# Calculating Forces in the Pulley Mechanical Advantage Systems Used in Rescue Work By Ralphie G. Schwartz, Esq

Save this PDF as:

Size: px
Start display at page:

Download "Calculating Forces in the Pulley Mechanical Advantage Systems Used in Rescue Work By Ralphie G. Schwartz, Esq"

## Transcription

2 Review of the Basics Fundamental Concept 1: According to the familiar paraphrase, Newton s Law of Reaction states: For every action, there is an equal, and opposite reaction. When we pull on a rope, the rope pulls back, and tension runs through the rope in both directions. Both ends are loaded equally! (See: Understanding Mechanical Advantage in the Single Sheave Pulley Systems Used in Rescue Operations) Fundamental Concept 2: In a theoretical frictionless system, a pulley equalizes the tension in both legs of the rope that passes through it. In the real world, the same principle applies, minus the effect of friction within the workings of the pulley in question. Fundamental Concept 3: Pulleys are force magnifiers! When the two weighted legs of the rope passing through a pulley are maintained in a parallel configuration, the forces brought to bear on the pulley s point of attachment are doubled! Fundamental Concept 4: Within a pulley hauling system, a pulley can function in one of two ways: as a standing pulley, or as a traveling pulley. The standing pulley: o Attaches to the anchor system o Does not move o Changes direction only (directional), and o Does not contribute to mechanical advantage. The traveling pulley: o Attaches to either the resistance or to the interior of the system o Does move o Changes direction, and o It does contribute to mechanical advantage. 2

3 Tracking Stresses Through the Pulley MA System For the moment, let s revert to use of the T system, forgoing actual numbers in order to illustrate some key principles by the simplest means available. Consider the following: T-2 T-2 T-1 Input T-1 T-1 T-1 (T-1 + T-2 = T-3) MA= 3:1 T-1 T-2 R Figure 1: A Simple 3:1 System Figure 1 The R in the rectangular box at the bottom of the figure represents the resistance. The pulley at the top of the figure is the standing pulley. The bottom pulley is the traveling pulley. The big T-1 (upper right) represents an input force of 1. These theoretical friction-free pulleys equalize the tension throughout the system. Thus, the T-1 force runs throughout the system, and each leg of the rope carries a T-1 force. The law of reaction reminds us that even though the rope moves through an active system in one direction only, there is equal tension at each end of the rope, hence, the double-ended arrows. Each pulley carries two T-1 loaded rope segments, and therefore, transfers a T-2 (2:1) force to its point of attachment. o The standing pulley (top) applies a T-2 force to the anchor o The traveling pulley (bottom) applies a T-2 force to the resistance (R) In addition to the T-2 pulley force, the resistance is attached to a single T-1 loaded ropeleg for a total force of T-3. (T-2 + T-3; MA= 3:1) 3

4 T-2 T-2 T-1 Input T-1 T-1 T-1 T-2 T-2 T-1 + T-2 =T-3 MA= 3:1 Figure 2 Figure 2: The Simple 3:1 System Rigged with a prusik R This is the same simple 3:1 system from Figure 1, but this time rigged with a 3-wrap prusik connecting the traveling pulley to the main line coming from the resistance (represented by the thin, diagonal line). This is consistent with standard practice in rescue applications. The T-1 tension continues to run through the entire system. Because the traveling pulley is rigged within the system, it adds its T-2 force to the T-1 force already running through the system. The forces within the system are as shown. Ultimately, there is a T-2 force applied to the anchor and a T-3 force applied to the resistance, just as in Figure 1. (T-2 + T-3; MA= 3:1) Real Numbers, Real Forces In the remaining diagrams, we ll replace the T-1 symbolic load with a 2 kn (450 lb.) load held in equilibrium. We ll follow this force through the system and calculate the stresses at all critical points. 4

5 In order to remind the reader of the forces transferred to the anchor, the stress on the anchor system will be expressed as a percentage of the main load. Because it s not uncommon to route the haul line through a directional pulley, we ll calculate that stress as well. In doing so, we ll assume that the two legs of the rope passing through the directional pulley run parallel to one-another. In the real world this may not be the case. When the rope angle at the pulley is greater than 0, the stress on the pulley and anchor is reduced more later (p. 19). 225 T-2= 450 Directional Pulley T-2= Input T-1 (225) + T-1 (225)= T-2 (450) Figure 3 Stress on the anchor = 225 lb., or 50% of the 450 lb. output force If the main and directional anchors are shared, the stress on the combined anchors= 675 lb., or 150% of the 450 lb. output force Fig. 3 shows a 2:1 MA system The T-1 input force is 225 lb. Each of the two rope legs carries 225 lb. of force The stress on the anchor is 225 lb. In practice, it is likely that this system will be set up separately from the main haul-rope and connected to it by a 3-wrap prusik 5

6 Notice that if a directional is used, and configured as shown here, the stress on that anchor is the same as the stress brought to bear on the main load T-2= 300 T-2= 300 T-2= 300 T-2= 300 Directional Pulley Input T-2= 300 T-2= 300 T-1 (150) + T-2 (300)= T-3 (450) 450 Figure 4 Stress on the anchor = 300 lb., or 66% of the 450 lb. output force If the main and directional anchors are shared, the stress on the combined anchors= 600 lb., or 133% of the 450 lb. output force Fig. 4 illustrates the same 3:1 MA system diagrammed in Figure 2 with the addition of an optional directional The T-1, 150 lb. input force runs through all 3 legs of the system The traveling pulley doubles the force to T-2= 300 lb. 6

7 This is added to the running 150 lb. force in the rope segment running between the prusik and the load, to produce a 450 lb. force. Compound Systems The next four diagrams show compound, or piggy-back systems in which MA rigs are joined together in series. T-6= 300 T-2= 100 T-2= 100 Directional Pulley Input T-3= T-3= 150 T-2= 100 T-1 (50) + T-2 (100)= T-3 (150) T-2= 100 T-6= 300 T-6= 300 T-3 (150) + T-6 (300)= T-9= (450) 450 Figure 5 7

8 Stress on the main anchor = 300 lb., or 66% of the 450 lb. output force Stress on the piggy-back anchor = 100 lb., or 22% of the 450 lb. output force If the main and piggy-back anchors are shared, the stress on the combined anchors= 400 lb., or 89% of the 450 lb. output force Fig. 5 is a 3:1 piggy-backed on a 3:1 to create a 9:1 MA system The (T-1) 50 lb. input force runs throughout all three legs of the piggy-backed 3:1 MA system The first traveling pulley (upper right) doubles the input force (T-2= 100 lb.), and adds it to the (T-1) 50 lb. running force, creating a (T-3) 150 lb. input force which is passed into the second 3:1 MA system The (T-3) 150 lb. force enters the second 3:1 system and is equalized through all three legs The second traveling pulley (lower left) doubles the T-3, 150 lb. force (T-6, 300 lb.) which is added to the T-3, 150 lb. running force, for a total of T-9= 450 lb. Warning: Remember that these high force outputs increase the stresses throughout the system. Of particular concern is the prusik nearest the load. 8

9 T-4= T-2= 150 Directional Pulley Input T-2= 75 T2= T-2= 150 T-2= 150 T-4= 300 T-4= 300 T-2 (150) + T-4 (300)= T-6 (450) 450 Figure 6 Stress on the main anchor = 300 lb., or 66% of the 450 lb. output force Stress on the piggy-back anchor = 75 lb., or 16% of the 450 lb. output force If the main and piggy-back anchors are shared, the stress on the combined anchors= 375 lb., or 83% of the 450 lb. output force Figure 6 shows a discreet 2:1 system piggy-backed on a 3:1 by means of a 3-wrap prusik, to produce a 6:1 system 9

10 The (T-1) 75 lb. input force runs through both legs of the piggy-backed 2:1 MA system The traveling pulley of the 2:1 doubles the input force (T-2= 150 lb.) into the 3:1 MA system The (T-2) 150 lb. force enters the 3:1 system and is equalized throughout all three legs The traveling pulley doubles the T lb. force (T-4, 300 lb.) which is added to the T-2, 150 lb. running force, for a total of T-6= 450 lb. Warning: Remember that these high force outputs increase the stresses throughout the system. Of particular concern is the prusik nearest the load. T 3= 225 T 2= 150 T 2= 150 Directional Pulley T 1= 75 T 1= 75 T 1= T 3= T 1= T 1= 75 T 2= 150 T-1 (75) + T-2 (150)= T-3 (225) T 3 (225) + T 3 (225)= T 6 (450) 450 Figure 7 10

11 Stress on the main anchor= 225 lb., or 50% of the 450 lb. output force Stress on the piggy-back anchor= 150 lb., or 33% of the 450 lb. output force If the main and piggy-back anchors are shared, the stress on the combined anchors= 375 lb., or 83% of the 450 lb. output force Figure 7 shows a 3:1 system piggy-backed on a discreet 2:1 to produce a 6:1 system, all of which is attached to a separate main haul-line, by means of a 3-wrap prusik, The (T-1) 75 lb. input force runs through all three legs of the piggy-backed 3:1 MA system The first traveling pulley (upper right) of the 3:1 doubles the input force (T-2= 150 lb.) This (T-2) 150 lb. force is added to the 75 lb. force running through all three legs of the 3:1 system to create a (T-3) 225 lb. force The (T-3) 225 lb. force enters the 2:1 system and is equalized through both legs The second (bottom) traveling pulley doubles the T-3, 225 lb. input force (T-3 [225] + T-3 [225]= T-6 [450]), which is transferred to the separate, main haul-line by means of a 3-wrap prusik to produce a cumulative 450 lb. force Warning: Remember that these high force outputs increase the stresses throughout the system. Of particular concern is the prusik nearest the load. 11

12 T-3= T-2= 225 T-1 (112.5) + T-2 (225)= T-3 (337.5) Directional Pulley T-2= Input T-2= 225 T-2 (225) + T-2 (225)= T-4 (450) T-4 (450) 450 Figure 8 Stress on the main anchor= lb., or 75% of the 450 lb. output force Stress on the anchor for the Directional Pulley= 225 lb., or 50% of the 450 lb. output force If the main and directional anchors are combined, the force = lb., or 1.25% of the 450 lb. output force 12

13 This discreet 4:1 piggy-back system connects to the main haul line by a 3-wrap prusik It is rigged by using a knot such as a figure-of-eight loop tied near the middle of the rope to create two working ropes from one The T-1 (112.5) input force is equalized between the two legs of the first 2:1 rig, through its pulley, and up to the knot This upper-most of two traveling pulleys doubles the input force (T-2= 225) The T-2, 225 input force is equalized between the two legs running through the second (lower) traveling pulley, and up to the knot The second (lower) traveling pulley doubles the T-2, 225 force to create a total output force of 450 The anchor stress is a composite of the T-1, force from the first 2:1, and the T-2, 225 force from the second 2:1 In use, the main haul-line is routed through a 3-wrap prusik used as a progress capture device and anchored separately, which offers an additional degree of redundancy In the real world, the rope legs entering and exiting the pulleys are parallel Warning: Remember that these high force outputs increase the stresses throughout the system. Of particular concern is the prusik nearest the load. Complex Systems Notice that in each of the simple MA systems considered so far, the traveling pulleys have moved in the same direction as the resistance. If the force generated by the simple system in question proves inadequate, this can be rectified by adding-on another similar system in an in-line configuration, to create one of the compound MA systems discussed in the previous section. Complex MA systems offer an alternative solution to this problem. In these systems, a traveling pulley is introduced into the interior of the simple system in order to increase the amount of force running through the equalized legs, thus increasing the final MA. As will be seen, the add-on traveling pulley can move in a direction opposite to that of the load, a most interesting situation, indeed. As one might expect, this configuration makes it more difficult to calculate the stresses within, and to understand the resulting MA. Because complex systems are sometimes viewed as requiring less equipment, and being easier and faster to set-up compared to compound systems, they may be chosen for reasons of expedience when the MA of a simple system proves to be less than desired. As is so often the case in life, such convenience can come at a cost. A closer look at our sample complex systems will reveal that it is good to have a thorough understanding of a tool before putting it to work. 13

14 T-6= 540 T-1 (90) + T-1 (90) + T-2 (180) + T-2 (180)= T-6 (540) T-2= 180 T-2= T-2= Input 90 T-2= 180 T-2= 180 T-1 (90) + T-2 (180) + T-2 (180)= T-5 (450) 450 Figure 9 The stress on the anchor = T-6, 540 lb., or 120% of the 450 lb. output force! 14

15 Notice that this 5:1 system includes two traveling pulleys. Each doubles a T-1 (90) input force to T-2 (180), and applies that force to the system at separate locations The traveling pulleys direct their respective forces in opposite directions Because the first (upper) traveling pulley directs its T-2 (180) force toward the standing pulley, and this is added to the running T-1 (90) force, the T-1 (90) input force is tripled in both legs passing through that pulley, creating a T-6 (540 lb.) force at the anchor It breaks down as follows The T-1 (90) input force is equalized by the various pulleys and runs through all legs of the system The first (upper) traveling pulley doubles the input force to T-2 (180), which is added to the T-1 (90) running tension via the 3-wrap prusik. This (T-1 [90] + T-2 [180]= T-3 [270]) force passes through the standing pulley, and is equalized in both rope legs, doubling the T-3 (270) force and passing it on to the anchor T-6 (540 lb.). The second (lower) traveling pulley doubles the T-1 (90) input force to T-2 (180) and transmits it to the main haul line via the (lower) 3-wrap prusik The net force applied to the load combines the original T-1 (90) running tension, plus the T-2 (180) force contributed by the first (upper) traveling pulley, plus the T-2 (180) force added by the second (lower) traveling pulley: T-1 (90) + T-2 (180) + T-2 (180)= T-5 (450) Discussion Notice that the force applied to the rescue load is T-5 (450 lb.), while the force applied to the anchor system is T-6 (540)! Doesn t it seem that we might be better off turning this system 180? If we do so, this becomes nothing more than a 3:1 on a 2:1= 6:1 compound system, requiring the same gear, plus an anchor (See: Figure 7) Alternatively, this could be re-configured into a 2:1 on a 3:1= 6:1 with the same equipment (See: Figure 6) In either case, the MA goes up from 5:1 to 6:1 while the anchor stress is reduced from 120% to 83% of the 450 lb. output force, this, in the worst case scenario, assuming that the compound system uses only one anchor o If a 2:1 on a 3:1= 6:1 compound system is rigged from separate anchors, the stresses drop to 16% (75 lb.) and 66% (300 lb.) of the 450 lb. output force o respectively If a 3:1 on a 2:1= 6:1 compound system is rigged off of separate anchors, the stresses drop to 33% (150 lb.) and 50% (225 lb.) of the 450 lb. output force respectively (The preferred set-up: this 3:1 on 2:1 configuration requires less frequent re-setting compared to the 2:1 on 3:1 [Shokoples, 1994]) Warning: Remember that these high force outputs increase the stresses throughout the system. Of particular concern is the prusik nearest the load. 15

16 T-6= T-3 (192.84) + T-3 (192.84)= T-6 (385.68) T-2= (T-1 [64.28] + T-2 [128.56]= T-3 [192.84]) T-2= C T-2= T-2= T-2= T-4= T-2 (128.56) + T-1 (64.28) + T-4 (257.12)= T-7 (450) 450 Figure 10 16

17 Stress on the anchor = lb., or 85.7% of the 450 lb. output force This interesting 7:1 complex MA system features two traveling pulleys and a 2:1 MA system built into the interior of a simple 3:1 rig to produce an impressive force output without subjecting the anchor system to excessively high stresses The T-1 (64.28) force is equalized throughout the three legs of the 3:1 core system The first traveling pulley (upper right) doubles the lb. input to transfer a T-2 (128.56) force into the interior 2:1 system The T-2 (128.56) is equalized between the two legs of the interior 2:1, and passed on, through a carabiner (the oval- C ) and prusik (thin line), to add to the T-1 (64.28) running force in the 3:1 core system (T-1 [64.28] + T-2 [128.56]= T-3 [192.84]) The T-3 (192.84) force passes through the standing pulley (top) undiminished, into the third leg of the core, 3:1 rig (creating a T-3 [192.84] + T-3 [192.84]= T-6 [385.68] stress on the anchor) The interior 2:1 system (lower traveling pulley) passes along a T-4 (257.12) force to the third leg of the core 3:1 system and the load, via another 3-wrap prusik The final result is: T-2 (128.56) + T-1 (64.28) + T-4 (257.12)= T-7 (450) Discussion This system produces a high output force at the working end with acceptable stresses at the anchor because both traveling pulleys direct their forces toward the resistance, rather than the anchor. Because: o The length of the internal 2:1 system is fixed o o And sized to fit inside the foundational 3:1 system While the overall MA is high (7 ft. of rope must be pulled through the system to move the resistance 1 ft.) It is likely that this complex rig would require frequent re-setting, making it slow and cumbersome to use Warning: Remember that these high force outputs increase the stresses throughout the system. Of particular concern is the prusik nearest the load. 17

18 T-2= 180 T-2= 180 T-1 (90) + T-2= 180 T-1 (90)= T-2 (180) T-2= T-2= 180 T-4= 360 T-1 (90) + T-4 (360)= T-5 (450) 450 Figure 11 Stress on the primary anchor= 180 lb., or 40% of the 450 lb. output force Stress on the piggy-back anchor= 180 lb., or 40% of the 450 lb. output force 18

19 This promising 5:1, complex system is created by interposing a 2:1 set-up between the traveling pulley and the prusik of a simple 3:1 rig The fortuitous combination of strong mechanical advantage and low anchor stress is the result of dividing the load between two anchors and directing the forces of both traveling pulleys toward the resistance, instead of the anchors As always, the T-1 (90) force is shared, undiminished, by all three legs of the 3:1 rig The traveling pulley of the 3:1 doubles the T-1 (90) force to pass on a T-2 (180) input force to the internal 2:1 system In the internal 2:1 system, the T-2 (180) running force is doubled by the second (bottom) traveling pulley to pass on a T-2 (180) + T-2 (180)= T-4 (360) force to the third leg of the 3:1 In the final analysis, the T-1 (90) running force of the 3:1 is added to the T-4 (360) force generated by the internal 2:1 to produce a final force of T-1 (90) + T-4 (360)= T-5 (450) This diagram has been expanded horizontally for the sake of clarity. In practice, the rope legs should be set-up as close to parallel as possible Directional Pulleys and Interior Angles Rescue bosses may decide to append a directional pulley onto a hauling system in order to accommodate the local vegetation and terrain, or to direct the pulling crew away from the edge in order to create a safer working environment. Thus far, directional pulleys have been illustrated with the two rope legs maintained in a parallel configuration. In practice, this is fairly unusual, and this is a good thing. When creating a pulley mechanical advantage system, it is crucial to keep those rope legs parallel, or the force brought to bear on the resistance is degraded. When we attach a pulley to an anchor system, we want the force to be degraded. This is exactly what happens when we open up the rope angles. Let s take a look at some examples. The numbers are accurate; the angles in the diagrams are approximations. 0 Yields 2:1 60 Yields 1.73:1 (Multiply the running force X 2 (Multiply the running force X 1.73 to calculate the anchor stress) to calculate the anchor stress) 90 Yields 1.41:1 120 Yields 1:1 (Multiply the running force X 1.41 (The running force equals the anchor stress) to calculate the anchor stress) 19

20 A Summary of Costs and Rewards In the Table Below: Anchor stresses are listed in both pounds and percentage of the sample 450 lb. (2 kn) rescue load The shared anchor stresses apply to situations in which: o The main and secondary anchors are shared, or o The main and directional anchors are shared with parallel rope-legs in all pulleys Fig. MA Anchor Stresses Stresses on Main Secondary Directional Shared Anchors lb. % lb. % lb. % lb. % Simple Systems 3 2: NA NA : NA NA Compound Systems 5 3:1/3:1=9: NA NA :1/3:1=6: NA NA :1/2:1=6: NA NA :1/2:1=4: NA NA Complex Systems 9 5: NA NA NA NA NA NA 10 7: NA NA NA NA NA NA 11 5: NA NA NA NA Conclusion: The Take-Home Messages Pulleys double their input forces wherever they attach, as long as the rope legs are parallel Forces move in both directions throughout the system These forces are transferred to all parts of the system The lead 3-wrap prusik is a probable weak link: watch it for slippage! Systems that produce high MA ratios should be used with extreme caution, or not at all Load the system smoothly when hauling Avoid combining main and directional anchors when using 2:1 systems Avoid complex systems in which a traveling pulley aims its force at the anchor Shokoples, Cyril (1994). Pulleys & the 3:1 Pulley System, 2 nd. Revision Sincere Thanks to: Dr. Scott Grinnell, Assistant Professor of Physics, Northland College, Ashland, WI USA for removing the scales from my eyes, thereby making this article possible Paul Van Horn, Assistant Professor of Outdoor Education, Northland College, Ashland, WI USA for sharing his practical observations and asking the right provocative questions that led to this project Copyright 2007 Ralphie G. Schwartz 20

### MTR Rope Skill Summary

MR Rope Skill Summary 1. Good rope habits Long-term storage: keep dry, store away from sunlight, solvents, rodents, and unwanted users Short-term handling: avoid stepping on the rope or loading it over

### International Technical Rescue Symposium Presented by John McKently

Some of the factors affecting pulley efficiency in theoretical and real world rescue systems. International Technical Rescue Symposium Presented by John McKently 2011 It is generally accepted that pulleys

### CHANGES IN FORCE AND MOTION

reflect CRACK! That s the sound of a bat hitting a baseball. The ball fl ies through the air and lands over the fence for a home run. The motion of a batted ball seems simple enough. Yet, many forces act

Navigation with Leeway Leeway, as we shall use the term, means how much a vessel is pushed downwind of its intended course when navigating in the presence of wind. To varying extents, knowledge of this

### Developed by Firefighter Ty Drage January NFPA 1670 Standard on Operations and Training for Technical Search and Rescue Incidents

Q UICK A CCESS K IT (1.1) Developed by Firefighter Ty Drage January 2011 NFPA 1670 Standard on Operations and Training for Technical Search and Rescue Incidents T ASK S KILL DESCRIPTION AND DETAIL Every

### Friction Testing and Pulley Systems in Vertical Rescue

Friction Testing and Pulley Systems in Vertical Rescue By Alan Sheehan B.E. 15 September 2004 Executive Summary The most important factor affecting pulley friction is sheave diameter. Bigger diameter pulleys

### Important / remember. Accessing the edge of the crevasse to evaluate the situation

MICRO TRAXION EXPERIENCE This «Product Experience» document is a supplement to the Instructions For Use, which provides feedback from field experience and tips for using your product. It is inseparable

### Rescue Technician Site Operations

Note Taking Guide Rescue Technician Site Operations Maryland Fire and Rescue Institute University of Maryland Steven T. Edwards Fall 2009 Copyright 2009 by the Maryland Fire and Rescue Institute. All rights

### Technical Rescuer Rope Rescue Level I NFPA 1006

Standard Area: 6.1.3 General Skill Requirement 6.1.3 General Skill Requirements JPR #RRI-1 Candidate: : Candidate #: STANDARD: 6.1.3 Level I, 2013 Edition TASK: Construct a multiple-point anchor system,

### GEORGIA FIREFIGHTER STANDARDS AND TRAINING TECHNICAL ROPE RESCUER INSTRUCTIONS TO THE CANDIDATE

Objective(s) NFPA 1006-08: JPR: 5.5.2, 5.5.14 Primary Task: ANCHOR EXTENSION Skill No. AE1 PERFORMANCE EVALUATIONS & INSTRUCTION SHEET (PG 1 OF 2) INSTRUCTIONS TO THE MONITOR/ EVALUATOR 1. The candidate

### Applications of trigonometry

Applications of trigonometry This worksheet and all related files are licensed under the Creative Commons Attribution License, version 1.0. To view a copy of this license, visit http://creativecommons.org/licenses/by/1.0/,

### BC CLassic Longline Kit

BC CLassic Longline Kit Made in the USA Complete Slackline Kit Instructions for handling and use - Please read in full before using this device Germantown, MD 20875 United States FX: +1 (805) 617-1744

### Name: Section: Force and Motion Practice Test

Name: Section: Force and Motion Practice Test Directions: For each of the questions or incomplete statements below, choose the best of the answer choices given and write your answer on the line. 1. Which

### In Quest of the Holy Grail. Presented By. Gregory L. Churchman

In Quest of the Holy Grail Presented By Gregory L. Churchman The Quest It all began with the ISC Sarab. They sent me one because I was looking for a reversible descent control device, that would work with

### RehabPro Speed Pulley (M100S & M100FS) User Manual

RehabPro Speed Pulley (M100S & M100FS) User Manual 1. Inspection of Delivery Before unpacking the Pulley please inspect the packaging for shipping damage. Observable damage should be noted prior to signing

### Serenity Houseboat. Standard Operating Procedures for:

Serenity Houseboat Standard Operating Procedures for: Docking I. Safety a. Never get between the houseboat and the dock or other larger object. b. Always wear PFDs during docking. c. Always wear snug fitting,

### Army Mountain Warfare School Ethan Allen Firing Range Jericho, VT Military Mountaineer Course Knot Guide

Army Mountain Warfare School Ethan Allen Firing Range Jericho, VT 05465-9796 Military Mountaineer Course Knot Guide 2 - Basic Knot Tying 071E9002 INTRODUCTION: There are many knots used in mountaineering.

### Modeling of Hydraulic Hose Paths

Mechanical Engineering Conference Presentations, Papers, and Proceedings Mechanical Engineering 9-2002 Modeling of Hydraulic Hose Paths Kurt A. Chipperfield Iowa State University Judy M. Vance Iowa State

### Level 1 Student Preparation Guide

National Cave Rescue Commission Level Student Preparation Guide NCRC requires all students to demonstrate basic skills prior to participation. Level students must be able to tie the knots listed below

### Troop 226. Knot Master Program

Troop 226 Knot Master Program Knots are a skill taught at every level of scouting. The Knot Master program is designed to provide each scout an opportunity to learn essential knots. In addition to learning

### Technical Rescuer Core NFPA 1006

Standard Area: 5.2 Site Operations Candidate: JPR #CORE- : _ Candidate #: STANDARD: 5.2., 5.2.2, 5.2.3, 5.2.4, 203 Edition TASK: Perform size-up, manage hazards and resources and implement termination

### Work and Machines. Work occurs when a force causes an object to move in the direction of the force.

Work and Machines Work occurs when a force causes an object to move in the direction of the force. You just finished reading and summarizing an entire chapter in your science textbook. In the scientific

### Alternate Sked Lashing Methods From Roco Rescue. Approved by Skedco.

Presented by: Roco Rescue Roco Rescue, Inc. 12-11-12 Alternate Sked Lashing Methods From Roco Rescue. Approved by Skedco. Warning: Proper training is required prior to use of this or any other rescue equipment

### Ma Long's forehand Power Looping Backspin Power looping backspin is the most common attacking method, and it is one of the most powerful forehand

Ma Long s Technique Ma Long, the latest men-single winner in Asian games, has beaten lots of top players in the world. Characteristic of his game is obvious - very good at initiating attack, fast and fierce,

### Transcript of Ping Pong Ball Launcher Research and Design

Transcript of Ping Pong Ball Launcher Research and Design Objective To construct a mechanism to launch a ping pong ball into a garbage bin 2, 4, 6, and 8 metres away from the launcher, with restrictions:

### NOTES: Information Booklet 3. Basic Pioneering. Compiled For Cambridgeshire Scouts September2013

NOTES: Information Booklet 3 Basic Pioneering 12 Compiled For Cambridgeshire Scouts September2013 Basic Pioneering It is important that you read this before attempting any Pioneering Project. Pioneering

### CSMC Glacier System Canadian Drop Loop

CSMC Glacier System Canadian Drop Loop Overview This document provides an overview of the Canadian Drop Loop (CDL) system used by the Calgary Scrambling and Mountaineering (CSMC) club and some of its prerequisites.

### Optimist Tuning Guide

Optimist Tuning Guide Sail Care: To help you re new racing sail stay in top condition as long as possible here is some tips - Try not to crease your sail, some creases can cause MIT tears in your sail

### Grain Bin Safety: Entrapment Prevention Kits

Grain Bin Safety: Entrapment Prevention Kits At SCAFCO Grain Systems Company, we are always focused on safety, which is why we are now offering grain entrapment prevention kits for all flat bottom bins

### The use of a pulling device implies serious risks of injuries, property damage or even death. Do not underestimate its potential danger.

Introduction Portable Winch Co. wishes to thank you for purchasing a PCW5000 Portable Capstan Winch TM. This manual was written to help you make the best use of your new winch and to use it in the most

### TECHNICAL RESCUE JPR s ROPE RESCUE TECHNICIAN SKILLS LEVEL I

- 1 - TECHNICAL RESCUE JPR s ROPE RESCUE TECHNICIAN SKILLS LEVEL I Reference Source: 2013 Technical Rescuer Professional Qualifications TABLE OF CONTENTS - 2 - Certification Requirements JPR S/Rope Rescue

### Silencing a bell simply with a piece of rope

Silencing a bell simply with a piece of rope You need about 14 feet / 4½ metres of bellrope. It will last better if the ends are whipped or backspliced. MAKE SURE THE BELLS ARE DOWN FIRST Position yourself

### Chain Drives. Chain Drives 759 C H A P T E R

Chain Drives 759 C H A P T E R 21 Chain Drives 1. Introduction. 2. Advantages and Disadvantages of Chain Drive over Belt or Rope Drive. 3. Terms Used in Chain Drive. 4. Relation Between Pitch and Pitch

### HARDWARE Ascenders. Rope Grabs Descenders Snaps Carabiners Links

HARDWARE Ascenders Rope Grabs Descenders Snaps Carabiners Links Ascenders KONG Twin Ascender Aluminum color anodized WLL: 100 grams Rope Diameter: 8-13mm Weight: 17.5oz (496g) Dimensions: 207mm x 162mm

### The diminishing loop counterbalance (DLC)

Thomas Evans The diminishing loop counterbalance (DLC) Not my idea Taught to me by others Someone else deserves the credit It is brilliant I am sharing it to help others Introduction/Overview Required

### Theoretical Analysis of Rescue Belay Behaviour

Theoretical Analysis of Rescue Belay Behaviour by Alan Sheehan B.E. Senior Vertical Rescue Instructor New South Wales State Emergency Service 36 About the Author Al Sheehan is a practicing professional

### The Science of Golf. Test Lab Toolkit The Swing: Driving. Grades Education

The Science of Golf Test Lab Toolkit The Swing: Grades 9-12 Partners in Education Science Technology Engineering Mathematics Table of Contents Welcome to the Test Lab 02 Investigate: Centripetal Force

### Secondary Physics: The Compass Rose, Cars and Tracks

Secondary Physics: The Compass Rose, Cars and Tracks Secondary Physics at the NASCAR Hall of Fame The Great Hall and Glory Road Focus object or destination in the Hall: Compass Rose, 18 compass lines,

### IMPROVISED RESCUE TECHNIQUES

Chapter 7 IMPROVISED RESCUE TECHNIQUES The previous chapter covered rescues using the full range of specialist equipment available to an RAF MRT. However, the situation may occur when team members become

### Squirt Part IV: BHE, FHE, and pivot-length calibration

David Alciatore, PhD ( Dr. Dave ) ILLUSTRATED PRINCIPLES Squirt Part IV: BHE, FHE, and pivot-length calibration Note: Supporting narrated video (NV) demonstrations, high-speed video (HSV) clips, and technical

### Wilson County Emergency Management Agency 110 Oak Street Lebanon, Tennessee 37087

SOG Name: High Angle & Rope Rescue SOG Number: 403.09 Effective Date: February 2, 2015 Approved: Joey Cooper, Director Reviewed: Scope The purpose of this procedure is to establish guidelines for conducting

### Stand-N-Fish FULL DETAIL INSTALLATION INSTRUCTIONS

1 Stand-N-Fish FULL DETAIL INSTALLATION INSTRUCTIONS Thank you for purchasing the incredible new Stand-N-Fish Kayak Fishing System. Once installed on your kayak the Stand-N-Fish will take your kayak fishing

### SQWUREL Testing, Certifications and Quality Control

SQWUREL Testing, Certifications and Quality Control This document outlines thoughts on testing, certification, quality control and defines BG Gear test methods. This document also contains a section describing

### Rope Runner. This device is intended for work-at-height experts. Misuse may result in death or serious injury.

Rope Runner This device is intended for work-at-height experts. Misuse may result in death or serious injury. Original Drawings by Will Ott, Certified Arborist i User s Guide The Singing Tree Rope Runner

### Lifting Slings. Before equipment use, please read this operation manual carefully. Serial Number: Date Purchased:

Lifting Slings OPERATION MANUAL This operation manual is intended as an instruction manual for trained personnel who are in charge of installation, maintenance, repair etc. Before equipment use, please

### Short Rope Tests. Alpine Recreation & Lincoln University Outdoor Leadership course

Short Rope Tests Gottlieb Braun-Elwert Alpine Recreation & Lincoln University Outdoor Leadership course Objective: Measure the probability of a guide s ability to hold a fall using different short-roping

### Which student do you agree with (if any)? Please explain your reasoning.

Practice Test 1 1. Shown below is a speed-time graph for a cart moving in front of the motion sensor. For convenience it has been divided into five sections (A,B,C,D,E). B C D A E During each of the five

### Activity 3: Pulleys. Background

Activity 3: Pulleys Background Pulleys are simple machines that consist of a grooved wheel that turns around a fixed point, similar to the fulcrum of a lever. A rope, cord, or chain runs along the groove

### Uncontrolled copy not subject to amendment. Principles of Flight

Uncontrolled copy not subject to amendment Principles of Flight Principles of Flight Learning Outcome 1: Know the principles of lift, weight, thrust and drag and how a balance of forces affects an aeroplane

### User Instructions 1789 Parapet Wall Anchor

User Instructions 1789 Parapet Wall Anchor This manual is intended to meet the Manufacturer Instructions as required by ANSI Z359.1 and should be used as part of an employee training program as required

### NHL & NHLPA Future Goals Program Hockey Scholar TM

Curriculum Guide NHL & NHLPA Future Goals Program Hockey Scholar TM Your local NHL team has made it all the way to the Stanley Cup Final and now you just need to win 4 games to bring home the cup! You

### On the Use of Pickets and Flukes as Snow Anchors

On the Use of Pickets and Flukes as Snow Anchors ART FORTINI Sierra Madre Search & Rescue International Technical Rescue Symposium Denver, CO November 2002 Pickets Placements Traditional vertical Horizontal

### In the liquid phase, molecules can flow freely from position. another. A liquid takes the shape of its container. 19.

In the liquid phase, molecules can flow freely from position to position by sliding over one another. A liquid takes the shape of its container. In the liquid phase, molecules can flow freely from position

1 SECTION 1 - Wire Rope WIRE ROPE General Information Terminology & Properties Terminology With precise, moving parts, designed and manufactured to bear definite relationship to one another, Wire Rope

### In the liquid phase, molecules can flow freely from position to position by sliding over one another. A liquid takes the shape of its container.

In the liquid phase, molecules can flow freely from position to position by sliding over one another. A liquid takes the shape of its container. In the liquid phase, molecules can flow freely from position

### BIOMECHANICAL MOVEMENT

SECTION PART 5 5 CHAPTER 12 13 CHAPTER 12: Biomechanical movement Practice questions - text book pages 169-172 1) For which of the following is the athlete s centre of mass most likely to lie outside of

### PHASE 1 WIND STUDIES REPORT

PHASE 1 WIND STUDIES REPORT ENVIRONMENTAL STUDIES AND PRELIMINARY DESIGN FOR A SUICIDE DETERRENT SYSTEM Contract 2006-B-17 24 MAY 2007 Golden Gate Bridge Highway and Transportation District Introduction

### Anchor Building on Multi-Pitch Climbs

Anchor Building on Multi-Pitch Climbs Anchors are a crucial and important piece of the multi-pitch technical system but they are still only one piece. A well-built anchor alone cannot fully protect you

### National Maritime Center

National Maritime Center Providing Credentials to Mariners (Sample Examination) Page 1 of 7 Choose the best answer to the following Multiple Choice Questions. 1. On a small boat, which knot is best suited

### THERMALLING TECHNIQUES. Preface

DRAFT THERMALLING TECHNIQUES Preface The following thermalling techniques document is provided to assist Instructors, Coaches and Students as a training aid in the development of good soaring skills. Instructors

### Basics, Types, Use and Applications

Basics, Types, Use and Applications 2015 by Brilliant Classes 2015 by Brilliant Classes Science : Physics Unit : Friction Friction : Basics, Types, Use and Applications The following topics are included

### Homework of chapter (3)

The Islamic University of Gaza, Civil Engineering Department, Fluid mechanics-discussion, Instructor: Dr. Khalil M. Al Astal T.A: Eng. Hasan Almassri T.A: Eng. Mahmoud AlQazzaz First semester, 2013. Homework

### Dressage Training to Help Any Horse

Dressage Training to Help Any Horse Learn a dressage-based exercise created by Ellen Eckstein and Tom Dorrance that teaches your horse the beginning of self carriage. An Excerpt from Bringing It Together,

### Information Booklet 3

TAKING. IT FURTHER Create lessons to demonstrate and learn how to tie the following knots: Timber hitch Highwayman s hitch Sheepshank Bowline Sheet bend Groups could then build knot boards showing how

### INCLINOMETER DEVICE FOR SHIP STABILITY EVALUATION

Proceedings of COBEM 2009 Copyright 2009 by ABCM 20th International Congress of Mechanical Engineering November 15-20, 2009, Gramado, RS, Brazil INCLINOMETER DEVICE FOR SHIP STABILITY EVALUATION Helena

### I hope you earn one Thanks.

A 0 kg sled slides down a 30 hill after receiving a tiny shove (only enough to overcome static friction, not enough to give significant initial velocity, assume v o =0). A) If there is friction of µ k

### CAMPOREE COMPETITION EVENTS Cahuenga District Camporee/Cuboree 2015 Prepared. For Adventure!

CAMPOREE COMPETITION EVENTS Cahuenga District Camporee/Cuboree 2015 Prepared. For Adventure! Veterans Memorial Park - April 24-26, 2015 1 - Emergency First Aid Troop 1 2 - Knots & Lashings Troop 18 3 -

### From Constraints to Components at Marin Bicycles

From Constraints to Components at Marin Bicycles A Case Study for The Mechanical Design Process Introduction This case study details the development of the Marin Mount Vision Pro mountain bicycle rear

### Simple Machines. Dr. John B. Beaver and Dr. Barbara R. Sandall

By Dr. John B. Beaver and Dr. Barbara R. Sandall COPYRIGHT 2002 Mark Twain Media, Inc. ISBN 978-58037-864-2 Printing No. 1558-EB Mark Twain Media, Inc., Publishers Distributed by Carson-Dellosa Publishing

### TEKS Lesson 6.8E: Machines

6.8E Investigate how inclined planes and pulleys can be used to change the amount of force to move an object. : Machines What is a machine? A machine is a device that allows you to do work in a way that

### ESCONDIDO FIRE DEPT TRAINING MANUAL Section DRIVER OPERATOR Page 1 of 14 Hydraulics Revised

DRIVER OPERATOR Page 1 of 14 HYDRAULICS Hydraulics applied in the dynamic fire ground environment is an art that comes with study and experience. The following describes the factors that must be mastered

### Rescue Technician: Rope Rescue II

Rescue Technician: Rope Rescue II Skill Sheet Package Based on NFPA 1006: Standard for Technical Rescue Professional Qualifications, 2013 Edition. Alabama Fire College August 2016 REVISED 02/10/2017 Alabama

### End. Standing Part. An underhand loop is made by crossing the end under the standing part.

Knot Board Learn to tie the four basic camping knots as illustrated as well as others you might add. Practice them until you can tie them well. Display them on a knot board made from a square of peg board

ADVENTURE EDUCATION HIGH ROPES History and Overview Ropes courses could be found in the United States as early as the 1960s. Outward Bound was a leader in these types of adventure activities with their

### Instructions for Dual Retractable Web lanyards Type 1. Instructions for E6 Energy Absorbing Y, Bypass Lanyards. For Worker Mass Range of 90 to 175 kg

P.O. Box 3026 Sherwood Park Alberta T8H 2T1 Phone: (780) 464-7139 Fax: (780) 464-7652 e-mail: inquiries@ safetydirect.ca Web site: www.safetydirect.ca Instructions for Dual Retractable Web lanyards Type

### High Altitude Deployment Article By Jim Jarvis Rockets Magazine, June 2011 Edited May 2013

High Altitude Deployment Article By Jim Jarvis Rockets Magazine, June 2011 Edited May 2013 I usually use a CO 2 device for high altitude deployment and it works pretty well. However, in the interest of

### Basic Offensive Fundamentals

Basic Offensive Fundamentals Footwork Developing proper footwork will help with each player s balance and quickness while on the court. Emphasizing the importance of footwork from the beginning of the

### PhysicsAndMathsTutor.com

PhysicsAndMathsTutor.com 6. Figure 2 3 m 0.5 m A D B June 2005 C 30 A uniform pole AB, of mass 30 kg and length 3 m, is smoothly hinged to a vertical wall at one end A. The pole is held in equilibrium

### Knots, Hitches and Bends

Knots, Hitches and Bends It is hard to define clearly the terms knot, hitch and bend because their functions overlap. However, the terms may be generally defined as follows: Knots Hitches Bends Knots are

### Heavy climbers beware! Page 1 of 8

Heavy climbers beware! Page 1 of 8 To my fellow 176 pound (80 kg) and up climbers, please continue reading! You can consider yourself a heavy climber for the purposes of this article. To those of you in

### Transfer Chain (SA-1002) & Adjustable I-Beam Clamp (SA-1039 or SA-1040) Operating Instructions

Transfer Chain (SA-1002) & Adjustable I-Beam Clamp (SA-1039 or SA-1040) Operating Instructions SPIDER Page 1 of 8 702127 Rev A Using Transfer Chain with Adjustable I-Beam Clamp Safety Notes Do not use

### Where no fly has gone before...

FlyFishing & FlyTying / November 2012 Where no fly has gone before... PHILIP BAILEY and Massimo Magliocco explain how the Italians adapt their casting for fast, turbulent and overgrown streams and improving

### National 400B. Certification CraneSafe Certification. CraneSafe + Fulford Harbour Group Tel:

Load Chart PRACTICE Exercises Stiff TRUCK CRANE 40 Tonnes & under National 400B Stiff Boom Truck 40 Tonnes & Under PRACTICE EXERCISES LCR.SB40.NA400B.PE1 30 July 2009 + Fulford Harbour Group Tel: 604.952.6033

### Fall Protection Training

Fall Protection Training Reference: OSHA 29CFR 1910 OSHA 29CFR 1926 ANSI Z359.1-1992 (R1999) Introduction Deaths occurring from falls during 1996 increased five percent over 1995 figures. This accounts

### Use of the AZTEK Kit. Use of the AZTEK Kit Pg. 1 Team Skills Rescue Seminar

Use of the AZTEK Kit Pg. 1 Use of the AZTEK Kit Introduction: It has often been said that necessity is the mother of all invention. Truly, when thinking of technical rope rescue, nothing could be more

### Pressure Sensor Bridge Configurations

Pressure Sensor Bridge Configurations 1. Purpose Describe different pressure sensor bridge configurations, when each can and cannot be used, and the advantages and disadvantages of each. 2. Introduction

### Basic Types of Passing

Basic Types of Passing Now that we have introduced the basic pass and Receive concepts, there are several basic types of passing that we would like to acquaint you with along with basic drills to teach

### Serving. Petrochemicals Power Semiconductor Waste Treatment Oil & Gas Transmission Lines Bulk Gas Plants

Serving Petrochemicals Power Semiconductor Waste Treatment Oil & Gas Transmission Lines ulk Gas Plants Mining & Metals Pharmaceuticals Pulp & Paper Mills Sugar Mills Nuclear Desalinization Plants NOTES:

### P R I M A X. The Most Advanced Shoring Devices SAFER - FASTER - DEEPER - CHEAPER THE ULTIMATE SHORING TECHNIQUES ARE NOW ON YOUR HANDS

P R I M A X The Most Advanced Shoring Devices SAFER - FASTER - DEEPER - CHEAPER SLIDE RAIL SHORING ENGINEERING SLIDING STRUT SHORING TRENCH SHIELD SELF PROPELLED SHIELD CONSULTING SHORING DESIGN MANHOLE

### OIL & GAS. 20th APPLICATION REPORT. SOLUTIONS for FLUID MOVEMENT, MEASUREMENT & CONTAINMENT. Q&A: OPEC Responds to SHALE BOOM

Process VARIABILITY & Equipment RELIABILITY Are PROCESS SAFETY & CYBERSECURITY Related? Q&A: OPEC Responds to SHALE BOOM 20th 1995-2015 SOLUTIONS for FLUID MOVEMENT, MEASUREMENT & CONTAINMENT special section

### Multiple Levels of Teaching & Training in Tang Soo Do Jack Sanders-Reed Sam Dan Essay November 11, 2005

Multiple Levels of Teaching & Training in Tang Soo Do Jack Sanders-Reed Sam Dan Essay November 11, 2005 As I progress in Tang Soo Do, I am beginning to come to the conclusion that many of the outwardly

### Analysis of Shear Lag in Steel Angle Connectors

University of New Hampshire University of New Hampshire Scholars' Repository Honors Theses and Capstones Student Scholarship Spring 2013 Analysis of Shear Lag in Steel Angle Connectors Benjamin Sawyer

### Cattle Handling Pointers R. Gill, Ph.D and R. Machen, Ph.D., Professors and Extension Livestock Specialists

Cattle Handling Pointers R. Gill, Ph.D and R. Machen, Ph.D., Professors and Extension Livestock Specialists Safe and effective cattle handling has always been important. In the last few years there has

### Pitfalls Surrounding PPE Modification. Mark Bridge, treemagineers Ltd. (Rannoch, Scotland)

Pitfalls Surrounding PPE Modification Mark Bridge, treemagineers Ltd. (Rannoch, Scotland) As an industry, we have progressed a long way from simply Bosun s chair and selftied harnesses as they were used

### Raising a Yagi Using A Tram Without the Need for Tag Lines

Raising a Yagi Using A Tram Without the Need for Tag Lines The photo slide show that follows was presented to the FRC Meeting of 12/14/10. The narrative and diagram in this PowerPoint presentation was

### SPH3U Sec.9.2.notebook. November 30, Free End Reflections. Section 9.2 Waves at Media Boundaries

Section 9.2 Waves at Media Boundaries Wave speed depends on some of the properties of the medium through which the wave is travelling. For example, the speed of sound in air depends on air temperature,

### ECO 199 GAMES OF STRATEGY Spring Term 2004 Precept Materials for Week 3 February 16, 17

ECO 199 GAMES OF STRATEGY Spring Term 2004 Precept Materials for Week 3 February 16, 17 Illustration of Rollback in a Decision Problem, and Dynamic Games of Competition Here we discuss an example whose

### OPEN ROUND SLING 60 cm (WEBBING) OPEN ROUND SLING 120 cm (WEBBING) 1.5 m ANCHOR STRAP (PVC SLEEVE PROTECTOR) Product Code: HS2/001 SLINGS

Our slings, come from years of practical experience to understand what actually works as an anchoring sling. They can be used for technical Rope Access aid climbing, to Fall Arrest and rescue anchoring