What happens to recovery gear when exposed to sun damage?
We visited the destruction lab to find out…
It happened by accident, but got way out of control. I was washing my old snatch strap after a muddy trip away, and sort of forgot about it. Not for a week or two, but for a full 12 months. Oops. The strap itself was (I use ‘was’ for obvious reasons) in good used condition, with two easy recoveries on its record. There were no signs of wear or tear, but the previous flashy red colour was now looking like a sickly faded mulberry. Instead of getting sad about potentially ruining a good strap by exposing it to UV damage, we turned that frown upside down and decided to take it back to the same NATA test lab we have used for previous destruction tests. The aim of this experiment was to see just what happens to sun-damaged and neglected recovery gear.
This isn’t a brand-based comparison; more a case study. For the trainspotters at home the strap used was an old TJM OX 8,000kg snatch strap (and they aren’t even on the market anymore). We have tested TJM recovery gear in the past, and it has proven to be up-to-task. I purchased the strap many moons ago from TJM Parramatta and have, as mentioned, used it twice for easy recoveries; then stored it behind the back seat of my Nissan Patrol. Well… before it found a final resting place in my backyard for the last 12 months.
Pretty simple really, we used the same lab and technician as we have used with all of our recovery gear destruction tests. The only difference this time was we only had the one strap. So we had to get it right. This also meant we recorded less data – as we have previously tested three straps per manufacturer to get a good spread of results. So, would the old sun-damaged 8,000kg strap be able to reach that rating after a few uses and a year in the sun?
TJM OX 8,000kg SNATCH STRAP (left in sun for 12 months)
Broke at: 5,550kg
Result: Failed at 2,450kg below the 8,000kg rating
Reason for failure: UV damage
So, what is UV damage?
UV degradation causes materials to weaken after exposure to sunlight. Pigments and dyes can also be affected, which is why my strap went from being red to a sad pink colour. Digging out the high school science book, bonds interact with tertiary carbon bonds to form free radicals (no, not that crappy band from the ’90s). These react with oxygen present in the air, producing carbonyl groups in the main chain – basically allowing the product to crack, while becoming discoloured and ultimately weaker. This is of major concern for industries concerned with outdoor rigging (and even abseiling), where sun damage is unavoidable… especially when combined with abrasion from use.
I’ll keep this to the point: Don’t leave your recovery gear in the sun. Wash straps and rope after use, dry them and store them somewhere safe and out of direct sunlight. This applies to synthetic winch rope, too – keep it covered if possible. This is in no way a bad rap for TJM; this is a bad reflection on me… the owner of a product that I ruined through misuse. I’ll take complete ownership of that. At least now we know for sure – UV damage drastically reduces the load capacity of recovery gear.