Full-Scale Measurements on a Polar Supply and Research Vessel During Maneouver Tests in an Ice Field in the Baltic Sea

2014 ◽  
Author(s):  
Anriëtte Bekker ◽  
Mikko Suominen ◽  
Oskari Peltokorpi ◽  
Jakke Kulovesi ◽  
Pentti Kujala ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Time History ◽  
Full Scale ◽  
Whole Body ◽  
Research Vessel ◽  
The Baltic Sea ◽  
Ice Loads ◽  
Ice Field ◽  
The Baltic ◽  
Ice Impacts

Full-scale measurements were performed on the Polar Supply and Research Vessel, the S.A. Agulhas II during ice-trials in the Baltic Sea. Ice loads on the ship hull and propulsion system were measured concurrently with ice-thickness and whole-body vibration comfort for controlled maneuvers in a level ice field. These measurements were aimed at establishing the links between ice-properties, hull- and shaft loads and the vibration feedback received by the operator of the vessel. Results indicate that maneuvers significantly increase the frequency and magnitude of ice loads at the stern shoulder area as well as the ice impacts on the propellers. The number of ice impacts on the instrumented port side shaft line increased for turning maneuvers in a starboard direction. Occupants on the Bridge did not receive feedback through vibration transmission from ice impacts on the hull as a time-history of discrete events. Instead, ice passage excites the global bending modes of the vessel. Blade impacts between ice debris and the propellers are however perceivably transmitted to vessel operators. Although vibration exposure on the bridge is increased by operations in ice subjective experiences of vibration did not reach levels that caused discomfort.

scholarly journals Effect of Maneuvering on Ice-Induced Loading on Ship Hull: Dedicated Full-Scale Tests in the Baltic Sea

2020 ◽  
Vol 8 (10) ◽  
pp. 759
Author(s):  
Mikko Suominen ◽  
Fang Li ◽  
Liangliang Lu ◽  
Pentti Kujala ◽  
Anriëtte Bekker ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Measurement Data ◽  
Full Scale ◽  
The Baltic Sea ◽  
Load Duration ◽  
Ship Control ◽  
Level Ice ◽  
The Baltic ◽  
Full Scale Tests ◽  
The Impact

Maneuvers in level ice are common operations for icebreakers and polar supply vessels. Maneuvering exposes the midship and stern area to ice interaction, influencing the magnitude and frequency of ice-induced loading in these areas. However, full-scale measurements do not typically cover the midship and stern areas, as measurements have commonly focused on the bow area. Controlled maneuvering tests were conducted during the ice trials of S.A. Agulhas II in the Baltic Sea. During these tests, ice-induced loading at different hull areas was measured simultaneously with ship control, navigation, and ice condition data. This work studied the effect of maneuvers on the characteristics and statistics of ice-induced loading at different hull areas and compared the impact to ahead operations. The study showed that the maneuvers had minor impact to the magnitude, frequency, and duration of loading at the bow and bow shoulder. On the other hand, maneuvers had a clear effect on the load magnitude and frequency at the stern shoulder. Additionally, a statistical analysis showed that the load magnitude increased as a function of load duration in all hull areas. Furthermore, the analyzed measurement data are presented and made available with the paper.

scholarly journals Reconstructing N<sub>2</sub>-fixing cyanobacterial blooms in the Baltic Sea beyond observations using 6- and 7-methylheptadecanes in sediments as specific biomarkers

2019 ◽  
Author(s):  
Jérôme Kaiser ◽  
Norbert Wasmund ◽  
Mati Kahru ◽  
Anna K. Wittenborn ◽  
Regina Hansen ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Time History ◽  
Atlantic Multidecadal Oscillation ◽  
Cyanobacterial Blooms ◽  
The Baltic Sea ◽  
Natural Processes ◽  
Baltic Sea Region ◽  
History Of ◽  
Diazotrophic Cyanobacteria ◽  
The Baltic

Abstract. Summer cyanobacterial blooms represent a threat for the Baltic Sea ecosystem, causing deoxygenation of the bottom water and the spread of the so-called dead zones. The time history of the Baltic Sea cyanobacterial blooms is known from in situ and satellite observations since the early 1980s, but still not well understood. By comparing both weekly-resolved trap sediments and a well-dated sediment core from the Eastern Gotland Basin with monitoring and satellite cyanobacterial data of the last ca. 35 years, it is shown here that 6- and 7-methylheptadecane lipids (expressed as 6+7Me-C17:0) are robust semi-quantitative biomarkers for diazotrophic cyanobacteria, and likely mainly for Nodularia spumigena. Using this organic proxy, it was thus possible to reconstruct the history of cyanobacterial blooms beyond the observational period with a resolution of 2–4 years since 1860. Cyanobacteria were constantly present, but in relatively low abundance until 1920, when they started to alternate between periods with high and low abundance. Interestingly, there seems to be no significant increase in cyanobacterial abundance in the 1950s, when eutrophication and deoxygenation of the Baltic Sea increased considerably. Decadal to multi-decadal fluctuations are likely rather related to variability in the Baltic Sea surface temperature and, ultimately, to the Atlantic Multidecadal Oscillation. A 7000 years long 6+7Me-C17:0 record from the Bothnian Sea also suggests a relationship with the mean summer temperature in the Baltic Sea region, but at a multi-centennial to multi-millennial timescale. The intensity of the cyanobacterial blooms in the Baltic Sea is thus likely mainly related to natural processes such as temperature variability, at least at a multi-decadal to multi-millennial timescale.

scholarly journals A Statistical Approach to Extreme Ice Loads on Lighthouse Norstro¨msgrund

2006 ◽  
Author(s):  
Lennart Fransson ◽  
Jan-Eric Lundqvist
Keyword(s):  
Baltic Sea ◽  
Statistical Methods ◽  
Strong Influence ◽  
Statistical Approach ◽  
The Baltic Sea ◽  
Ice Load ◽  
Ice Conditions ◽  
Ice Loads ◽  
The Baltic ◽  
Ice Pressure

Data from full-scale measurements of ice loads on lighthouse Norstro¨msgrund has been analyzed using basic statistical methods. Questions like scaling, duration of ice interaction and correlation of extreme ice loads on different segments of the structure are discussed. Typical ice conditions in the Baltic Sea are described in general and the region is divided into areas with similar ice and ice movements. Indications of strong influence of structure diameter on the effective ice pressure were confirmed by results obtained on other lighthouses in the area. The result can be used in simulations of ice load probabilities for fixed vertical structures with small diameters located in the Baltic Sea.

scholarly journals Complex research during the 33-rd cruise of research vessel “Akademik Nikolaj Strakhov”

2019 ◽  
Vol 59 (2) ◽  
pp. 305-307
Author(s):  
V. V. Sivkov ◽  
A. A. Peyve ◽  
E. S. Bubnova ◽  
V. R. Akhmedzyanov ◽  
V. A. Kreehik ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Baltic Sea ◽  
Research Vessel ◽  
Geological Samples ◽  
Digital Models ◽  
The Baltic Sea ◽  
The Baltic ◽  
Echo Sounder

The 33rd cruise of the R/V “Akademik Nikolaj Strakhov” was in the Atlantic Ocean and the Baltic Sea, and included a complex of geological, hydrological and hydrochemical works. According to the results of a multibeam echo sounder survey of the bottom, digital models of bottom landscapes were constructed. Using the dredging method, new geological samples were obtained, and the values of geothermal flows in the Atlantic Ocean were measured.

scholarly journals Imagining Godzilla: An Art Research Network Platform

2021 ◽  
pp. 293-330
Author(s):  
Andy Best
Keyword(s):  
Baltic Sea ◽  
Research Network ◽  
Research Vessel ◽  
Research Projects ◽  
The Baltic Sea ◽  
Creative Research ◽  
Network Platform ◽  
Art Research ◽  
The Baltic ◽  
Visual Technologies

This chapter is an extended contribution from a collection of artists headed by Andy Best and Merja Puustinen. Best and Puustinen’s project, ‘Imagining Godzilla’, turned their Polynesian-style sailing catamaran into a research vessel on the Baltic Sea. With other artists on board, the catamaran became a mobile platform for creative-research projects on topics ranging from undersea Internet cables, new materialist explorations of phosphate circulation, audio-visual technologies and knowledge, and performative/auto-ethnographic accounts that probe the boundaries of life on land and sea.

Temporal and spatial sedimentation rate variabilities in the eastern Gotland Basin, the Baltic Sea

Boreas ◽  
2002 ◽  
Vol 31 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Christian Christiansen ◽  
Helmar Kunzendorf ◽  
Kay-Christian Emeis ◽  
Rudolf Endler ◽  
Ulrich Struck ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Sedimentation Rate ◽  
The Baltic Sea ◽  
Gotland Basin ◽  
Temporal And Spatial ◽  
The Baltic

Russian Oil: Production and Exports

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto
Keyword(s):  
Baltic Sea ◽  
Statistical Data ◽  
Oil Production ◽  
The Baltic Sea ◽  
North West ◽  
The North ◽  
Oil Transportation ◽  
Sea Ports ◽  
The Baltic

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.

Paleoecological study of bottom sediments of the lake Goluboye (Karelian Isthmus) according to the results of diatom analysis

2019 ◽  
pp. 265-269
Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Bottom Sediments ◽  
Modern Science ◽  
Karelian Isthmus ◽  
The Baltic Sea ◽  
Diatom Analysis ◽  
North West ◽  
The North ◽  
Important Direction ◽  
The Baltic

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)

2008 ◽  
Vol 37 (4) ◽  
Author(s):  
Małgorzata Leśniewska ◽  
Małgorzata Witak
Keyword(s):  
Baltic Sea ◽  
The South ◽  
Gulf Of Gdańsk ◽  
The Baltic Sea ◽  
Southern Baltic Sea ◽  
Gulf Of Gdansk ◽  
Southern Baltic ◽  
The Baltic ◽  
Palaeoenvironmental Changes

Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)The palaeoenvironmental changes of the south-western part of the Gulf of Gdańsk during the last 8,000 years, with reference to the stages of the Baltic Sea, were reconstructed. Diatom analyses of two cores taken from the shallower and deeper parts of the basin enabled the conclusion to be drawn that the microflora studied developed in the three Baltic phases: Mastogloia, Littorina and Post-Littorina. Moreover, the so-called anthropogenic assemblage was observed in subbottom sediments of the study area.

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