The University of Southampton
University of Southampton Institutional Repository

Reliability Case Notes No. 6. Risk assessment of the Ellsworth probe: development, design and deployment

Record type: Monograph (Project Report)

The Natural Environment Research Council is partly funding the development and deployment of a scientific probe in the Antarctic subglacial Lake Ellsworth. The deployment will take place in 2013.

This report aims to quantify the technical risks of the probe development, design and deployment. A high level representation of the entire probe deployment process is captured in a Markov chain – a form of graphical probabilistic model. The transition from one state, or phase of the deployment, to the next depends on several factors, including: reliability of components and reliability of processes. We use fault trees to quantify the probability of failure of the complex processes that must take place to facilitate the transition from one state to another. The Shelf expert judgment elicitation package was followed to elicit expert judgments for the probability of failure for each failure mode.

The top two technical risks are:
• Failure to clean Jacket of the hot water drill hose: 95% quantile at 0.96.
• Probe electronic failure: 95% quantile at 0.11. Here, the top failure mode is optical connector failure.

The Markov chain was used to estimate the availability of the probe from different phases of the
deployment.
• From on-site probe cleaning: 95% confidence that the probability of success is higher than 0.7.
• From on-site testing: 95% confidence that the probability of success is higher than 0.73.
• From sheave deployment: 95% confidence that the probability of success if higher than 0.83.
• From probe positioning: 95% confidence that the probability of success is higher than 0.90.

Finally, the probability of a successful probe deployment following the probe pre-deployment is
greater than 0.87, with 95% confidence.

PDF NOC_R&C_03.pdf - Other
Restricted to Registered users only
Download (1MB)

Citation

Brito, M.P., Griffiths, G., Mowlem, M., Waugh, E., Saw, K., Wyatt, J.B., Tsaloglou, M-N., Fowler, L., Campbell, J. and Rundle, N. (2011) Reliability Case Notes No. 6. Risk assessment of the Ellsworth probe: development, design and deployment , Southampton, UK National Oceanography Centre 40pp. (National Oceanography Centre Research and Consultancy Report, 3).

More information

Published date: 2011
Additional Information: Deposited at authors request
Keywords: Sub-glacial lake, scientific probe, risk assessment, expert judgment elicitation, judgment aggregation, fault tree analysis, markov chain ISSUING ORGANISATION National Oceanography
Organisations: Ocean Technology and Engineering

Identifiers

Local EPrints ID: 187347
URI: http://eprints.soton.ac.uk/id/eprint/187347
PURE UUID: 50c24ed8-386f-4ff5-bc56-b6e6dfcce161

Catalogue record

Date deposited: 16 May 2011 13:38
Last modified: 18 Jul 2017 11:45

Export record

Contributors

Author: M.P. Brito
Author: G. Griffiths
Author: M. Mowlem
Author: E. Waugh
Author: K. Saw
Author: J.B. Wyatt
Author: M-N. Tsaloglou
Author: L. Fowler
Author: J. Campbell
Author: N. Rundle

University divisions


Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×