New device

Discussion in 'Search, Rescue and Technical Skills' started by Jeff Randall, Oct 14, 2020.

  1. Jeff Randall

    Jeff Randall ESEE Knives / Randall's Adventure & Training Staff Member

    Messages:
    11,371
    Likes Received:
    18,229
    Gender:
    Male
    Location:
    Alabama
    We use a lot of Sterling PowerCord in our regular operations. We’ve rappelled on it with various devices but none have ever provided a comfortable ride due to the small diameter cord in your brake hand. I’ve been thinking about a new concept specifically designed for PowerCord and today I finally got around to doing a proof-of-concept sample in the shop. It gives a very smooth ride on PowerCord and is more controllable than other devices I’ve used due to the coefficient of friction between the aluminum and nylon and the degree of contact per the Capstan Equation. Total weight of the device is 3.4 ounces and it’s a little over 3” long. There are still improvements to be made but the point is the concept works and now just needs tweaking. I realize there will be those that shudder at the thought of using a 5.9mm cord to rappel or lower on and that’s fine be me. My thoughts and uses are solely my own and not suggesting anyone go outside their scope of practice or comfort zone. With that said, PowerCord is rated at 19.7 kN, so it has the potential of making a very lightweight emergency system since a lot more cord can be carried in for its weight. This is the beta model of the device. Again, there are improvements that needs to be made and once again I realize this is not for everyone.

    1.jpg

    2.jpg

    3.jpg

    4.jpg

    5.jpg
     
    Bushman5, JV3, Adventurer and 3 others like this.
  2. Andy the Aussie

    Andy the Aussie Administrator of the Century Staff Member

    Messages:
    12,766
    Likes Received:
    18,541
    Gender:
    Male
    Location:
    Australia
    If my office is burning (or an angry ex appears) I would be happy to slide down the wall on a shoelace ! For a lightweight system that you will have with you (like the .45 vs .32 argument) when you may need it I think it is great.
     
    Strigidae likes this.
  3. Strigidae

    Strigidae Administrator Staff Member

    Messages:
    21,001
    Likes Received:
    15,831
    Gender:
    Male
    Location:
    United States
    Add the skull logo and ill buy one.

    Cant wait to take a ride on it the next ropes course.
     
    Bushman5 likes this.
  4. CWB

    CWB Member

    Messages:
    1,867
    Likes Received:
    3,654
    Gender:
    Male
    Location:
    MO
    Ill run the pulleys for you on swiss machines
     
  5. Bushman5

    Bushman5 Member

    Messages:
    12,319
    Likes Received:
    26,033
    Gender:
    Male
    Location:
    west
    I know you were thinking of me here...
     
  6. Bushman5

    Bushman5 Member

    Messages:
    12,319
    Likes Received:
    26,033
    Gender:
    Male
    Location:
    west
    @Jeff Randall any concerns with the Sterling PowerCord rubbing against itself here? (Rope on rope friction)

    99B8A52F-C2D1-453F-963D-F153EFCBDCC5.jpeg
     
  7. shaneadams90

    shaneadams90 ESEE Knives Marketing Director Staff Member

    Messages:
    2,217
    Likes Received:
    7,361
    Gender:
    Male
    Location:
    30721

    This is a doubtful concern as it is never rubbing in the same spot continuously....think about a Munter hitch...same principle int that the rope is traveling over itself.
     
  8. Bushman5

    Bushman5 Member

    Messages:
    12,319
    Likes Received:
    26,033
    Gender:
    Male
    Location:
    west
    ah good point.
     
  9. shaneadams90

    shaneadams90 ESEE Knives Marketing Director Staff Member

    Messages:
    2,217
    Likes Received:
    7,361
    Gender:
    Male
    Location:
    30721

    We use a Munter a LOT....usually on a wet and dirty rope....given the shape of a Munter hitch I'd say there would be more tension and high friction in the rope than on the device that Jeff designed...If anything...the actual belay device might get pretty hot on a longer rappel..I had a scar on my forearm from a ATS on a near 200' rap....quite a burn...think Jeff has one too in the same spot on his arm..
     
    Bushman5 likes this.

Share This Page