Vecima Technology (United Kingdom)

In the context of national school reform, teachers’ voices are critical but often missing from official policy discussion. While there is much literature on schooling policy at a national level that has examined different elements of politics, policy, bureaucracy or global influences on education, there has been limited attention given to the discourses utilised in these elements and the way these impact how teachers perceive themselves within the national policy environment. This study sought to bridge this gap between national policy and teachers’ experiences by examining the overlapping spheres of politics, schooling bureaucracy and teachers and the way actions in each of these reverberate through the schooling system to impact other parts of the policy cycle. Paper 1—Funded, then Forgotten: Politics, Public Memory and National School Reform—provides the foundation for the study, by using ministerial media releases over the life of Australia’s National School Reform Agreement as a lens to analyse how federal education ministers attempted to shape public perception of schools, schooling and school reform. Paper 2—The Aporia of Education Policy: National School Reform and the Limits of Policy Enactment—examines the elements contributing to the aporia in schooling bureaucracy, revealing that factors such as government timelines, evaluation processes and the placement of accountability on schools prevents policy from being mediated to schools as intended. Paper 3—Teacher Narratives of National School Reform: Storying the Effects of Education Policy Flows on Teachers’ Work and Lives—considers the perspectives of teachers regarding national school reform through ‘storied’ post-qualitative, composite narratives which depict how national policy is perceived by teachers ‘on the ground’. Finally, Paper 4—Bridging the Extremes of Policy Research: a Narrative Exploration of the Impact of National Education Policy on Teacher Constitution of Self—presents further post-qualitive narratives of teacher perspectives regarding how national policy affects them on a personal level and how they constitute themselves as professionals within this reform environment. Overall, this study demonstrates how policy breakdowns and aporia occur at various points as national schooling policy flows towards schools and teachers. By using narrative storying to give voice to teachers’ experiences of national school reform, this study highlights how teachers’ perspectives of schooling reform are vital to their potential success and calls for a change in the relational culture between all levels of school politics, bureaucracy and school contexts.

A home-network is expected to spread now. We considered the security issues on home networks based on power line communication, because these topics have not been sufficiently considered. We discuss the issues, risk and required countermeasures. These issues are categorized into control network, information network, AV network and community network. We also discuss differences on the security between the power line communication and wired-LAN or wireless-LAN.

ABSTRACT The components of the Hutton TLP tension legs are assembled using integral rotary shouldered couplings. This taper threaded coupling was purposed designed to withstand the severe fatigue and high static loads imposed by the environmental and pretension requirements. As no previous work had been undertaken on the design of high strength taper threaded couplings for this application a carefully coordinated design and manufacturing programmer had to be developed. The paper outlines the design and analysis techniques used, together with the testing performed and the results obtained. In addition, the task of ensuring that design requirements were met during manufacture and installation wi11 al so be discussed and solutions, in particular the purpose designed electronic gauging system, described. INTROUCTION Installation of the TLP at the Hutton Field was completed on the 15th July, 1984 with the mooring system's sixteen tension leg assemblies, four at each platform corner, connected to the seabed foundations. The two days of tension leg deployment was the final test for coupling computability when components from three different manufacturing sites were connected together for the first time. A total of 256 joints were "made up" to the prescribed design limits required to ensure satisfactory performance throughout the platform operating life. Proceeding this short installation period was a design process which lasted four years and encompassed extensive analysis and testing. During this time material requirements were pushed to extremes, new attitudes were required in production and new technology introduced into thread gauging practices to enable the manufacture of couplings in accordance with stringent performance requirements. In addition the assembly and make up requirements for this coupling were more demanding than that required for conventional drill collars. MOORING SYSTEM DEFINITION Each tension leg assembly (1) comprises seventeen components as shown in Figure 1. At the upper end of each leg is a tension adjusting assembly which transfers the leg load to the hull structure via the load block assembly. The load path extends down three tension 1eg elements to the crossload bearing which is located at the base of the tension leg shrouds. A further eleven tension leg elements extend below the crossload bearing terminating at the anchor connector which locks into the foundation template. A 75mm bore is provided down the centre of each tension leg to allow hydraulic operation of the anchor connector, this is filled with a corrosion inhibitor which also acts as a couplant for the in service NDE' system. Angular displacement of the tension legs due to the horizontal motion of the platform is accommodated by elastomeric flex joints in the anchor connector and cross load bearing. The seventeen components are connected by integral rotary shouldered screwed couplings as shown in Figure 2.

ABSTRACT Installation of the Hutton TLP required precise simultaneous control of several complex systems. This paper describes the equipment and operations involved in the deployment and connection of the sixteen tension legs, and the documentation used for control. The equipment trials and personnel training programmes undertaken to ensure the first-time success of this unique operation are presented. The paper concludes with an appraisal of the installation process and the significance of the principles employed to the development of deep water TLPs. INTRODUCTION Installation of the Hutton Tension Leg Platform, a new concept in oilfield development(l), was carried out in under four days. The process of installation involved translation of the free floating vessel into a vertically restrained platform. This operation was unprecedented in its reliance on multiple systems, novel equipment and specially trained personnel. It entailed the assembly and deployment of sixteen tension legs, their connection to four pre-installed foundations, and the application of 13,000 tonnes of tension. These unique operations required the deve1opment of detail ed procedures to control the installation systems and activities. The use of equipment unproven in service and personnel inexperienced in the special operations necessitated intensive trials and training programmes to ensure a safe and efficient installation. The installation of the TLP, 90 miles north-east of the Shetland islands and in a water depth of 148 metres, was completed on 15th July and first oil produced on 6th August, 1984. PRINCIPLES OF INSTALLATION The TLP is a compliant structure where the vertical motions of heave, pitch and roll are suppressed by leg tension. The tension is induced by an excess of buoyancy over platform weight. This concept can be represented by the equation of static equilibrium:(Equation available in full paper) The static 'pre-tension' must be sufficient to maintain the legs in tension for all operating conditions and extreme environmental events. Approximate values are:(Equation available in full paper) This condition is achieved by restraining the platform approximately 10 metres deeper in the water than its free floating draft. Significant changes in operating loads, riser tensions and platform centre of gravity can be accommodated by the transfer of ballast. Installation requirements were a major factor influencing the design of the mooring system, thus engineering for installation proceeded in parallel with mooring system design. An early decision in the design process was the method of 'stabbing' the legs into the foundation mooring sleeves. Unaided stabbing was considered the most reliable, efficient and easily engineered method, provided the platform position could be maintained within acceptable tolerances. The design environmenta1 conditions were established as a wind speed of 10 m/s and a sea state typically of 2m significant wave height and 7s period. Analyses and model tests demonstrated acceptable leg motions and established a vessel positioning tolerance requirement of 1.5m during stabbing.

For the dynamic analysis of structures or machines supported on piles it is convenient to use the substructuring technique and to replace the soil-pile system by frequency-dependent impedances at the structure-pile interface. These impedances represent the dynamic stiffness and damping of the system under harmonic excitation. Analytical evaluation of these properties is possible only in certain idealized cases (Nogami and Novak, 1976; Novak and Nogami, 1977), and the more generally applicable finite element method could be quite expensive. An alternative method, which is approximate but has quite wide applicability, involves treating the soil surrounding the pile as a Winkler medium so that the soil reaction at a point on the pile depends only on the displacment of the pile at that point. With this technique it is possible to treat any end condition at the pile-tip, arbitrary variation of cross section with depth and layering of the soil medium.

ABSTRACT A new integrated deck concept is presented which utilizes a single barge to transport the deck and a specially designed substructure. The details and advantages of the concept are discussed in detail. The concept, called HIDECK, is presently being used on the Maureen Field Development in the North Sea and details are inc1uded. Methods for accomplishing mating of a HIDECK to a previously installed substructure offshore are presented and potential future applications of the concept are discussed. INTRODUCTION HIDECK, a new integrated deck concept, has been developed during the past three years to reduce the cost of offshore platform decks, reduce the time for field development and improve the constructability, operational characteristics and safety of decks. Typically in the North Sea, offshore platform decks are composed of eight to twenty modules which must be set on a substructure by a large marine derrick barge and then hooked-up. The hook-up, together with rather extensive commissioning, has required an average of approximately 1,000,000 man-hours and ten months. HIDECK is completely fabricated and outfitted onshore, then towed and set on the substructure in one piece using a large transport barge. In this way, the derrick barge plus 90-95% of the offshore hook-up are eliminated. The deep open truss structure of HIDECK permits a more orderly lay out of facilities and straighter piping and cabling runs which reduce onshore construction costs when compared with the construction cost of modules. Hence, not only is offshore hook-up cost nearly eliminated, but onshore construction cost is also reduced. North Sea modular decks, including modules and module support frame, commonly consist of up to 60% structural steel, and this percentage generally trends upwards as modules are built larger. Much of the steel in a modular deck is required for structural integrity of the module during offshore transportation and lifting into place on the platform. Hence, during the operation of the deck, this steel is stressed to only a small proportion of the allowable stress. HIDECK, which is built and transported in one piece, utilizes a "balanced stress" design to reduce the percentage of steel required to approximately 30-40% of the total deck weight. The balanced stress concept makes most of the principle steel work at near its allowable stress during both transportation and operation of the deck. As an example of the steel savings introduced by HIDECK, consider a modular deck and a HIDECK each containing 10,000 tonnes of equipment (dry). The modular deck would require approximately 15,000 tonnes of steel for a total deck weight (dry) of 25,000 tonnes. The HIDECK would require approximately 6,000 tonnes of steel for a total deck weight (dry) of 16,000 tonnes. Hence, HIDECK would save approximately 9,000 tonnes of steel. On both levels of HIDECK, access lanes are provided for forklift trucks for accessing equipment during maintenance procedures. These access lanes also provide direct escape routes thus enhancing the safety of the deck. Such access lanes are impossible, of course, in a modular deck.