Static Lateral Stability of Tractor with Rear Wheel Ballast Weights: Comparison of ISO 16231-2 (2015) with Experimental Data Regarding Tyre Deformation
, Rudolf Abrahám 1, Zdenko Tkáč 1, Róbert Drlička 2, Eva Matejková 3, Katarína Kollárová 4 and Jan Mareček 5
Round 1
Reviewer 1 Report
It is not clear to me if the tractor was overturned every time or if only reach unstable equilibrium point and then return to horizontal position.
Throughout the work you talk about an increase in deformation of the downstream wheel, there cannot also be an increase in the upstream wheel due to a reduction in load. If the consideration is made within the discussion on increasing the inflation pressure, it is necessary to explain better.
Figure 3: The deformation of the tire as a result of the inclination is evaluated, but the tire remains on a horizontal surface. Could there be variations if the assessment had been made with the downstream wheel positioned on the inclined plane?
End of page 1, page 2, page 15 – Mazzetto instead of Mazzetoo
Page 16, 2nd paragraph: please uniform the number of decimal digits
Author Response
Response to Reviewer 1 Comments
Point 1: It is not clear to me if the tractor was overturned every time or if only reach unstable equilibrium point and then return to horizontal position.
Response 1: The tractor reached unstable equilibrium point and then returned to horizontal position. The explanation was added to the text (line number 146 and 147)
Point 2: Throughout the work you talk about an increase in deformation of the downstream wheel, there cannot also be an increase in the upstream wheel due to a reduction in load. If the consideration is made within the discussion on increasing the inflation pressure, it is necessary to explain better.
Response 2: We agree with the consideration about the reduction of the load acting on the upstream wheel when the tractor is inclining. We also agree with the results published by the Bietresato and Mazzetto (2020) (Applied Science) who presented that the upstream wheel deforms in opposite direction to downstream wheel when the tractor was inclined at various angles. The tyre deformation causes the COG shift. We evaluated the tractor inclined at the static overturning angle when the tractor rested in the state of the unstable equilibrium. In this state, we considered the effect of upstream wheel deformation on the COG position as negligible, and we considered only the effect of the vertical tyre deformation on the vertical position of COG (line number 209 – 215).
Point 3: Figure 3: The deformation of the tire as a result of the inclination is evaluated, but the tire remains on a horizontal surface. Could there be variations if the assessment had been made with the downstream wheel positioned on the inclined plane?
Response 3: Considering the sentence presented by Gibsom (1973) “When the tractor is used on a side slope or travels around a curve, or when the skidded load pulls the winch line to one side, a side thrust on the tires exists”, it is clear that the tyre deforms under various tractor operation conditions. Therefore, the tyres deform in case of all tractor wheels on the platform and also in case of the two wheels on the platform, but the tyre deformation is not the same and depends on other factors, such as for example tyre type, inclination angle, weight, etc. In our case, we choose the contact of downstream wheel on the horizontal surface.
Point 4: End of page 1, page 2, page 15 – Mazzetto instead of Mazzetoo
Response 4: Names were corrected in respective positions.
Point 5: Page 16, 2nd paragraph: please uniform the number of decimal digits
Response 5: Page 16 is the chapter References. Please, state the correct page.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The central idea of the work - Static lateral stability of tractor with rear wheel ballast weights: comparison of ISO 16321-2 (2015) with experimental data regarding tyre deformation.
The authors present a static lateral stability of a sub-compact tractor MT8-070 Mini in relation to a safe tractor operation. On its example, they calculate the static tipping angle with the loads on the rear wheels (30.5 kg, 61 kg, 91.5 and 122 kg) with the standard and extended overall width on the tires.
The obtained data is very interesting and brings new knowledge in the field of tractor statics and their influence on soil.
I propose to consider adding provide more detailed technical data of the agricultural tractor that was used for the research.
In my oppinion scientific importance of the paper is high.
The structure of the article is very transparent. Proposed methodology and conclusion are good discribe.
Author Response
Response to Reviewer 2 Comments
Point 1: I propose to consider adding provide more detailed technical data of the agricultural tractor that was used for the research.
Response 1: Detailed technical data of the tractor was added to the manuscript (line number 94, 95 and 96).
Author Response File: Author Response.docx
