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A wide spectrum of power tongs can accommodate the increasing interest in mechanized operations at the rig floor. The importance of a torque-turn recording has been stated in many papers as a good control method for the make-up process and the reliability of a drill string can be improved using feed back of make-up recordings. State-of-the-art devices not only allow the precise mechanized make-up of connections but they also provide sufficient data to analyze the quality of the connection make-up. The motivation behind the research performed is the wish to make use of the data already provided to increase the lifetime of the connections and the reduction of drill string failures especially for drilling under extreme downhole conditions like HPHT or deep water. This paper presents a new algorithm to evaluate the slope of the torque-turn recordings and to extract information that can be used to predict the quality of the process with application to extreme drilling situations. This work is based on more than 300 make-up and break-out laboratory tests.

In this paper a meta-analytic approach is used to examine the distribution of fish schools and school clusters of five pelagic clupeid schooling species in three different habitats and between different years of observation. To quantify and characterize the spatial distribution of clupeid fish schools sonar data was collected during surveys off the coast of Nambibia in 1994 (pilchard anchovy and round herring) off Angola in 1995 (sardinella) and in the Norwegian Sea in 1997 and 1998 (Norwegian spring-spawning herring). On the basis of sonar recordings an attempt was made to quantify the horizontal distance between pelagic schools in a cluster and between different clusters. Also the diameter of school clusters was estimated.

The expected configuration of the nonlinear sea surface over the region of large waves in extreme seas has been of increasing practical and theoretical interest in recent years. The theoretical expected structure of large non-linear waves can be described using the Gram-Charlier approximations of Jensen et al (1995) and Jensen (1996 2005) and the quasi-deterministic model of Fedele and Arena (2005). The second-order narrow-band approximation offers a simpler alternative to these models as recently suggested in Tayfun and Fedele (2006). This latter alternative is elaborated here deriving theoretical expressions for predicting the expected shape of large waves conditional on somewhat more general constraints than those previously considered. The theoretical results are verified favourably with oceanic measurements gathered at deep and transitional water depths in the North Sea. Some comparisons of the present model with those of Jensen et al (1995) and Fedele and Arena (2005) are also given showing that all three models do in fact reasonably well in representing the expected profile of large waves in storm seas.

At the beginning of the paper the principle and arrangement of a 2-CCD Digital Particle Image Velocimetry (PIV) system are simply introduced then experimental results of velocity vector maps of a horizontal circular cylinder in a wave field got by using PIV system have been presented wave profile in-line and lift forces acting on the cylinder have been measured simultaneously with PIV images. The Kc number equals 2.4 for the cylinder placed far from plane boundary no influence of free surface and plane boundary and Kc number equal to 11.8 for the cylinder placed near the boundary in which the gap ratio is equal to 0.5.

Here is the story of 20th century passenger shipping, from the first of the superliners (the German Kaiser Wilhelm der Grosse) to Cunard's Queen Elizabeth and Queen Mary, right up to Queen Elizabeth 2, and including such other favourites as Mauretania, the Lusitania, the Normandie and the legendary Titanic. From the early four-stackers to the post-jet transition to cruising, the accent is on the North Atlantic trade, but other routes such as Australia, Africa and Latin America are also included in this superbly illustrated look at the past, present and future of ocean travel.

The fatigue life of high-strength steel offshore structures has been studied. The steel had a yield stress of 800-1000 MPa and high weldability and toughness properties. Fatigue tests were carried out on full-scale tubular joints and smaller welded-plate specimens made of either high-strength steel or conventional structural steel. Variable amplitude loading was generated by a computer program developed at the Technical University of Denmark (TUD). When compared with the results of the constant amplitude fatigue tests the variable amplitude tests showed shorter fatigue lives than expected from the linear fatigue damage accumulation formula. In general longer fatigue lives were obtained from the high-strength steel specimens than the conventional steel specimens.

Current fatigue design rules for girth welded tubes for offshore applications are believed to be over-conservative particularly for good quality welds made from only one side. In order to address this issue fatigue tests were performed under axial loading on large-scale girth welded tubes representative of tension leg platform (TLP) tendons and from small-scale strips cut from girth welded tubes or butt welded plates. The welds were made from one or both sides using a variety of mechanised welding processes. The results were used to compare the fatigue performance of one and two-sided welds to assess the influence of weld quality and joint misalignment to compare the fatigue performance of small-scale and large-scale specimens and to assess the applicability of current European and US fatigue design curves.

This paper addresses riser fatigue using a fatigue reliability model that is relatively simple but still captures the important elements of the fatigue problem. A model for combining wave-induced and vortex-induced vibration (VIV) is introduced together with the best available data and reference to industry work in this technology area. A recently completed joint industry project on riser reliability provides good calibration points for the critical fatigue reliability variables. Reliability and sensitivity studies are performed to demonstrate the effect of the uncertainty parameters. An approach to selecting deterministic fatigue design factors that yield specified reliability targets is developed and illustrated. The study provides a rational approach to selecting safety factors for design of deepwater risers taking into account both wave and VIV-induced fatigue damage.

A set of methods is described that makes it possible to estimate the position of a feature inside a 3D space by starting from a sequence of 2D acoustic images of the seafloor acquired with a sonar system. A state-of-the-art motion analysis is presented for objects imaged along a sequence with particular attention to the acoustical imaging field. The feature-tracking module is then described. It is explained how 3D position estimation can be carried out starting from the tracking of a feature along a sequence of 2D acoustic images. Results obtained on both simulated and real image sequences are reported. Finally some conclusions are drawn.

The industry trend of more oil and gas exploration in deep and ultra deep water has put focus on finding faster and cheaper methods for installation and construction work at these water depths. One significant driver in this picture is the weight of the lifting line. The weight penalty of steel wire is increasing rapidly with depth and is becoming a significant cost driver for depths beyond 2000 meters. A solution to this is to avoid the weight penalty by using lifting line that is close to neutrally buoyant in water. Using fiber rope as substitute for steel wire for deep water installation is an attractive solution. However several challenges with regards to handling of fiber rope must be solved and a corresponding handling system must be available in order to take advantage of this opportunity. This has been the purpose of the development and field demonstration of the patented CTCU technology through several Joint Industry Projects since 2002. The background for the development and the status and results so far as well as future plans are presented in this paper.

Conf held in London 1 - 2 March 1982 Papers are 1.3 Micron wave length devices for long haul optical fibre systems High power high speed GaAIAs D H LEDs for optical communications Expanded beam connectors Fibre gyro for sensitive measurement of rotation Optical fibre sensors - principles and applications R f field measurements using an optical fibre link Semi conductor lasers and their military application Fibre optic transmitters and receivors for military applications Rugged fibre optic cables for military use The development of high performance optical fibre data links Monomode fibre systems for telecommunications A 140 Mbit/s long haul optical fibre digital line system Nuclear radiation effects on fibre optics The PTARMIGAN optical fibre subsystem Experimental GINA optical data bus in the Mirage 4000 aircraft The fibre optic signal transfer system for the ground launched cruise missile Fibre optic component specification to meet the requirements of defence equipment projects Standardisation and measurement of optical fibres for telecommunication systems I E C standards for optical fibre and cables and components Portable test equipment for optical cable link evaluation

The events of the shipping market during the 1980s have demonstrated both unpredictability and risk to an astonishing degree, despite the increase in shipping efficiency and financial sophistication. The purpose of this book is to discuss the management of marine commercial risk, comparing traditional period timechartering, contracts of affreightment against newbuildings and joint ventures with freight futures, a new method of commercial risk management. The freight futures markets, BIFFEX and INTEX offer banks shipowners, charterers, and operators cheap, flexible and ease-to-use tools for the management of commercial risk and the author explains how to employ them effectively. The book also foes on to explain how the industry can use the financial futures market to control both currency and interest rate risks.

In shipbuilding it is necessary to join large plates by butt-welding. It is impossible to avoid deformation during welding. If the welding condition is not properly selected end cracking may occur. Thus it is very important to predict the welding deformation and the formation of end cracking. To accurately predict welding deformation and cracking in real situations in shipbuilding it is necessary to consider the influence of the root gap and tack welds. In this report FEM (finite element method) using temperature dependent interface element is proposed in order to analyse the influence of the root gap and tack weld. The gap is introduced into the interface element as an additional variable to represent the transient behavior of the root gap during welding. Using this proposed method the influence of the welding condition the tack weld interval and the tab plate on the deformation and the formation of end cracking are clarified.

US Coast Guard records show that between 20-30 per cent of all fishing vessel casualties occur in the category 'capsizing floundering and flooding'. A particularly dangerous situation arises when a vessel capsizes. There is often no time to transmit a distress signal and little time to don exposure suits and deploy a life raft. Traditionally naval architects have carefully examined the static stability of fishing vessels to ensure that they meet IMO guidelines. The results of testing a fishing vessel model in the natural environment are examined. Response spectra and response amplitude operators are calculated for a series of model tests at various levels of static stability for a heavily loaded model. One of the primary conclusions based on many model tests is that the IMO guidelines provide a margin of safety against capsizing. Every effort should be made to ensure that fishing vessels achieve this level of stability under all potential loading conditions.

Powers of ocean waves or tidal currents are tiny in renewable energy resources for electric generation. Accordingly in using the tidal current power it may be necessary to prepare a high specific speed hydraulic turbine such as a conventional axial flow type a cross flow type or Darrieus type. Then the machine with the low speed runner must be ordinarily equipped with accelerative gears or pulley systems because the output voltage is proportional to the rotor speed of the generator. Such a mechanism makes the hydroelectric power unit complex and overly large in size. To overcome these weak points a unique machine is proposed in which two stage runners successfully counter-rotate the inner and outer rotors of the peculiar generator. This machine has remarkable advantages with not only a sufficient output voltage but also rotational moments that hardly act on a mounting bed.

This book is a bibliography that contains more than 1,800 citations of books and articles on the subject of floating islands. All aspects of floating islands are addressed, including their formation, the causes of their buoyancy, their role in the ecology of lakes and wetlands, their flora and fauna, their role in the dispersal of plants and animals, and methods for controlling and managing them.

Conventional floatover deck (FOD) installation on a jacket substructure requires the top of the structure to be recessed appropriately either in the longitudinal or transverse direction to accommodate the vessel transporting the deck. The recess direction is very important to the design of the jacket and influences the outfitting of appurtenances the shape of the deck and the floatover concept as a whole. This study investigates the structural integrity of typical longitudinal and transverse jackets suitable for FOD installation under both in-place and installation conditions. The study also assesses the structural efficiency of the two options under various installation conditions and benchmarks their structural performance against more conventional jackets associated with lift-installed decks.

Until recently single skin flowlines were practically limited to short and medium length flowlines. To achieve longer flowline lengths with acceptable fluid outlet temperatures it was common to rely on pipe-in-pipe (PIP) technology. However PIP is quite difficult to manufacture difficult to install difficult to repair and all around more expensive than single skin flowlines. Recent advances in flowline burial have demonstrated that buried and coated (B&C) flowlines have thermal properties that make single-skin pipe systems feasible for many projects thought possible only with PIP. This paper presents some new found thermal properties of B&C systems and the steady state and transient performance benefits such properties provide to oil/gas flowlines.

The paper addresses a CALM (catenary anchor leg mooring) monobuoy arrangement. There are several monobuoys installed in deeper waters from 400 m to 1000 m or more. This increases the mooring line effects on the first order monobuoy behaviour and unlike the much larger drilling and production platforms they cannot be neglected. As shown in a frequency domain approach it is possible to devise restoring force effects damping effects and even inertial ones. Hence the full understanding of the behaviour is only reached if the mooring lines are properly considered. Model tests an ad hoc linear diffraction theory computer program (ProMono) and a fully nonlinear time domain computer program are used in the analysis.

The paper addresses a CALM (catenary anchor leg mooring) monobuoy arrangement. There are several monobuoys installed in deeper waters from 400 m to 1000 m or more. This increases the mooring line effects on the first order monobuoy behaviour and unlike the much larger drilling and production platforms they cannot be neglected. As shown in a frequency domain approach it is possible to devise restoring force effects damping effects and even inertial ones. Hence the full understanding of the behaviour is only reached if the mooring lines are properly considered. Model tests an ad hoc linear diffraction theory computer program (ProMono) and a fully nonlinear time domain computer program are used in the analysis.