Modernization of Heavy Loaded Tram Radial Effect on Noise and Vibration
Round 1
Reviewer 1 Report
The authors investigates the influence of the modernisation of on tram line in Bratislava on noise and vibration produced by tram traffic, which is purely applied study, where statistics is applied for analysis, but without sufficient scientific soundness. The paper is of certain interest for readers, so it can be recommended for publication after minor revisions if it corresponds to the journal aims and scope.
- Figure 5 seems to be more or less useless for academic paper.
- Two peaks around 65 Hz in Figure 10 are not below each other, so it is suggested to keep the same frequency ranges in the right part of Figures 10 and 11.
Author Response
The authors' responses to the reviews are in the attached file.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The article has done a lot of analysis and data collection, with rich contents and sufficient analysis. The contents and test results of relevant track reconstruction and modernization should be helpful to readers.
Author Response
The authors' responses to the reviews are in the attached file.
Author Response File: Author Response.docx
Reviewer 3 Report
1. The text in figure 10 (11, and 19） is too small, please modifiy it.
2. If appendix A and B are not necessary, please delete them.
Author Response
The authors' responses to the reviews are in the attached file.
Author Response File: Author Response.docx
Reviewer 4 Report
Thank you for your work, I have a few remarks:
1. Could you give some theoretical background (equations) for given calculations e.g., vibration, noise and sound pressure analysis.
2. Could you provide additional recommendations that should be considered in such a study and verification?
Author Response
The authors' responses to the reviews are in the attached file.
Author Response File: Author Response.docx
Reviewer 5 Report
Opinion:
Upon reading of the submitted manuscript, it is to emphasize that the general intention of this paper is not quite comprehensible. The authors describe in the manuscript: historical aspects of the tram infrastructure development, modernization of the tram line, measurement methods and techniques, and the places of measurements. However, in the summary of the manuscript, they state that "electric vehicles and tramways" states have the most significant influence on vibrations, completely putting aside the aspects of the described modernization of the tram line.
It should also be stated that the paper of an engineering nature. In the paper concerns with very important issues in fields of noise and vibration occur by operation of tramways in cities. Nevertheless, the content of the entire manuscript is in the form of a report, not a scientific article. The sum of the presented experimental results does not help us understand the content and purpose of the paper. The authors of the paper did not show any novelty or contribution to the field of technology.
Comments and remarks:
1. Many of the descriptions in the manuscript are very laconic and general in nature. The paper does not contain any substantive content related to the minimization of vibrations through the modernization of tram lines. Reading this material, one gets the impression that we are reading a report on construction works on the modernization of the tram line, and not a technical/scientific article.
An example is some contents from the paper:
“Therefore, in a vibroacoustic study of the modernised line, our Department did not only monitor the noise emitted by the tram traffic but also the vibration, to create a comprehensive picture of the environmental burden from the operation of a modernised section of the Bratislava tram line”;
“The first part of the modernisation included a complete replacement of the tram substructure, superstructure and drainage. These modifications increased the comfort of passengers and also minimised the negative effects of the tram operation (noise and vibration) on the surrounding urban zone”;
“The structural elements that most limited the track speed and led to noise and vibration were obsolete turnout structures and curves of small radii”;
“In the case of the carriageway imperfections, various dynamic impacts occur during the driving at the wheel-rail contact, while the noise level is also affected by its routing in the terrain in the traffic area”;
“Drainage of junction boxes, switch rails and heating rods was led to the nearest drainage shafts. Rainwater from the concrete surfaces of the tram line is drained by drainage devices based on the principle of linear drainage pipes perpendicular to the line”;
“The drainage system is based on the principle of draining rainwater through a drainage pipe placed in a drain trench. The drainage pipe was led into plastic control shafts with a diameter of Ø 400 mm and Ø800 mm. The drainage system drains the raised drainage water from the substructure and permanent way and discharges it into the existing sewerage”;
“To capture secondary vibrations from the operation of the tram line more efficiently, a sub-ballast damping mat was placed directly under the ballast bed. In the sections of the track, where the space conditions allowed it, the areas between the tram line and the parallel roads were covered with grass”.
2. In addition, the entire investigations was carried out in accordance with standards, which also indicates routine engineering works, and not novelty science research:
“The assessment of the noise situation in the external area of the area of interest was performed in accordance with the Act on the Protection, Support and Development of Public Health of the National Council of the Slovak Republic no. 355/2007 and Decree of the Ministry of Health of the Slovak Republic no. 237/2009 Coll. [2] (Supplements the Decree of the Ministry of Health of the Slovak Republic No. 549/2007 Coll.) that establish the permissible values of noise, infrasound and vibration in the environment”;
„All measurements were performed in the first stage of measuring accuracy with an automatic measuring apparatus. The selected methodology complied with the set conditions of the relevant legislative documents [7], [8], [9]”.
3. In the manuscript, the authors describe known phenomena in the field of track vibrations, without showing any new phenomena and observations resulting from the modernization of tram tracks:
„Noise from their passage is significantly affected by several factors: • technical condition of the tramway (overall track layout and geometry, quality of rail 290 joints, corrugation of rails, stability and overall condition of track switches), • track substructure”;
“The resulting vibrations propagate through the material half-space as surface and shear waves from the source and their character is stochastic, with variable power in time and space”.
4. Reading this manuscript, one gets the impression that the main goal of the work is to measure vibrations and analyse them:
„The first objective of the experimental measurements was to determine the current noise situation by measuring the noise (..). The second objective was to measure vibrations in the vicinity of the foundation (..)”.
5. The article also requires a linguistic correction. One of the examples: the use of the phrase "locality" in the work is not correct. For a better understanding of the content should be "location", especially since all the research took place in one town in the capital of Slovakia.
6. In chapter 5 of the "Conclusion" manuscript, the first paragraph of this chapter gives a general definition of reduction of noise and vibration. It doesn't bring anything new to the work. Moreover, the paragraph "Conclusion" refers to the statement that the condition of the vehicles has an influence on noise and vibration of the track. Moreover, the statement "The most significant factors generating noise and vibration emissions are the conditions of the electric vehicles and tramways" is inconsistent in the content of this chapter concerning the study of the modification of tram lines to reduce slogan and vibrations. The subject of electric vehicles is not mentioned in the entire manuscript. On the other hand, the above provision concerning the influence of the technical condition of tramways on the increase in noise and vibrations is obvious and does not require the performance of the measurement results presented in the study.
Comments for author File: 
Comments.pdf
Author Response
The authors' responses to the reviews are in the attached file.
Author Response File: Author Response.docx
