Ropes & Knots

Ropes & Knots

Objectives

• All objectives meet NFPA 1001

• After completing this lesson, you will be able to identify and properly knot, use, and maintain various types of rope.

Rope Terminology

• Strand

• Yarns

• Fibers

• Sheath (Jacket, mantle)

• Core (Kern)

Rope Materials

• Two basic categories:

• Natural Fibers

• Synthetic Fibers

Natural Fibers

• No longer accepted in life safety applications

• Utility Purposes Only

• Manila - made from the trunk of the Abaca plant found in Manila

• Sisal - ¾ the tensile strength of Manila. Used as binder’s twine

• Cotton - soft and pliable. Strength much less than Manila

Disadvantages

• Short noncontinuous strands = poor tensile strength. Decays easily

• Deteriorates quickly

• Water - loses half its tensile strength when wet

• Humidity - loses half strength in one year

• Abrasion and Chemicals - Severely affected when exposed to these hazards

• Charing - Chars at 190°C (380ºF) and loses strength at 82ºC (180ºF)

Advantages

• Inexpensive

• Biodegradable

Sealing

• Searing rope ends

• Bind with twine and dip in varnish or white glue

Synthetic Fibers

• Used for rescue

• Resists mildew/rotting

• Stronger and easily maintained

• Continuous fibers that run entire length of rope

Nylon

• One of the best and strongest materials• Has high resistance to abrasion• High tensile strength. 3½ times

stronger than Manila• Resists moisture and most chemicals

maintains 80%

• Melting point of 204º - 260ºC (400º - 500ºF)

• Not suitable for vehicle stabilization as the rope stretches under load

Polypropylene

• Very lightweight

• Floats and resists water damage

• Resists rotting, mildew, and abrasion

• Affected by heat.Loses strength at 93ºC and melt at 140º

• Difficult to secure into good knots

Polyester

• Not subject to water, sunlight, and most chemical damage

• Loses strength at 149ºC and begins to melt at 232ºC

Kevlar Aramid Fiber• Resists temperatures of 260ºC

• Easily damaged by abrasion

• Hard to tie knots with

Rope Construction

• Laid (Twisted) Twisted yarns form strandsThree stands twisted form ropeUsed for natural and synthetic ropesEasily inspected

• Braided RopeReduces or eliminates twistingHas no outer sheath or coreSubject to direct abrasion and

damage

• Braid-On-Braid RopeOften confused with Kernmantel Rope

due to having a jacketHas braided core and sheathSheath has herringbone patternStatic type rope and very strongOuter sheath may slide along core

• Kernmantel RopeHas braided sheathInner core may be twisted or braided

and made of high strength fibersComes in both static and dynamic

types of rope

Rope Catagories

• Static = Low stretch of 1½ - 2% Used for Rescue

• Dynamic = High stretch 8 - 12% Used for climbing

• NFPA 1983 states breaking elongation should not be less than 15% and no more than55%

Rope Classifications

• Life Safety - Only used once to support rescuers and victims (Except for training). Must be made of a continuous filament fiber

• Utility - Used for anything except life safety.

Elements of a Knot

• Bight - a loop that does not cross over itself

• Loop - a bight that crosses over or under the standing part

• Round turn - End of rope continued around top of loop until standing lengths are parallel

• Underhand and Overhand loops

• Working end (forms knot)

• Running end (Used for work i.e. pulling, hoisting, and belaying)

• Standing part (Used for work)

Types of Knots• Overhand knot

• Bowline

• Clove Hitch

• Figure of Eight

• Double Figure of Eight

• Figure of Eight on a Bight

• Double Loop Figure of Eight

• Becket or Sheet Bend

Half Hitch & Overhand

• Half HitchHoisting toolsStabalizing tall objects

• Overhand KnotFoundation knot for beginning other knotsSafety knot to secure other knots

(especially synthetic ropes)

Bowline

• Used to form a loop that will not constrict object

• Easily untied

• Primarily used for utility and life safety (Rope rescue harness)

• Inside and outside working ends equally as strong. Inside preferred.

Clove Hitch• Basically two Half Hitches

• Used to attach a rope to an object

• Used with Overhand Knot for hoisting tools

• Withstands pull in either direction without slipping

• MUST NOT BE USED IN LIFE SAFETY APPLICATIONS

Figure-Eight Knot

• Has replaced the Bowline Due to synthetic rope

• Less likely to damage rope

• Stronger

• Easier to tie, untie, inspect, and keep neat

Uses of the Figure-Eight

• Figure-Eight - Foundation knot

• Figure-Eight Follow Through - Joins ropes of equal size

Uses of the Figure-Eight cont...

• Figure-Eight on a Bight - Securing loop in middle or end of rope (Used for safety lines, safety harness, litter and rescue equipment and anchor lines)

Uses of the Figure-Eight cont…

• Double-Loop Figure-Eight - Rescue HarnessWebbing harnesses are recommended

for life safety applicationsDouble-Loop Figure-Eight

recommended over Bowline

Becket Bend/Sheet Bend

• Used for joining unequal diameter ropes or rope to chains

• Unlikely to slip when wet

• Utility applications ONLY

Hoisting

• Before hoistingcomplete all preparationsEnsure solid footingCheck for electrical hazards

Hoisting

• During HoistingUse hand -over-hand methodprotect rope pulled over sharp edgesWork in teamsAll personnel are clearUse a tag lineSecure with Overhand Safety Knot

Hoisting

• Hoisting of air cylinders and fire extinguishers is NOT RECOMMENDED

Rope Maintenance• Identify all ropes• Inspect periodically and after each use• Maintain Rope Log• Test or tag and dispose worn or

damaged rope• Remove and tag used rescue rope

Removing Rope from Service

• Excessive sheath wear

• Severely shock loaded/overloaded

• Chemically contaminated

• Old

• Lacks uniform diameter/texture

• Used for life safety

Cleaning and Storage

• Stored by coiling or bagging

• Washed by hand in cool water (No detergents) Note: Rope Washers and Washing Machines used by other Dept.’s.

• Rinse and dry

Drying Rope

• In clothes dryer with no heat

• Air dried on flat surface out of sunlight

• Hung in hose tower

Figure Eight on a Bight

Figure of Eight Re-threaded

Review Rescue Knot Video Click Link

• http://www.expertvillage.com/videos/knot-tying-uncommon-fireman.htm