Influence of Chain Sharpness, Tension Adjustment and Type of Electric Chainsaw on Energy Consumption and Cross-Cutting Time
Round 1
Reviewer 1 Report
The introduction of the article well characterizes the current state and importance of partially mechanized logging technologies in world forestry. Among other things, the authors emphasize the favorable properties of modern electric chainsaws powered by their own batteries. Based on the study of professional sources, the authors consider the saw chain and its tension to be key elements that influence the cutting power of a chainsaw and its energy consumption. We can agree with this assumption (hypothesis). Among other things, they are of the opinion that it would be appropriate to automate the tensioning of the saw chain.
In the section Material and method, the procedure for performing experimental measurements is clearly described. I recommend specifying more precisely "blunt chain" and "sharp chain" - I did not find in the text the characteristics of these states of the chain (for example, it would be appropriate to state the radii of rounding of the cutting edge of the blade for sharp and blunt chain). Likewise, the "chain tension" could be expressed more precisely (eg by measuring the force by which we move the chain a certain distance from the edge of the saw bar. Perhaps an interesting indicator would be the resistance of the chain note on this part: the tested saws differed from each other not only in their motor parts, but also in the saw blades and chains. This fact could have a significant effect on the final evaluation. for all three saws of the same cutting part, a statistical analysis of the achieved results seems to me to be sufficient for the given purpose.
In the Results section, the authors emphasize at the outset that the amount of tension in the saw chain was not confirmed to be significant in terms of time consumption during cross-cutting. In the light of the above comment, this should be supplemented by information expressing the degree of chain tension. Information on differences in energy consumption in cross sections is acceptable. Equally acceptable is the statement about the higher energy requirement and the size of the cross-sectional time when using a blunt chain (line 168).
In the Discussion, the authors reiterate that the chain tension did not affect the amount of vibration transmitted to the worker's hands and with the saw, nor the amount of energy consumption or the amount of time required to make a cross section. As I mentioned earlier, this finding is, in my opinion, conditionally valid - if the chain were really tightened to the maximum, this fact would certainly have to be reflected in energy consumption or cutting time. Again, I recommend expressing the chain tension more accurately in a suitable way. I have no comments on the knowledge of the influence of different types of saws on energy consumption and cutting time. However, I recall my comments above on the appropriateness of expressing the parameter for a "sharp" and "blunt" chain more precisely.
Comments: I recommend checking and correcting formal deficiencies in the text (typos, etc.), eg on lines 36 and 37, 101, 103, etc., spaces for punctuation marks (commas, dots) are incorrectly used or not used, there is no space between the number 30 and mark %, the upper exponent is not used for marking m3 etc.
Author Response
Response to Reviewer 1 Comments
The reviewer’s text has been copied into a file, and the author’s comments are below in red color.
Point 1: The introduction of the article well characterizes the current state and importance of partially mechanized logging technologies in world forestry. Among other things, the authors emphasize the favorable properties of modern electric chainsaws powered by their own batteries. Based on the study of professional sources, the authors consider the saw chain and its tension to be key elements that influence the cutting power of a chainsaw and its energy consumption. We can agree with this assumption (hypothesis). Among other things, they are of the opinion that it would be appropriate to automate the tensioning of the saw chain.
In the section Material and method, the procedure for performing experimental measurements is clearly described. I recommend specifying more precisely "blunt chain" and "sharp chain" - I did not find in the text the characteristics of these states of the chain (for example, it would be appropriate to state the radii of rounding of the cutting edge of the blade for sharp and blunt chain).
Response 1: Blunt is now used in the whole of text instead of dull.
The characteristics of the blunt or sharp chains were not measured in terms of the radii of the chain's teeth. The problem is that the radius of teeth has not been standardized for sharpness. Therefore the authors recommend that such classification be developed in the discussion section:
L217 ”Large differences in cross cutting efficiency and energy use in relation to the level of chain sharpness indicate that scientific approach to chain sharpness levels is required to enable comparisons between research. The method development could be based upon the radius of cutter tooth, which increases with wear [32].”
For sharp chains the authors have relied on the manufacturer's recommendations regarding sharp chains by using a brand new, factory-sharpened chains of the precise chain type and producer prescribed by the saw’s producer.
For blunt chains we have prepared new store bought chains of the exact same type as for sharp chains and were then blunted by pushing the saw into quartz sand.
The method of blunting is described in the methods section;L121 “Blunt chains were prepared by pushing the working saw under full throttle into a bucket of quartz sand (granulation 1-2 mm) for 20 seconds [29].«
As nothing was stated in the text regarding sharp chains, a sentence was added into methods section.
L121“Sharp chains are brand new, factory-sharpened chains recommended by the respective saw’s producer.”
Point 2: Likewise, the "chain tension" could be expressed more precisely (eg by measuring the force by which we move the chain a certain distance from the edge of the saw bar.
Response 2: The method of chain tensioning is described in text (line 118-123) “The chain saw tensioning has to be done in a manner that the chain has to move freely through the bar, without any of the drive links being visible from the side of the bar. To achieve that, when setting the normal chain tension an empirical rule of three visible drive links when the chain is elevated in the middle of the saw bar was followed. When the overtensioned saws were prepared for trial the chains were weighed down by a 1190 g weight, while the rule of three visible drive links was still being considered. “
In praxis the chain tension is always checked by raising a chain by hand and if the three drive links are visible (no more or less) then the chain tension is proper. The same method was used in research, although the method of tension measure proposed by the reviewer was also contemplated during trial setup phase, however was not applies, as chains and saw blades used in trial differ significantly. Force would have to be standardized, as different force has to be applied to longer chains, and chains with different chain pitch. With rise of both parameters the force of chain tension increases. When preparing the over-tensioned saws, we have taken care to burden the chains with more force than usual, however at the same time not to damage the chain tensioning mechanism. The latter is made of plastic on all three saws, and therefore excess applied force could result in damage to the saw.
The authors agree with the reviewer on the subject of chain tension and are aware of the problem, however at the moment no such classifications are available. In the article we do call for advancements in this field:
Line 227-230: Although the statistical significance of the influence of chain tension onto cutting speed has not been confirmed, the chain tension should be controlled in all scientific publications. We therefore propose, that the mass with which the chain is tensioned is standardized in relation to chain length and pitch.
Point 3: Perhaps an interesting indicator would be the resistance of the chain note on this part: the tested saws differed from each other not only in their motor parts, but also in the saw blades and chains. This fact could have a significant effect on the final evaluation. for all three saws of the same cutting part, a statistical analysis of the achieved results seems to me to be sufficient for the given purpose.
Response 3: The authors agree, the saws had different motor parts, design, blades and chains. This is however a saw that a producer has manufactured, and that can be bought in store as such.
Point 4: In the Results section, the authors emphasize at the outset that the amount of tension in the saw chain was not confirmed to be significant in terms of time consumption during cross-cutting. In the light of the above comment, this should be supplemented by information expressing the degree of chain tension. Information on differences in energy consumption in cross sections is acceptable. Equally acceptable is the statement about the higher energy requirement and the size of the cross-sectional time when using a blunt chain (line 168).
In the Discussion, the authors reiterate that the chain tension did not affect the amount of vibration transmitted to the worker's hands and with the saw, nor the amount of energy consumption or the amount of time required to make a cross section. As I mentioned earlier, this finding is, in my opinion, conditionally valid - if the chain were really tightened to the maximum, this fact would certainly have to be reflected in energy consumption or cutting time. Again, I recommend expressing the chain tension more accurately in a suitable way. I have no comments on the knowledge of the influence of different types of saws on energy consumption and cutting time. However, I recall my comments above on the appropriateness of expressing the parameter for a "sharp" and "blunt" chain more precisely.
Response 4: Please see the comments above where the respected reviewer’s questions regarding chain tension were addressed.
In the discussion section a sentence has been added into methods section addressing the respected reviewers concerns regarding how much can a chain be tensioned.
L 123 The weight was in line with the saws’ tensioning mechanism, as higher weight could result in damage to the tensioning mechanism
Point 5: Comments: I recommend checking and correcting formal deficiencies in the text (typos, etc.), eg on lines 36 and 37, 101, 103, etc., spaces for punctuation marks (commas, dots) are incorrectly used or not used, there is no space between the number 30 and mark %, the upper exponent is not used for marking m3 etc.
Response 5: The manuscript has been subject to extensive english revision. All punctuation in numbers ex. 32.5 is now in dots, upper exponents, %, and spaces between numbers and units have been revised thorughout the text and mistakes corrected.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript describes a test performed on electrical chainsaws. Due to the novelty and impact of "electrification" of all productive and every-day-life sectors, I consider this paper very interesting. The study is simple and circumscribed to a very specific aspect, but this is also a merit: goes to the point and provides brief and effective information to readers.
Nevertheless, the manuscript requires an extensive language revision. The present form is not acceptable, being difficult to read and in some points to understand.
Furthermore, all sections require also a polishing of technical form. For instance, at the beginning of Materials and Methods, you start mentioning chainsaws 1, 2 and 3 without any reference to which is what. At the beginning, the impression is that you do not want to make a comparison of brands and models (which would be a very scientific approach). But reading the rest of the paper, it seems clear that this was not the intention. If this is the case, I suggest that Table 2 is moved in first place, and a line is added where you specify that Makita is chainsaw 1, Stihl chainsaw 2 and Husqvarnda chainsaw 3.
Once this is set up and clear (also from the text), you can place table 1 (which becames table 2) describing the trial setup.
"Results" and "Discussion" also require revising and polishing, not only of language style, but also to provide a more clear understanding.
A final note, in the section "Conflicts of Interest" you leaved all the journal's instructions rather than providing your responses. In theory, this is sufficient to prevent publication. Do fill this section carefully.
Author Response
Response to Reviewer 2 Comments
The reviewer’s text has been copied into a file, and the author’s comments are below in red color.
Point 1: The manuscript describes a test performed on electrical chainsaws. Due to the novelty and impact of "electrification" of all productive and every-day-life sectors, I consider this paper very interesting. The study is simple and circumscribed to a very specific aspect, but this is also a merit: goes to the point and provides brief and effective information to readers.
Nevertheless, the manuscript requires an extensive language revision. The present form is not acceptable, being difficult to read and in some points to understand.
Response 1: Extensive language revision has been made.
Point 2: Furthermore, all sections require also a polishing of technical form. For instance, at the beginning of Materials and Methods, you start mentioning chainsaws 1, 2 and 3 without any reference to which is what. At the beginning, the impression is that you do not want to make a comparison of brands and models (which would be a very scientific approach). But reading the rest of the paper, it seems clear that this was not the intention. If this is the case, I suggest that Table 2 is moved in first place, and a line is added where you specify that Makita is chainsaw 1, Stihl chainsaw 2 and Husqvarnda chainsaw 3.
Once this is set up and clear (also from the text), you can place table 1 (which becames table 2) describing the trial setup.
Response 2: The authors do not wish to disclose which saw is which. The reason for that is the fact that the saws were borrowed from the respective producers on basis of their good will. No agreement exists in which the producers are allowing us to disclose the details of the saws’ performance, and because of that we do not wish to disclose the make of saws 1, 2 and 3.
The authors believe that the scientific value of the study is not diminished for not disclosing which saw is which, as omitting the producer is very common in scientific literature in the field of forest operations.
Point 3: "Results" and "Discussion" also require revising and polishing, not only of language style, but also to provide a more clear understanding.
Response 3: Revision of language, its polishing and revising were done in order to facilitate better understanding. Comments of editor and all reviewers were considered.
Point 4: A final note, in the section "Conflicts of Interest" you leaved all the journal's instructions rather than providing your responses. In theory, this is sufficient to prevent publication. Do fill this section carefully.
Response 4: The section »conflict of interest« has been revised.
Author Response File: Author Response.docx
Reviewer 3 Report
Keyword: Words from the title should not be used as keywords. In addition, the number of keywords is excessive.
Lines 36-52. This section is not appropriate for the aim of the study. I suggest to improve the paper with direct concepts about the objective of the research and not explain generally the forests of the world or the concept basilar of forestry mechanization.
In the title is used the concept of “cross‐cutting time” but in introduction section this topic is not discuss. What mean? Productivity is correlated to time and so I consider necessary to give an approach about the necessity to study the influence of “cross-cutting time” on productivity of forest work. I suggest to add international and recent references about productive work time, semi‐mechanized felling and the study of time motion study.
Material, Results and Conclusion are not correctly developed
Author Response
Response to Reviewer 3 Comments
The reviewer’s text has been copied into a file, and the author’s comments are below in green color.
Point 1: Keyword: Words from the title should not be used as keywords. In addition, the number of keywords is excessive.
Response 1: In the original Forests template for submitting manuscripts it is stated in regard of keywords: “List three to ten pertinent keywords specific to the article; yet reasonably common within the subject discipline.”
As no further limitations are provided in regard to the use of keywords the authors believe we are within allowed parameters in regard to the listing of keywords. Nevertheless, we have removed the keywords: cross cutting and wood harvesting
Point 2: Lines 36-52. This section is not appropriate for the aim of the study. I suggest to improve the paper with direct concepts about the objective of the research and not explain generally the forests of the world or the concept basilar of forestry mechanization.
Response 2: The longer introduction section emphasizes the importance of plantation forestry in global perspectives, as plantation forests are forests in which the electrical saws will be used on larger scale due to relative proximity of electrical infrastructure and smaller dimensions of trees, which are therefore more suitable for use of smaller saws. New articles from the field of forestry mechanization dealing with forestry mechanization have been cited (articles 6-11), as well as new articles regarding electrification for motor-manual felling (articles 20,21 and 23)
The section has been reviewed and shortened:
“Forests are supplying the world with almost 3.97 billion m3 of wood annually [1,2], and as wood is appreciated for its intristic qualities and general versatility [3], it is immensely valuable to humanity since the earliest prehistoric times [4]. Today most of wood is supplied from natural, planted forests and plantations [5]. “
Point 3: In the title is used the concept of “cross‐cutting time” but in introduction section this topic is not discuss. What mean?
Response 3: The concept of »cross cutting« is detailed in standard ISO 7182:1996 (L103). The entire article and experiment setup revolve around this standard, as the choice of saws, their preparation for measurement, length of the saw bar, the choice and dimensions of wood are all regulated. In the standard also, the cross cutting is specified, as the time in which the saw makes a full cross cut of the standardized beam with standardized force.
We recognize that the cross-cutting has not been discussed in detail, that is why a sentence has been added to the manuscript:
L 111: “The time of cross cutting, which is defined as time in which the saw cross-cuts the beam under full throttle, was determined with an analysis of a digital recording made using a handheld camera (Sony HDR-XR200).”
Point 4: Productivity is correlated to time and so I consider necessary to give an approach about the necessity to study the influence of “cross-cutting time” on productivity of forest work. I suggest to add international and recent references about productive work time, semi‐mechanized felling and the study of time motion study.
Response 4: As the entire cross-cutting time is in accordance with standard ISO 7182:1996, as explained above no efforts were made to study the influence of cross-cutting time onto work productivity, as such efforts would demand a separate study.
Nevertheless, it has to be emphasized that the cross-cutting time does influence the productivity of forest work. Productivity can be characterized with the input of time and energy and the output of end product- usually m3 of wood. If the time consumption can be influenced via the cross-cutting speed it is clear, that the productivity will change. It is however hard to correlate cross-cutting time to productivity of forest work, as the latter is under influence of many factors; the skill and technique of the worker, , sizes and species of trees, just to mention a few. That is why in the article we did not endeavor to make comparisons in the sense of - if saw 1 is used the productivity will rise or fall. That was never a goal to this study as they are beyond the experimentative setup of the trial, and the results of the study cannot be generalized for modeling the differences in productivity of forest operations.
References regarding new articles from the field of forestry mechanization dealing with forestry mechanization and productive work time have been cited (articles 6-11), as well as newest articles regarding electrification of motor-manual felling (articles 20,21 and 23).
Reference in relation to time motion study have been added. L111 “was determined with an analysis of a digital recording made using a handheld camera (Sony HDR-XR200) according to harmonized time-motion studies guidelines [28]”
Point 5: Material, Results and Conclusion are not correctly developed
Response 5: Materials, results and conclusions have been edited in accordance with the recommendations of the editor.
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
The paper had been improved by the authors. The document submitted by the authors is clear and organized and it represents a good study.
However, I confirm my disapproval about conclusion section, not correctly developed and discussed. The same results (e.g. 6.2-6.7 6-fold difference) are repeated three times (abstract, results and conclusion) using similar or same sentences. The same problems about others repetitive sentences.
Author Response
Response to reviewer 3 comments:
The paper had been improved by the authors. The document submitted by the authors is clear and organized and it represents a good study.
Point 1: However, I confirm my disapproval about conclusion section, not correctly developed and discussed.
The same results (e.g. 6.2-6.7 6-fold difference) are repeated three times (abstract, results and conclusion) using similar or same sentences. The same problems about others repetitive sentences.
Response 1:
Conclusions have been re-written, with a different developed and discussion. The figures are not reported again.
Abstract has been re-written with the sentences in question edited or removed.
