Ropes And Knots Flashcards
What NFPA covers Ropes, Harness and Hardware?
NFPA 1983
Standard on Fire Service Life Safety Rope, Harness, and Hardware
Minimum safety margin of rope and harnesses?
15:1
Class I Load Specifications
300 lbs. – T (technical / personal) rated equipment – 27 kNewtons
Class II Loads Specifications
600 lbs. – G (general) rated equipment – 40 kNewtons
5 Different Rope Types
- Kernmantle
- Laid (Twisted)
- Braided
- Braid on Braid
- Nylon Webbing
Kernmantle Core vs Sheath strength:
Core: 70-95% of strength
Sheath: 5-30% of strength
2 Different Types of Kernmantle
Static / Dynamic
What is kernmantle made of?
100% Nylon
Static Kernmantle Core Bundle
Parallel Core Bundle
Static Kernmantle elongation:
normally 1% to 10% at 10% of the rated breaking strength (NFPA 1983 requirement)
A rope is considered “static” if it:
Stretches no more than 20% at its breakpoint
Are utility and life safety bags on all TFD rigs?
Yes
Dynamic Kernmantle bundle construction?
Dynamic core has twisted bundle construction
Dynamic Kernmantle Elongation:
normally 8% stretch w/200 lb. load, 60% near failure
Dynamic Kernmantle use:
Used for climbing and training only by TRT
Dynamic Kernmantle can be:
- “tight” weave – better abrasion resistance but harder to tie knots
- “loose” weave – easier knot-tying but less abrasion resistance
Diameter of Static Kernmantle used by TFD:
1/2 In.
Static Kernmantle minimum breaking Strength:
9000 lbs
Static Kernmantle maximum working load:
600 lbs.
Static Kernmantle weight:
7 lbs. per 100’
Static kernmantle used by TFD lengths carried by suppression units and TRT?
- Suppression units carry 150’ in length
2. TRT carries up to 600’ in length
Identification Markers in core bundle tells you what 3 things?
- company name
- place of manufacture
- year of manufacture
Problem with Identification Marker on outside of rope?
If it is on the outside of the rope, identification marker is usually destroyed by abrasion or normal wear and tear
Laid Rope Description:
Natural fibers (manila hemp) – 3 twisted fibers (yarns) bundled together to form strands
All fibers exposed
• High stretch characteristics
Laid Rope Twist Style:
Rope will twist in opposite direction of lay when under load
What is Braided Rope made of?
Made of synthetic material: Nylon & Polypropylene
Does braided rope have a core or outer sheath?
No
Problem with Braided rope:
Load-bearing fibers are exposed to direct abrasion and damage
Braid on Braid Load Share:
50% core
50% Sheath
Braid on Braid Characteristics: (2)
Less abrasion resistance than kernmantle
High stretch characteristics
TFD uses polypropylene for: (1)
Swift Water Rescue
Nylon webbing is Issued to all uniformed members and used exclusively for:
Hansen Harness
Nylon Webbing Construction
continuous nylon fibers woven in a spiral weave to produce tubular shape
Nylon Webbing minimum breaking Strength:
4000 lbs.
Has Manilla Hemp been replaced by ropes made from synthetic fibers?
Yes
Manilla Hemp is used for: (1)
exclusively for non-life safety utility work