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Petroleum oils discharged into natural waters undergo changes in composition described as weathering with the result that the oil becomes less harmful to aquatic life. The rate of weathering depends on factors such as temperature sunlight mixing processes in both air and water and metabolism by microorganisms. A fuel truck overturned at a bridge over the Cameron River Northwest Territories Canada in March 1983. The spilled diesel penetrated the snow cover moved along the frozen surface of the ground and entered the ice-covered Cameron River. A sample from the river eight days after the spill was compared with the original cargo using three quantitative and independent methods (gas chromatography with a comparison of the sample patterns by principal component analysis acute toxicity to fish and tendency to taint fish with an oily taste). The two samples were essentially the same in all respects. It is shown that the low ambient temperatures and cover by ice and snow greatly reduced the weathering phenomenon often described with spilled oils and permitted the oil to retain its toxic and tainting properties.

This paper characterises the assemblages of demersal elasmobranch on the bottom trawl fishing grounds along the continental shelf and upper slope and in unexploited deeper areas of the middle and lower slope off the Balearic Islands. Experimental trawl surveys are analysed for the main species in terms of species composition community structure and distribution and population structure. The aim is to provide information relating to the diversity and abundance of elasmobranches which could serve as a reference for the monitoring of future trends in the same area and would allow comparison with other Mediterranean areas. A look is taken at materials and methods followed by results and discussion.

The LPA Watercraft is a 25-metre aluminium landing craft that has been designed to DNV's HSLC rules and the Commonwealths requirements to meet the requirement of Defence Project JP2048 Phase 1a. The Watercraft significantly improves the deployment capabilities of HMAS Manoora and Kanimbla reducing the time it takes the RAN's (Royal Australian Navy's) amphibious ships to unload a battalion-size group of soldiers equipment and stores by at least 30%. Equipped with 130 square metres of open vehicle deck sufficient to accommodate 5 ASLAVs (8 wheeled Light armoured vehicle) rather than the present limit of 2 onboard the current landing craft the LCM8s. It has full drive-through capability with bow and stern doors can carry 65 tonnes of vehicles and-or cargo and is able to undertake independent open water passages with full accommodation for crew. The vessel has been designed so that it is capable of being stowed on the HMAS Manoora and Kanimbla foredeck and handled by the ship's crane which has meant strict weight and size restrictions. Twin Detroit Diesel series 60 diesel engines coupled to two Doen DJ260 waterjets provide significantly improved manoeuvrability beach landing capability and a range of in excess of 700 nautical miles. The contract also includes the full suite of deliverables

MODUS (MObile Docker for Underwater Sciences) is a versatile deep-sea intervention system for heavy loads. As the German part of the European project GEOSTAR 2 MODUS is dedicated to deploy and recover an innovative deep-sea benthic observatory with underwater communication system for long-term missions at abyssal depths (4000 m water depth). The system is developed manufactured and tested during the project. The paper focuses on design hydrodynamic and hydroelastic analysis and full-scale tests. Thus it documents the iterative process of computer aided design (CAD) and hydrodynamic analysis (CFD) illustrated by three concurrent design variants. In addition the entire system with ship umbilical and the prototype sub-sea modules is evaluated and preliminary results of hydroelastic simulations are presented. The paper closes with preliminary results from the deep-sea trials in the Tyrrhenian Sea (September 2000) in water depths up to 3500 m employing the Italian research vessel R/V Urania.

Conf held in Douglas Isle of Man 31 May - 2 June 1978 Papers are Small engines - an energy perspective CEC contribution to the SAE proposed two stroke cycle engine classification Lubrication of small engines Quality and performance of evaluation of 50cc two stroke engine oils Independent lubrication system for two stroke cycle engines Modern stepped piston engines Future fuels for small internal combustion engines Evolution of electronic ignition on motor cars Computer aided design of small two stroke engines for both performance characteristics and noise levels The small company approach to engine design and production Some new development aspects of a small capacity high output two stroke engine with reed valve induction Aspects of two stroke design viewpoints from outboard developments The development of a novel design of vibration free two stroke small engine The design and development of intake and exhaust silencers for high performance Cylinder components for small internal combustion engines

Field development with floating production storage and offloading (FPSO) vessels and subsea wells and manifolds is increasing. However FPSOs are often too expensive to consider for a single field unless they can be decommissioned and sold on at the end of the field's life. The ability to do this is hampered by the fact that many FPSOs are designed for specific sites. FPSO topsides vessels moorings risers and subsea systems are considered individually in terms of their site-specific nature and suitability for re-use. Suggestions for making FPSO design more suitable for re-use are also made.

Innovative shallow suction anchor piles have been used to permanently moor a process and accommodation barge on a field developed by Elf Congo in the Gulf of Guinea. The design of the anchoring system is presented together with a description of the suction pile installation by under pressure. The monitored performance of the piles during installation is evaluated and appears to be very smooth. Measured penetration resistances agreed perfectly with predicted values. This demonstrates the reliability of the installation method. Future applications are briefly highlighted.

A great number of new deepwater developments are currently being considered not only for the offloading of oil but also for the offloading of LNG from LNG FPSOs. Offloading operations have a large impact on the design and operation of FPSOs. The safety of personnel and the offshore structure together with the possible environmental impact have been of concern to regulating authorities as well as to the oil and gas industry. There are two stages in the offloading process: the approach and connection of the export tanker to the FPSO and the departure from the FPSO; and the offloading phase. During the design process the evaluation of each phase requires specific tools and methods. Both phases are discussed. Pages 15 and 19 contain diagrams only.

In this paper the design concepts of manufacturing X80 and X100 linepipes by UOE process were described in relation to the effects of micro-alloying elements and plate rolling conditions on the metallurgical and mechanical properties. The mechanical properties of the X80 and X100 grade linepipes were presented. For evaluating the deformation behaviour of an actual pipe a hydrostatic pressure test was conducted using the X100 grade pipe and the results were compared with the tensile test using ordinary API specimen which has full-thickness but is deformed to a flattened shape. Results of the statistical investigations in mass production of the X80 linepipes were also introduced.

Modern naval vessels have comprehensive platform management capabilities that allow them to achieve unprecedented levels of operational effectiveness and contribute to crew reduction. The design of advanced platform management systems requires an in-depth analysis of the consequences they will have on the vessel design and operation during the early project definition phase. The paper contends that analysis should be performed by a team with different expertise and shall include the system architecture and technology the level of functional integration the human-system integration the applicable standards and rules and the survivability of the system.

This paper deals with the four Agip/Elf steel gracity platforms designed by Tecnomare to be installed at Loango field (offshore Congo-Brazzaville). The origin of the particular structural geometry is explained together with the necessity for a gravity platform rather than a piled one. Design methods and steps are described. Static and dynamic behaviour of the structure is shown, and design hypotheses compared with operative conditions during the main installation and construction phases. The construction phases are summarised, and construction and installation techniques described and discussed on the basis of model test data and of observations made during the phases. Problems which arose during construction are analysed and reviewed.

The cost of meeting API 653 recommendations for fuel tank inspection is governed by the expense of removing tanks from service and cleaning them for manned entry. Raytheon Service Company has developed a system called Tank Ray that can verify the integrity of above-ground fuel-storage tank floors without removing its contents. The Tank Ray system consists of a multi-sensor inspection system and an acoustic navigation system carried on a remotely operated vehicle (ROV). The ROV crawls over the tank floor and brushes aside sediment to allow inspection. The navigation system is used to map floor thickness data. The inspection methodology and requirements tank environment and ROV requirements are briefly discussed. A commercial system is now being manufactured by Perry Tritech.

Since 2002 the Marine Advanced Technology Centre (MATE) has sponsored a nation-wide remotely operated vehicle (ROV) competition. This year's competition consisted of two mission tasks based on ocean observing systems to be completed in less than 30 minutes at a depth of 12.2 metres. Taking a different approach from previous years the MIT ROV team designed its main ROV MTHR not only to compete in the MATE competition but also to be used afterwards for both didactic and practical purposes. In addition to MTHR a second ROV JR1 was built to act as a flying-eye to aid in navigation during the competition. Working together these two ROVs create a powerful system capable of completing complex tasks and providing a valuable research and teaching platform. After some introductory information a look is taken at the MTHR design followed by the JR design. Next results are considered.

This paper presents the results of analysis performed to clarify the limits for mono-column TLPs and explores means to extend the applicable range of TLPs to ultra-deep water. Detailed coupled motion and fatigue analyses were carried out for a realistic production case over a wide range of water depths (1000 to 3000m) for moderate (Gulf of Mexico) and mild (West Africa) conditions. The existing Matterhorn SeaStar TLP design was used as the test platform for the study. The topsides payload and surface-well count were held constant while adapting the hull and tendons for increasing water depth. Consideration was given to both conventional and non-conventional but near-term tendon solutions. Following the engineering analysis design alternatives are compared on an economic basis.

The IHD-NSWC (Naval Surface Warfare Center Indian Head Division along with the rest of the US Navy community is very concerned with the increasing restrictions placed on shipboard waste disposal. Overboard discharge and traditional disposal of excess solid wastes produces a variety of pollutants and waste. IHD engineers are developing MSO (molten salt oxidation) technology as an efficient and flexible waste treatment solution. Exactly how waste materials are treated in this process is described. IHD engineers developed a feasibility study in order to determine the usefulness of MSO technology in the destruction of Navy shipboard wastes. The current MSO system in operation at IHD requires a footprint of only 34" x 34" for the heaters and reaction vessel. This relatively small size together with the reasonable cost for implementing a new MSO system shows that MSO could be an efficient method for the destruction of certain shipboard wastes.

Electric voltage measurements have been carried out using long submarine cables to obtain the strength of the toroidal field and its variation at the core-mantle boundary. Several observational constraints on the toroidal field have been obtained. The physical plausibility of them is examined by carrying out the simple but systematic computation of kinematic dynamo surrounded by electrically conducting mantle. It is confirmed that the strength of the toroidal field variation obtained observationally can be generated by the hynamo naturally. The ability of the electric signal coming from the geodynamo to detect is re-examined against those electric signals coming from magnetotelluric or motionally-induced electric fields. Understanding the decadal variation of ocean flow is indispensable for detailed discussion of the toroidal field using submarine cable voltages.

Conventional electronic noses called eNoses can produce a recognisable response pattern using arrays of dissimilar but not specific chemical sensors. However eNoses cannot identify or quantify the concentration of VOCs in wastewater because they do not separate the individual chemical compounds. A new type of eNose called the zNose is presented. This is used to measure volatile organic compounds in water. It is based upon ultra-fast gas chromatography and can provide a cost-effective on-site measurement solution. It is able to perform analytical measurements of volatile organic vapours in near real time with part-per-billion sensitivity

An innovative bottom acoustic survey technique involving an Autonomous Underwater Vehicle (AUV) is presented. In this technique the AUV carries a low frequency broadband acoustic source and a towed acoustic array and operates close to the seabed. The proposed technique has great potential to improve the capability of detecting and classifying buried or half buried targets and providing a more reliable sub-bottom geoacoustic inversion method over a large area for geological and geophysical surveys. Results from numerical simulations based on synthetic data are presented to demonstrate how the geometric and physical properties of the seafloor sub-bottom and buried targets influence the received echoes in either the time domain the frequency domain or both. The simulation results are discussed.

In February 2000 nearly 700 m3 of Orimulsion 400 (a bitumen- in-water emulsion) spilled from a pipeline and a storage tank into a bounded area in a power plant on the NW Sardinian coast. A small portion of it poured into the plant rainwater outlet and was supposed to have reached the sea flowing together with the thermal outflow. Given that Orimulsion 400 is water continuous the majority of the micron-sized bitumen droplets would be expected to rapidly disperse. However any remaining aggregates could in theory be washed ashore and-or possibly sunken. This hypothesis is evaluated by carrying out surveys and sampling campaigns. Samples of bituminous material were collected and analyses were performed to compare the fingerprinting of all of the samples taken with samples of Orimulsion 400. The efficacy of the analytical approach (fingerprinting technique) is shown as a tool to single-out identify and distinguish a specific product.

The Ross Worm (Sabellaria spinulosa) can when found in sufficiently high densities form a biogenic reef that attracts other fauna to the same vicinity. Such reefs are now protected as an Annex 1 habitat under the European Union Habitats Directive. As a result companies proposing to lay infrastructure such as pipelines and cables or place structures such as rigs anchors or piles on the seabed are obliged to move their proposed structure's location if a sabellaria reef is found within the survey area. The only way of conclusively confirming the presence or otherwise of sabellaria is through direct sampling such as video and camera work or grab sample. However because they are all limited spatially it is prohibitively expensive to carry out such as survey. Additionally grab sample destroys the very habitat that should be protected. A habitat survey in the SNS (Southern North Sea) used remote sensing by side-scan sonar to identify reefs as characterised by the seabed's hummocky nature. This included patches of potential colonisation within areas of gravel and coarse sands