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Pipeline systems in service are commonly exposed to corrosive and erosive environmental conditions. As such conditions may change over time some form of corrosion/erosion monitoring program is crucial for the maintenance of a safe level of operation. Ultrasonic measurement of wall thickness is widely accepted as the most accurate method for assessment of corrosion. Likewise ultrasonic methods are very well suited for detection and monitoring of cracks. However when very high levels of accuracy or defect sensitivity is desired ultrasonic methods suffer from practical limitations in repetitiveness of measurements. The performance of these methods may be increased by the use of permanently mounted ultrasound probes - this is the main idea with ULTRAMONIT. Two versions of this system are developed one for use on subsea pipelines and one for use topside or on land facilities.

An industry-wide international network is needed to collect reliability availability and maintainability (RAM) data that will enable continuous improvements in safety and cost-effectiveness in the shipping industry. RAM/SHIPNET is the first module of such a network that concentrates on ship machinery and structures currently under development. The network was started with seed funding through SNAME and is continuing under the Ship Operations Cooperative Program with funding from the Gulf Coast Region Maritime Technology Center. First generation data collection and processing tools have been completed and the project is now moving into full-scale tests validation and roll-out.

Pollution prevention is a key element in meeting the challenges of the Navy's Fleet in the new millennium. The P2 (pollution prevention) Afloat program was established in 1995 to develop pollution prevention strategies for the US Navy Fleet. Its goal is source reduction of HM (hazardous materials) used in standard shipboard maintenance and other afloat activities. Executive Order 12856 requires federal facilities to reduce the release of hazardous substances by 50 per cent by 1999 compared to a 1994 baseline. Studies show that up to 70 per cent of the hazardous waste processed at Navy facilities is obtained from HM offloads from ships. The P2 Afloat Team is achieving source reduction goals by identifying assessing and implementing source reduction opportunities aboard ships and focusing on the direct use or minimal re-engineering of COTS (commercial off-the-shelf) products. There have been many challenges and lessons learned during research procurement test and evaluation installation and return on investment analyses of P2 Afloat equipment. Applying these lessons learned regarding pollution prevention in the maritime environment is essential in order to meet the challenges of the Fleet in the new millennium.

Increased fuel prices have made the performance of hull underwater paint systems an increasingly important aspect of ship operation since paint roughness can affect the ship's speed. The paper describes a method for working out an individual hull painting strategy for each ship in a fleet. This uses microcomputer based techniques to process and display hull roughness data including colour graphic display which quantifies in colour the areas of high and low roughness values highlighting areas requiring grit-blasting and recoating. Cunard's experience in hull roughness maintenance over the years is commented upon and it is shown that the up-keep of a good coating is a team effort involving the shipbuilder the shiprepairer the painting contractor the painting inspector and the ship's crew. The importance of self-polishing anti-fouling paints is stressed. An appendix lists the variables used in the microcomputer program.

The maintenance of maritime trade and commerce activities includes the dredging operations in harbours and fluvial and estuarine areas. The volume of dredged materials poses problems to harbour managers. A method of solidifying dredged sludge using cement is presented. The treated sludge is partially contaminated by some heavy metals. The objective of the research program is to treat and reuse the solidified sludge as road or civil construction materials. To evaluate the mechanical performance of the geomaterials obtained axial compressive tests are run on cylindrical samples taking into account the percentage of cement and additives the type of storage the initial water content of the sludge. The environmental performances are obtained using leaching tests on samples which are broken or not in relation to the rate of heavy metals contaminants the porosity and the ingredient materials. This paper presents the main results from the analysis of the mechanical and environmental tests being mainly the relationships between the mechanical physical and environmental properties.

Pipeline Integrity Management (PIM) processes are risk-based systematic processes that identify the controls required to maintain integrity. They can be used to deploy funds and resources to the areas of highest risk to reduce the likelihood of internal corrosion failures and can be applied to any pipeline system from the simplest to the most complex. Failure modes and effects analysis (FMEA) within the process identifies the pipeline function operating envelopes deterioration mechanism associated risks and maintenance requirements. The basis of a successful PIM program is accurate characterisation of the internal corrosion hazard profile. The way in which two-phase modelling data is used to identify the formation of detrimental fluid flow patterns contributing to corrosive environments in sour gas pipelines is demonstrated. A description of the protective scale disruption processes that underlie the technical assessment of risk within the FMEA model is given. Three sour gas production pipeline case studies are presented.

This study was made to serve as the first phase of a multi-phase Ship management Information System Program, in which the Maritime Administration supported the development of computer/communication applications in diverse areas such as payroll, shipboard maintenance and crew data. This was carried out in different tasks. This volume brings the result of tasks I and II, which concerned with the collection, classification and evaluation of all shipping company management information requirements directly involving the vessel, regardless of whether the information is collected by the ship for its own or home office use or is sent to the ship form external sources. The product of these tasks is a manageable and practical list of shipboard information requirements to be used in subsequent tasks of the study.

A condition survey carried out to study the extent and distribution of corrosion in the water ballast tanks (WBT) of 22 in-service ships is reported with particular reference to the effects of ship age (4-20year) corrosion protection system used (hard coating with tar-epoxy paint with and without back-up sacrificial anode) service conditions (extent of immersion and temperature) and maintenance schedule on effective life. A program of laboratory studies using coated test pieces in simulated WBT conditions was also carried out to clarify factors (including paint composition thickness and integrity) affecting the deterioration of coating with age. The findings are used to propose an effective corrosion protection system for the expected life of WBTs and other hull structures. An appendix explains the definitions for ratings of hull condition.

An ongoing program of advanced double hull research is described. The focus is on unidirectional longitudinal framing systems to obtain improved producibility maintainability and resistance to casualties. There are three principal areas of investigation: (1) structural integrity including stress and collapse behaviour fatigue life and resistance to grounding; (2) affordability including automated fabrication methods corrosion protection inspection maintenance and repair and design integration; and (3) survivability including resistance to explosions damage stability and control. Results are applied to the design of commercial product and crude oil tankers and naval combatants. Interim results of analytical experimental and design studies are presented with corresponding tentative conclusions. Ongoing and pending investigations and design applications that will be presented in future publications are reviewed.

NOVA Gas Transmission Ltd has supported research programs in the area of longitudinal pipeline/soil interaction modelling. These programs investigated key parameters governing this interaction based on controlled and full-scale field tests. Application of the new interaction models could result in significant cost reductions in the design of new facilities as well as the maintenance planning of operating pipelines. Research programs are described the new interaction models presented and the potential implications of applying the new models are discussed.

A research study into water jetting of stiff cohesive soils is presented. This sets out to investigate the effect of water jetting on stiff to very stiff clay soils which have until now been generally beyond the capabilities of the industry's existing cable burial and maintenance ROV fleet. However it is becoming an increasing requirement for operators to be able to extend the range of seafloor conditions in which burial can take place effectively. The background and methodology of the testing program is described and the selection of suitable soil test beds which were used to model stiff clay seafloor conditions are detailed. The test apparatus and procedures are also described and indications and discussion of the result trends obtained are given. It is intended that the project will eventually lead to the delivery of a new range of high capability jet burial equipment. Graphs and photographs appear on pages 5 to 7.

Composite wrapping has been used extensively over the past few years particularly in seismic retrofits and for structural maintenance. Corrosion-damaged reinforced concrete structures are wrapped with composite materials in an attempt to starve them of oxygen moisture and chlorides. The wraps have typically been in the form of FRP (fibre-reinforced plastic) composite materials. Theoretically this could arrest the corrosion process if the necessary ingredients for corrosion are eliminated. It may be difficult to stop the process if efforts are not taken to address the corrosion activity directly. Therefore the procedure may be more effective if corrosion inhibitors are applied before wrapping. Some manufacturers are even suggesting that wrapping should be used in new construction particularly where the exposure conditions are expected to be severe as in offshore environments. Laboratory and field investigations are carried out on columns and beams that have suffered corrosion damage due to chloride penetration. The process of composite wrapping and its potential to provide protection to offshore structures is discussed based on the findings from these investigations and an actual field installation. The performance of FRP composite wraps which have been applied to bridges for the purpose of mitigating ongoing corrosion are described. The effectiveness of the FRP wrap is assessed in part based on corrosion rate measurements derived from embedded probes which were placed at various locations within the bridges. To help in this assessment a complementary laboratory test program has been developed to simulate cylindrical and rectangular97492

The way in which the Royal Netherlands Navy (RNLN) is using the variety of system concepts possible with integrated electrical energy systems onboard ships is reviewed. The reasons why energy and propulsion systems will become further integrated in the future are outlined. The importance of a functional analysis is demonstrated as well as the differences between this type of analysis and the system breakdown structure. The energy concept forms a firm basis to describe direct mechanical and all electric concepts with the same type of block diagrams. In order to facilitate the analysis of integrated and complex energy systems during the pre-design stage of ships a specific computer program was developed - GES - Geintegreerde Energie Systemen - Integrated Energy Systems. Models for energy transformation weight and dimension cost and reliability and availability and maintenance costs are described. The NATO study Maritime Operations in the year 2015 (MO2015) and in particular the input to the Future Reduced Cost Combatant study (FRCC) is an example of a project where a structured approach to conceptual design is being applied to a complete platform.

Seasonal hypoxia occurs in bottom waters on the northern Gulf of Mexico inner continental shelf from May to September over extensive areas. The two main factors leading to development and maintenance of hypoxia are physical stratification of the water column and decomposition of organic material. Spatial and temporal variation in the distribution of hypoxia water masses is related in part to freshwater discharge from the MRB (Mississippi River Basin) circulation patterns nutrient loadings and a close coupling with net primary productivity. Significant increases in nitrogen and phosphorus loadings and decreases in silicon loadings have occurred in the Mississippi River this century and have accelerated since 1950. Mathematical models can be useful to synthesise environmental data and to provide better understanding of cause-effect mechanisms that lie behind experimental observations. They can also be useful to forecast possible responses of environmental systems to different management scenarios. The NECOP (NOAA Nutrient Enhanced Coastal Ocean Productivity) programme included development of a mathematical model together with an observational program. The principal benefits from the model were a better understanding of environmental processes controlling primary productivity dissolved oxygen dynamics on the LIS (Louisiana Inner Shelf) and an assessment of how these parameters might be influenced by changes in nutrient loadings from the MRB. The modelling approach and its application88813

Over the last ten years the numbr of floating assets has increased significantly for most operators. Many of these are in remote areas where a thoroughly planned and executed integrity management becomes all the more critical. Several of these fields are also in harsh environments with limited weather windows for routing maintenance. Some are in deepwater and have a very complex field architecture putting a higher demand on the integrity planning. Several of the assets especially the FPSO units are converted tankers with a long cumulative service life with its associated structural integrity challenges. All of these factors call for a well-planned integrity management system to ensure asset integrity and minimise production downtime. This paper provides a broad overview of a general framework adopted by EMPC (ExxonMobil Production Company) to promote and achieve performance excellence in asset integrity management across their global network of production operations. The general scope of the integrity and reliability management framework are discussed and also the organisation and the process by which the plan is executed the primary tools used including the RBI (risk-based inspection) plan the performance indicators used to measure the effectiveness of the program and the overall assessment and feedback used for continuous improvement of the system.