Round 1

Reviewer 1 Report

Thank you very much for the interesting article. The article can have an important contribution in the field of port activity with regard to port waterfront environmental monitoring and for clarifying the emerging green concept from the perspective of STS (Ship-To-Shore) crane emissions. 

1. The main research question for the authors is based on how can ports improve their sustainability performance by  measurement of CO₂ emissions of port cranes with the aim of getting results on which cranes are most environmentally friendly without compromising the profitability of port operations.

2. The research findings of the article in my opinion are relevant for Port Authorities and terminal operators because it provides them with the correct decision – making option for choosing the most environmentally adequate crane while at the same time preserving commercial viability and profitability of the container terminal.

3. Current literature on port emissions is mainly focused on measuring and minimizing carbon emissions of ships within the vicinity of the port area. The originality of the article is recognized by addressing the literature gap in identifying cranes as an important source of CO₂ pollution due to constant loading and unloading of cargo. Cranes are an indispensable part of every container terminal, and this paper has provided methodological steps via DEA and fuzzy MCGP method for analyzing their environmental performance on a real – world practical example. The environmental performance of cranes was further evaluated with the novel Green Energy Index.

4. The paper adds the new body of knowledge in understanding the emerging ''green port'' concept from the perspective of the port area (in terms of the container terminal stacking yard). This is reflected on the provision of the methodology and information to terminal managers and Port Authorities on how to improve the sustainability of port operations by mitigating the negative environmental externalities of cranes while at the same time preserving commercial viability of their terminal operations.

5. The paper is written in a structured, coherent and systematic manner. The text is easy and enjoyable to read. The only remark is that the defined novel Green Energy Index is not mentioned in the abstract as an important finding also.

6. The main goal of the article (aiding port managers in the selection of the most adequate terminal machinery in terms of environmental preservation and financial viability and operational efficiency) was elaborated by strict adherence towards the research methodology. Thus the conclusions of the article are adequate and correct in comparison to the methodologic elaboration (DEA, fuzzy MCGP and Green Energy Index) utilized to realize them. 

 

Author Response

Reviewer Comments:

1. The main research question for the authors is based on how can ports improve their sustainability performance by measurement of CO₂ emissions of port cranes with the aim of getting results on which cranes are most environmentally friendly without compromising the profitability of port operations.

Ans: Thanks for your valuable comments.

The research findings of the article in my opinion are relevant for Port Authorities and terminal operators because it provides them with the correct decision – making option for choosing the most environmentally adequate crane while at the same time preserving commercial viability and profitability of the container terminal.

Ans: Thanks for your valuable comments.

1. Current literature on port emissions is mainly focused on measuring and minimizing carbon emissions of ships within the vicinity of the port area. The originality of the article is recognized by addressing the literature gap in identifying cranes as an important source of CO₂ pollution due to constant loading and unloading of cargo. Cranes are an indispensable part of every container terminal, and this paper has provided methodological steps via DEA and fuzzy MCGP method for analyzing their environmental performance on a real – world practical example. The environmental performance of cranes was further evaluated with the novel Green Energy Index.

Ans: Thanks for your valuable comments.

1. The paper adds the new body of knowledge in understanding the emerging ''green port'' concept from the perspective of the port area (in terms of the container terminal stacking yard). This is reflected on the provision of the methodology and information to terminal managers and Port Authorities on how to improve the sustainability of port operations by mitigating the negative environmental externalities of cranes while at the same time preserving commercial viability of their terminal operations.

Ans: Thanks for your valuable comments.

1. The paper is written in a structured, coherent and systematic manner. The text is easy and enjoyable to read. The only remark is that the defined novel Green Energy Index is not mentioned in the abstract as an important finding also.

Ans: Thanks for your valuable suggestions. The authors have ad novel Green Energy Index d to abstract section.

1. The main goal of the article (aiding port managers in the selection of the most adequate terminal machinery in terms of environmental preservation and financial viability and operational efficiency) was elaborated by strict adherence towards the research methodology. Thus the conclusions of the article are adequate and correct in comparison to the methodologic elaboration (DEA, fuzzy MCGP and Green Energy Index) utilized to realize them. 

 Ans: Thanks for your valuable comments.

 

 

 

Reviewer 2 Report

In general, exhaust emissions (e.g.,CO₂ or sulfide) are difficult to monitor in and around ports, and data on such emissions are often incomplete. To solve this problem, this paper aimed to formulate a method for collecting CO₂ emissions data at their source; this method was applied to collect real-world operating data from a large container-handling company in Taiwan. Specifically, to account for undesirable outputs, authors formulated a method that combines (1) data envelopment analysis based on a modified slack-based measure and (2) a multichoice goal programming approach. The main result of this paper is: i) They found that rubber-tired gantry cranes are the greenest and should be used. ii) Their findings aid port managers in selecting port equipment that best balances between environmental protection and profitability.This paper has the comprehensive analysis process and a certain level of innovation. I think the paper has a solid contribution to the literature. However, I do have some concerns that I think should be addressed.

Major Concerns

1. DEA is often used in evaluation the ports. The authors should give more reasons (or related literature) to explain why the proposed DEA is efficient in this paper.
2. As the paper is related to green operations, more recent papers should be cited to show the contribution to the literature. For example:

Evaluating the environmental performance and operational efficiency of container ports: An application to the maritime silk road. International Journal of Environmental Research and Public Health, 2019, 16(12), 2226.

The benefit of manufacturer encroachment considering consumer’s environmental awareness and product competition, Annals of Operations Research, 2021.03, in press.

Electric Vehicle Routing Problem with Battery Swapping Considering Energy Consumption and Carbon Emissions. Sustainability, 2020, 12, 10537

Manufacturer's encroachment strategy with substitutable green products. International Journal of Production Economics, 2021, 235, 108102.

3. In section 3.2, personally, it is not clear that the content represented by the symbols in the equations.
4. In section 4.4, “This means that RTG is a suitable crane.”(See page 19, paragraph 490).Why this conclusion can be drawn？I feel a bit vague, and it would be nice to have some descriptions or references to make it more convincing.

Minor Issues

1. In Section 2, there only have section 2.2 and section 2.3. So this part needs to be checked carefully.
2. In Sections 3 and 4, the equations expression format is not standardized, I think it needs to be revised carefully.
3. The format of the reference section needs to be carefully revised.

Totally, although I find some novelties in this paper, it is not well written and there are many typos and errors. Thus, I suggest this paper should make a major revision.

Author Response

Reviewer Comments:

1. Major Concerns

(1) DEA is often used in evaluation the ports. The authors should give more reasons (or related literature) to explain why the proposed DEA is efficient in this paper.

As the paper is related to green operations, more recent papers should be cited to show the contribution to the literature. For example:

1.Evaluating the environmental performance and operational efficiency of container ports: An application to the maritime silk road. International Journal of Environmental Research and Public Health, 2019, 16(12), 2226.

2. The benefit of manufacturer encroachment considering consumer’s environmental awareness and product competition, Annals of Operations Research, 2021.03, in press.
3. Electric Vehicle Routing Problem with Battery Swapping Considering Energy Consumption and Carbon Emissions. Sustainability, 2020, 12, 10537
4. Manufacturer's encroachment strategy with substitutable green products. International Journal of Production Economics, 2021, 235, 108102.

Ans: Thanks for your valuable suggestion; the authors have added it to the literature review section.

(2) In section 3.2, personally, it is not clear that the content represented by the symbols in the equations.

Ans: Thanks for your valuable comments; the authors have carefully revised section 3.2. we add DEA Flow charts and DEA evaluation processes and defined symbols in the equations .

(3) In section 4.4, “This means that RTG is a suitable crane.”(See page 19, paragraph 490).Why this conclusion can be drawn？I feel a bit vague, and it would be nice to have some descriptions or references to make it more convincing.

Ans: Thanks for your valuable suggestion, the authors have provided MCGP programming and explain decision making variable detail in section 4.4.

 

2. Minor Issues

(1) In Section 2, there only have section 2.2 and section 2.3. So this part needs to be

checked carefully.

(2) In Sections 3 and 4, the equations expression format is not standardized, I think it needs to be revised carefully.

(3)The format of the reference section needs to be carefully revised.

Ans: Thanks for your valuable suggestion, the authors have revised all.

 

Reviewer 3 Report

You will find the reviewer's comments in the attachment of this message.

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have addressed my concerns and thus this manuscript can be accepted in this version.

Author Response

Reviewer Comments:

The authors have addressed my concerns and thus this manuscript can be accepted in this version.

Ans: Thank for your review our manuscript. Thanks!

Reviewer 3 Report

The authors performed all the necessary revisions, but the overall text should be re-checked. The text under the flow chart should be adjusted. The English language and accompanied expressions should be improved.

Author Response

Reviewer Comments:

The authors performed all the necessary revisions, but the overall text should be re-checked. The text under the flow chart should be adjusted. The English language and accompanied expressions should be improved.

Ans: Thank for your review our manuscript. The authors have carefully revised overall text by professional expertise, and re-adjust our study flow chart and processes. Thanks!