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Analysis of dynamic strength of friction knots used in military climbing
Telvák, Radek ; Michalička, Vladimír (advisor) ; Braum, Zdeněk (referee)
Title: Analysis of dynamic strength of friction knots used in military climbing Objectives: The aim of this work is to determine the resulting impact force generated by selected friction systems at different values of the fall factor. To calculate what maximum values of auxiliary Reep cord length and maximum load weight can be achieved without system failure. Determine the correlation between the magnitude of the impact force and the slip length. Methods: This thesis describes an experiment in which the resulting impact force acting on a friction system at different drop factors was determined. A 6mm Reep cord and an 11mm rope and friction knots used in military climbing techniques were selected for analysis. Testing was carried out in a polygon on a drop tower. Each of the friction knots was subjected to 5 tests at the same fall factor. The individual knots were statistically compared with each other in terms of impact force and slip. Using direct proportionality, the maximum possible values of the auxiliary Reep cord length and the weight of the load were determined. A correlation analysis was used to establish a correlation between impact force and slip. Results: It was found that at all measured values of the fall factor, the Twist prusik achieved the lowest values of the resulting impact force...
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Comparison of impact force values amongst improvised and traditional rope fixed instalations
Kučera, Václav ; Michalička, Vladimír (advisor) ; Gajdošík, Jan (referee)
Title: Comparison of impact force values amongst improvised and traditional rope fixed instalations. Objectives: The aim of this work is to measure the resultant impact forces acting on a climber during a fall from an improvised fixed installation, using an improvised ferrata set, by means of an experiment. Furthermore, to compare the measured impact force values with those already measured for traditional fixed installation using ferrata fall arresters. Methods: This paper describes an experiment in which the actual impact force acting on a climber during a fall from an improvised fixed installation using an improvised ferrata set was determined. The aim of the first experiment was to determine the values of the impact forces for a given length of fall. At the same time, to determine the maximum value of the impact force at which the reep cord forming the improvised ferrata set will not break. The second test aimed to determine the resultant values acting on the load when falling into the sag from the dynamic rope, which were then used to compare with the results of the first test. The purpose of the last test was to compare the resultant values of improvised and traditional fixed installations. Each fall length was tested for ten trials whereby after each fall the textile material was replaced...
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Comparison of human physiological response in different one-rope ascending techiques
Doležal, Jan ; Michalička, Vladimír (advisor) ; Baláš, Jiří (referee)
Title: Comparison of the physiological response rate of the organism using different one-rope ascent techniques Objectives: The aim of this study was to compare the rate of the physiological response of the organism using 3 different one-rope ascent techniques during constant speed. Methods: It was an empirically based study of experimental character (quasi-experiment). The measured research group (n = 12) consisted of the military students (21 ± 1.1 years; 183 ± 4.9 cm; 80.6 ± 7.8 kg) of full-time study at the Faculty of Physical Education and Sport of Charles University (VO FTVS UK). The physiological response rate was measured with the Cortex Metamax 3b and Polar sporttester during one-rope ascending techniques ("using Prusik knot" = P", "using jümar = B", "using Garda knot = G") at a constant speed of 3 m·min-1 for 7 minutes. The rating of the perceived exertion was also recorded on the Borg RPE scale. The data were comparatively analyzed in the SPSS statistic program, furthermore the analysis of variance (ANOVA) was also employed. Results: The study demonstrated statistical differences (p ≤ 0.05) between techniques: while B is the easiest, the greatest differences were observed between technique B, P and G. The G technigue appeared to be the most difficult. The average HR was: 162 ± 9 bpm...
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Static strength analysis of friction knots used in military climbing
Telvák, Radek ; Michalička, Vladimír (advisor) ; Baláš, Jiří (referee)
Title: Analysis of static strength of friction knots used in military climbing. Objectives: Strength determination of selected knots on static ropes under static load. Methods: This bachelor thesis shows a laboratory experiment, where the influence of friction knots on the strength of the Reep cord tied to a static rope under static load was determined. For the purposes, a 6mm Reep cord and 10.5mm rope and friction knots used in military climbing techniques were selected. The experiment was run on a vertical test rig. Each of the selected knots was tested 10 times. Every knot was compared among the others in the first slip, slip length, maximum strength, nominal strength drop and the point of failure. Results: The highest average values of the first slip and the maximum strength were achieved by the Twist prusik. The lowest value of the slip length was measured at the Blake friction knot. Compared to other of the selected knots, the lowest decrease in nominal strength by 14 % was found on the Blake knot, while the highest decrease in nominal strength is found in the Twist prusik. The Reep Cord failed in 81 % of all attempts. Keywords: military climbing, friction knot, knot strength, slip, point of failure, nominal strength
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Comparison of human physiological response in different one-rope ascending techiques
Doležal, Jan ; Michalička, Vladimír (advisor) ; Baláš, Jiří (referee)
Title: Comparison of the physiological response rate of the organism using different one-rope ascent techniques Objectives: The aim of this study was to compare the rate of the physiological response of the organism using 3 different one-rope ascent techniques during constant speed. Methods: It was an empirically based study of experimental character (quasi-experiment). The measured research group (n = 12) consisted of the military students (21 ± 1.1 years; 183 ± 4.9 cm; 80.6 ± 7.8 kg) of full-time study at the Faculty of Physical Education and Sport of Charles University (VO FTVS UK). The physiological response rate was measured with the Cortex Metamax 3b and Polar sporttester during one-rope ascending techniques ("using Prusik knot" = P", "using jümar = B", "using Garda knot = G") at a constant speed of 3 m·min-1 for 7 minutes. The rating of the perceived exertion was also recorded on the Borg RPE scale. The data were comparatively analyzed in the SPSS statistic program, furthermore the analysis of variance (ANOVA) was also employed. Results: The study demonstrated statistical differences (p ≤ 0.05) between techniques: while B is the easiest, the greatest differences were observed between technique B, P and G. The G technigue appeared to be the most difficult. The average HR was: 162 ± 9 bpm...
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The Choice of Universal Abseiling Aids for the Requirements of the Czech Armed Forces
Strnad, Jakub ; Barták, Erik (advisor) ; Pevný, Jiří (referee)
Title: The Choice of Universal Abseiling Aids for the Requirements of the Czech Armed Forces Objectives: Choosing abseiling - belaying aids in accordance with the needs of the Czech Armed Forces. Methods: A mixed empirical research was involved. In order to analyse the results, closed questionnaires created in MS Excel were produced and evaluated later on. They were split into two phases. The analysis of the relationships of the variables was carried out using methods of descriptive statistics. To collect data, the Delphi research method was used. The survey was conducted in cooperation with chief instructors of military climbing. Respondents were selected according to their qualifications. Results: It was chosen ATC Guide like the most acceptable abseiling aid for the requirements of the Czech armed forces by informant with help research method Delphi. Keywords: Research method Delphi, Special physical education, Army climbing, Descent, ATC Guide. J. STRNAD 10.4. 2011
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