scholarly journals DESIGN, ANALYSIS AND FIELD TEST OF A DYNAMIC FLOATING BREAKWATER

1976 ◽  
Vol 1 (15) ◽  
pp. 159 ◽  
Author(s):  
D.J. Agerton ◽  
G.H. Savage ◽  
K.C. Stotz

Interest in floating breakwaters has been generated in recent years because the concept offers the potential of providing a less expensive alternative to traditional, solid wall type barriers for providing permanent wave protection to the thousands of new recreational boat harbors and marinas that have been built in the past 20 years. Also, they may be able to provide temporary, mobile wave protection during construction and installation of offshore facilities for oil transfer and production operations, defense facilities and other offshore structures in deeper water (depths exceeding 50 to 100 feet). The engineering director of one of the largest and most active offshore oil producing companies recently stated that they would be willing to pay up to $6 million for a mobile, floating breakwater that had the proven capability to significantly reduce risks due to wave action during offshore erection in the North Sea or elsewhere. Considering the investment in just one deep water oil production platform already exceeds $100,000,000, the worth of such a reusable, wave protection system during the critical erection period of a platform should be large.

1981 ◽  
Vol 18 (2) ◽  
pp. 171-178 ◽  
Author(s):  
R. E. Gibson ◽  
B. E. W. Dowse

The selection of the type of drilling or production platform appropriate to a particular off shore site depends, chiefly, upon the likely severity of the marine environment, the nature of the seabed, and the geotechnical properties of the underlying soils and whether there exists a requirement for on-site oil storage. Although these physical factors have all played important roles in shaping the evolution of offshore structures, particularly in the North Sea, economic considerations and the national preferences of client companies have on occasion been decisive.This paper traces the evolution of offshore oil production structures for the North Sea with particular emphasis on the role played by geotechnical engineering during the conception, design, and construction of some of the largest movable structures in the world.


1994 ◽  
Vol 29 (3) ◽  
pp. 37-41 ◽  
Author(s):  
W. G. Cazemier

In the past, the anadromous salmonids, Atlantic salmon (Salmo salar) and sea-trout (Salmo trutta), have formed natural populations in the river Rhine. From the beginning of the nineteenth century onwards, the greater part of the drainage area of the river has been gradually altered from a more or less rural and agricultural area, into a highly industrialised one with subsequent industrialisation, river-engineering and heavy pollution. These developments are considered to be the major cause for the disappearance of the populations of anadromous salmonid fish in the 1950s. The water quality has recovered significantly during the past 25 years. From about 1975 onwards, this process gave rise to a recovery of the anadromous trout population. Results of recent studies of the sea-trout migration pattern are presented. They reveal that nowadays these salmonids can complete their up- and downstream migrations from the North Sea to places, situated at hundreds of kilometres upward the river and vica versa. The numbers of recorded Atlantic salmon and catch locations in inland waters are presented. They show a significant increase since 1989. These phenomena can be understood as promising signs of the recovery of the Rhine aquatic ecosystem.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Johan van der Molen ◽  
Luz María García-García ◽  
Paul Whomersley ◽  
Alexander Callaway ◽  
Paulette E. Posen ◽  
...  

Author(s):  
Tor E. Berg ◽  
Gunnar Gudmundset ◽  
Ulf Klevstad

Recently there have been a number of incidents involving drifting ships and offshore structures in the North Sea. Increasing traffic density combined with harsher weather and less experienced crews has led the Norwegian Coastal Administration to focus on improving the skills of personnel on board emergency response vessels operating off the coast of Northern Norway. This is order to reduce the consequences of incidents with disabled vessels sailing in the vulnerable coastal environment of the Norwegian and Barents Seas. In addition to field exercises involving dedicated Norwegian emergency response vessels and different types of vessels made available by shipping companies, training takes place on full mission bridge simulators. As part of an ongoing R&D project, MARINTEK and SMS invite stakeholders to participate in short workshops on topics related to the specification of functional requirements for emergency towing vessels and the sharing of experience from recent emergency towing operations.


2018 ◽  
Vol 203 ◽  
pp. 01011
Author(s):  
Mohamed Latheef ◽  
Nasir Abdulla ◽  
Mohd Faieez Mohd Jupri

MetOcean conditions in the South China Sea (SCS) indicates that unlike other locations such as the North Sea, the magnitude of the currents can be relatively large. In addition, these currents are strongly sheared. The present study focused on the typical design problem of calculating the ultimate base shear and overturning moments for slender fixed structureswiththe inclusion of the interaction between the currents and the wave field. It has been found that the loads on average can be around 15% larger when this interaction is accounted for in the calculation of the loads, highlighting the importance. In addition, the level of these amplifications were found to be dependent on the sea state steepness and the relative water depth. While no clear trend was found (changed case by case) in the present work, incorporating the vertical structure of the current was found to change the pattern of the amplification of the loads.


Antiquity ◽  
2017 ◽  
Vol 91 (358) ◽  
pp. 1095-1097
Author(s):  
Hans Peeters

Over the past decade or so, the submerged prehistoric archaeology and landscapes in the area that is known to us today as the North Sea have received increasing attention from both archaeologists and earth scientists. For too long, this body of water was perceived as a socio-cultural obstacle between the prehistoric Continent and the British Isles, the rising sea level a threat to coastal settlers, and the North Sea floor itself an inaccessible submerged landscape. Notwithstanding the many pertinent and pervasive problems that the archaeology of the North Sea still needs to overcome, recent research has made clear that these rather uninspiring beliefs are misplaced.


2019 ◽  
Vol 20 (3) ◽  
pp. 537-551 ◽  
Author(s):  
Juan Estrella‐Martínez ◽  
Bernd R. Schöne ◽  
Ruth H. Thurstan ◽  
Elisa Capuzzo ◽  
James D. Scourse ◽  
...  

Author(s):  
M. H. P. Kimm ◽  
D. Langlands

This Paper covers various aspects with respect to the selection and operation of air filtration associated to offshore gas turbine installations. As the Offshore North Sea industry moves into its second decade, Operators are still trying to improve machine availability and reduce maintenance costs. One of the main contributing factors in their failure to achieve the ideal condition has been poor inlet air filtration caused by bad design and incorrect filter selection. The majority of offshore installations are equipped with filter systems which were originally designed for use on ocean-going vessels. The performance of what has become known as the “High Velocity Salt Eliminator System” has, in most cases, been unsatisfactory, thereby creating a necessity for a continuing search into alternative filter systems. The experiences of most Operators in the North Sea have been very similar, and examination of the platform environment explains why this should be the case. To emphasize the affects of poor air filtration and the savings that can be achieved by the Operator in recognising and correcting the problems, specific reference is made to the experience of Mobil North Sea with the Beryl Alpha Production Platform.


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