The Effect of Technological Progress on Yarder Productivity: An Example from the Bulgarian Mountains
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe draft article investigate an interesting topic on cable yarding productivity in Bulgaria. The introduction, literature review, study method and results have been well presented. The results of this study can be of use to the readers working on steep terrain logging. I have only a suggestion on modelling part. Equation (1) presented in line 156 contains both payload and piece count per cycle. These variables may have high correlation which may cause collinearity in the model thus it is worth to drop one of them. Piece count per cycle may be dropped (as it is also difficult to accurately measure it in the practice).
Author Response
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Reviewer 2 Report
Comments and Suggestions for Authors- Abstract contains very little information about obtained results,
- Complete the Introduction with current literary sources,
- line 50 – 51 what does it mean „medium-sized tower yarder“?,
- line 66 – 67 there is no information about the mean volume of harvested stems, the harvested volume in individual stands, tree species composition, it would be more appropriate to place information about stands in table,
- line 75 – 86 information about the cableway should be placed in table, there is lack information about the cableway system for example: cableway carrier, rope diameter, length of the cableway line, describe the type of cableway carriage, etc., authors can add pictures of the machines,
- line 127 – 134 shows the use of different types of analysis (parametric, non-parametric), was the normality of the data also tested?,
- line 93 – 126, mark the measured variables with the symbols v1, v2......,
- it is not stated the length of the work shift, the age of the workers, length of workers experience etc.,
- line 128 – 134 describe in more detail what analyzes were used for individual variables,
- line 140 – 147 the description of the variables should be placed in the methodology,
- line 156 – 158 formulas should be placed in the methodology,
- line 181 the term "older technology" line 186 "older machines" what types of machines are meant by this terminology (Larix, Steyr KSK 16) ? it is also not clear in Fig. 2,
- line 190 – 191 it is stated "the performance of the new yarder is 1.3 to 2 times larger than that of the older machines" in my opinion to compare the Mounty 4000 - a heavy cableway system on a truck chassis with older cableways as agricultural tractors adapters is not appropriate because these are technologically completely different systems,
- fig. 4 has no informative value. The assembly time is influenced by a large number of factors, e.g. yarding up or down the slope, the number of supports in the cableway line, yarding distance, etc.,
- the discussion chapter is too long,
- Conclusion should contain the most important findings listed in bullet points or recommendations for forest management,
- the literature contains a few new and high-quality sources.
Author Response
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Reviewer 3 Report
Comments and Suggestions for AuthorsA very well-written paper.
But I still have some notes:
If you google "processor tower yarder in Bulgaria", several papers made in Bulgaria come up. You could include them in the Introduction section.
line 28 - Wyssen sledge yarders are better formulated;
line 96 - Tm is written twice;
line 153 - table 2 is untitled;
line 187 - At very short (lateral or longitudinal?) yarding distances...
Missing Fig. 3.
Author Response
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