm , Rz ~μm), which is likely
to be due to rubbing of the bearing against the casing resulting inn smoothing of the typical woven cloth type
initial surface texture observed in the unworn areas.
Conclusions:
 Wear could be due to movement perpendicular to axis (due to uneven load on blade); possibility of uneven
flow, swirl or contraflow above and below an axis of rotation. Load on blades in top and bottom positions can
vary, leading to excessive wear of bearing. Forces generated through turbulence.

Presence of contamination between bearing and casing, if seal failure had occurred
Failure mode: Material/Unexpected Service Conditions
Table 5 Tubular composite bearing analysis results
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Failed component: Fibre optic
cable
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Fault: Fibre optic cable detached
from nacelle’s cable connector
Failure analysis method:
 SEM analysis

Mechanical tests
Nature of failure:
 Fracture surface features visible from SEM images; dent on fractured surface

Repeatable results gained from cable with insulation and stainless steel core; no anomalies in terms of loss of
tensile strength
Findings:
 Dent like features visible on the SEM images of both the detached end and the nacelle end of the cable,
indicating that the strength of the cable may have been compromised due to possible external damage.

Fracture surfaces exhibit features which for the most part are consistent with fast fracture. There is a
suggestion that this may have been initiated with localized fatigue linked to a surface stress raiser.

The mechanical tests were repeatable and did not show any anomalies indicating any loss of strength in the
stainless steel core. The maximum tensile strength of the stainless steel core of around 1250MPa is consistent
with it being cold drawn.
Conclusions:
 Failure due to external damage to cable which might have progressed from outer insulation

Combination of external damage along with constant turbulent flow of sea water creating cyclic loading
conditions may have resulted in fatigue failure of fibre optic cable
Failure mode: Unexpected Service Conditions
Table 6 Fibre optic communications cable analysis results
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Failed component: Sensor
cable
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Fault: Breakage of cable’s
armour
Failure analysis method:
 Fourier Transform Infrared (FTIR) spectroscopy to evaluate polymer degradation, such as oxidation/ reduction

SEM used to evaluate fractures and pitting; analysed to evaluate indicative factors of erosion, corrosion and
fractures (morphology and composition)

X-ray powder diffraction (XRD) used to investigate changes in texture/ structure; rapid analytical technique
primarily used for phase identification of a crystalline material
Nature of failure:
 Severe trauma with consequent breakage of cable’s armour

Failure of the electric flow had happened at the connector position
Findings:
 Subtle changes visible in section of connector sleeve in close proximity to connector
Conclusions:
 Failure occurred at connector position; likely cause is degradation of polymer on connector surface
Failure mode: Material
Table 7 Pod sensor cable analysis results
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Failed component: 5kg marine
shackle
Fault: Failed at the bottom of both legs of the U,
after 2-3 weeks at EMEC test site.
Failure analysis method:
 Fracture analysis and objective analysis of microstructure and mechanical properties on the component and
determine the cause of the failure.

Assessment of the suitability of the material and component design for operation with the operational
environmental which it has been used.

Characterisation of the fracture surfaces. Study the sample under SEM and Optical Microscopy to establish the
characteristics of the fracture and identify the failure mechanism

Characterisation mechanical behaviour of component and material. Determined mechanical properties (e.g.
yield, strength) for the component and prepare report detailing findings

Characterisation of material microstructure evolution in the heat affected zone to understand the link between
the failure mechanism and local microstructure. Studied the samples under the SEM and Optical Microscopy to
established the microstructure changes in the heat affected zone. Undertook comparison between the
characterisations to link the failure mechanism into the materials microstructure.
Nature of failure:
 Failed shackle with evidence of corrosion and radial cracking lines.
Findings:
 Initial analysis of the fracture surfaces indicated characteristic fatigue failure occurring at the two identical
failure points. It was also identified that there were few weld marks present on the component which may have
created the residual stress in excess of the operational stresses in the heat affected zones in the vicinity of the
welds.

Identified stress-corrosion cracking through the weld; microstructural analysis showed weakness through the
weld

Significant corrosion was situated in the welding area and the central wear ring.

Nucleation of the crack happened in the contact area of the welding. Some local reheating may have happened
during the process of welding, and formation of chloride ions and sodium hydroxides may cause SCC failure.

SEM analysis identified signs of tensile overloadings.

Structural changes were observed in the areas of the component with close proximity to the weld. Likely to be
due to the diffusion process which occurs during the welding cycle, where the volume fraction of ferrite
increases and the material becomes softer.

Welding zone present on the component is not uniform. Some voids in the contact are that they may cause non
uniform stress distribution during loading of the shackle.
Conclusions:
 Stress-corrosion cracking was the reason of the failure due to the combined effects of tensile stress and
corrosive environment.

Corrosion reaction identified as one of the reasons for failure.

Strength of component altered during welding, resulting in fracture in shackle when undergoing stress.

Analysis confirmed the fractography results indicating the crack propagation began from the inner weld area to
the centre of the shackle.
Failure mode: Material / Unexpected Service Conditions
Table 8 Marine shackle analysis results
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Failed component:
Steel bolt M16
used in attachment
Fault: Fractured in the thread area of the bolt.
Failure investigation method:
 Fractography analysis to characterise the fracture surfaces was undertaken using Quanta 250 FEG SEAM and
Alicona Infinite Focus G4. Specimens were sonicated for approximately 30 minutes in acetone, dried by hot air
stream and kept in a desiccator when not under analysis.

Characterisation of the mechanical behaviour of component and material.

Investigation into fracture surface, microstructure and mechanical properties
Nature of failure:
 Fracture in bolt and degradation of thread surface.

Located at the junction of several parts within the wave energy device creating an additional load on the bolt.

The thread is a stress concentrator, which can cause nucleation of fatigue crack and subsequent fracture.
Findings:
 Fatigue cracks from the outer edge of the surface and then propagate to the centre of the bolt in many different
directions. Multi-level cracks were also observed.

Mechanical behaviour analysis was conducted in accordance with ASTM E8 /E8M – 13a Standard Test
Methods for Tension Testing of Metallic Materials. The tension tests provide information on the strength and
ductility of materials under uniaxial stresses. These test methods cover the tension testing of metallic materials
in any form.

Fractographic analysis of the destroyed areas demonstrate a brittle-ductile fracture. The outer area (which is
presumably hardened with zinc plating) corresponds to brittle fracture. Behind the ductile area of the bolt where
was some quasi-cleavage facets. These cleavage planes can be evidence of the brittle fractures at the same
time it is characterised by the fact that along with the signs of brittle fracture, there are signs of plastic
deformation.

Fractography analysis confirmed the presence of fatigue and mores specifically, brittle-ductile failure within the
components analysis.
Conclusions:
 Cause of failure was uneven stress on bolt

Fracture of the bolts occurs is the result of fatigue crack propagation. Internal turns of a thread act as stress
concentrator that in turn becomes a source of fatigue crack propagation by the impact of cyclic loadings

Inappropriate material grade for component use

The current fatigue properties (endurance life) of the component do not appear sufficient to ensure long-term
operation of bolted connections
Failure mode: Material
Based on the analysis undertaken, AFRC has made the following recommendations: The grade 8.8 bolt could be
substituted for a medium carbon steel material higher strength bolt such as grade 9.8; the manufacturing and
assembly records should be reviewed; heat treatment should be checked to achieve the nominal hardness for the
8.8 grade; the shape of the thread should be modified to square or even round and stress modelling and
simulation can be applied in order to predict stress distribution process in terms of material properties and thread
shape.
Table 9 Bolt analysis results
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4 Conclusions and Recommendations
Initial feedback from the developers is that they have benefitted from the findings in the AFRC
and Brunel ETC analytical reports.
The results from some of the tests suggest that the material grade of some components may be
unsuitable for the induced stresses. Therefore, a better understanding of the required material
grades is essential when choosing components during the manufacturing phase. For example,
the AFRC has recommended that the steel M16 bolt used for attachment purposes be
substituted for a medium carbon steel material high strength bolt (grade 9.8). Similarly, the
AFRC has recommended that the brake calliper bolt (steel grade 12.9) should have protective
corrosion resistant coating or that a more corrosion-resistant grade is selected. In addition, the
design of specific components may need to be adjusted to strengthen particular areas that are
susceptible to high stresses and potential fractures. During component testing on the marine
shackle, it was noted that the likely cause of failure was the welding. Some problems that can
be found in welds include; cracks, porosity, poor workmanship for example. This highlights the
need for review of the weld inspection reports to ensure welding standards (AWS were adhered
to including the Working Load Limit is not compromised by alterations or additions to a
component. Although the shackle functionality was not evidenced, DNV provides guidelines on
shackle allowable safe working loads. (DNV-GL, 2014)
Other causes of component failure have been attributed to constant turbulent marine flow
creating cyclic loading conditions or unexpected uneven stress across the components’
surfaces. Stress modelling can be conducted in order to predict stress and wear distribution
within material properties. This has been highlighted as important for both bolt and bearing
components that have undergone testing during this project, with particular relevance to the
thread design in bolts. Further research into the effect of uneven stress on bolt threads, and
potential modifications, would potentially be beneficial. It is recognized that adopting an
approach for real sea measurement of operational conditions and real time load data would
improve understanding of possible failure modes or design weaknesses.
In general, if a component is known to be at high risk of failing, as identified in a FRACAS report
(Failure, Reporting, Analysis, and Corrective Action System), reducing the number of those
components in the deployment is one corrective action to reduce the likelihood of failure.
However, there is a lack of failure reporting and component testing results to establish failure
rate estimates in the wave and tidal industry. (Philipp R. Thies, 2011) To successfully move to
commercial scale deployments, the sector will need marine components that are fully tested
and proven, because the cost of field failures is high, especially if the initial component failure
leads to cascading failures.
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The conclusions above are supported by the limited information given on the use and structure
of the components. More component operational background information is needed, for
example;
 Material specification/certificates (and manufacturing and testing records if the details are not
contained within the certificates)
 Component drawings
 Usage
 Functionality (primary use)
 Loading/Fixture points
Further to these listed above, it is essential that the environmental conditions in which
components have been in use is recorded in sufficient detail as to provide the necessary
information when undergoing analysis. Details such as depth, temperature and salinity tend to
be required.
Further and more detailed analyses can be undertaken using the above information if available.
A recommendation is to provide industry with a guide to handling and tagging components prior
to submission for analysis in order to provide the environmental, operating conditions at the time
of the failure.
It is anticipated that the outcome of these analyses will not only influence the future design and
procurement strategies for those developers who supplied the components for testing but will
also directly inform the design and manufacturing processes across the industry. This will
support lowering O&M costs and supporting further development within the sector as a whole.
Whilst the analyses conducted to date should help to inform future device or subsystem
development, there is considerable potential to expand this collaborative approach to continual
component testing as part of a preventative maintenance plan.
It is essential that lessons learned from the early-stage deployments are shared with the rest of
the sector. In this context, the industry needs to recognize the value of collecting this
information and having access to a simple platform for sharing it. Suggestions have included a
component failure database identifying the common failure mechanisms of marine renewable
energy components; however, the value of such a database is dependent upon developers and
the supply chain systematically recording the relevant information. A successful example of a
database anonymised for offshore wind farm performance and maintenance data is SPARTA
(System Performance, Availability and Reliability Trend Analysis). (Offshore Renewable Energy
Catapult, n.d.)
To facilitate the uptake of industry, support and process, a guide to best practices for
component collection and handling has been produced and a database of component
information is being compiled. The guide uses information from the AFRC on component
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preservation that has been employed during this pilot component testing project. The database
is being developed and will likely form part of the Wave and Tidal Knowledge Network1. The
database will categorise the failures and uses of the components and will provide an example of
the information that needs to be gathered during the component collection and analysis phases.
In considering the next steps for addressing the issue of component failure in the marine
renewable energy industry, a number of findings and recommendations were identified:
1. A standard taxonomy be developed, potentially based on the AFRC’s proposed taxonomy
structure of common failure modes (see Appendix 1).
2. The need for a systematic approach to the handling and recording of failed components in
the sector.
3. Industry should include costs for component analysis during O&M planning to ensure a
contingency is in place for testing the components that are failing in real sea conditions.
ORE Catapult will develop the component classification and failure taxonomy building on the
work that has already been undertaken on the Marine Energy Supply Chain Gateway
construction and classification. In addition, ORE Catapult will establish the component database
website.
5 References
Advanced Forming Research Centre (ARFC). 2015. Component Analysis Knowledge Exchange
Workshop Report. Publication Number 319. University of Strathclyde.
DNV-GL. 2014. Lifting Operations (VMO Standard - Part 2-5). DNV Rules and Standards.
Available online: https://rules.dnvgl.com/docs/pdf/DNV/codes/docs/2012-01/Os-H102.pdf.
European Marine Energy Centre (EMEC) Ltd. 2015. Component Analysis Project: Knowledge
Exchange Workshop Summary Report. REP527-01-02.
Offshore Renewable Energy Catapult (ORE Catapult) & The Crown Estate. n.d.. System
Performance, Availability and Reliability Trend Analysis (SPARTA). Available online:
https://www.sparta-offshore.com/spartaweb/login.
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Appendix 1
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AFRC Proposed Taxonomy Structure
Failure Causes
Design concept error
Poor specification
Modification
Design
Incorrect assumptions (operating conditions)
Incorrect assumptions (behavior)
Design for manufacture / assembly / repair / maintenance
Selection
Defect or Flaw
Variation within specification
Material
Variation outside of specification
Processing history
Service history
Residual stress
Quality compliance
Method change
Supplier change
Manufacture
Variability
Poor specification
Processing history
Inappropriate method selection
Loading
Temperature
Pressure
Unexpected Service Conditions
Dynamics
Electromagnetic
Corrosive
Abrasive
Wear and tear / lack of maintenance
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Fatigue
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Failure Causes
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Design concept error
Corrosion
Contamination
Repair vs OEM standards
Maintenance schedule definition
Maintenance schedule adherence
Abrasion
Handling damage
Degradation during storage
Damage / abuse
Use outside of specification
Use for alternative purposes
Vandalism
Standards - compliance
Standards - definition
Cleanliness
Fabrication / assembly
Fastener selection
Design for manufacture / assembly
Modifications / additions
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Contact
ORE Catapult
Inovo
121 George Street
Glasgow, G1 1RD
T +44 (0)333 004 1400
F +44 (0)333 004 1399
ORE Catapult
National Renewable Energy Centre
Offshore House
Albert Street, Blyth
Northumberland, NE24 1LZ
T +44 (0)1670 359 555
F +44 (0)1670 359 666
[email protected]
ore.catapult.org.uk
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