When is it Time to Retire a Lead Rope?

When is it time to "Retire" a Lead Rope?? - Marty Comiskey 

I've been climbing seriously for about 15 years and I have heard/seen this question asked many times; but never a definitive answer. Usually, the "official" answer by the rope manufacturer is something along the lines of:

- casual use - several years
- moderate use - 2-3 years
- severe use - one year 

As I said, not a clear/precise answer. I was recently looking at the Mammut website (Swiss manufacturer of ropes and other climbing gear) and found an "off the cuff" comment about maintaining a rope log that had an equation for calculating the life of a rope (I would really like to know where/how they derived this equation). 

In any event, here is the description as printed in their rope technical manual: 

"Of particular use for commercial ropes. A rope log simplifies the maintaining of the usage history of the rope. The entries include the number of days used, the number of meters climbed (multiplied by 0.33) and the rappelling, lowering or top roping meters (multiplied by 1.66). From this, the total usage meters can be calculated. Ropes with 5-7 standard falls can usually be used for about 1500-5000 meters, those with 7-9 standard falls 5000-10,000 meters, and those with more than 9 standard falls 10,000-20,000 meters." 

I did a few calculations, first assuming I never rappelled and was able to walk off the route. To further simply the problem, I assumed the average pitch was 100 ft. long (obviously, some shorter, some longer). 

- thin rope (5-7 falls) - life of rope 1500-5000 meters (4920-16,400 ft.)divided by 0.33 divided by 100 ft = approx. 150 to 500 pitches (at 100ft/pitch) 

- moderate rope (7-9 falls) - 5,000- 10,000 meters (16,400-32,800 ft.)divided by 0.33 divided by 100 ft. = approx. 500 pitches to 1000 pitches) 

- heaviest rope (9+ falls) - 10,000-20,000 m (32,800-65,600 ft) divided by .033 divided by 100 ft. = 1,000 to 2,000 pitches  

Mammut also makes this statement in their rope manual regarding rappelling and lowering: 

"Rappelling reduces the life span of a rope by a factor of 2 to 3 compared to normal climbing. Lowering and top roping accelerates ageing by a factor of 5 to 10." 

So let's re-do the calculations for worst case scenario (every route climbed is rappelled). For example: 1000 ft. climbed and then 1000 ft. rappelled would translate using the Mammut equations as: 

1000 ft. x .33 plus 1000 ft. x 1.66 = 330 ft. plus 1660 ft. = 2000 ft. total rope usage. 

- thin rope - approx. 25 to 80 pitches (at 100ft/pitch)

- moderate rope - 80 to 160 pitches
- heavy rope - 160 to 320 pitches 

Since we don't always rappel as many pitches as we climb, our projected rope life is going to be somewhere between these two extremes. 

I wonder, "How many of us maintain a rope log?" Well, now you know when to retire a rope. The answer is "it depends."   

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