Chapter 7: Ropes and knots Flashcards
life safety rope:
designed to be used only for rescue and other emergency operations
o also used to raise, lower or support firefighters during training
o should not be used for any other purpose
NFPA 1983
specifies that only rope of block creel construction using continuous filament virgin fiber for load bearing elements is suitable for life safety applications
block creel construction
method of manufacturing rope without any knots or splices; a continuous strand of fibre runs the entire length of the ropes core
In order to be reused in life safety situations, the standard also requires that ropes met the following criteria:
o No abrasions
o No exposure or heat or direct flame
o No exposure to any impact load
o No exposure to the liquids, solids, gases,mists or vapours of any chemical or other material that can deteriorate rope
Remove a life safety rope from service if
it has been subjected to an impact load, fails inspection, has been used only as utility rope, or is marked for destruction
Life safety rope that has been converted to utility rope is referred to as
downgraded
rope log
Start and keep a rope log throughout the ropes working life
Utility Rope
can be used to hoist equipment, secure unstable objects or cordon off an area
- NFPA does not have standard s
- Inspect utility rope regularly to see if its damaged
Synthetic fibers
are used to construct both life safety and utility ropes while natural fibers are only permitted for utility ropes
The main difference between syntetic and natural fibers ropes is
the material used for the construction, which affects the use and longjevity of each type of rope
Synthetic ropes are replacing natural ropes as utility ropes because
natural fibrer rope loses its strength when it gets wet and rots rapidly
Synthetic fibers include:
o Polypropylene
o Nylon
o Kevlar
o Polyester
o Polysteel
o Spectra
A disadvantage of synthetic fibers
is that they will melt when exposed to heat
Synthetic fiber rope has the following advantages;
o Excellent resistance to water, mildew, mold, rotting and shrinkage
o Longer life span than natural fibre rope
o Lightweight yet very strong
o Easy to maintain
Most natural fiber rope is made from
plant fibers such as:
o Manila
o Hemp
o Sisal
o Cotton
natural fibre rope should not be used for
Should not be used for life safety applications
natural fibre disadvantages
-Prone to mildew and mold
-Deteriorates when exposed to chemicals and It burns
Natural fiber rope does have the following advantages
o More resistant to sunlight than synthetic rope
o Chars rather than melts (fails) when exposed to heat
The most common types of rope construction are
o Kernmantle
o Braided
o Laid
o Braid on braid
Kermantle rope
jacketed synthetic rope composed of a braided covering or sheath (mantle) over a core (kern) of the main load-bearing strands
kermantle core
- The core strands run parallel with the rope’s length and work in conjunction with the covering to increase the ropes stretch resistance and load characteristics
- The core is made of high fibers usually nylon which accounts for 75% of the total strength of the rope
kermantle rope sheath
The sheath protects the core from abrasions and contamination
Comes in both ______ and _______ types
Comes in both dynamic (high stetch) and static (low stretch) types
Dynamic rope and advantages
is used when long falls are a possibility
o To reduce the shock of impact in falls, dynamic rope is designed to stretch without breaking
dynamic rope disadvantage
when trying to raise or lower heavy loads, dynamic rope is not used for hoisting applications other than as belay line
Static rope
is used for most rope-rescue operations
o It is designed for low stretch without breaking
o Used for rescue, rappelling and hoisting where falls are not likely
NFPA 1983 low stretch rope must not elongate more than ____ when tested under a load equal to ____ of its breaking strength
NFPA 1983 low stretch rope must not elongate more than 10% when tested under a load equal to 10% of its breaking strength
Laid ropes
are constructed by twisting fibers together to form strands then twisting the strands (typically three) together to make the final rope
- Used exclusively as utility ropes
One disadvantage of laid ropes is
that they are susceptiple to abrasion and other physical damage
o Damage also immediately affects the ropes strength
One advantage of laid (twisted) rope
this strand exposure is that it makes laid ropes easy to inspect
Braided rope
constructed by uniformly intertwining strands of rope together in a diagonally overlapping pattern
- Used as utility rope
- Most braided ropes are synthetic
advantage and disadvantage of braided rope
It is less likely to twist during use than laid rope but its load bearing fibers are still vulnerable to direct abrasion and damage
Braid on braid rope:
consists of a braided core enclosed in a braided sheath
- Braid on braid rope has a braided core running the length of the rope
- Very strong
- Half its strength is in the sheath and the other half is in the core
- Used as utility rope
A disadvantage of braid on braid rope is
that it does not resist abrasion as well as kermantle rope
o The sheath may slide along the inner core of rope
Double braided rope is sometimes confused with
kermantle
Personnel should inspect all ropes when?
after each use and inspect unused rope at least once a year
If any of the following damage is found, remove the rope from service and have it destroyed:
o Imbedded shards of glass
o Metal shavings
o Wood splinters
o Foreign objects that can damage the fibers
Inspecting kermantle rope for damage is somewhat difficult because
the damage may not be obvious
- When inspecting put a slight tension on the rope while feeling for lumps, dpressions, or soft spots
o Soft spots are caused by bends of knots
o If you feel a soft spot inspect the outer sheath; if the sheath is damaged, the core is probably damaged as well
- If there is any doubt about the ropes integrity, it should be removed from service, downgraded to utility status or destroyed
In addition to inspecting kermantle rope for damage to the core and sheath, inspect the rope for:
o Irregularities in shape or weave
o Foul smells
o Discoloration from chemical contamination
o Roughness
o Abrasions
o Deterioration (fuzziness)
Rope that is excessively fuzzy in one spot or overall should be removed from service
Synthetic laid rope
should be untwisted so that all the sides of each strand can be inspected
- Mildew must always be removed, after which the rope should be cleaned and reinspected
When inspecting synthetic rope look for the following:
o Sift, crusty, stiff or brittle spots
o Cuts, nicks or abrasions
o Dirt or grease
o Excessive stretching
o Chemical damage
o Other obvious flaws
When inspecting natural rope, look for the following signs of damage:
o Ruptured fibers and powdering between strands indicates the rope has benn overloaded
o Dark, red, brown or black spots between the strands, along with a sour, musty, acidic odor indicate rot and mildew
o Powdering between strands indicates internal wear
o Brittle or ruptured fibers, dark red or brown spots, salt incrustation, or swollen areas indicate chemical damage
o Rust spots which occur on ropes in pre rigged pulley systems or ropes that are stored with other metal devices indicte weakened fibers and reduced holding power
o Accumilations of heavy, greasy materials indicate adverse effects on rope strength and reduce holding power
When rot is discovered the rotten rope and any surrounding ropes must be immediately removed from servie, cleaned and reinspected because
Rot will quickly spread from a rotten rope to new rope if they are stored next to one another
Visually inspect braided rope for
exterior damage such as nicks, cuts, heat sears and excessive or unsual fuzziness
Visually inspect braid on braid rope for: and feel for:
o Heat sears
o Nicks
o Cuts
- Feel for lumps which indicate core damage
- For the ropes diameter has shrunk this may indicate a break in the core
- Check to see if the sheath slides on the core: if it does, cut the end of the rope, pull off the ecess material and then seal the end
Following guides can help to esure that ropes remain in good condition:
o Avoid abrasion and uncessary wear:
o Avoid sharp angles, bend and knots
o Protect ends from damage
o Avoid sustained loads
o Avoid rust
o Prevent contact with chemicals
o Reverse ends of the rope periodically
o Do not walk on rope
Avoid abrasion and uncessary wear:
rope can be weakened from constant vibration against apparatus compartment surfaces, compression when stored in tight spaces and surface damage due to chafing or dragging over splintered, rough or gritty surfaces
Avoid sharp angles, bend and knots
sharp angles, bends and knots can reduce strength by as much as 50%
Protect ends from damage
whip or tape cut ends to prevent unravelling
Avoid sustained loads
natural fiber ropes have less ability to bear sustained loads than synthetic fiber ropes
If they are subjected to heavy loads for long periods of time they can break well below the rated load limit
Never exceed the load limit of any rope or subject it to sustained loads for more than two days
Avoid rust
keep all synthetic or natural fiber ropes away from rust, which can weaken rope in as little as one to two weeks
If ropes become rust stained, inspect the extent of the stain. If it is halfway through the rope then it may have lost as much as half its strength. The rope should be removed from service and destroyed
Prevent contact with chemicals
natural fibre rope is extremely vulnerable to chemicals and solvents
Sythnetic rope is not entirely resistant to dmage from oils, gas, paint and chemicals
Do not let rope contact storage battery solution, washing compunds or solutions or animal waist
Reverse ends of the rope periodically
uncoil the rope and recoil it with the location of the ends changed. This will ensure even wear along all portions of the rope
Do not walk on rope
walking on rope grinds dirt and debri into the strands and bruises the strands by compressing them
Cleaning rope: Synthetic fiber ropes
mild detergent or fabric softner added in lukewarm to warm water
The following three methods are used for cleaning synthetic ropes
o Washing by hand
o Rope washing device
o Washing machine
Natural fiber ropes
wipe or gentley brush the rope to remove as much of the dirt and grit as possible
Rope storage (3)
- The rope should be in a clean, dry, unheated area with freely circulating air currents
- Ropes should not be stored in the same compartments where gasoline powered tools of fuel containers stored
- The best method for storing rope is to place it into a nylon or canvas storage bag
Webbing
used in conjunction with rope for both life safety and utility applications
webbing- Comes in many forms and may be a:
o Piece of material
o Ladder belt
o Loop
o Rescue harness
Webbing is constructed from
the Same materials used to make synthetic rope
____ inch webbing is the most commonly used
1 inch
Any webbing used for life safety applications must be
NFPA 1983 compliant
Flat webbing
flat webbing is constructed of a single layer of material that resembles an automobile seat belt
o It is stiffer and more difficult to tie into knots
o Mainly used for straps and harnesses
Tubular webbing
commonly used for rescue applications
o Two types of tubular webbing are edge stitched and spiral weave
edge stitched webbing
webbing is formed by folding a piece of flat webbing lengthwise and sewing the edges together
Spiral weave webbing
tubular webbing also known as shuttle loom construction is preffered for rescue work
Care cleaning and maintenance of webbing
follow the same guidelines used for synthetic rope
Knots:
join ropes and webbing together, attatch ropes and webbing to people and object, and form ropes and webbing into loops
parts of a rope
working end
running part
standing part
The working end:
is used to tie the knot or hitch
The running part
is the free end that is used for hoisting or pulling
The standing part
the section between the working end the running part
Dressing
tighten knots until snug, after tying all slack should be removed
Prevent such failures is to tie an overhand safety knot in the tail of the working end
Knot must
be easy to tie and untie , be secure under load and reduce the ropes strength as little as possible
Bight,loop or round turn
names for the bends that a rope undergoes when tying a knot or hitch
Knots and hitches
are a combination of bights, loops and round turns
how to form a bight
simply bendinmg the rope back on itself while keeping the sides parallel
how to form a loop
Make a loop crossing the side of a bight over the standing part
how to make a round turn
Make a round turn by further bending one side of the loop
Most common types of knots and hitches include:
o Overhand safety
o Clove hitch
o Figure eight
o Figure eight on a bight
o Figure eight follow through
o Water knot
Overhand safety knot
can be used when tying any type of knot
- Eliminates the danger of the running end of the rope slipping back through the knot causing the knot to fail
A clove hitch
principally used to attach a rope to an object such as a pole, post, or hoseline
- Can be formed anywhere in the rope
Figure eight bend
primarily on life safety rope to tie ropes of equal diameters together
Figure eight on a bight and how to tie
is a good way to tie a closed loop
- Form a bight in the rope and then tie a simple figure eight with a bight in the doubled part of the rope
Figure eight follow through:
and how to tie
used for securing objects
- It is basically a figure eight on a bight that is around the object
The water knot:
the preferred knot for joining two pieces of webbing or the ends of the same piece when a loop is needed
- Because the water knot has a tendency to slip, dress the knot properly and have the webbing as flat as possible when forming the knot
o Allow at least 3 inches for the tail
OSHA prohibits hoisting
pressurized cylinders, such as SCBAs
Tag lines
are non load bearing and help prevent tools from spinning or snagging while being hoisted
o Firefighters on the ground use tag lines to prevent the equipment from striking the structure or other objects
Carabiner:
is a snap link made from aluminum, titanium, or steel with a spring or screwed gate that connects ropes to other mechanical gear
Pulley
simple device used to create a mechanical advantage or a change in direction
o It consists of a grooved wheel through which a rope can run to change the direction or point of application of a force applied to the rope
Always use the following safety
o Be sure that you are balanced and standing firmly on the ground before starting a hoisting operation
o Use the hand over hand method to maintain control of the rope
o Use an edge roller or padding to protect rope from physical damage when pulling over sharp edges
o Use a pulley system for heavy objects
o Work in teams when working from heights
o Make sure that all personal are clear of the hoisting area
o Avoid hoisting operations near electrical hazards- if not possible use extreme caution
o Secure the nozzles of any charged hose lines to prevent accidental discharge
o Use a tag line to help control the hoisted object
o Avoid hoisting tools and equipment if it is safer to hand carry them up stairs, a ladder or an aerial device
Hoisting an axe
The procedure for attaching and hoisting is the same for either a pick-head axe or a flat head axe
Hoisting a pike pole
- Raise a pike pole with the pike up
- Thai a clove hitch near the butt end of the handle, followed by a half hitch in the middle of the handle and another half hitch around the head
Hoisting a ladder
- Tie a figure 8 on a bite and slip it through two runs of the ladder, about 1/3 of the way from the top of the ladder. Pull the loop through and slip it over the top of the ladder.- Secure a tag line to the ladder near the foot
Hoisting hoselines
- Use caution to avoid damaging nozzle or coupling when hoisting hose line to upper floors
- Charged hose lines can be hoisted but it is safer and easier to hoist dry hose line
Hoisting a power saw
-Tie a figure ate on a bite through the clothes handle, then attach a tagline through the handle
Other emergency scene uses what rope
- Utility rope and webbing may also be used in other applications such as designating control zones, establishing a search lifeline, and stabilizing objects
Use life safety rope for:
o Rappelling
o Lifting victims and rescuers
o Removing victims from ice and swift water situations
Control zone perimeter
-Clove hitchs with overhand safety knots are used to tie the rope to trees, sign posts, or other stationary objects
Search lines
are used to assist search teams working in dark smoke-filled are confined spaces.
what search lines are used for
- They allow team members to remain in contact with each other and with firefighters at the lines entry point
- Provide a physical means of finding an exit route
- Branch lines are sometimes attached to the main search line allowing team members to search larger areas away from the search line while still remaining in contact with the team
Object stabilization
- Before any work is preformed around the object you must be certain that:
o The Rope or webbing in the anchor point or strong enough to hold the weight of the object
o The knots are tight and safety knots are in place
o The attachment points at both ends are secure and will not pull free
o Personnel are clear from the stabilizing line in case of breaks and snaps back
