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Wednesday
May012013

Rope, Line, & Practical Confined Space

            As you can tell by my earlier postings “Knot-of-the-Day; New Beginnings” rope, line, and knot crafting is a passionate hobby of mine. While varying purposes are the blueprint for design advancements, no one can deny the abilities of modern rope/line. New materials to deliver strength and dexterity of knot crafting are truly amazing.

One of the many reputable modern companies committed to quality and strength of materials can be reached at www.neropes.com. New England Ropes offers various types of line for various uses as you can see by their home page. It is critical to appreciate all elements of construction of different lines for different applications. For example, a water rescue line would place your team at great disadvantage if it sank. While this is simplistic, you can appreciate the concept of varying materials and how they will react in your environment of use. Hazardous Materials Teams infrequently use line, but when they do, we also fall under NFPA {National Fire Protection Agency} guidelines for safety and strength. This is due to our close association under the Fire Service umbrella.

When hazardous materials teams do use rope it is usually for life safety purposes. Working on top of industrial vats, tank wagons, or climbing on top of chemical refining equipment positions us for life threatening slip and fall potentials. When railcars need attention, they may be in a variety of positions that require responders to supplement with high angle personnel safety lines in order to reach the needed valve assemblies. Even when not overturned, climbing to reach these is akin to being on top of a tall garage. Add to all this, the possibility of poor lighting, slippery surfaces from leaking or spilled contaminant, and you begin to see the importance of a steadfast safety line that will catch your fall. While some CPC {Chemical Protective Clothing} have added anchor points for safety line, this feature along with the additional cost is frequently cut during the final purchase decision. All additional features of CPC should be carefully considered during committal to the final purchase.

One technique we improvise, comes through the addition of a class three {3} safety harness over the exterior of the hazardous materials ensemble along with a safety tether  for securing to the tank top once we reach the work area. For “workability” we commonly tie this harness from a piece of webbing. This is accomplished by donning “webbing” or ladder belt, over the exterior of the level “A” or “B” CPC. While in many chemical environments this may weaken the webbing fibers, this a small price to pay to prevent a “free-fall” from 15 to 20 feet above ground. Anchor points for leverage are usually improvised to the existing tank or equipment, due to the fact that “typical” confined space anchor “tri-pods” require more “base” area than is available on top of rail-cars and trailer tank-wagons.

When using modern line/rope “fibers” become exposed to hazardous materials, you can expect the common rescue safety ratio of 15 to 1 to decrease. In these situations “workability” must take a role emphasizing completion of the task rather than the mathematical “ideal” of practiced safety goals. For this complete study see my new book “Practical Confined Space” available on this website page.

Modern fiber materials, construction, and the likeness to the marine industry are the general direction we parallel. These parallels between the marine environment and hazardous materials sites, in respect to rope are interesting. Both are usually wet, either from spilled contaminant or weather, both is usually slippery, and both have multiple sharp edges and variable material surfaces. Some of these physical hazards may be manipulated and some may not. Rope fibers and strengths along with stretch and durability become critical.

Rope fibers and modern rope components are complex systems that complement each other working together as a “team” resulting in a lines composition and resultant properties under use. Nylon is recognized for its outstanding strength and ideal applications where energy absorption is critical such as in a sudden fall. Nylon also suffers minimal strength loss when exposed to sunlight.

Polyester has many of these qualities, but without the capabilities of stretch. This material becomes superior when the loads are constant and durability is needed. The newer yet, "Aramid" fibers such as Technora and Dyneema are both high strength, low stretch lines that offer other abilities. The black version of Technora has superior UV degradation, while Dyneema has superior water resistance. There are many factors to consider when choosing a fall protective line as there are pre-planning scenarios where it could be called into service. Always practice planning for the worst case scenario and hoping for the best case results.

Regardless of your choice for line you will find two “inner-line” construction styles. Polyester in all its forms covers a wide variety of environmental hazards, so it has become the beginning material of choice. Polyester lines will either be categorized as spun, (fuzzy) or filament, (smooth) types. This material has excellent weathering abilities and abrasion resistance, wet or dry.

The lines “formed” using these synthetic materials and varying configurations of each, increase overall strength with diameter reduction while also increasing the “feel” of rope handling typical features. Handling characteristics are very important when wearing multiple layers of chemical protective gloves for setting the line and tying knots. “Single braid” lines resist kinking and deliver strength. Useful, when long safety lines are laid. “Double braid” lines consist of a braided cover that surrounds a braided core, producing a line strong, durable, shape holding and easily handled. A “parallel core” is a unidirectional core with a braided cover creating a much stronger line with smaller dimension. Three strand line forms a larger dimension but has superior handling with age. Also, a larger diameter may become more functional with chemical protective gloves. This line is long lasting and flexible. As you can see, this is a separate field of study all in itself. Dealing with a line manufacturer may be wise for your rope selection when making purchases for unique applications.

If you decide to implement an additional safety policy to your team, pre-planning on the types of knots you will exclusively use must be considered. They should be useful and relatively simple to tie. Always opt for simpler knots rather than fancier ones, to avoid “spillage.” Spillage occurs by two means, from improper knot construction and or line materials chosen. Spillage is the term for a knot that does not hold its “form” a subsequently unties itself, sometimes due from an incorrect match between knot “type” and knot materials/line configuration. Training for this discipline is especially well received, as it can be completed within a few minutes every time your team meets. See “knot-of-the-Day” New Beginnings on www.hazmatmike.com for free access to my knot tying videos.

It also becomes fun for the team to test their skill, while frequently using these knots off duty, more than on duty! Your team will have to decide on rope rotation insofar as it relates to rope replacement. Unused life-lines are downgraded to utility lines every five (5) years per NFPA standards, whether they are used or not. Remember, your use for hazardous materials will probably entail fall protection with heavy chemical contact. Guidance from “Practical Confined Space” will secure competent decision making for this field of study. Discussion between Team members to gain a reasonable consensus for fall protection needs is always a plus. Team trainers will find that any small amount of practical training on this matter is fun for the Team and enhances moral and capabilities on site much more than passive classroom activities.

                    Haz Mat Mike  

 

 

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