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Monday
Sep062010

Knot of the Day; Beginnings

Click here for the Knot of the Day Youtube Channel
or Scroll down to the end of this article for an Embeded viewing!

     One of my passions in the fire service is knot-crafting. Knot-crafting involves many issues that should be addressed with every practical knot evolution you decide will enhance your response teams effectiveness. Line size, line material, line construction, line care, color coding, all figure in to your overall operation and relate to its end success, which is a rescued viable patient ready for transport. A victim that becomes exposed to hazardous materials accelerates the need for quick knot-crafting to safely extricate from the exclusion zone. A long “sked-board” coupled with knot-crafting is one of the most effective ways to save these victims.

     Line size, is relative to choices in the fire service, as most departments maintain a standard of 12mm, or ½ inch in diameter. This balance was adopted for several reasons. Load forces and multiple line attachment are among the foremost. In the rescue business, the term “Hardware” refers to anything that line passes through to accomplish a desired result, in our case, the quick extraction of a victim. Most fire service “Hardware” is designed for 12mm or ½” line for this reason. This is critical as an oversized line will not function in under-sized hardware and subsequently jam and lock! When this occurs a rescue can quickly turn into a body recovery. Whenever upgrading rescue systems, remember to maintain the acceptable line diameter for your hardware system.

     For a long while natural materials dominated the constituents of sea-faring line from the ancient Romans forward to modern times. “Cordage” {or line} was made from the shredded fibers of plant leaves such as sisal and manila, seeds like cotton, stems from flax hemp, jute, and even from other sources such as “coir” from the husks of coconuts. Whatever was available in a given geographic area could become line material to the early sailors. There were many challenges for these types of materials in “workability”. The stronger a line was needed, the larger the diameter had to be constructed. The elements were hard on natural fibers causing excessive wear and short lives of usability. Water exposure often swelled and seized natural fiber line causing knot-craft difficult to undo if needed. Around 1950 nylon became the first UK {United Kingdom} invention that propelled knot-craft and line materials into the modern world of present day synthetics. Today, 95% of all working ropes are synthetic as the higher strength, increased durability; and small diameter makes secure knot-crafting and life safety the only way to go.

     Line construction also followed the modern trend with line materials due to the dynamics of the modern lines themselves. Natural-fibre cordage was spun from material fibres into yarns that were then grouped into three strands. The yarns were then twisted left-handed or counterclockwise to form the strand. These strands were then laid right handed or clockwise to create the actual rope or line {cordage}. With the onset of the synthetic fibers, line constituents could now be double or even triple braded around an inner core of parallel yarns. This dynamic allows for much stronger line at smaller diameters. Modern rescue lines are usually upwards of a breaking strength of 9,500 lbs of force weight loaded onto them.

     Line care is much simpler with the new synthetics, as     washing with mild detergent and line drying is usually all that is required. UV {Ultra-Violet} rays from the sun are its major enemy. Generally speaking, a line is at its best when it is new, stiff and difficult to tie knots in. When the rope gets “broken in” to the point where it is a pleasure to work with, it is beginning to show signs of weakening and should be suspect as a life-line. Even if rescue line is new, and has been properly stored, time can weaken its strength. Generally, five {5} years of storage {of a new line} without use is regarded as the common lifetime of a tactical life-line. After this, most rescue companies delegate it down to that of utility {or non-life holding} line.

     While coloring slightly lowers the strength of some lines depending on the material, it can be a huge benefit on a scene with multiple lines trailing alongside each other into a space or rescue area. Having all life-lines the same color would insure no one would be attached to a utility line for rescue. Coloring line for different purposes also insures the proper use of different line types.

     After line choice is made, remember a cardinal rule of knot crafting; “A knot is either tied correctly or wrong, if wrong it may “spill” and let go causing great danger.” Therefore, follow the link provided to view the Knots-of the-Day. I have chosen a series of the most usable knots for fire-service operations. Note, that these have alternate uses as most knots originally came from seafaring history. Other useful knots shall be mixed in, due to their helpful functionality. The videos will include useful “tidbits” of uses. I will not remove a knot that you may find challenging to master, but others may be added in the future. Be sure to check back frequently for all the “Knots-of the-Day”.

     Lastly, you will constantly hear specific terminology for the knots in the video clips. It is important to understand knot-craft terminology. All knots fall into categories. It is critical to learn the correct term for the knot you are tying. If knot terminology is misunderstood, you may tie an incorrect knot that will not support a life load, this could be fatal. All knots are either a “knot”, “hitch” or “bend”. 1] A knot is tied in a line to secure itself to the line. This is sometimes referred to as an “anchor” knot. 2] A hitch is tied around an object, and is often used as an “anchor point” for life loads. 3] A bend is tied to connect two or more pieces of line together. Depending on the bend, these can be constructed of equal or un-equal diameter lines. Learning this will assist you in understanding the audio portion of the video knot construction. Also, all knot-crafting will be shown from the position you will see when you tie the knot. This is the safest and best way to train you in knot-crafting. This is called “building a knot” and assures you have tied it correctly. A correctly “built” knot holds an in-correct one may not. Enjoy!
                                  
                             Haz Mat Mike      

See the rest of the Knots right here, and subscribe for future videos!

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