When we put this kit together, there was no shortage of devices to choose from for our descender. The Rock Exotica Mini 8 showed up early as a possibility because of its size, weight and flexibility, you can read more about it here: Rock Exotica Mini 8 Descender Instructions.

I hope that some of the information here is useful to others, but please remember, your needs may be different than mine. I don't run into burning buildings to jump out the windows, I don't play Tarzan of the jungle, and I don't interfere with natural selection. I have no objection to anyone doing these things, but I don't have those forms of experience. If you do any of these, you should form your own opinions.

His parting reminder is:

Remember, natural selection works, and it's forever.

Despite years of conventional wisdom to the contrary, ropes age from use, not from sitting on a shelf.  The article below by Pit Schubert summarizes 17 years of European data. In that time, no accidents were the result of rope age, but due to falls on sharp rocks, and exposure to sulfuric acid.  He reports that ropes of 15, 25 and even 30 years old  "broke in tests accordance with the standard; they still held at least one drop; this means they will not break in practice, unless loaded over a sharp edge, in which case they may break".

At the time of this article (March 2000), Pit Schubert was the President of the UIAA Safety Commission, the German National Delegate, the Technical Director for the German Language, and chief of the Department for Research Safety of the Deutscher Alpenverein DAV (German Alpine Club).  He was one of the first Germans to scale the three classic big North faces of the Alps, the Eiger, Matterhorn and Grand Jorasses, and his climbing career includes almost fifty first ascents in the Alps, as well as several first ascents in Greenland and the Himalayas.

According to the folks at On Rope 1, "Not unless you are wearing ice crampons or razor blades.  There is even recent discussion that claims crampons in snow just pass through the rope fibers and cause no harm to the rope."

They go on to report:

"Jim Kovach, in an exhaustive 8 month study in Ohio, and reported to/by ITRS (International Technical Rescue Symposium) including using rope as a doormat for months, and then driving over the same rope while it lay on beds of broken chards of bricks and a glazier's pile of broken glass. Then the rope was pull tested! Although the kernmantle showed minor signs of wear, in testing no loss of strength was seen. There is no evidence that stepping on a rope will grind dirt past the kernmantle into the core."

Perhaps equally interesting: 

"In other testing done by CMC out of California, rope were immersed in various substances for long periods of time and then tested. Some of these included paint, tar, sap, gasoline, oil and vomit. Most of the test items, including gasoline and oil, did not cause strength problems (although an oily rope is tough to use, it did not weaken the rope). Acidic materials, like vomit and animal urine, can cause a 30 percent or more strength reduction."

So the bottom line:  It's more dangerous to have your packaged patient puke on your rope, or for a SAR Dog to lift a leg on your rope than for you to walk on it.

For as long as I can remember, there was a rumor that dropping carabiners was bad for them; it generated hairline cracks, and was a deathtrap waiting to happen.  Not.

Myth 1: Carabiners are fragile  

Myth:  "Carabiners are susceptible to hair-line fractures if they are dropped. These fractures cannot be seen by the naked eye, but can drastically weaken a carabiner. So NEVER DROP YOUR CARABINER. If you do, it is best to discard it immediately and replace it with a new one."  (source: http://www.cbcnsw.org.au/docs/AbseilGuidelines.pdf)

Reality:  This is not true of modern carabiners.  First, the "grain" of the aluminum runs parallel to the stock, not perpendicular, so undetectable hairline fractures spontaneously causing carabiner failure just isn't true. Steve Nagode, a quality assurance engineer with REI, conducted an experiment in which carabiners were dropped six times from a distance of 10 meters onto a concrete floor.  The breaking strength of the carabiners was then determined with a 50-kN load cell.  The results:  no reduction in strength was observed when comparing the dropped carabiners with carabiners that had not been dropped.  

Black Diamond's website says this:  "It's best to inspect dropped gear for dings and significant trauma. If only light scratching is visible and gate action is still good, there is a good chance it is fit for usage."

Here's a more colorful test, this time done with a Petzl Reverso:  I call this "Reverso VS .357 Magnum". Shooting a small object with a snubnose .357 from a safe distance is tricky, but yields thrilling results.  This is akin to throwing the Reverso into a rock surface at 67m/s*, which would require dropping it 240m (790 feet).  And these calculations omit air resistance, which limits the terminal velocity of the Reverso free-falling to around 35m/s (the terminal velocity of a baseball).  In actuality, the piece of gear would not reach 68m/s even falling this far.  The Reverso bent various ways, but it took 5 direct hits before it actually broke.  This seems to indicate that a single, short drop for a piece of hardware does little to no damage.  

While the specifics of rope care vary slightly from manufacturer to manufacturer, here are some general guidelines:

• Inspect every inch of your rope before and after each use. Pay close attention to any nicks, cuts abrasions, or any area where the rope feels "mushy", or has a flat core.
• Keep your rope as clean as possible, dirt and grit can work its way into the fibers and accelerate wear.  When working with a rope in camp, put it on a tarp to help keep it clean.
• Sunshine and UV are not your rope's friend. Store them in the shade, out of direct
  
  sunlight whenever possible.  Bluewater Rope mentions that they incorporate UV inhibitors into their rope, but they degrade with time.
• Keep your rope away from strong chemicals, such as battery acid and bleach.
• Only mark your rope using "approved" markers; this usually means normal Sharpies, which are alcohol-based, are bad.  Most vendors seem to be happy with laundry markers, with Rub-A-Dub brand being recommended.  Here's the quote from the Bluewater Rope FAQ:
"Marking pens are fine to use on ropes as long as they are water based laundry markers. Years ago solvent based markers were the norm. Some of the solvents used in these old pens could reduce the strength of the sheath strands marked. These days most pens are water based so this is not as much of an issue as in years passed. We recommend a Sharpie "rub a dub" laundry marking pen." 

• Wash your rope per published guidelines.  Also from Bluewater:

"Mild soap and cool to lukewarm water. A bathtub or large pail works well to allow complete submersion. Place rope in soapy water and agitate to remove dirt particles. Rinse well in several baths of clean water. It is extremely important to remove all soap residue. Leftover soap residue will attract dirt like a magnet. After rinsing, loosely coil your rope and air dry in the shade. Never use cleaners with bleach or bleach substitutes. Remember- it a soap is harmful to your skin then it is harmful to your rope!"


• For really dirty rope, you can get a Dobi Rope Brush,
  pictured above, or similar devices from CMI and other vendors that hook onto a garden hose, or build your own.
• You can also daisy chain or loosely coil your rope, put in a laundry bag, and put it in your washing machine on a gentle cycle.  Details here.  

• For more information on rope care, see the REI Rope Care webpage:
  http://www.rei.com/learn/expert-advice/rope-care.html