Modeling the Future of Liquefied Natural Gas Transportation: Regression Analysis of Historical Data and Fleet Development Scenarios
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
File attached
Comments for author File: 
Comments.pdf
Author Response
Reviewer 1:
- Comment 1: Who will be the beneficiary of outcomes of such a study?
The authors: The sentence is inserted in the article with the statement: “These data should be useful to researchers in the field as well as experts in analyzing future developments.”
- Comment 2: The data is already available in this report, so what additional advantage does the current study provides?
The authors: This part is combined with comment E from reviewer 3, according to which the study is largely based on IGU reports and should be combined with other data sets (BP Statistical Review, EIA). Therefore, this study also combines findings from different data sets.
- Comment 3: Would be good to discuss the method used in comparison to other available methods. Also discuss the impact thee methods may have on the outcome of this study.
The authors: The paragraph is inserted into the article: “The linear regression method used in this study provides a simple, transparent and accessible approach suitable for clear communication and basic trend analysis. However, more advanced methods such as time series models, machine learning algorithms, simulation techniques or econometric models could provide more accuracy and insight by capturing complex patterns and market uncertainties. While these require more expertise, they could significantly improve the depth and reliability of study results.”
- Comment 4: Why there is a big difference in the figure in the year 2024 but not in the table?
The authors: Thank you for noticing our error. We have corrected the data in the table.
- Comment 5: Why is it irrelevant here?
The authors: The authors thank you for your comment, this is the error in the translation, i.e. it sounds different in the original language. In any case, we have rephrased the sentence.
- Comment 6: If extrapolated to additional number of years the difference would increase making the prediction wrong. How do you justify using the same method to predict in the current study?
The authors: The answer to this question is given in the paragraph under Table 2 and in Chapter 3.6.
- Comment 7: Huge difference. Please state the reasons why the actual trade volume is different.
The authors: The answer to this question is given in the paragraph under Table 3 and in Chapter 3.6.
- Comment 8: Same here the difference is huge. Please discuss the reasons for this.
The authors: The answer to this question is given in the paragraph under Table 4 and in Chapter 3.6.
- Comment 9: What are these? Please explain here.
The authors: Added two paragraphs in the paper. Quote: “The company Winterthur Gas & Diesel (WinGD) developed a low-pressure injection system with a high air-fuel ratio in the cylinder. It was based on a well-known Sulzer slow speed engine using Wartsila’s dual-fuel technology, in which a lean air-gas mixture is burned in the Otto cycle and injected in the gas mode, while a small amount of diesel pilot fuel is injected into the cylinder for ignition at top dead center (TDC). The first XDF engine was delivered in 2017. [34].
The MEGI engine type stands for the M-type electronically controlled gas injection, developed by MAN B&W. This engine type is based on the fact that the fuel is injected into the cylinder at a high pressure of between 250 and 300 bar, with a minimum amount of pilot fuel and an injection angle close to top dead center (TDC). This type of injection enables a dynamic response to the gas-oil combustion of the slow speed MAN ME-C engine. [35]”.
- Comment 10: The fuel consumption also depends on the distance. What distance this fuel consumption is for?
The authors: The consumption (according to [7]) is given for NCR for an engine of average size (30 000 kW) for 24 hours. These parameters are calculated using the SFOC, the distance was not taken into account in this calculation.
- Comment 11: Do you expect the prediction to be linear or is it only because a linear regression method was used?
The authors: With linear regression, there will be deviations over the period, but this type of prediction gives relatively good results using a simple method, in our opinion. Perhaps better results could be obtained using a model, but that would make the whole process much more complex. A sentence with the above meaning is inserted in Chapter 4.
- Comment 12: This just does not makes sense. The irregularity of the past exports show that the predictions cant be trusted. How do you justify it?
The authors: In this case, the prediction shows that the expected number of countries will increase by 1 in the period of one year. The irregularity of exports to date shows that the prediction is off by only 5%. In our opinion, an error of this magnitude is more than acceptable when projected over the future period.
- Comment 13: More discussion on the reasons of implications of the current predictions should be presented in a separate section. Also, please include discussions on the effect of wars or economic recession in the future in your prediction.
The authors: A new subchapter is created with the effects of wars or economic recession in the future in your prediction.
Note: - all changes have been marked with yellow,
- the title of the paper has been changed, according to Mr. Eden Ma and the Board Members. The new title now is: Modeling the Future of LNG Transportation: Regression Analysis of Historical Data and Fleet Development Scenarios
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors
Dear authors
Your manuscript, "LNG trade analysis,” has valuable ideas. Still, I prefer to provide some recommendations that are not mandatory to be applied, but they help to provide better quality for your manuscript. These are as follows:
1. The abstract is short. You also have to provide some information about the research's outcome in the abstract and the method used to conduct the research in the manuscript.
2. Section one, the introduction, does not need any subsection then eliminate subsection 1.1.
3. In the introduction, you must clearly provide information about four main issues, including “main objectives, research gap, target audience, and novelty of your research.” Please provide this information clearly.
4. What does the research address the main question?
5. All citations have to be at the end of the sentences.
6. The manuscript suffers from unsuitable paragraphing. Each paragraph needs to be 4-8 words, depending on the text and context. Then, you have to revise the entire manuscript based on this advice.
7. The manuscript suffers from unsuitable English grammatical and typo errors. I recommend that you send your manuscript to a native English speaker or use some English proofreading services to resolve this issue.
8. In section 2, which is about methodology, you have used some irrelevant citations and references. Review this section and eliminate some irrelevant references. Also, the method of conducting the research is not clear. Please provide a clear methodology section to explain in detail how you conducted this research study.
9. The figures have unsuitable captions. Please provide scientific, precise, relevant info and well-captioned figures. For example, does Figure 1 need three references? It does not seem so.
10. In Figure 2 and the caption, you must mention the period completely, for example, 200-2025.
11. I recommend you provide a figure with two parts: on the right side, imports and on the left side, exports can be shown. On the other hand, you can merge Table 3 and Table 2 into one table, too, and only need to provide an extra column entitled exports and other entitled imports. The same issue can be applied to Figures 3 and 4 and used in Tables 3 and 4.
12. Your manuscript suffers a section called “discussion,” which interprets the data and information that you have obtained and presented in the section “finding.” It compares the results with the predictions and forecasts you provided in section 3.
13. In conclusion, please clearly explain the three main issues, the study's primary outcome, your limitations when preparing this research or collecting information, and recommendations for future studies in the relevant field.
14. Are the conclusions consistent with the evidence and arguments presented?
15. Regarding references, why have you not used more updated references that are for recent years (less than 3 years)
In summary, I believe your manuscript suffers from scientific structure and aspects. If you want to publish it, you have to provide a better manuscript with many revisions in format, explanation, English proofreading, and scientific interpretation. The idea and the topic have the potential to be excellent research work. Still, as I mentioned, the manuscript suffers from many issues in presentation and scientific aspects at this moment.
Thanks for your attention.
Comments on the Quality of English Language
The manuscript suffers from typos and grammatical errors that have to be rectified.
Author Response
Reviewer 2:
Comment 1: The abstract is short. You also have to provide some information about the research's outcome in the abstract and the method used to conduct the research in the manuscript.
The authors: The abstract has been completely rewritten and expanded. Now the abstract is slightly longer than the maximum length of 200 words stipulated in the journal's guidelines.
Comment 2: Section one, the introduction, does not need any subsection then eliminate subsection1.
The authors: Agreed, there is no need for a subsection, it is eliminated.
Comment 3: In the introduction, you must clearly provide information about four main issues, including “main objectives, research gap, target audience, and novelty of your research.” Please provide this information clearly.
The authors: The necessary information in the introduction has been supplemented accordingly.
Comment 4: What does the research address the main question?
The authors: In the introduction, we have added a section containing the answer to the question posed.
Comment 5: All citations have to be at the end of the sentences
The authors: Corrected, thanks for pointing this out.
Comment 6: The manuscript suffers from unsuitable paragraphing. Each paragraph needs to be 4-8 words, depending on the text and context. Then, you have to revise the entire manuscript based on this advice.
The authors: We have reviewed the entire work and corrected everything according to your advice.
Comment 7: The manuscript suffers from unsuitable English grammatical and typo errors. I recommend that you send your manuscript to a native English speaker or use some English proofreading services to resolve this issue.
The authors: Thank you for your comment. We ran the work through an English language improvement program and then had it checked by a native speaker who specializes in this topic.
Comment 8: In section 2, which is about methodology, you have used some irrelevant citations and references. Review this section and eliminate some irrelevant references. Also, the method of conducting the research is not clear. Please provide a clear methodology section to explain in detail how you conducted this research study.
The authors: This part is combined with comment E from reviewer 3, according to which the study is largely based on IGU reports and should be combined with other data sets (BP Statistical Review, EIA). Therefore, this study also combines findings from different data sets. The paragraph is inserted into the article: “The linear regression method used in this study provides a simple, transparent and accessible approach suitable for clear communication and basic trend analysis. However, more advanced methods such as time series models, machine learning algorithms, simulation techniques or econometric models could provide more accuracy and insight by capturing complex patterns and market uncertainties. While these require more expertise, they could significantly improve the depth and reliability of study results.” We have also changed the reference list to reflect this comment.
Comment 9: The figures have unsuitable captions. Please provide scientific, precise, relevant info and well-captioned figures. For example, does Figure 1 need three references? It does not seem so.
The authors: Thank you for pointing this out. The headings have been rewritten and the references updated. Please also note that most of the illustrations correspond in part to the illustrations from the cited sources, so in our opinion all three references should be listed.
Comment 10: In Figure 2 and the caption, you must mention the period completely, for example, 200-2025.
The authors: Thank you for this comment. This has been rechecked and corrected.
Comment 11: I recommend you provide a figure with two parts: on the right side, imports and on the left side, exports can be shown. On the other hand, you can merge Table 3 and Table 2 into one table, too, and only need to provide an extra column entitled exports and other entitled imports. The same issue can be applied to Figures 3 and 4 and used in Tables 3 and 4
The authors: During the preparation of the paper we had a similar idea, but we abandoned it in order to present a simpler and clearer paper, guided by the idea of dividing each research into a table and a figure.
Comment 12: Your manuscript suffers a section called “discussion,” which interprets the data and information that you have obtained and presented in the section “finding.” It compares the results with the predictions and forecasts you provided in section 3.
The authors: We have changed the work so that this problem is solved as far as possible.
Comment 13: In conclusion, please clearly explain the three main issues, the study's primary outcome, your limitations when preparing this research or collecting information, and recommendations for future studies in the relevant field.
The authors: The conclusion has been considerably altered and expanded and now contains everything that is in the commentary.
Comment 14: Are the conclusions consistent with the evidence and arguments presented?
The authors: The conclusion has been considerably altered and expanded and now contains everything that is in the commentary.
Comment 15: Regarding references, why have you not used more updated references that are for recent years (less than 3 years)
The authors: We thank you for this reference. We have refreshed and updated the references. The reference list now contains a total of 47 entries.
Note: - all changes have been marked in yellow,
- the title of the paper has been changed, according to Mr. Eden Ma and the Editorial Board Members,
- now the new title of the paper is: Modeling the Future of LNG Transportation: Regression Analysis of Historical Data and Fleet Development Scenarios
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors
The article has some weaknesses that, in my opinion, should be corrected and eliminated.
A.
On the one hand, linear regression is useful for identifying trends, but unfortunately it can oversimplify the impact of many non-linear factors, such as geopolitical disruptions (e.g. attacks in the Red Sea) or technological changes (e.g. discontinuation of the ME-GA engine).
The use of more sophisticated models (e.g. machine learning) could improve accuracy.
B.
The article briefly mentioned COâ‚‚ emissions from LNG, but did not thoroughly explore the contradiction between LNG's "green" reputation and its impact on the climate (e.g. methane leakage).
C
The sudden rise and fall of ME-GA engines was highlighted but not thoroughly explained. A deeper understanding of why this technology fails (e.g. regulatory hurdles, technical failures) would add value.
D
The authors note the impact of the Russia-Ukraine war on trade routes, but conclude that it had no impact on overall LNG trade volumes - which requires further evidence or sensitivity analysis.
Because it doesn't seem right.
E
The study relies largely on IGU reports. References to other data sets (e.g. BP Statistical Review, EIA) could be made more reliable and error-proof.
Author Response
Reviewer 3:
Comment A: On the one hand, linear regression is useful for identifying trends, but unfortunately it can oversimplify the impact of many non-linear factors, such as geopolitical disruptions (e.g. attacks in the Red Sea) or technological changes (e.g. discontinuation of the ME-GA engine). The use of more sophisticated models (e.g. machine learning) could improve accuracy.
The authors: With linear regression, there will be deviations over the period, but this type of prediction gives relatively good results using a simple method, in our opinion. Perhaps better results could be obtained using a model, but this would make the whole process much more complex. A sentence with the above meaning is inserted in Chapter 4.
Comment B: The article briefly mentioned COâ‚‚ emissions from LNG, but did not thoroughly explore the contradiction between LNG's "green" reputation and its impact on the climate (e.g. methane leakage).
The authors: The article briefly mentioned LNG's COâ‚‚ emissions, but the contradiction between LNG's "green" reputation and its impact on the climate (e.g. methane leakage) was not thoroughly explored. We briefly touched on this topic in the article as it was the main reason why the ME-GA plant was taken out of production. We have not gone into this topic in detail as we believe this would require new and different research.
Comment C: The sudden rise and fall of ME-GA engines was highlighted but not thoroughly explained. A deeper understanding of why this technology fails (e.g. regulatory hurdles, technical failures) would add value.
The authors: A large explanation of more than 300 words is added to 3.5.
Comment D: The authors note the impact of the Russia-Ukraine war on trade routes, but conclude that it had no impact on overall LNG trade volumes - which requires further evidence or sensitivity analysis.
The authors: According to the available data, the war does not seem to have had an immediate impact on the market, even if there has been a slight slowdown in recent years. It remains to be seen what the reason for this is. A comment on this topic is included in 3.6.
Comment E: The study relies largely on IGU reports. References to other data sets (e.g. BP Statistical Review, EIA) could be made more reliable and error-proof.
The authors: This part is combined with reviewer 1 comment 2. Now, this study also combines insight from different data sets.
Note: - all changes have been marked in yellow,
- the title of the paper has been changed, according to Mr. Eden Ma and the Editorial Board Members,
- now the new title of the paper is: Modeling the Future of LNG Transportation: Regression Analysis of Historical Data and Fleet Development Scenarios
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
No further comments
Author Response
Comment 1: No further comments.
Response 1: We thank you for the consumed time and an honest review.
Reviewer 2 Report
Comments and Suggestions for Authors
Dear authors
Your revised manuscript, "Modeling the Future of LNG Transportation: Regression Analysis of Historical Data and Fleet Development Scenarios,” has improved my understanding of valuable ideas. Still, I prefer to provide some recommendations that are not mandatory to be applied, but they help to provide better quality for your manuscript. These are as follows:
1. In the first round, I asked you to insert all citations at the end of sentences, but I can still see citations in the middle. Please rectify this issue in the entire manuscript.
2. In different parts of manuscript I can see you mention a short sentence and then provide 2 or 3 references for that one which don’t seems necessary and only sems to wanted to provide more references, you can see this issue in line64-66 which for only three sentences you have provided seven references which are not necessary. It will affect the attitude of the peer reviewer about your manuscript.
3. In the last round, I asked you to explain the research gap in the introduction, but I still can not see anything about this issue in your manuscript.
4. In the last round, I asked about suitable paragraphing, but there are still some paragraphs with more than 15 lines where the context does not continue, and you can separate them into two paragraphs. Example line189-205.
5. In lines 274- 276, you mentioned a context about IMO regulation; you have to provide a suitable citation for this context.
6. In the last round, I recommended that you provide a discussion section, and you mentioned that you have done so, but I can not see it. My suggestions are not compulsory, but if you did follow them, don’t mention that you followed them.
7. The conclusion section is very wordy, and you have explained a lot about the main procedure and the current situation of the issue in the world in very long paragraphs from lines 411 to 441. I believe you can summarize this information because the conclusion needs to include three main components: the main outcome, limitations, and recommendations for future actions. There is no need to reiterate the issues mentioned in the introduction and literature again.
Thanks for your attention.
Author Response
Dear authors
Your revised manuscript, "Modeling the Future of LNG Transportation: Regression Analysis of Historical Data and Fleet Development Scenarios,” has improved my understanding of valuable ideas. Still, I prefer to provide some recommendations that are not mandatory to be applied, but they help to provide better quality for your manuscript. These are as follows:
- In the first round, I asked you to insert all citations at the end of sentences, but I can still see citations in the middle. Please rectify this issue in the entire manuscript.
Authors: Thank you for highlighting this issue, we fixed it in the entire paper.
- In different parts of manuscript I can see you mention a short sentence and then provide 2 or 3 references for that one which don’t seem necessary and only sems to wanted to provide more references, you can see this issue in line 64-66 which for only three sentences you have provided seven references which are not necessary. It will affect the attitude of the peer reviewer about your manuscript.
Authors: These references are inserted to support the assertions (or facts) made in this part of the text. If they were deleted, it would turn out that we had proved and created the above facts, which we wanted to avoid. In our opinion, they should be retained, but if you, the reviewer, insist, the above references will be removed.
- In the last round, I asked you to explain the research gap in the introduction, but I still can not see anything about this issue in your manuscript.
Authors: Thank you for noticing. We explained the research gap through the following paragraph that has been inserted in the “Introduction”. “This paper aims to address key gaps in the existing research by exploring the following questions: Has a concept or new idea remained entirely unexamined? Is there a question or problem within a specific field that existing studies have yet to resolve? Is the available literature on the topic outdated? Has a particular population, location, or age group been overlooked in previous research? These predictions should be useful for researchers in the field as well as experts in analysing future developments.”
- In the last round, I asked about suitable paragraphing, but there are still some paragraphs with more than 15 lines where the context does not continue, and you can separate them into two paragraphs. Example line 189-205.
Authors: Solved, same issue found in few more places. Thank you for the comment.
- In lines 274- 276, you mentioned a context about IMO regulation; you have to provide a suitable citation for this context.
Authors: Thank you for noticing. A proper reference has been inserted.
- In the last round, I recommended that you provide a discussion section, and you mentioned that you have done so, but I can not see it. My suggestions are not compulsory, but if you did follow them, don’t mention that you followed them.
Authors: According to comments 6 and 7, authors wrote a more extensive conclusion and thought the problem has been solved. Now, the conclusion is divided into 2 separate chapters. One is “Discussion”, and the second one is “Conclusion”, which also solves the comment 7.
- The conclusion section is very wordy, and you have explained a lot about the main procedure and the current situation of the issue in the world in very long paragraphs from lines 411 to 441. I believe you can summarize this information because the conclusion needs to include three main components: the main outcome, limitations, and recommendations for future actions. There is no need to reiterate the issues mentioned in the introduction and literature again.
Authors: Solved together with comment 6. The conclusion is summarized and the possible issues in the world that might affect the LNG trade are now written in the “Discussion” chapter.
Thanks for your attention.
Author Response File: 
Author Response.docx
Round 3
Reviewer 2 Report
Comments and Suggestions for Authors
Dear authors
Your revised manuscript, "Modeling the Future of LNG Transportation: Regression Analysis of Historical Data and Fleet Development Scenarios,” has many improvements that I can feel, and also has many valuable ideas. After considering my recommendations, you can proceed with sending the manuscript for publication. You must insert the axis scales and units in figures 1-5 and 7-10. Figure 6 is a pie chart, and you have to mention the percentage in the chart too.
Thanks for your attention.
Author Response
Comment 1: You must insert the axis scales and units in figures 1-5 and 7-10.
Authors: Thank you for noticing, we fixed it in the entire paper.
Comment 2: Figure 6 is a pie chart, and you have to mention the percentage in the chart too.
Authors: Corrected as well, thank you once again for highlighting it.
Authors thank you for the honest review and for the acceptance of the paper.
Author Response File: Author Response.pdf
