CMI Rope Jack
The CMI Rope Jack is a Mechanical Advantage tool for pre-tensioning static lines, light lifting and cabling. The Rope Jack is small enough and light enough to be carried aloft by a climber for Mechanical Advantage within the crown. The length of the handle on the Rope Jack limits excessive loading to avoid rope damage.
Details
Under no circumstances should a cheater bar be used to increase leverage as it may damage the unit, the rope, or severely injure personnel. lt is designed to be used by only one individual using one hand only; lt shall be removed before any'shock' load is applied; lt shall NOT be used for heavy or dynamic loads as there are other tools available for those applications. It can attach mid-line and can run virtually any length of rope. The MA is approximately 3:1 - no pulleys, no extra rope, minimum weight, minimum friction, quick, easy on-off, works well 'topside', too. The CMI Rope Jack is used to remove slack & stretch for lowering and to lift the tips on light limbs without having to break out the big guns. It is NOT for heavy loads. Cams, even 'untoothed' like a Rescucender and Gibbs, have been shown to shred a rope with high loading. There are much better tools for the heavy work.
The rope jack is approved for life support use as long as another form of progress capture device is used in conjunction with the device. Never use the Rope Jack by itself for hauling human cargo. The CMI Rope Jack is approved for static ropes from 3/8-5/8" diameters. Testing has shown that a single person can generate somewhere between 300-80O pounds of force while using the Rope Jack. Testing revealed CMI ascenders will strip the sheath of brand new 1/2" rope at roughly 1500lbs). To remove a load from the Rope Jack, pull the handle and allow the trailing cam to loosen, then pull handle again and allow the forward cam to loosen. Releasing the Rope Jack will take a little practice. The Rope Jack should be relieved from tension a little bit at a time off each cam.
Fits Static Rope Size: 3/8 inch to 5/8 inch
Weight: 2.05 lbs
Body Material: Aluminum
Cam Material: Cast Steel
Handle Length: 22 inches
Overall Length: 13 inches (Ascender to Ascender)
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Customer Questions
If you are talking about a carabiner that goes from a sling to the portawrap I would recomend any of the steel carabiners.
If you are talking about the carabiner that connects the rope jack to the portawrap I would recommend any of the aluminum carabiners that have a rating over 5,000lbs or 22.5kN.
Awesome!
This thing absolutely rocks! Today we had a small / medium pine tree leaning over a fence. We used this tool to rig that tree up to a taller pine tree next to it. We hoisted the tree upright and then lowered it avoiding the fence all together, really impressed with this tools ability so far.
Handy bit of hardware
I use it to pretension on the portawrap--it's great for that and lighter pulling scenarios. It does takes a bit of practice to get it popped off the rope under tension.
Pretty Sweet
Awesome Piece of kit, can lift smaller pieces fairly easily and takes almost no time to set up. Love it for pulling trees in the woods especially. 2 to 1 and go
Rope puller
The CMI Rope Jack is a great rope puller, not too complicated, compact, and relatively light.
It pulls!
Love how light, compact and quick to install this thing is! I use a Masdaam as well, but the CMI Rope Jack is much more versatile, not being restricted to 3-strand rope and midline attachable. It wouldn't be my go to for big trees, but definitely enough power to pull over some decent sticks. Worked great to tension a guy line on an uprooted tree the other day and was so easy to connect on the Portawrap.
The perfect weapon
When going into battle, you need to be well equipped. The CMI Rope Jack is equivalent to taking a gun to a knife fight. When you sweat the line out of the porty and you give it your all, the cut is made and you still see the lead give a little before holding its place. The Rope Jack takes that “little give” and applies enough tension to start lifting. Depending on how fluid your rigging scenario was built, get rid of all of your unwanted friction by installing rings or pulleys in those natural crotches and you’ll truly see what this weapon can do.
Great
Great innovative product… and extremely useful for lifting trees, and felling trees against their natural lean. The only problem I’ve found with the CMI Rope Jack is that it’s extremely hard to get a 5/8 rope out of the device under load. The bolts for the cams protrude enough to make getting larger ropes in and out very tough. Other than that, great device, but I would recommend sticking with 1/2 inch ropes.
Useful and very helpful
I have used the CMI Rope Jack sucking slack out of lines for rigging, drawing tag lines tight and lifting fallen sections of trees. plus its made in USA Read the instructions! I had an issue getting it off the first time I used it.