CT RollNLock vs. Ropeman 1

[Newhunter1]

I am going to sell 2 of my 3 ropeman1's and was considering the CT RollNlock. One of the reviews that I am looking at states that it has a 20 kN rating for a load capacity. About 5:06 into the video...here's the video...

.

The second video I am reviewing shows a 4kN rating.

. The concern comes at 1:05 in the video...

Any rock climbing or arborist's guru's advice for or against the CT? What about a prussic tender? I have multiple rings that I outfitted me and my son's hammocks and no longer use as I switched those over to dutchware clamps.

 

[skyjacker]

He explains what he thinks the 4kn rating is in this video starting at 0:55. Here's my take on the rope grabs. I have seen zero load testing on the Ropeman 1 or the Duck. Richard has been kind enough to do some load testing on the RollNLock and the results are good. It's a beast. Maybe the other rope grabs are beast too. There's no way to know unless some one can get these things tested. Out of the Ropeman 1, Duck, and RollNLock, I like the RollNLock. You get more for your money. You get a pulley and rope grab in one. I use the pulley quite a bit. We used it last year with a gimbal to clean and quarter some game. Two of them make a really nice two to one mechanical advantage. A lot of people complain the RollNLock and Duck make more noise. Put camo form on your biner for a tight fit and it makes zero noise. It actually makes less noise than a Ropeman 1. As far as an eye to eye and tender, I've never used one. Thinking about trying it though.

 

[EricS]

The ropeman has been tested and failed around 4kn also. The ropeman itself is tested at 14kn but will damage the rope well before that. The advantage of the ropeman is it’s smaller/lighter and because of the way the teeth pinch the rope against the carabiner it’s quiet. The downsides to that compared to others are different carabiners will perform better than others. It also usually has a smaller window of suitable ropes. That can be stretched some based on carabiner size and shape but it’s at the users own risk.

 

[ThePreBanMan]

The Ropeman 1 gets some hate here. Not sure why that is. The ropeman itself is stout (15 KN). It has been shown to damage some ropes at lower fall forces than that. 4KN seems to be the consensus (900 pounds of force). Okay, so assuming a 200-pound man falls 3 feet, he generates less than half that. I 300 pound man falling 3 feet generates 600 pounds of force. Still comfortably below the 4KN "failure" I see cited here.

Honest question, who has that much slack in their tether or lineman's belt? One of the examples often cited about saddles is that you're always attached to the tree and the tether never has any slack. So falls aren't possible.

So if that's the case, it would seem to me that the only real way the ropeman 1 could fail is if the user is doing something drastically wrong such as introducing excessive slack in their lines.

But if you're still worried, you can always use the ropeman 2. Or use a better, more durable rope. Or both. There are "rescue" ropes available that are designed to be highly abrasion-resistant and even heat/fire resistant (used by firefighters). Point being if you're really concerned you can get a better rope.

 

[LooyvilleLarry]

^^ This..

 

[Newhunter1]

So after watching the last video, I am confident in the CT as my new ascender and should I fall in the unfortunate event I'm confident that it will not break at 4kN...the rope broke at 28.2kN but the CT did not. My body wouldn't be able to handle 6000+lbs of force on it.

 

[Newhunter1]

hmmm

The Ropeman 1 gets some hate here. Not sure why that is. The ropeman itself is stout (15 KN). It has been shown to damage some ropes at lower fall forces than that. 4KN seems to be the consensus (900 pounds of force). Okay, so assuming a 200-pound man falls 3 feet, he generates less than half that. I 300 pound man falling 3 feet generates 600 pounds of force. Still comfortably below the 4KN "failure" I see cited here.

Honest question, who has that much slack in their tether or lineman's belt? One of the examples often cited about saddles is that you're always attached to the tree and the tether never has any slack. So falls aren't possible.

So if that's the case, it would seem to me that the only real way the ropeman 1 could fail is if the user is doing something drastically wrong such as introducing excessive slack in their lines.

But if you're still worried, you can always use the ropeman 2. Or use a better, more durable rope. Or both. There are "rescue" ropes available that are designed to be highly abrasion-resistant and even heat/fire resistant (used by firefighters). Point being if you're really concerned you can get a better rope.

Something to think about...

 

[skyjacker]

The Ropeman 1 gets some hate here. Not sure why that is. The ropeman itself is stout (15 KN). It has been shown to damage some ropes at lower fall forces than that. 4KN seems to be the consensus (900 pounds of force). Okay, so assuming a 200-pound man falls 3 feet, he generates less than half that. I 300 pound man falling 3 feet generates 600 pounds of force. Still comfortably below the 4KN "failure" I see cited here.

Honest question, who has that much slack in their tether or lineman's belt? One of the examples often cited about saddles is that you're always attached to the tree and the tether never has any slack. So falls aren't possible.

So if that's the case, it would seem to me that the only real way the ropeman 1 could fail is if the user is doing something drastically wrong such as introducing excessive slack in their lines.

But if you're still worried, you can always use the ropeman 2. Or use a better, more durable rope. Or both. There are "rescue" ropes available that are designed to be highly abrasion-resistant and even heat/fire resistant (used by firefighters). Point being if you're really concerned you can get a better rope.

This is not how fall factors work. The problem is not falling and reaching a force when hitting the ground. The problem is the force of the rope suddenly stopping you.

https://roperescuetraining.com/physics_fall_factors.php

 

[ThePreBanMan]

This is not how fall factors work. The problem is not falling and reaching a force when hitting the ground. The problem is the force of the rope suddenly stopping you.

https://roperescuetraining.com/physics_fall_factors.php

Which is exactly why I used a fall force calculator to come up with the cited figures. Double-check if you like.

 

[elk yinzer]

The Ropeman 1 gets some hate here. Not sure why that is. The ropeman itself is stout (15 KN). It has been shown to damage some ropes at lower fall forces than that. 4KN seems to be the consensus (900 pounds of force). Okay, so assuming a 200-pound man falls 3 feet, he generates less than half that. I 300 pound man falling 3 feet generates 600 pounds of force. Still comfortably below the 4KN "failure" I see cited here.

Honest question, who has that much slack in their tether or lineman's belt? One of the examples often cited about saddles is that you're always attached to the tree and the tether never has any slack. So falls aren't possible.

So if that's the case, it would seem to me that the only real way the ropeman 1 could fail is if the user is doing something drastically wrong such as introducing excessive slack in their lines.

But if you're still worried, you can always use the ropeman 2. Or use a better, more durable rope. Or both. There are "rescue" ropes available that are designed to be highly abrasion-resistant and even heat/fire resistant (used by firefighters). Point being if you're really concerned you can get a better rope.

You're calculating energy not impact force. Bad info. Agree there should never be 3 feet of slack once set up. I've seen people do it climbing.

 

[ThePreBanMan]

You're calculating energy not impact force. Bad info. Agree there should never be 3 feet of slack once set up. I've seen people do it climbing.

No, I'm using a fall force calculator to calculate the exact impact force. As mentioned, feel free to double-check it if you think the info is bad.

 

[skyjacker]

Here is the calculator results from the site I posted above. https://www.junkfunnel.com/fallforce/

90 kg is 200 lbs
3% is the elongation of Samson Predator rope
2.4 m is 8 ft - tether length
0.9 m is 3ft - amount of fall till it catches

6.8 kn is 1528.7 lbs

According to the testing on the Ropeman 1, your rope is cut and you've hit the deck. What calculator are you using?

 

[elk yinzer]

I think its straight effed up we have internet experts throwing numbers out that are patently wrong. The calculation above is way jacked up too. 8 feet of tether? You're calculating from your connection point to the anchor, not the entire tether. Take the common case of one-sticking where its hard not to climb above your tether. Lets say worst case scenario you have 1 meter tether and climb 1 meter above, you're now falling 2 meters with a fall factor of 2. The impact force of that on a 200 lb person will be around 15 kN. Even reduce fall factor to 1.3, so 30% above the length of your tether and you are around 10 kN. That's probably our worst case scenario. It's all theoretical calculations and I am no physicist, but saying you'd never see 5 kN is pure idiocy. Enjoy your broken back if your equipment survives.

 

[EricS]

The Ropeman 1 gets some hate here. Not sure why that is. The ropeman itself is stout (15 KN). It has been shown to damage some ropes at lower fall forces than that. 4KN seems to be the consensus (900 pounds of force). Okay, so assuming a 200-pound man falls 3 feet, he generates less than half that. I 300 pound man falling 3 feet generates 600 pounds of force. Still comfortably below the 4KN "failure" I see cited here.

Honest question, who has that much slack in their tether or lineman's belt? One of the examples often cited about saddles is that you're always attached to the tree and the tether never has any slack. So falls aren't possible.

So if that's the case, it would seem to me that the only real way the ropeman 1 could fail is if the user is doing something drastically wrong such as introducing excessive slack in their lines.

But if you're still worried, you can always use the ropeman 2. Or use a better, more durable rope. Or both. There are "rescue" ropes available that are designed to be highly abrasion-resistant and even heat/fire resistant (used by firefighters). Point being if you're really concerned you can get a better rope.

That’s what everyone keeps telling me. I haven’t researched the formulas and tried to do the math myself. I have typed in this information into various calculators online and every single one says if you fall three feet on a ropeman you need to be worried. Some calculators show you need to be deploying a parachute. I’m not saying any of these rope grabs are bad. The really risky ones I have seen as far as slack were single stick climbing. They easily get 3’ of slack in their system if they don’t adjust their tether until they are standing on the stick. Don’t get me wrong I own six ropeman 1’s and don’t back them up but I don’t introduce slack into my system when using them. This particular calculator shows a little over 4kn. Bump that climber weight to 250 and it’s over 5.5kn. That tells me that if you’re going to be using some climbing methods you need to either be very observant and proactive in making adjustments while climbing on your aiders or use a prussic. If I’m wrong on these figures please show me where.

 

[Madgrad02]

Being new to saddle hunting, and still getting used to my equipment, I already have the stock prussic knots on my Kestrel above (backing up) my Ropeman 1s, just as I am new to using them and it just felt safer to me. I still don't foresee an instance where I would ever be in a situation to generate some of the forces mentioned, but that being said, and since I am already using a backup friction knot, if there was some failure of the tether rope at the Ropeman, how far above the Ropeman will be prussic need to be to ensure that is grabs still? Currently, my banana hands can grip the Ropeman and the prussic to move as needed, but is that backup knot too close then (if that is making any sense)? Would I be better served moving to a Blake's Hitch perhaps or something that would create more distance between the backup knot and the Ropeman?

 

[elk yinzer]

Real world, common sense, the danger as it relates to this is basically climbing above your tether. Understand fall factor. If your tether is 3 feet and you climb a foot above it, you fall 4 feet. Climb 2 feet above, you fall 5 feet. I use a ropeman, I don't backup anything, and I'm really not a safety nut. But seeing incorrect calculations posted really chaps my rear.

 

[skyjacker]

That’s what everyone keeps telling me. I haven’t researched the formulas and tried to do the math myself. I have typed in this information into various calculators online and every single one says if you fall three feet on a ropeman you need to be worried. Some calculators show you need to be deploying a parachute. I’m not saying any of these rope grabs are bad. The really risky ones I have seen as far as slack were single stick climbing. They easily get 3’ of slack in their system if they don’t adjust their tether until they are standing on the stick. Don’t get me wrong I own six ropeman 1’s and don’t back them up but I don’t introduce slack into my system when using them. This particular calculator shows a little over 4kn. Bump that climber weight to 250 and it’s over 5.5kn. That tells me that if you’re going to be using some climbing methods you need to either be very observant and proactive in making adjustments while climbing on your aiders or use a prussic. If I’m wrong on these figures please show me where.
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The math is complicated. I will point out in the calculation above, there is some give from the belayer. Take that out. In our scenario there is no give only slack. Give in a rock climbing scenario involves the belayer and the belay device. It also heavily depends on rope elongation. Use the calculators and change the elongations. 3% elongation (a typical static rope) vs 10% elongation (a typical dynamic rope).

In my first calculation example above I put in 8ft for tether length ... that is wrong. I didn't take into account the wrap around the tree. The length should be from the girth hitch. So let's say it's now 6 ft of rope from the girth hitch to your bridge and you fall on 3ft of slack. It's actually worst.

Look, I'm not saying you're going to die. I'm saying slack is the enemy in our game and these fall forces on static rope are real. Keep slack out of your system the best you can. This is why I will never choose a climbing method where I'm tethered in pulling up slack. I think it's too hard to keep slack out during the climb. I'll take my risk with an LB or better yet keep working on SRT. I'm still using a mechanical rope grab.

 

[ThePreBanMan]

I think its straight effed up we have internet experts throwing numbers out that are patently wrong. The calculation above is way jacked up too. 8 feet of tether? You're calculating from your connection point to the anchor, not the entire tether. Take the common case of one-sticking where its hard not to climb above your tether. Lets say worst case scenario you have 1 meter tether and climb 1 meter above, you're now falling 2 meters with a fall factor of 2. The impact force of that on a 200 lb person will be around 15 kN. Even reduce fall factor to 1.3, so 30% above the length of your tether and you are around 10 kN. That's probably our worst case scenario. It's all theoretical calculations and I am no physicist, but saying you'd never see 5 kN is pure idiocy. Enjoy your broken back if your equipment survives.

Why don't we inject a little common sense then? Seems we have a few fly by night physicists here. Get out a step ladder. Climb up 3 rungs. Jump off. Did you die? Did you break your back? Yea - didn't think so. Okay now, that common sense has once again been established and we've determined that your interpretation and application of the formulas are wrong, can we get back to reality?

Your ropeman 1 will be just fine in a 3-foot fall. If you have a lifeline, tether, etc' with more slack than that than you should reexamine what you're doing.

If you don't want to use an ascender - than don't. Use whatever you're comfortable with. But a 3 foot fall isn't going to blow up your ropeman 1. Jesus - I do 3 foot box jumps at the gym like 3 days a week... I should be dead!

 

[fathead88]

Wow.

 

[ThePreBanMan]

Weight, distance, acceleration, mass, etc, these things do not change just because the ropeman isn't in the example. It's a far more applicable example than you may want to consider. That's fine. But that doesn't make it any less applicable.