1. 2010 University of Scouting Pioneering Class
Topics
Pioneering Materials
Planning Projects
Lashings
Knots
Anchors
Introduction, etc. 10:00 – 10:10
Lecture portion (Materials, Planning, Modeling) 10:10 – 10:45
Lashings, knots review 10:45 – 11:00
Project time (Lashings, knots, anchors) 11:00 – 11:50
Purpose of the class: To educate scouters on how to run a pioneering event or program.
Instructors:
Will Hamilton
3/27/2010

2. Types of Rope Natural Fiber Synthetic Fiber Cotton Manila Sisal Nylon
Soft and pliable, easy on the hands.
Lacks strength and durability.
Rots easily.
Manila
Strongest natural fiber rope available.
Rots when exposed to water over time.
Sisal
Less strength and durability than manila.
Degrades quickly when exposed to weather.
Tends to mildew when wet.
Synthetic Fiber
Nylon
Resists abrasion and will last 4-5 times longer than natural fibers.
Very strong and elastic. Can absorb shock loads.
Polypropylene
Lightweight, strong, floats in water.
Strength degrades when exposed to sunlight. Can melt at 150°F.
Type
(3 strand, ¼ inch)
Tensile Strength (lbs)
Cotton
200
Manila
540
Sisal
430
Nylon
1500
Polypropylene
1250
Strength numbers taken from US Rope and Cable, a rope supplier.
3/27/2010

3. Rope Strength
Tensile Strength – the average breaking strength of a new rope under laboratory conditions
Working Load – a fraction of the tensile strength that gives plenty of room for safety and longevity of the rope, usually between 15% and 25% depending on use
Knots in a rope effectively cut the tensile strength in half. Certain knots can damage the line less than others but 50% loss of strength is a good rule of thumb.
What size rope should you use for the main line in a monkey bridge that boys will walk on?
A one inch piece of manila rope has a tensile strength of 8100 pounds. Reduce that number by half due to knots and it becomes 4050 pounds. Divide by a factor of 20 for safety reasons and to preserve the life of the rope and you get 202 pounds. This is acceptable as long as you are sure that only one boy at a time will use the bridge.
Interpretation of Rope Strength –
One area of misunderstanding that needs to be brought to the surface is the proper interpretation of rope strength, appropriate usage and care. Let's start by defining two important terms: "tensile strength" and "working load". Tensile strength is the average strength of new rope under laboratory conditions. This is determined by wrapping the rope around two large diameter capstans and slowly tensioning the line until it breaks. The manufacturer's recommended working load is determined by taking the tensile strength and dividing it by a factor that more accurately reflects the maximum load that should be applied to a given rope to assure a comfortable safety margin and longevity of the line. Of course that factor varies with the type of fiber and the weaving construction. There are however always exceptions, most notably the fact that rope is susceptible to degradation and damage in numerous ways that are not controllable by the manufacturer.      
It may surprise you to find out that the working load for most kinds of rope is between 15% and 25% of the tensile strength. Now consider the fact that any time you tie a knot in a rope you effectively cut the tensile strength in half. The knot when tensioned cuts the line. While certain kinds of knots damage the line less than others, the 50% loss of tensile strength is a good general rule to live by
3/27/2010

4. Typical Tensile Strength
Manila
1/4"
540 lbs.
1/2"
2,380 lbs.
1"
8,100 lbs.
Polypropylene
1/4"
1250 lbs.
1/2"
4,200 lbs.
1"
14,000 lbs.
Nylon
1/4"
1,490 lbs.
1/2"
5,750 lbs.
1"
22,600 lbs.
Strength numbers taken from US Rope and Cable, a rope supplier.
3/27/2010

5. Care of Rope
The ends of new rope should be fused or whipped to prevent fraying.
A good rope is expensive and should be handled carefully.
Muddy or dirty rope can be washed with a hose. Dirt or grit left in the rope should be shaken out after it has dried. Never allow wet rope to freeze.
When storing rope, coil loosely and keep in a dry place and out direct sunlight. Storing rope when wet will lead to rot and mildew. Large plastic buckets work well.
Whipping Rope
3/27/2010

6. Project Planning
The Guide to Safe Scouting stresses constant inspection of all pioneering projects and materials before, during and after use.
All platforms, ropes, etc where a Scout may stand or climb may never be built over five feet above ground.
Monkey bridges may be no longer than 40 feet.
Project ideas can come from many sources.
Pioneering Merit Badge booklet
Resources on the internet
The boys’ imaginations
2009 G2SS
3/27/2010

7. Modeling Drawings and models are great ways to plan projects.
They let you create a bill of materials, determine a project’s feasibility and estimate the time required to construct it.
Models can be made with sticks, dowels, string, rubber bands, etc.
Model making and drawing are excellent activities for troop meetings.
3/27/2010

8. Pioneering Knots
Two half-hitches – used for binding a rope to an object
Taut-line hitch - useful when the length of a line will need to be periodically adjusted
Timber hitch - used to attach a single length of rope to a piece of wood
Clove hitch – liable to slip when only loaded at one end, used in lashing
3/27/2010

9. Pioneering Knots, cont.
Square knot - used to connect two ropes of equal size
Bowline - used to form a fixed loop at the end of a rope
Sheepshank - used to shorten a rope or take up slack, comes apart easily, should not be used with synthetic rope
Sheet bend - useful when joining two ropes of different diameter
Round turn with two half-hitches - used to secure the end of a rope to a fixed object such as a post, won’t slip down the post
3/27/2010

10. Lashings
Most structures are made from a combination of square lashings and diagonal lashings.
Square lashings are used primarily, especially on load bearing spars.
Diagonal lashings are used for cross bracing or anywhere that two spars do not touch.
Lashing procedure:
All lashings start with a knot.
The rope is then “wrapped” to secure the two spars together.
“Frapping” is then done to tighten the “wraps”.
The lashing ends with another knot.
3/27/2010

11. Square and Diagonal Lashing
Square Lashing
Clove Hitch
Timber Hitch
Diagonal Lashing
3/27/2010

12. Anchors
Most projects will need to be anchored to the ground for safety.
Types of Anchors:
Natural (trees, rocks, etc)
3-2-1 stake
Log and stake
Dead man (buried)
3-2-1 Stake Anchor
Log and Stake Anchor
3/27/2010

13. Class Project Planning
Monkey bridge sketch:
Shear Lashing
Square Lashing
X-Trestle
3/27/2010

14. Monkey Bridge Materials
Two X-trestles
Six logs
Four square lashings – 15’ long ¼” rope
Two shear lashings – 15’ long ¼” rope
Foot line – 30’ long 1” rope
Two hand lines – 30’ long ½” rope
Four stringers – 10’ long ¼” rope
Pad for the foot line – carpet scrap
Log and stake anchor
Six stakes
Two ropes for windlass – 5’ long ¼” rope
Short log
Mallet
3/27/2010

15. Monkey Bridge Build Plan
Split into three teams
Team 1, Assemble the two x-trestles.
Team 2, Lay out the foot line, hands lines and tie the stringers between them.
Team 3, Construct the anchor.
Everyone assemble the final bridge and pull the lines tight.
3/27/2010