CMC MPD ~ Two Rope Offset ~ TTRS
The MPD allows you to go from lowering to raising without changing hardware. More than nine years of research and development went into the patented Multi-Purpose Device (MPD), which features major innovations in advanced technical hardware for rope rescue professionals. The MPD’s high-efficiency pulley, with an integral rope-grab mechanism, allows it to be used as a lowering device on the mainline and belay line systems and be quickly changed over to a raising system without switching out or replacing hardware. The combination of essential features into a single device simplifies on-scene rigging, expediting the rescue. The revolutionary MPD increases user safety with:
- Reduced Weight
- Fewer Components
- Faster Rigging
- Quick Changeovers
- Simplified Training
- Lower Risk
- Max load of 272 kg (600 lbs)
The operation we ran here was a major two rope offset. Simply put, it’s just two tension systems working together, one on one side and one on an opposing side. The objective here was to take the litter and a victim from one side and move them to the far side. It can take the place of a highline. It can be a highline alternative, but there’s a couple of things that need to be taken into consideration that are very specific to a two rope offset. The most important thing from a safety perspective is probably to keep that rescue package nice and low. The reason being is that creates a nice deep “v” angle in between the ropes coming from both sides and it ensures that we don’t over tension the system.
As that rope gets flatter and flatter, the forces increase and what we end up with is a horizontal highline, which we’re not rigged for. To monitor that kind of stuff happening, we have Enforcers load cells on both of our MPDs on the near side. This way, we’re able to see if the forces are getting a little bit higher than what we would like. The way we rigged it was we had a double long-tail bowline from this side, which was the near side and the other side, which was the far side. Both of them came to an anchor plate. The anchor plate is a little bit different than how some people have traditionally rigged the two rope offset.
The anchor plate can be seen as a critical point, so if the anchor plate were to blow into pieces right now, there would be a catastrophic failure of the system. However, the team and I analyzed what we were doing, analyzed the forces we were going to be putting on the system, and came to the conclusion that the probability of the anchor plate catastrophically failing is next to nothing. We rigged for the probable, not necessarily the possible, and decided that the anchor plate, being a critical point, was an acceptable risk to take. We put both double long-tail bowlines to the main connection on the anchor plate and that’s how we controlled our side-to-side movement.
Peace on your Days