Prussik Minding Pulleys - do they do this?

[jared_j]

I've not used 'prussik - minding' pulleys such as this. In your experience, are they effective at keeping the prussik knot out of the pulley without being 'tended', say, while being used in a mechanical advantage system in crevasse rescue?

[hafilax]

I believe that is what is meant by 'Prussik minding'.

[Gary_Yngve]

you just pointed to a heavy (12 oz) and strong (38 kN) pulley intended for professional rescue.

 

SMC also makes a much smaller, lighter, and cheaper pulley (green) that is a nice crevasse rescue pulley. the mountaineers found it performs slightly better than the nearly equivalent REI blue pulley.

 

what you need to keep in mind is that self-tending performance will depend on the pulley, the diameter of the rope, and the diameter of the prusik cord.

 

[jared_j]

You're right about me pointing at a beefcake pulley - that was accidental. I just meant that variety of pulley in general. I interpret your 'it depends' statement as stating "if the pulley can accept an 11mm rope, but you're only feeding through an 8mm rope, then there's more of a gap between the rope and pulley where the prussik could get sucked in" and "if you have relatively thinner prussik cord, it is relatively more likely to get sucked in". Hopefully this is a correct interpretation of your post.

[Gary_Yngve]

yes, that's correct. wetness/iciness of rope/cord can also have an effect. you can also use a belay device to tend the prusik.

 

still, no matter how good your "self-tending" pulley is, keep an eye on it and help it out if it's getting jammed.

[mountainmandoug]

I've used those big Petzle Prusic Minding Pulleys (PMP) for rescue work with big (12mm) static rope and 8mm prusics. They worked flawlessly, the nicest ratchet you could ask for. It really does depend on your rope and your cord though. Reportedly the little blue Petzle PMP is the best of the small ones for skinnier ropes. Always try before you fly.

[Maine-iac]

I have the Petzl Mini, and love it. The standard set up i use is a 10.2mm rope with 6mm prusik cord and it works great. Of course, you need to mind the pulleys though, because if you are hauling something, you need to reset the prusik so that you dont loose the extra few inches that the prusik travels before hitting the pulley. But i have never had my cord sucked into the pulley if that is what you are asking. Hope that made sense, if not make a system and it will, especially if you are in a vertical setting.

[JohnGo]

Can anyone explain why a prusik minding pulley is close to $30, and a "standard" pully is about $10? It's always been a mystery to me. Construction seems to be about equally simple in both cases, and it's hard to see why one should cost so much more than the other.

[ken4ord]

I have been curious too, what is the deal, any of you know?

[counterfeitfake]

Maybe they had to spend money proving that it actually minds the prusik.

[Clarence]

Can anyone explain why a prusik minding pulley is close to $30, and a "standard" pully is about $10? It's always been a mystery to me. Construction seems to be about equally simple in both cases, and it's hard to see why one should cost so much more than the other.

 

The more expensive pulleys generally have ball bearings to give them smoother movement and a longer life. The Petzl Mini Pulley has sealed bearings within it which is why it costs more.

[PeakDream]

The question is, do they translate into real world performance? Personally, I don't mind paying the extra if I'm in a rescue scenario if these pulleys actually make the rescue faster, and safer.

[mike1]

Maybe they are rated for higher kn's?

You can use an atc with a standard pulley to create a pmp too.

[hafilax]

I've been looking at the Petzl Mini Traxion for solo top rope, light hauling and as a crevasse rescue tool. They're quite pricey though.

[fenderfour]

There is a pretty big difference between a pulley with bushings and a pulley with bearings. The bearings reduce friction quite a bit more, which translates into easier, faster hauling.