When to Retire Your Rope
Let’s be honest boating is one of the harshest environments you can put rope and webbing through. Boaters often complain that their gear is constantly falling apart and that gear doesn’t last due to the harsh strain we put on our gear. Between the water, microscopic sand, mold, and whatever else is hiding in the water, materials breakdown super quickly. With this in mind we wanted to take a look at how quickly ropes break down and when to retire our ropes.
There are numerous occasions when you might need to put a rope under heavy strain and those situations can be critically important to the success of a trip. Wraps put the most strain on your ropes and can even destroy the rope entirely after a single use of the forces are great enough. Vertical extractions, big swims, or moving an inured patient up a steep bank with a rope are another set of circumstances where rope failure can be life threatening. Setting up rope systems under tension to rescue an entrapped swimmer are another circumstance where rope failure means someone is not coming home. With all this on the table you want to make sure that your rope is in excellent shape at all times, so we reached out to our friends at Sterling Rope to figure out what to look for and we want to start with the review phase.
Review
First, it’s a good idea to check and see when your ropes were manufactured to ensure they have not already exceeded their shelf life. (What is a rope’s average shelf life)? If you don’t know the age of a rope, here’s a handy tip: using scissors, cut off a 1-meter section of the rope from one end and remove the identification tape from inside the core strands. It should list the manufacturer, the year and quarter it was made and the certifications it meets. If the tape does not have this information, or is missing altogether, retire the rope from use immediately. Now that you know the age of the rope, you can do a physical inspection. Any physical inspection should cover the following points:
Excessive fraying – inspect the rope fibers for fraying or strands pulling out of the rope which might indicate that the fibers of the rope are not tight together.
Softness or stiffness – if a rope feels unusually soft or stiff this can be a sign of damage or problems with the rope.
Exposed cores – This can be a sign of damage to the rope and is a sure sign that the strength of the rope is compromised. Since the bulk of the strength is in the sheath then this rope is likely to break the next time it is under tension.
Damage due to glazing or hard spots - This may be a sign that a prusik bit into the rope too much and may have melted or welded itself to the rope. It may also be a sign of excessive friction against a surface while the rope was under tension. Either way if the rope looks glazed, hard or melted then there is definitely going to be a problem in the future.
Lack of uniformity in diameter, color, or texture – this can be the sign of several issues including core separation, material has worked its way into the rope, or even just damage from UV exposure. Either way a lumpy rope will not slide properly through a pulley and worse it may be compromised and you just can’t see it yet.
Retire
So, the burning question and why you came here in the first place is: When should you retire your rope? The working life of your rope depends on the frequency and type of use. Here are some general retirement timelines given average and proper use…which we as boaters may want to look at critically since we fall into the harsh use category:
Extensive use: Retire after 1 year
Regular to occasional use: Retire after 5 years
Rarely used: Retire after 10 years
During your physical inspection, if you noticed any of the five conditions listed under “REVIEW”, it’s probably time to retire the rope from service. Additionally, if your rope has been exposed to excessive UV light, sharp edges, or any type of chemical contamination, retire the rope immediately. Never store ropes near chemicals, because even the fumes can dissolve the rope’s filaments (think sulphuric acid from a car battery, etc.). The damage can be invisible to the naked eye, making it especially dangerous.
Questions for Sterling
Q: Are the sheath and core of your water ropes bonded in some way? From a visual inspection is there any way to tell if the sheath and core are separating in a way that would compromise the integrity of the rope?
A: There is no physical bond between the core and cover. Its very unlikely in water rescue applications, but in more severe friction scenarios the sheath of the rope may feel loose around the core, this is called milking. To get rid of it you just need to grip the rope and slide the excess sheath slack to the end of the rope. There will be a short section of just sheath when this happens. You can just cut this off the end of the rope and heat seal again.
Q: Where do you get most of the strength in the rope? Should we be more concerned with the integrity of the core or the sheath?
A: For water rescue applications, the smaller diameter ropes due use some nylon, the bulk of the strength is in the polypro sheath on these ropes though. They are fine to use in wet conditions and are designed for that purpose. The larger, 7/16” and ½” sterling ropes have a braided polypro core with a center nylon filler. The nylon filler is only to help keep the rope round and is not load bearing. HMPE or high modulus polyethylene (also known under the trade names Spectra and Dyneema) core these materials are not affected by water in terms of elongation or break strength.