Plastic piping has become more common onboard marine vessels, but plastics have additional requirements over metallic piping materials. While plastics offer superior corrosion resistance and weight savings over metals these benefits must be weighed against the effect of fire on plastic piping. These requirements vary based on system, location, and regulatory ruleset which can cause confusion when discussing the application. This paper attempts to clearly summarize the requirements as well as highlight some of the benefits and weaknesses of various plastic piping materials.

Coatings are used on offshore steel structures to prevent corrosion and to preserve their appearance. Conventional coating systems require repainting after only 10-15 years. Fluoropolymer coatings have been used on offshore structures since the mid-1980’s. These coatings offer excellent corrosion protection as well as good gloss and color retention for more than 30 years in some cases. Using fluorinated coating systems can substantially lower life cycle coating costs and require fewer maintenance cycles than conventional coatings.

Free-spanning pipelines is a phenomenon occurring on uneven seabed and scouring phenomena around the exposed pipeline. To study how free-spanning pipelines are affected from these phenomena, it is necessary to study environmental hydrodynamic flow conditions surrounding the pipeline, such as steady flow due to current, oscillatory flow due to waves and combined flow due to current and waves. Combined wave and current loading include the long-term current velocity distribution, short-term and long-term description of wave-induced flow velocity amplitude and period of oscillating flow at the pipe level and return period values. The bending stresses and associated fatigue life are determined from the given span length and boundary conditions accounting for bending due to self-weight and environmental loading from combined direct wave action and vortex induced vibrations (VIV). The fatigue damage is calculated and integrated over all selected directions, corresponding long-term sea-states and current. Fatigue life is calculated for the in-line response model, in-line force model and the cross-flow response model. The design fatigue life for the in-line mode is a combination of the response model and the force model. Peak dynamic stresses are found from the extreme wave and current conditions and are calculated for cross-flow and in-line response. The premises for this paper are based on application development within pipeline free span evaluation in a software development project based on DNVGL recommended practice, DNVGL-RP-F105. It provides a brief introduction to a software application used to calculate parameters addressing how free-spanning pipelines are affected considering stresses, damage and fatigue life.

Tanks and critical spaces requiring a MIL-PRF-23236 Type VII Ultra High Solids (UHS) epoxy coating system have the option of retaining a Pre-Construction Primer (PCP) or the first coat of a multi coat Type VII UHS system throughout unit construction. PCP is not intended to last longer than 6 months, and is not a sufficient corrosion protection barrier, while UHS coatings are easy to damage and expensive to repair, making neither option an ideal coating for unit construction. MIL-PRF-23236 Type VI epoxy primers, on the other hand, are durable and easy to repair, making them a suitable candidate for retaining as a protective coating throughout unit construction. This project presents the material testing data to propose retaining a Type VI epoxy under Type VII UHS as a suitable alternative to the Type VII UHS coating system.

In 1993, Richard D'Souza (Fellow), the principal author and his co-authors presented a landmark paper reviewing the Semisubmersible Floating Production System (FPS) technology at the SNAME centennial meeting in New York. (D'Souza et al., 1993a). The paper captured the twenty year progression of the FPS beginning with the Argyll field in the UK Sector of the North Sea in 80 meters of water that was converted from a semisubmersible Mobile Offshore Drilling Unit (MODU) and began producing in 1975. During this period about twenty five FPSs were installed, primarily in the North Sea and Brazil. Most were converted from semisubmersible MODUs. The deepest was in 625 m, the largest displacing 45,000 mt and the maximum oil rate was 70,000 bopd. Over forty FPSs have been installed since then, most of which are purpose built platforms. The technology has expanded to a maximum water depth of 2400 m, displacements exceeding 150,000 mt and production rates of 300,000 boepd. The inherent versatility and flexibility of the FPS to adapt to a wide range of water depths, payloads, metocean conditions and future expansion, has resulted in the FPS superseding the Tension Leg Platform (TLP) and the Spar platform as the most widely used floating production platform after the Floating Production Storage and Offloading (FPSO) platform. Its field development applications range from marginal reservoirs to giant deepwater oil and gas fields across the globe. This paper, authored by Richard D'Souza with a new team of co-authors, is a sequel to the 1993 paper and is intended as a historical and technical archive of the evolution of the FPS technology in the ensuing twenty five years. It highlights the importance of the Naval Architect and Ocean Engineer whose role has evolved from a peripheral to a major player in the design, fabrication and installation of the FPS. This paper has two objectives. One is to inform Operators and Contractors engaged in developing deepwater fields by providing a historical overview of lessons learned and technology evolution of the FPS. The other is to inspire graduate and post graduate Naval Architects and Ocean Engineers to consider a career in the offshore industry where they will have an impactful role in shaping the future of deepwater floating production platforms.

In this paper a software suit is described which main purpose is to facilitate the engineering, design and analysis process such that consistency of input is assured and the risk of erroneous input is decreased, and such that results and documentation are automatically generated to increase quality of documentation. Current scope is a standard calculation tool covering different aspects of design in compliance with relevant offshore codes and standards. A modularization technique is used to divide the software system into multiple discrete and independent modules based on offshore codes and standards, which are capable of carrying out task(s) independently. These modules work as basic constructs for the entire software, but at same time these modules can be executed separately and independently. This modularization technique also includes other benefits, such as ease of maintenance and updates. The quality of an implementation of offshore codes and standards in software modules and their interaction among them are measured by defining the level of inter-dependability among the subsea engineering and analysis modules, and by defining the degree of intra-dependability within elements of a module. How modules interfere and interact with each other is defined by couplings. The improvements are related to the objectives of a state-of-the-art procedure of performing engineering, design and analysis by use of offshore codes and standards implemented in this software suit to assure a consistent way of working.

Conveying hydrocarbons from offshore production facilities to onshore receiving stations presents risk to the environment, public health and safety. Pipelines are the most effective mode of hydrocarbon transportation but like every other asset they age due to various reasons. Despite their age, the use of pipelines often continues after their designed lifespan has ended and the major risk posed by aging pipelines is leakage. A substantial amount of major export pipelines in the United Kingdom Continental Shelf (UKCS) have exceeded their design life. To ensure safety, it is important to manage the integrity of aging pipelines still in use and to extend any lifetime analysis of the system well beyond its designed end of use. This paper highlights a management cycle to justify the technical and operational integrity of aging carbon steel pipelines to ensure continuous safe operation beyond their design life. The paper focuses on time based degradation mechanisms and uses the results of a Failure Mode Effects and Analysis (FMEA) risk assessment in conjunction with pipeline safety regulations to obtain a robust method for determination of safe methods for extended lifespan use of pipelines.

Inaccessible voids are commonly found within a ship's hull. By nature of a ship's construction, these typically cannot be coated traditionally, potentially leaving the steel subject to corrosion. Specifically, inaccessible voids with one or more boundaries exposed to seawater, standing water, or a water-filled tank are prone to temperature gradients that can promote condensation. This corrosion concern increases significantly if a crack develops in a void below the waterline, facilitating ingress of seawater and other contaminants. Voids have typically been "coated" with a petroleum solvent-based compound to prevent corrosion. Other methods such as vapor phase corrosion inhibitors (VCIs) and inert gas purging have also been used. This paper describes the treatment methods currently in practice and compiles application and performance data on each. Shipyard considerations, health and safety factors, and design and production considerations are briefly discussed for each treatment. Effects on reparability and potential impacts to performance when a void floods are also addressed in this paper. The reader is referred to the NSRP project report for a more detailed discussion.

Dry docking is the scheduled time when the fouling control coating is assessed, the hull refurbished and new coatings applied. The decisions made during this period will affect the performance of the ship for several years. Royal Caribbean Cruises Ltd. has funded research at the Florida Institute of Technology to develop a strategy to improve their selection, application and management of ship hull coatings. The purpose of the research was threefold: establish an in-house baseline of performance to improve selection, maintenance and life cycle costs of the different commercially available coatings; improve quality control of dry dock procedures to include surface preparation and coating application; and insure that the ships are operating in compliance with both local and international regulations. The paper will present the methods that have been developed to measure specific aspects of the dry dock process and how this data may be used for quality control and coating selection.

Bend stiffener are conical structures used in flexible riser systems in order to ensure smooth stiffness transition between riser and floating units, preventing excessive curvatures and protecting from failure. Made in polyurethane, the vast majority of analysis of bend stiffener-riser systems generally assume the material behavior as linear elastic or hyperelastic; time dependence, creep or stress relaxation are not considered. This work presents a parametric structural study of bend stiffeners, considering linear elastic and linear viscoelastic behavior using fourth order Prony series considering the temperature dependence on relaxation times. Different subroutines in FORTRAN based in UMAT -ABAQUS methodology are developed in order to calculate the mechanical response of bend stiffeners (deflection and curvature), assuming homogeneity, symmetry and isotropy. Case studies using solid finite elements made for different geometrical and material models and finally were compared with other works from different authors.

This paper is seeking to provide feedback on the use and application of both API-RP-17N & ISO 20815 in subsea field developments and in the progression of floating production system designs by presenting findings and design study recommendations, which are collectively pushing engineering boundaries in the recovery of oil and gas from difficult operational and environmental locations. Lessons Learned, key issues encountered and feed-back are provided from the installation of a subsea facility infrastructure that will deliver gas into the U.K. network from a long distance subsea tieback West of Shetland in the UK Continental Sector and from various FPSO projects and from deep-water FLNG design developments.

The objective of this work is to present a review of recently performed experimental tests of large and small scale steel corroded specimens. Four types of tests are discussed here: corrosion deterioration, ultimate strength, tensile strength and fatigue strength material properties. Two large scale specimens, in the form of box girders simulating the midship section of tanker ship where corroded in a natural open sea condition. The corrosion degradation and its distribution around the structural components of the box girders are presented and discussed. The effect of the severity of corrosion degradation on the strength of the corroded steel specimens is experimentally evaluated, where the box girders are tested under four-point loading, producing a constant bending moment along the box girder until collapse. The experimental results of fatigue strength tests of small scale corroded steel specimens, cut from the same corroded box girders, are also presented. Finally, the experimental tensile strength tests are performed using small-scale corroded specimens, cut from the corroded box girders after the ultimate strength test was completed. The test identifies the effect of the degree of degradation to the mechanical properties of the specimens, namely modulus of elasticity, yield stress, tensile strength and total uniform elongation are also presented. The results of the experimental tests, presented here, are highly important and need to be accounted for when linear or nonlinear structural analyses are performed to evaluate the structural capacity of ageing marine structure.

The maritime industry is currently going through a significant number of changes due to the introduction of tighter emission regulations. A stronger awareness in preserving the environment has pushed forward more stringent IMO (International Maritime Organization) legislation that imposes on ship owners and managers the use of new technologies which affect the day by day running of the vessel, starting with the choice of fuel, through changes in the engine operational parameters, and culminating in a severe reduction in allowable exhaust emissions. These changes combined with a volatile fuel market, high competition in cargo rates, the pressure to reduce operating costs and the introduction of new technological advancements have brought the industry into uncharted operational territories, abandoning the ‘comfort zone’ that has been enjoyed in the last twenty years or so. The present changeable environment has a significant impact in the way two-stroke, slow speed, diesel engines are managed, introducing new challenges for different fuel types, different lubricants and ancillary equipment required to meet the new requirements. Field experience has shown that all these factors can lead to unintended consequences, including engine damage caused by poor fuel quality, lack of training/knowledge of the operators, incorrect lubrication choice and poor set up. This paper discusses how the combination of offline and online condition monitoring techniques, both on-board and on-shore, can be successfully used to prevent engine damage and avoid unplanned maintenance costs due to downtime.

Non-welded pipe fitting connections have been available in the maritime industry for years but with advanced engineering the market is opening up to the technology. As the US shipbuilding industry experiences an influx of business and skilled welders are in high-demand, non-welded pipe fitting technology is becoming a go-to product in shipyards across the country. In this presentation,, Fred Loomis, will share his experiences with non-welded pipe fitting technologies, and discuss how this type of product benefits the shipyard and end user.

Polysiloxane coatings are the most recent high performance coatings developed to take advantage of the heat and oxidation resistant properties of silicone-based materials. Commercially available polysiloxane coatings predominately consist of organic-inorganic siloxane materials (though some pure siloxane materials are available). Recently, the US Navy has approved polysiloxane coatings as “High Durability” in their specification for exterior weather resistant coatings (MIL-PRF-24635 Type V and VI). Navy approval comes after over 20 years of industry development of polysiloxane coatings for high performance industrial and marine applications, yet issues remain with their cost-effective implementation in the Navy fleet. This paper will review experiences of the offshore and marine industry with polysiloxane coatings and provide an update on the Navy adoption of the technology.

The US Navy has implemented the use of Ultra High Solids (UHS) epoxies as tank coatings over the past 15 years. This paper reviews the evolution to UHS coatings, their performance benefits, and the environmental impact of using these materials. The next generation of UHS coatings incorporating single coat, rapid cure properties and optically active fluorescent pigments will also be explored.

Uniform wastage is often considered in ship design and construction; the more aggressive corrosions however are often not considered until too late. Practical shipboard corrosion problems may have multiple mechanisms, dependent on the materials of construction and the corrosion environment. This paper discusses specific examples of combined corrosions to include galvanic and crevice corrosion in saltwater, sensitization due to welding or heat treatment and exfoliation behaviors in addition to wastage. The primary mechanism as well as accelerating effects are identified with recommended strategies for prevention.

A successful offshore construction operation such as platform installation, decommissioning and subsea pipeline construction relies on good engineering and planning before the operation. Good planning is helped by having the ability to use the first available weather window to carry out the operation at the field offshore. Therefore, the ability to forecast the governing engineering criteria during the operation becomes an essential component. This paper presents the developed methodology to forecast events and a summary of the status of the development, including its limitations and applications. It is focused in three areas: forecast and monitor the dynamic motion characteristics of the operation, pile stick-up motion for jacket installation, and prediction of sag bend bending moment during subsea pipeline construction. It is concluded by presenting the proposed future development and advantages.

Floating Storage Production and Offloading (FPSO)host platform selection is an increasing trend due to economic sand versatility offered for field development. The industry is migrating toward more robust riser types to outfit these platforms. Steel Lazy Wave Risers (SLWRs) are an adaptation of Steel Catenary Risers (SCRs) and have been gaining traction in recent years as a viable solution to harsh environments in ultra-deepwater. The following paper will present an overview of the host platforms that could benefit most from use of lazy wave risers and a justification of their application. A case study highlighting the performance comparison of large diameter SCRs versus SLWRs attached to turret and spread moored FPSO platforms in a moderate environment will be presented. The results indicate that SLWRs prove feasible with sufficient margins in strength and fatigue when compared to simple SCRs.

Shipping plays an important role in the logistic chain. These a worthiness of ships transporting goods world wide is therefore crucial. One element defining these a worthiness of a ship is the condition of her ballast tanks. These tanks are an area of concern for ship owners and crew. They are subject to corrosion; and due to the enclosed environment and complex structure, maintenance is very difficult and costly. This paper gives the results of an “insitu” study of ballast tanks on board of more than 150 merchant ships. No selection criteria were applied from the start and the ships were surveyed as opportunity arose. Most of the ships are worldwide trading and the age varies between brand new and 36years. Figure 1 gives a good idea of the age distribution. Many types of ships are represented in the database amongst others 10oil tankers, 14 liquefied gas carrier, 25 chemical tankers, 28 bulk carriers, 23 full containers carriers, 5 general cargoes, 9 RoRo’s, 8 refrigerated ships. Surface corrosion was assessed, compared and the importance of condition and environmental parameters during coating application recognized. The paper also reveals the significant difference between the average corrosion regression line of the data base and the coating condition in the ballast tanks on board ships to where the operator invested in a superior coating system at new building, with extra attention to surface preparation and coating application. The need to reduce the environmental impact of shipping becomes more and more obvious. Blasting with shot and grit, vast amounts of water used for water jetting and rinsing, surface cleaning and high solvent coatings jeopardize our future generations. Luckily, there duction of the environmental impact has beneficial economic consequences a sit brings down significantly maintenance costs.