Search our collections

The status of coral reefs in the French Caribbean Islands and other islands of the Eastern Antilles and the MPAs is presented. The coral reefs surrounding the islands of the French West Indies and nearby islands have shown a slow but progressive decline since the early 1980s. This has stimulated a long-term monitoring project at 10 sites in Guadeloupe in 1999 and Martinique in 2001. The UNEP Regional Co-ordinating Unit in Jamaica and the Barbados Coastal Zone Management Unit have supported the Reef Check Eastern Caribbean Project for fish and benthic monitoring on St Vincent Grenada Dominica Antigua St Kitts and Tobago. These were designed as rapid assessments of coral reefs where there were no current data. The assessments were accompanied by considerable training of local fisheries and dive operator staff along with the provision of basic monitoring equipment.

The handbook provides the designer and engineer with a single source of information and data on the design and properties of steel castings. The main design requirements for ensuring sound castings are dealt with as is the selection of the appropriate type of steel. The mechanical and physical properties of a wide range of steels are presented in order to provide the basic data needed when selecting a material. Specifications, quality assurance and non-destructive examination are also dealt with. Whilst the fundamentals of engineering design are not included, design is dealt with in relation to fatigue, creep and fracture mechanics.

The storminess project is introduced. This project seeks to examine storminess as it affects the Atlantic coastline of the European Union. Its two principal aims are: to study changes in magnitude frequency and spatial pattern of storminess over a period of 2000 years; to study the impact of storminess on selected environmentally sensitive areas of the coastline in order to determine the response of such areas across the coastline as a whole to storminess change. Both these aims will involve the acquisition of basic data and analysis of this data and the development of conceptual or numerical models and then later the development of a sensitivity-based framework of coastal description directed at coastal zone managers. The project is currently in its first year. The methodology of the project is outlined techniques are discussed and some preliminary results are given.

Chikyu is a scientific drilling vessel which has been operating in a harsh environment especially in the high current area - the Nankai trough. The stage 1 expeditions will be done in areas with water depths up to 4060 m. The high current in the Nankai trough will increase the maximum stress on drill pipes which is combined with an axial static stress an axial dynamic stress and a bending stress exerted during drilling operation. This could lead to a crucially high stress. In order to make the drilling operation in the Nankai trough a success it is necessary to evaluate the strength of the drill pipes considering actually planned drill string configurations. It is also necessary to make slip-crushing consideration when the drill string is held by conventional handling tool slips. So strength evaluation of the drill pipe has been conducted using actual drill string configurations by analyzing the stresses mentioned above. Furthermore slip-crushing consideration for power slips which will be used in Chikyu has also been performed.

The study of the impact of through cracks on structural integrity of jacket platforms is still a challenge. In the context of risk-based inspection and monitoring of such structures a global methodology is proposed. The detection of large cracks is first addressed. A probabilistic model is proposed taking into account the in situ inspections performances and the probability of crack presence. This is achieved by the use of the detection theory. Second a finite element that is able to represent the structural behaviour of through cracked tubular nodes is proposed and a global structural integrity measure is suggested. Finally inspection results are introduced in order to compute the expected platform structural integrity. It is illustrated by considering FMD inspections results of a tripod structure.

The aim of this paper is to establish a procedure of Structural Reliability Analysis (SRA) for the assessment of Ultimate Limit State (ULS) of ships hull. Refined probabilistic models of both load (Wave-induced bending moment) and capacity (hull girder ultimate strength) have been derived by using direct calculation methods based on the latest analyzing techniques. An implemental procedure of SRA for estimating the ULS of typical merchant ships has been proposed. As application examples a series of SRA by using First Order Reliability Method (FORM) has been performed and the annual failure probability of tanker bulk carrier and container carrier for hull girder ULS has been calculated.

The outcome of a study in which both numerical and experimental investigations of three-phase slug flow were conducted is described. The experimental work was carried out on the Imperial College WASP facility. Measurements were made of the characteristics of the flows and the time - varying and time-averaged hold-up of the phases and pressure gradients using a scanning dual energy gamma densitometer. In the parallel computational study predictions were made of the slug flow characteristics using a modified two-fluid model which incorporated the influence of the additional liquid phase by using a "drif-flux" approach and mixing processes were represented by a model developed by Decarre & Fabre. The local liquid viscosity was calculated using the model of Brinkman. Despite the three-phase slug flow complexity the model was effective in predicting the measured flow characteristics.

This paper describes the probabilistic analysis of 54 ice events that occurred at Mt. Belair Quebec Canada between February 1998 and April 2000. The data from the experimental installation on a 315-kV line covers 1662 hourly records of icing rate and the related meteorological factors such as ambient air temperature wind speed and direction as well as relative humidity. Moreover the distribution of the total icing accumulation was investigated. For a better understanding of ice formation process the analysis is made separately for 1266-h in-cloud icing and 396-h precipitation icing. The evolution in time of an ice event is considered in its three phases accumulation persistence and ice shedding.

Ice masses can gouge more than five metres below the mudline causing damage to buried pipelines. A joint industry project (JIP) known as PRISE has demonstrated that even if the pipeline is buried too deep for the ice to reach damage can still be caused by deformations in the soil beneath the gouge zone. PRISE combined centrifuge modelling analytical and finite element studies of the gouging process and pipeline response and field studies of relic gouges to develop guidance on burial depths. Further verification and research is needed but preliminary results suggest pipelines should be buried at least 2.5 times deeper than the maximum gouge depth.

There is a large increase in offshore oil & gas production originating from subsea completed wells which requires high attention to subsea equipment and system performance. The demand for safe and cost-efficient operation requires an understanding of reliability mechanisms and the knowledge to identify and solve issues such as equipment failures operational problems and human errors. Subsea equipment reliability is vital for cost-effective design and operation of deepwater subsea concepts. The OREDA software and database system allows reliability performance to be monitored subsea system design to be optimised and infrastructure to be planned. Company reliability experiences and examples of industrial cooperation are given. The OREDA subsea software covers subsea equipment such as Xmas trees control systems template manifolds subsea pumps and includes critical components such as valves connectors and sensors. Data tables graphs and diagrams appear on pages 9 to 12.

The current use of fibre reinforced plastic (FRP) composite materials on offshore platforms are outlined. Next limit state design for advanced structural FRP composite materials is considered. This is followed by a case history for large composite structures designed by the limit state approach. After this the redesign of the Davy/Bessemer topsides with maximum use of composites is touched upon. Conforming and radical design solutions are looked at. The benefits of greater use of FRP composites for primary structures are discussed. Lastly the future of composites in the offshore industry is outlined.

A typical chemical plume tracing (CPT) is to navigate an autonomous vehicle to find a chemical plume that is transported in a turbulent fluid flow to trace the plume to its source and to declare the source location. CPT in the real world however is more complicated for example some test runs conducted in August 2002 on Clememte Isand California failed because of some "soft obstacles" such as kelp forest or seaweed in near-shore ocean environments. This paper presents a subsumption architecture for CPT with soft obstacle avoidance by integrating a Follow-Obstacle behaviour. The behaviour used herein can be grouped into two categories: soft obstacle avoidance and plume searching and tracing. The simulation studies of CPT with soft obstacle avoidance are performed using a simulated turbulent fluid environment.

Int conf held in Aberdeen on 29-31 October 1985 Papers are Evaluation of the last five years of ADS/ROV in drilling operations Dual ROV/manned vehicle Designing for drilling intervention - ROV dedicated vehicle Anti-fouling techniques Slippery paint Water-jetting by an ROV Hutton production risers - novel cleaning problem (an up-to-the-moment case history) The real life aspects of managing a lump sum contract Difficult contract clauses Mobilisation requirements for DSVs and diving superintendant The role of the clients rep and the diving superintendant Recent and future developments in undersea survey and intervention Intelligent transponder surveying Autonomous vehicles in survey Subsea installation and intervention - how to utilize the potential of ROV techniques ROV tooling technology - Montezana D2 field ROV intervention system The underwater shuttle A one-atmosphere transfer system for deep water production support A swage pile connection technique Overview and legal requirements Improving subsea MPI consistency ROV inspection systems (ROVIS) Electromagnetic inspection underwater

A number of metocean issues associated with ultra deep exploration and production are reviewed. The replacement of the design wave by the design of metocean environments is considered. Some recent efforts are reported to satisfy the needs of operators when specifying metocean environments for deep water and as well as a recently completed French effort to define such environments for waves: find those aspects of sea states that are most relevant to the design of novel offshore structures choose parameters that characterise them most adequately estimate their statistics and the associated confidence limits from the available information sources and adapt design tools either software or model tests so that they can accept such descriptions as input. Also addressed are other questions remaining open especially on wind and currents and examine some directions of research to answer them.

The practical sustainability of shipping in practice is considered. A project is presented to prove in practice what can be done to combine care for the environment with economic feasibility safety and the human aspects of the ship. During this project and over the next two and a half years the possibilities of implementing concepts of sustainability and upgrading parts of the ship will be investigated. If these changes prove feasible they will be implemented on a prototype ship in its next docking period. Advancing environmental legislation is considered. The concept of midlife updates is discussed. The wishes of the shipowner are outlined and a practical approach to sustainability is presented.

The Mobile Offshore Base (MOB) is designed to transit to anywhere in the world in the required time frame. During the research of MOB dynamical properties a non-linear system modeling and optimization tool using Reverse MI/SO (Multiple-Input / Single Output) techniques was developed and applied to different aspects of MOB dynamics analysis. MISO is based on statistical signal processing of the recorded time histories of the excitation and response of the non-linear multi-degree-of-freedom system. In this paper the model testing data in beam seas is analyzed using the Reverse MISO technique. The authors expected to identify significant nonlinear roll damping for the nonlinear integro-differential equation as is the case with ships. Instead a significant nonlinear heave damping related with the nonlinear relative heave velocity has been found during the analysis. This once again acts as a reminder that due to the strong nonlinearity of MOB motions in the severe sea ways nonlinear analysis methods such as Reverse MISO are important and need to be applied in order to fully identify the dynamics of the MOB motion.

The changing diversified business environment based on an inevitable necessity to establish an equitable global partnership to protect the integrity of natural and social environment in the economic developmental systems recognising the integral and interdependent nature of the 'Mother Earth' offers the Petroleum sector in general and the Exploration and Production Industry in particular many opportunities and challenges in terms of widening gap in demand and supply of oil and energy enhanced concern to degrading environmental issues and growing imbalances in economic and social priorities to achieve a sustainable developmental paradigm shift. The Petroleum Industry worldwide is shifting its emphasis to redefine growth strategies. A new paradigm of System Integration is described for providing a fast effective and cost-efficient way of analysing and improving overall asset value with sustainable growth of petroleum industry minimising economic and social imbalances in serving society and reduced environmental impact of oil and gas production.

The book contains the results from a programme of systematic model experiments planned by the authors that were carried out at the Swedish State Shipbuilding Experimental Tank. The purpose of these was to study the influence of main dimensions and centre of buoyancy on the resistance and propulsive qualities of model ships being tested. 9 ship models were designed, constructed and tested. The influence of variations in their length-breadth ratio, breadth-draught ratio and the longitudinal position of the centre of buoyancy were studied. The experimental results were converted to the scale of a ship having a displacement of 9750 tons and a trail speed of 16 - 16.5 knots. The results are also expressed in dimensionless form in order to facilitate their application to similar ships of different size.

CIMAC Congress - Kyoto The improvement of marine lubricant performance by making additions to the marine fuel is evaluated. A number of problems in the field can be attributed to the failure of the lubricant at the liner-piston ring interface to perform adequately. Two main examples of this are liner lacquering in medium-speed four-stroke engines and scuffing in large-bore two-stroke engines. The important factors in the adsorption of additives into the lubricant film present on the cylinder liner of ICEs (internal combustion engines) are identified. It is shown how having proved the theory in automotive applications this method of 'additivation' may be particularly advantageous for larger-bore engines used in marine and power generation applications combining both theoretical calculations and evaluation in fired engines.

A number of accidents in 1978 and 1979 with VLCC’s causing disastrous damages to the environment, resulted in many reactions, emotional or not. This report has tried to react on these events as objectively as possible by investigating the incidents and accidents with tankers larger or equal to 100,000 dwt. The incident and accident database has been subdivided in several was such as flag, management, age and size (chapter 3). The relation incidents/applicable number of tankers has been calculated in order to find casualty risk rates (chapter 4 & 5). The arising difficulties and restrictions to fulfil an investigation like this one are discussed in chapter 6 and 7.