Dynamic Response Analysis and Positioning Performance Evaluation of an Arctic Floating Platform Based on the Mooring-Assisted Dynamic Positioning System
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe article is well planned, the assumptions of the method and the results obtained are presented with due care, and the conclusions follow from the results obtained. In the reviewer's opinion, the article is suitable for publication in its present form.
The only minor comment concerns the legibility of some of the figures (especially 9). It would be useful to include digital versions of the figures.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Authors,
May I draw your attention to the following issues:
Abstract - PID is not defined, as are FEM or DEM.
2. Theoretical method. In equation (2), g and ω are not defined. Please check for the rest of the equations, as it can be seen that rho in equation 4 is also not defined, as well as i in equations 5 and 6.
3. Numerical model and validation. In which way is the prediction performed should be detailed.
In Figure 3, the numbers are very small, could they be a bit bigger?
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsDynamic response analysis and positioning performance evaluation of an arctic floating platform based on the mooring-assisted dynamic positioning system
Yingbin Gu , Zhenju Chuang, Aobo Zhang, Ankang Hu, and Shunying Ji
The manuscript addresses the general issue of the exploitation of oil and gas resources in the Arctic region considering the floating offshore platform technologies. In particular, the work deals with the design of the positioning system and the results of a numerical model, composed of a mooring-assisted dynamic positioning system and the Kulluk platform, are described. The topic is of interest, and in recent years there has been an increasing development of offshore floating technologies for the oil and gas resources exploitation and for the wind and wave energy production. The challenges are still many and several studies are focused on these issues.
Overall, the manuscript is well structured but some points and aspects need to be better discussed.
Major issues are highlighted hereafter.
1. The manuscript describes the results of the numerical model; it would be useful to mention the lack of a scale-model test and related comments;
2. The novelty of the work should be better highlighted. In the reviewer's opinion, two aspects should be underlined to better frame the manuscript in the context of the topic and to enhance the study carried out.
The state-of-the-art should preliminarily highlight the scientific and technological advances in the field of the floating offshore platform driven, in the recent years, not only by the traditional use for the oil and gas resources exploitation but also by the challenges relating to the wind and wave energy exploitation. The second aspect is related to the importance of these studies in areas that are still underexploited. In this context, studies have been carried out to evaluate the potential in sea basins that have been little exploited up to now, for example, for the high water depth or environmental conditions. The results of these studies, like that described in the manuscript, could favor the possibility of using these technologies also in new basins where the water depth or the environmental conditions have conditioned its applications. Overall, the trends on these issues in recent years are remarkable and the bibliography is extensive (see, e.g., Amaechi et al., Review on Fixed and Floating Offshore Structures. Part I: Types of Platforms with Some Applications, J. Mar. Sci. Eng. 2022; Samie, Practical engineering management of offshore oil and gas platforms, Elsevier, 2016; Ja'e et al. Optimisation of mooring line parameters for offshore floating structures: A review paper. Ocean Engineering, 2022; Stewart & Musculus. A review and comparison of floating offshore wind turbine model experiments, Energy Procedia, 2016; Tomasicchio et al. Dynamic modelling of a spar buoy wind turbine, Proc. 36 th Int. Conf. on Ocean, Offshore and Arctic Engineering, Am. Soc. of Mech. Eng. (ASME), Trondheim, Norway 2017. Zhang et al. Novel method for designing and optimising the floating platforms of offshore wind turbines. Ocean Engineering, 2022; Henderson & Loe, The Prospects and Challenges for Arctic Oil Developmen, Ogel, 2016; Pantusa & Tomasicchio, Large-scale offshore wind production in the Mediterranean Sea, Cogent Engineering, 2019).
I suggest to include in the Introduction section these aspects that can be useful to better frame the manuscript and its novelty compared to the current state of the art.
3. An important aspect is the validity of the obtained results. Since there is no a scale-model test, it would be interesting compare the results with other different mathematical models in terms of ice loads and mooring tensions. Comments on this aspect or on future research objectives in terms of validation and accuracy of the results should be included.
4. The manuscript could benefit from specific comments on choices/motivations in terms of platform selection, mathematical model, etc.
5. All data used should be better described. I miss a clear description of all the data used and of the sources of environmental data. Moreover, it would be useful a more detailed description of the Kulluk platform.
6. The manuscript should include some comments on the motivations for the choose of the Kulluk platform (considering that it is a dismissed platform) and if further studies on other similar platforms are planned (e.g. Golian platform ENI- Norwergian Arctic)
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThe authors proposed an interesting paper regarding a dynamic response and positioning study of an artic floating platform. Although the manuscript is, in general, well written, there are some points that need to be attended before a possible recommendation for publication in JMSE. The main concerns are related to: paper organization, validation information and methods descriptions.
C1. Abstract "Lines 24-25". This phrase seems redundant since it is well known that a positioning system plays an important role in ship motions in the horizontal plane. I suggest to provide more interesting results/findings, including, perhaps quantitative ones.
C2. Line 39. "of the Kulluk". This name appears for the first time in this line in the Introduction; however, no explanation is provided for the reader. Please introduce new terms/names as soon they appear. As the research is focused in the Kulluk platform, it could be interesting to introduce this concept or to provide a proper reference (perhaps the source research), to interested readers.
C3. Line 63. Please verify the citing style of JMSE. I am not sure if names' abreviations are allowed (e.g., J.S.; M.J.). Check this for all the manuscript.
C4. Line 86. I was expecting to fing the main contribution of the research in this paragraph. Please elaborate more in describing the objectives and main contribution of your research with respect to previous related research. This contribution needs to be permanent and clearly stated.
C5. Figure 1. Please organize the work following PRISMA MDPI guidelines for a research article. This figure seems to corresponds to a Methods/Methodology section rather than the Introduction. I understand that the end of the Introduction can provide some short guidence regarding the structure of the work; however,this figure can be more useful at the beginning of a methods section.
C6. Equations (variable descriptions). I suggest to organize the variables descriptions in paragraphs or in a symbols table.
C7. Calculation method of wave load. It is not clear if this potential theory method was developed by authors of if a software was employed. If a software was used, please provide details regarding this method, including proper references and numerical model setup including dimensions and initial conditions.
C8. "LS-Dyna" please provide the complete names of abreviations as soon as they appear, or include them in an abreviation list. This should be done for all the abreviated terms in the manuscript.
C9. Line 202. Please check this phrase. "The Kulluk platform is selected as the numerical calculation model" can be confuse. E.g., is the kulluk platform a numerical calculation model? Please rewrite this phrase.
C10. In Section 3. "Validation". Please provide more details regarding Validation (i.e., comparison with experimental results). There are no subsection regarding this. Please include the reference of the experimental data used for validation.
C11. There are figures in which is difficult to read the descriptions (e.g., Figs. 7, 9). Please organize the art work in a more readable manner. I suggest to improve the resolution/quality of the images.
C12. How these graphs were generated? It is not clear in the Methods what software/approach was employed to analyze the results.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper is satisfactory from my point of view.
Author Response
Thank you for your review.
Reviewer 3 Report
Comments and Suggestions for Authors The Authors' replies are not professional. They assume they are the "knowledge" and forget about the existing literature that must be reported in all scientific papers. Even the request for a more detailed description of the Kulluk platform has been ignored. Authors must be aware thar they did a detailed study of the existing Literature and they must favour people that will read their paper and need to be updated on the existing Literature.
Author Response
I'm sorry. The last reply was not very clear, and I did not understand your opinion well enough. It has been modified as requested to include references to relevant literature and a more detailed introduction to the Kulluk platform. The changes have been marked. Thank you for your correction!
Reviewer 4 Report
Comments and Suggestions for AuthorsAuthors considered most of my comments in the previous revision, improving significantly the quality of the manuscript. I have some minor comments that should be attended before a possible acceptance in JMSE.
C1. In this version, the results figures had low resolution. I suggest to export images as *.PNG, *.emf or *.SVG to improve resolution in the final version of the manuscript (please check if MDPI allows these formats).
C2. Line 380: did you mean "depicts"?
C3. Line 265. "....compared with field data." I recommend to include the appropriate reference regarding field data at the end of this phrase. In the present way is unclear how readers can track the data used for comparison.
C4. I suggested to take a look at variables descriptions style. I recommend to the editors to check the style to present the equation variables.
C5. Is the field data used for comparison in ref. [4]? To avoid this confusion, please attend C3, providing a more detailed explanation of which specific data was used for comparison, including the reference in the appropriate place.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
