I’m a film maker; flying a drone in a cave sounds a little risky. Take it from me. But if you are going to do it, why not choose some of the largest caves in the world? Check out this video and get a new perspective caving.
Early this year Petzl released a warning about worn out CROLL ascenders.
Possible consequences of using a worn out CROLL ascender
Under certain usage conditions related to environment and technique, using a CROLL ascender that is worn beyond the retirement criteria can result in a hole in the stainless steel wear plate. Once the hole starts to form, the opening enlarges to the edge of the stainless wear plate and creates a sharp edge that makes the CROLL unusable with a foot ascender: the sharp edge can catch on the rope, preventing the CROLL from sliding and possibly damaging the rope sheath.
The caver may then find it necessary to immediately stop using the CROLL, while he is still underground. Without a spare ascender, the only solution is to climb without a foot ascender, carefully, using only the footloop to avoid tensioning the rope in the CROLL.
Worn out ascender and rope damage resulting from its use.
Factors in determining when a CROLL ascender is worn out
In all cases the CROLL ascender must not be used and the product must be retired.
Cam is worn out
Indicated by significant wear of the teeth (see photos) or by ascender slippage.