Applying computational reliability engineering to the conservation of maritime heritage structures
Submitting InstitutionUniversity of Greenwich
Unit of AssessmentAeronautical, Mechanical, Chemical and Manufacturing Engineering
Summary Impact TypeCultural
Research Subject Area(s)
Engineering: Civil Engineering
Summary of the impact
The Centre for Numerical Modelling and Process Analysis (CNMPA) was asked
in 2004 to apply its expertise in computational reliability engineering,
usually used in high technology manufacturing, to help save the Cutty Sark
ship and in 2010 to help restore the Medway Queen. This case study details
how our computational expertise had impact and in particular:
- substantially aided the conservation and restoration of the historic
maritime heritage ships;
- developed a decision support tool for post-restoration maintenance of
- demonstrated interdisciplinary collaboration;
- contributed to the local and national heritage tourism industry.
CNMPA uses computational reliability engineering to assess the
performance of complex structures. It predicts how multi-component,
multi-material systems will behave in myriad situations including
variations in temperature, pressure, vibration, humidity, and over time.
In 2004 the Cutty Sark Trust turned to the university for help based on
our expertise in modelling composite structures such as printed circuit
boards [3.4]. The magnificent Victorian tea clipper, moored in Greenwich,
had fallen into such poor repair she was at risk of collapse. The ship
needed to be dismantled and there was only one chance to get it right.
Supported by the trust and the Knowledge Transfer Partnership funding, the
centre applied its expertise to aid the trust in saving this maritime
treasure for the nation.
The team made a digital model of the Cutty Sark which factored in the
materials' aged state and the hull's iron and timber makeup. Existing
techniques such as photogrammetry and data from laser scans were used to
digitise the ship's structure; acoustic and visual data to obtain data on
material loss due to corrosion; and finite element analysis to predict
structural behaviour. The finite element model required development of a
new shell element formulation to accurately capture the composite
structure's behaviour, made of iron and timber planks [3.1]. The main
feature of the above approach is the evaluation of the in-plane and
bending stiffness of the composite hull structure. This approach was
validated against experimental data at the university engineering
laboratory, where a small prototype of the ship's hull was built and
tested. Using this finite element model the team was able to predict
detailed structural behaviour of the ship (eg deformation and stresses)
for all the conservation scenarios being suggested by the trust.
The initial phase of the project was to dismantle the ship in order to
mend and preserve each component. What CNMPA was able to do, by using the
finite element model detailed above, was demonstrate what would happen in
14 different scenarios and give the trust confidence that it was choosing
the safest way to dismantle the ship before a single plank had been
lifted. CNMPA also applied its computational technologies to the ship's
reassembly. We were able to help the trust realise its ambition to raise
the Cutty Sark above ground in order to create a museum space, and allow
the public to walk beneath the magnificent sculptural hull. In theory our
research outputs suggested this would be possible but could it be
delivered in practice? Our initial work investigated the option of using a
sling to support the ship, but our results showed that this would impose
unacceptably high significant stresses on the iron frame [3.5]. Further
work produced a better pattern of supports which brought the stresses in
the hull down to a very low level. The trust's architect and structural
engineer used this information to develop the support structure actually
used. Our finite element model investigated the structural integrity of
the ship and this new support structure as well as the structural
behaviour of the dry dock.
Over 40 internal reports (http://bit.ly/H4JlGh)
were generated from our research efforts which helped guide the engineers
throughout the conservation programme (2006-2011). Unfortunately in 2007
the ship suffered a major fire which delayed the conservation project by
14 months. We continued to work with the chief engineer and the trust
throughout 2008-2009 to assess the structural behaviour of the fire
damaged ship, particularly in its planned new support structure.
The team has also developed a novel decision support tool to help
maintain the vessel, using Bayesian belief networks with data
from a physics model of corrosion, and statistical analysis of sensor data
for diagnostics and prognostics of the corroding iron structure [3.3].
Working in collaboration with the University of Portsmouth, it created
sensors that gather data on corrosion rates, and combined that with
environmental data to demonstrate the use of Bayesian belief networks as
part of a prognostics and health management system.
In 2011 CNPMA was approached by Medway Queen Preservation Society to use
the experience it gained on modelling the structural behaviour of the
Cutty Sark to help restore the Medway Queen (the Heroine of Dunkirk) to
its original 1924 design. A novel approach, never used before in such
detail to model the restoration of a riveted hull historic ship, used a
finite element model for assessing the strength of the rivets and hull
plates against a set of defined safety factors [3.2, 3.6]. Our assessment
on rivet strength for different sea and passenger loading conditions was
validated using tensile tests on samples at the university.
Professor Chris Bailey - Director of the Computational Mechanics and
Reliability Group within CNMPA and project manager; Dr Stoyan Stoyanov; Dr
Yasmine Rosunally - PhD student, now lecturer at University of West
London, Dr Pushpa Rajaguru, and Professor Peter Mason - Chief Engineer,
Cutty Sark Trust (2004-2009), Visiting Professor, University of
References to the research
(REF1 submitted staff in bold,**REF2 submitted output)
**3.1 Stoyanov, S., Mason, P., & Bailey, C. (2010). Smeared
shell modelling approach for structural analysis of heritage composite
structures - An application to the Cutty Sark conservation. Computers
& Structures, 88(11-12), 649-663.
3.3** Rosunally, Y. Z., Stoyanov, S., Bailey, C., Mason, P.,
Campbell, S., Monger, G., & Campbell, S. (2011). Fusion Approach for
Prognostics Framework of Heritage Structure. Reliability, IEEE
Transactions on, 60(1), 3-13.
3.4 Bailey, C., Lu, H., & Wheeler, D. (2002). Computational modeling
techniques for reliability of electronic components on printed circuit
boards. Applied numerical mathematics, 40(1-2), 101-117.
3.5 Finite Element Predictions for Sling Support for Cutty Sark (2006),
internal project report to Cutty Sark Trust. Report available from (http://bit.ly/H4JlGh)
3.6 Structural Assessment of the Hull of the Paddle Steamer "Medway
Queen" Final Report (2013)
Further evidence of the quality of the research and the transfer of the
knowledge generated in this case study is demonstrated by CNMPA being
awarded Times Higher Education Award for Outstanding Research Team (2009)
and Best Knowledge Transfer Partnership (KTP) Project for London (2008).
The Royal Academy of Engineering also acknowledged the collaboration
between the CNMPA and a local organisation as an example of best practice
in Knowledge Transfer in a consultation document to government.
3a C. Bailey. Cutty Sark KTP Project (Programme no: 000232)
2004-2008, continuation through funding from Cutty Sark into 2010. Awarded
to University of Greenwich, Total funding £150,000.
3b C. Bailey. Structural Assessment of the Hull of the Paddle Steamer
"Medway Queen". KTP Programme No. 1000672) Awarded to the University
of Greenwich, Total funding £51,000.
Details of the impact
The direct beneficiaries of the research detailed in section 2 are the
Cutty Sark Trust and the Medway Queen Preservation Society. The nation has
also benefited from our work, which has helped ensure the people can
continue to enjoy these ships, both of which demonstrate our rich maritime
1) Economic impact:
The results and recommendations arising from CNMPA's research work,
detailed in the reports made available to the trust, were implemented
throughout 2008-2011. Our work in 2006 led to a change in direction of how
the ship would be supported. This saved an estimated £500,000 (the cost if
the original option had progressed further) in particular during the
period from 2008 onwards, when detailed planning for lifting and
supporting the ship was put into practice. Our research helped minimise
the risk associated with both disassembly (2006-2007) and reassembly
(2008-2011) of the ship. It also reduced the time in planning the
procedures for disassembly and reassembly.
The overall cost of saving the Cutty Sark for the nation was £50M of
which the Heritage Lottery awarded £25m. Scientific underpinning provided
by the university was instrumental in securing Lottery funding, and
structural health monitoring work by the university was a condition of the
award. An aim was to minimise the amount of new conservation work required
for at least 50 years: we developed a decision support tool for
post-restoration maintenance of the vessel, ensuring that potential future
losses due to structural problems with the ship have been mitigated. Our
contribution has also secured local jobs for 20 people who now work on the
Cutty Sark. This international icon is helping to boost tourism which
plays such an important role in the UK economy, adding £12Bn per year to
GDP and supporting over 195,000 jobs.
Ian Diamond, Chair of Research Councils UK, following the team being
awarded the Times Higher Education Outstanding Research Team of the year
(2009), said of the university's contribution: "A rare combination of
outstanding research and real impact in an area not normally noted for
engineering. The application to cultural heritage will have an enormous
impact on the UK's long term economy." (http://bit.ly/15UsbEg)
The work on the Cutty Sark has exciting implications as our research is
generic, and could be used to conserve and maintain other heritage
structures. The trust has provided an introduction to a national network
of maritime conservation projects, leading to new application in the £5M
restoration of the Medway Queen, a survivor of the Dunkirk evacuation.
This was a unique ship - fast and light for her day. She was not built to
the design rules of the day and there are no modern rules for constructing
riveted ships - hence the need for a computational analysis. Our work
ensured the contractors' riveting process was safe, and able to withstand
the stresses the plating in the ship's hull imposed on the rivets. We also
identified safe operating conditions in terms of sea conditions and
passenger loading, and the response of the ship's hull to the placement of
heavy critical machinery. This helped the restoration programme
consultant, a naval architect, ensure the riveted ship would be
structurally sound. The Medway Queen Museum is now open in Gillingham,
providing training in maritime conservation skills and employing 24
2) Impact on culture and society:
Today the masts of the Cutty Sark stand tall once again over Greenwich.
The Queen reopened the much loved icon in April 2012 and by February 2013
over 320,000 people had visited, half from overseas. The aesthetic
pleasure of seeing the ship in that setting and the cultural identity it
gives are priceless. No other group has applied this kind of engineering -
sophisticated computational and numerical models which are based on
detailed physical analysis of failure mechanisms - to the conservation of
heritage artefacts. The project has become a popular case study for
school, undergraduate and postgraduate students, for instance through
annual Royal Institution master classes and IEEE events. Wide media
coverage, and prizes awarded to the group, attest to the reputation of the
project regionally and nationally. These include the Times Higher
Education Award for Outstanding Research Team (2009) and Best
Knowledge Transfer Partnership (KTP) Project for London (2008).
The London Development Agency, following the Knowledge Transfer Awards
2008, said: "The university's experts are using sophisticated computer
models to work out how to dismantle and reassemble the fire-damaged
Cutty Sark. They are now using their knowledge to understand how the
Cutty Sark's structure will age over the next 100 years. The university
is developing the technology to be used on other ships, protecting
maritime heritage across the globe." (http://bit.ly/17XqIKh)
The Medway Queen belongs to the national core collection of historic
vessels. The aim was for the paddle steamer to gain license to sail once
again, ie to meet latest maritime standards (Maritime Coastal Agency) yet
be rebuilt using the original 1924 design of a fully riveted structure (http://bit.ly/16kKoNU). Our results
ensured that safety requirements were met and the ship sailed from
Bristol, where she was rebuilt, home to Gillingham. In fact the amount of
detail we provided goes beyond what is usually required for MCA
certification and could possibly inform future MCA standards for heritage
ships. The Medway Queen Preservation Society aims to exhibit the vessel at
the 75th Dunkirk Anniversary in 2015, as well exhibiting at
ports around north-west Europe.
Sources to corroborate the impact
1) CEO, Cutty Sark Trust, Beneficiary, can provide a statement on the
economic and cultural impact our work has had in helping to save the Cutty
2) Member of Parliament for Greenwich, Beneficiary, can provided a
factual statement supporting the impact our work has had on the London
Borough of Greenwich through university collaboration with small
organisation such as the Cutty Sark Trust.
3) Chief Engineer Cutty Sark Trust (2004-2009), User, can provide s a
statement supporting the impact that our work had details of how our work
helped inform his engineering decisions and those of the contractors
working on the project.
4) Naval Architect & Consultant to the Medway Queen Preservation
Society, User, can provide statement to support the impact our work had on
the structural assessment of the Medway Queen for different sea and
passenger loading conditions.
5) Project Manager, Medway Queen Restoration Project, beneficiary, can
provide a statement to support the impact of our work on the Medway Queen.
6) BBC News: http://bbc.in/17CcYW1,
demonstrating outreach with the media and informing the public of our
7) Knowledge Transfer Partnership Case Study http://bit.ly/H8F6de,
details the results from our work and provides a case study for future KTP
projects funded by the TSB.
8) Time Higher Education article (http://bit.ly/GWvQrO)
Provides details on our project with the Cutty Sark being awarded best KTP
partnership for London (2008).