Students in our Confined Space Rescue Team Leader class (May 3-7, Sahuarita, Arizona) learn that a descender (like the Petzl I'D or CMC Clutch) is essential for mainline raising and lowering operations. The ability to grab and release rope under control (when lowering) and then act as a pulley (when raising) provides teams with an effective tool to conduct technical rope operations.
For decades, the Petzl I'D has been one of the most common descenders and we have used it extensively in class. But there are several others out there as well. In addition to the MPD, CMC Rescue recently introduced the Clutch. In our upcoming Confined Space Rescue Team Leader class, we will test this device (and others) so students can determine if the additional cost it provides a substantial benefit to their team.
One of the key advantages promised by CMC is reduced friction when the device is being as a pulley. Users of the I'D know that when used as a pulley, there are considerable losses. CMC claims that the Clutch can reduce this friction by about 12% over the typical descender, and the Clutch would provide about 7% more friction when compared with a typical pulley.
Knowing what equipment is available, how it can be best used, and what other options there are to accomplish the same goal is essential for a rescue team leader. At D2000 Safety we look forward to helping our students achieve that learning outcome along with the many others needed for success.