A Comparison between the Latest Models of Li-Ion Batteries and Petrol Chainsaws Assessing Noise and Vibration Exposure in Cross-Cutting

Round 1

Reviewer 1 Report

 The paper is on an interesting topic. There is need for linguistic improvement and some points are addressed below. This is the main weakness of the manuscript. Prior to further consideration, the following points should be addressed:

L21-22: … the battery-power Stihl MSA 300 and the petrol-powered….

L79: A comma is need after “aspect” and

L87: A space before [42,43].

L100: ..of two of the latest models...

L102: Please consider using professional forest workers instead of lumbermen (as you do in L136)

L197: Please rephrase this line.

L248: Please correct “”specie” in this line in some that follow.

L253-256: Please consider to rephrase this part of text derscribing the values measured per chainsaw model and tree species.

Figure 6: Please improve the x- and y- axis descriptions

Table 2: Please consider deleting EP and BP as you are including their full description.

L306-307: Please rephrase this line.

L309: “kinds of works”: do you mean “work tasks”?

L323: … with respect to …

L349: Consider rephrasing “”strong reduction” to “significant decrease”.

L367-376: Please consider improving this p[art of text.

L385: … under laboratory conditions…

L397: Please consider rephrasing into several work tasks

L399: Did checking the reliability of the two chainsaws belong to the objectives of the study?

L413: Please rephrase “conifer and broadleaf.

L424 …exhausting…

L433-435: Please consider rephrasing the first part of the text

Comments are included in the "Comments and Suggestions for Authors" section.

Author Response

Dear Reviewer 1, 

many thanks for your feedback. Please find enclosed our answers.

Best Regards,

The Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

I have completed my review on this manuscript.

Indeed, the results are useful for science and practice. However, some parts need your attention in phrasing to produce a better manuscript. Also, some discussion on what would happen under real operational conditions would be welcome since the results are experimental. One can imagine that the petrol-based option would expose more as compared to the electrical one.

Best regards,

Rev.

English is fine, only minor check is required here.

Author Response

Dear Reviewer 2,

many thanks for your positive feedback.

Please find enclosed our answers to your comments.

Best regards,

The Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

The motorized chainsaw is a traditional and, for many decades, completely predominant portable machine, used in forestry for felling trees, their debranching and cutting. Of course, the chainsaw is also intensively used in many other fields of human activity, e.g. in the care of public greenery, in the construction industry or in the production of lumber and, of course, in various hobby activities. It can be assumed that the chainsaw will be used for the mentioned purposes in the future due to its excellent useful properties, despite the fact that its use is associated with certain negative factors related to the health risks of its operators. Among the most significant of these factors are noise and vibrations generated by the engines and cutting parts of chainsaws. This topic is addressed in the presented article, which presents the results of a study in which the noise and vibration levels of gasoline and battery chainsaws were compared. Among other things, the article responds to the fact that the technical development of battery-powered saws has significantly advanced, which can be expected to have lower levels of noise and vibration than those achieved with saws with gasoline engines. For the stated reasons, the topic of the presented article can therefore be considered highly current and beneficial for the scientific sphere, manufacturers and practical users of chainsaws.

In Chapter 1 – Introduction, negative factors threatening the health of the chainsaw operator are characterized. The findings of various renowned authors on the effects of vibrations and noise of chainsaws on the human body are presented here. The next part of the text is a description of the positive consequences of progress in the construction of battery chainsaws related to the development of the technical solution of Li-Ion accumulators. These passages aptly introduce the main topic of the article. At the end of this chapter, the goal of the study solution, and thus of the article itself, is clearly defined. I would like to point out a new article that deals with a similar issue and is not cited here: https://sciendo.com/article/10.2478/forj-2023-0003. I recommend adding his quote to this chapter. I have no other comments about this chapter.

Chapter 2 – Materials and Methods first lists the limit values of vibration and noise levels according to current European regulations and standards. In my opinion, there is no inaccuracy or error in the given data. In the next part of this chapter, the conditions of experimental measurements of vibration and noise levels during trunk cutting are described in great detail. This part of the chapter is also processed very carefully and contains all the data necessary to understand the methodology used in the experimental determination of vibration and noise levels. At the end of the chapter, the method of statistical analysis used for evaluating the measured data is briefly characterized. In my opinion, chapter 2 is well prepared, it contains all the necessary information and I have no comments about it.

Chapter 3 – Results presents a comprehensive overview of the findings obtained within the study. It is clear that the research of vibration and noise parameters took place in four variants (2 saws, for each of them two types of wood), while each variant contained 49 measurements (the total number of measurements is therefore 196). I think that the given numbers of measurements are quite sufficient for the given purpose. Two motor chainsaws comparable in their use were selected for the research. I consider it particularly important that the Stihl MS 300 cordless chainsaw was chosen, which is equipped with an anti-vibration device (most cordless saws are not equipped with an anti-vibration device). The anti-vibration device thus helps dampen even those vibrations that are created by the action of the cutting device, and this is the case with all saws, i.e. also with battery saws. I consider this fact to be emphasized, as it multiplies the positive effect of driving the saw with an electric motor to reduce the overall vibrations transmitted to the hands of the operator. The described results unequivocally prove that the electric chainsaw achieves min. 50% reduction in vibration values compared to the compared gasoline saw. The obtained results are sufficiently statistically supported and shown in tables and graphics.

In the next part of this chapter, the result of the noise measurement for both types of tested chainsaws is presented. Even in this case, it is clearly proven that the noise level when working with an electric saw is significantly lower than with a petrol saw. This fact is documented by a suitable graph and table.

At the beginning of chapter 4 – Discussion, the authors first assess the effects of some technical parameters of both tested types of chainsaws, stating, among other things, that the electric chainsaw had a chain speed about 15% higher than the gasoline chainsaw. They consider this fact to be one of the important factors for the lower level of vibrations achieved with the electric saw. I have a comment about this: how did the authors determine this speed of the chain (by their own measurements or from the technical documents of the saw manufacturer) and what speed was it actually (maximum for an unloaded chain or working while cutting?).

Subchapter 4.1 discusses in more detail the issue of the result of the evaluation of the vibration level of the tested types of saws. I think the factors and connections mentioned are real and logical. I consider the statement that the favourable results of the vibration values of the electric saw to be a particularly important insight, not only due to the fact that the electric motor only rotates, but also because the given type of electric saw is (unlike other types of electric saws) equipped with special anti-vibration system. This could also be a significant impetus for chainsaw manufacturers to equip their products with anti-vibration systems.

In subsection 4.2, similarly to subsection 4.1 for vibrations, a significantly lower value of the noise level for electric saws is stated. The reason for this is again the rotational movement of the electric motor and the absence of front-to-back movement of the piston in the gasoline engine. Even in this context, the electric saw can therefore be considered more ergonomically friendly for the operator. An important side note is the fact that even this lower noise level of an electric saw exceeds the limit values for an eight-hour exposure.

Subchapter 4.3 deals with the effect of cut wood on noise and vibration levels. The authors demonstrate that the density of the wood (beech x pine) has an effect on these harmful factors, which also corresponds to the findings of other authors.

Subchapter 4.4 contains a comparison of the measured noise and vibration values with the values reported by the manufacturer of both types of saws. It is clear from the text and table no. 4 that both sources of this data are very similar, which testifies, among other things, to the objectivity of measuring these important parameters at the manufacturer.

Subchapter 4.5 deals with the application of electric chain saws in operational practice. One can agree with the authors' statement that, despite all the technical progress and positive ergonomic parameters of battery saws, it is impossible to consider their operational deployment in forest harvesting, especially in the framework of so-called large-scale production. The reason for this is the still low capacity of the accumulators, which would currently force a greater number of accumulators to be available at the workplace to ensure an 8-hour shift. On the contrary, the wide range of possibilities for using battery saws in small-scale forestry, arboriculture, urban areas, etc. is emphasized.

Chapter 5 Conclusions summarizes the knowledge described in the previous chapters of the article in an appropriate way. I have no comments on this chapter.

The References chapter is prepared in the prescribed form, I think it contains all cited sources of information and I have no comments on it.

My overall impression of the submitted article is favourable, the article fulfils the attributes of a scientific article, and therefore I recommend that the article be published after minor adjustments according to the above notes.

Author Response

Dear Reviewer 3,

many thanks for your positive feedback.

Please find enclosed our answers to your comments.

Best regards,

The Authors

Author Response File: Author Response.pdf