Knot Tying in Rigging Applications

Knot Tying in Rigging Applications

Presented by: Christopher G. LombardACED 4680

Overview

Throughout history, ever since humankind invented rope, skill in tying knots and the development of rope has played a vital role in early technological advancements and the building of civilizations.

• Although it is still unclear when the first rope was made, evidence suggests that it was during prehistoric times.

• This is due to the fact that the first rope was made of natural fibers that decomposed and did not survive the ages.

• The first ‘ropes’ were formed from naturally occurring plant stems, such as lengths of vine.

Overview• In order for rope to be useful, our early ancestors had to

develop some level of skill in tying knots.

• Fragments of rope have been discovered and dated back to approximately 15,000 BC.

• The early Egyptians were the first civilization to develop tools designed for rope manufacture and, thusly, have been credited with first mastering large-scale rope production.

Such ancient and rudimentary skills have seldom transcended the ages, however knot tying is one that remains pertinent to this day…

Knowledge and learning objectives

Upon successful completion of this topic the student will be able to:

• Recall at least three of the four methods of preventing a rope from unlaying, as presented in the instructional materials.

• Recite the meanings and definitions of at least eight of the twelve terms

presented in the instructional materials. • Visually identify the five knots commonly utilized in rigging applications, as

presented during instruction, with no errors.

Knowledge and learning objectives

• Recall seven of the ten basic categories and different types of fiber used to manufacture rope as presented in the instruction and course materials.

• As presented in the course materials and instruction, name the two

primary types of rope with no errors.

• Demonstrate ability to tie a bowline in the same manner as illustrated and performed during the course of instruction with no errors.

• Demonstrate ability to tie a square knot in the same manner as illustrated

and performed during the course of instruction with no errors.

Knowledge and learning objectives

• Demonstrate ability to tie a figure eight knot in the same manner as illustrated and performed during the course of instruction with no errors.

• As illustrated and performed during the course of instruction, demonstrate ability to tie a clove hitch sufficient to prevent untying of the knot when a pull is applied to the line with no errors.

• Demonstrate the ability to ascertain and tie the safest knot under a specified application to assure that a load will be held most securely with no errors.

• Recall the proper technique for backing a knot to prevent its loosening or

unraveling with no errors.

Terminology

In order to understand some uncommon and trade specific terms, we must review them:

• Back – to reinforce a knot, bend, or hitch with another.

• Bight – a pinch point or loop in a rope.

• Bitter end – the end of a rope.

• Coefficient of friction - a ratio between the force required to move one surface over another and the pressure exerted between them.

• Efficiency rating – the efficiency of a knot, expressed as a percentage, as it relates to breaking strength.

Terminology• Filament – fiber or a slender threadlike object.

• Frap – to bind something tightly.

• Fray – to become worn at the end or edges or unravel into separate filaments.

• Knot - intertwined loops of rope used to fasten one to another or to some other object.

• Strand – several filaments or fibers that are twisted, woven, or bundled together.

• Tail – a short portion of a rope adjacent to the bitter end.

• Unlay – untwist into the separate strands.

Categories of rope

Categories of rope:

1. Natural fiber• Examples are rope produced from jute, sisal, hemp,

manila, and cotton.

2. Synthetic fiber • Examples are nylon, polypropylene, and polyester.

Types of rope

Types of rope used in rigging applications:

1. Three strand – rope consisting of three intertwined strands.

2. Double braid – rope constructed of multiple strands woven together.

rope characteristics

With regards to knot tying and rigging, there are important advantages, disadvantages, and differences between rope types that must be considered:

• Breaking strength (synthetics have edge)• Suppleness/pliability (nylon, polyester, and cotton best)• Coefficient of friction (natural slightly better)• Durability (fairly even)

As you can see, there is a fairly even split between natural and synthetic. Selection is dependent upon application and desirable characteristics.

preventing unlaying

Methods of preventing a bitter end from unlaying:1. Taping or shrink wrapping (natural and synthetics)2. Heat treating (synthetics)3. Frapping or binding (primarily used on natural rope)4. Tying a knot

Tying with a rope

There are three basic ways to tie or bind using a rope:

1. Knot - intertwined loops of rope used to fasten one to another or to some other object.

2. Bend – an intertwining of two rope ends.

3. Hitch – attaching a rope to a post, ring, or other, usually round, object.

Efficiency ratings of knots, bends, and hitches generally fall between 50 – 75%.

primary rigging Knots

There is a combination of five knots and hitches that are used most often in rigging applications:

1. Bowline (knot)

2. Square knot

3. Clove hitch

4. Half hitch

5. Figure eight (knot)

BOWLINePurpose/application: whenever a loop is required

Advantages: will not bind/cinch under strain, unties easily

Efficiency: 50%

Square knot

Purpose/application: attaching the ends of ropes together

Advantages: quick to tie once proficient, not prone to loosening

Efficiency: 50%

CLOVE HITCH

Purpose/application: attaching a rope to poles, rings or other round objects

Advantages: self cinching, easily tied/untied, high efficiency

Efficiency: 75%

half HITCH

Purpose/application: used to hold a line, keep long objects upright, back up other knots/bends/hitches

Advantages: very easily tied/untied, self cinching, high efficiency rating

Efficiency: 70%

The Half Hitch

Figure Eight

Purpose/application: used to tie down/secure objects, prevent rope from unlaying

Advantages: easily tied, self cinching under strain

Efficiency: 50%

SUMMARY

Categories of rope (2):1. Natural2. Synthetic

Types of rope (2):3. Three strand4. Double braid

Important rope properties/characteristics (4):5. Breaking strength 6. Suppleness/pliability7. Coefficient of friction8. Durability

SUMMARY

Basic ways to tie or bind using a rope (3):1. Knot - intertwined loops of rope used to fasten one to

another or to some other object.2. Bend – an intertwining of the ends of two different ropes.3. Hitch – attaching a rope to a post, ring, or other, usually

round, object.

Methods to prevent unlaying (4):4. Taping or shrink wrapping (natural and synthetics)5. Heat treating (synthetics)6. Frapping or binding (primarily used on natural rope)7. Tying a knot

Review

A CB

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Associate the knots pictured with their names:

Square knot

Bowline

Half hitch

Figure eight

Clove hitch

RESOURCES/REFERENCES

• http://listverse.com/2007/10/07/top-10-ancient-inventions/

• http://www.igkt.net/beginners/what.php

• http://www.2020site.org/knots/

• http://www.animatedknots.com/indexbasics.php?Categ=basics&LogoImage=

LogoGrog.jpg&Website=www.animatedknots.com

All Images sourced from Google Images.

conclusion

Questions?

The end