Stien RC 3002 Lowering Device.....Anyone got one

[Old Monkey]

It doesnt matter where you tie it the load is the same.

Not true. The weight of the load is the same but the force varies based on how much free fall the piece does before you start slowing it. Even an extra foot of fall can add a lot of force.

I used ten feet as an exaggeration to make the physics easier to picture. The less distance between the block and the first attachment point, the better.

 

[treesmith]

I sometimes try to center-tie pieces if the groundie needs to maneuver it, but only when rigging smaller stuff. I wouldn't attempt it on big stuff.

 

[tophopper]

This is good though. Some great discussion here. Id like to see some dyno tests to see if there are any gains or losses from these scenarios.


This type of discussion doesnt happen at the other forum. Its all good.

 

[SouthSoundTree]

replying to Bonner's comment- from what I have read, (ignoring pulling in slack) it is really the center of mass/ gravity (there is supposed to be some difference, and I don't know which it is in this case) of the work piece in relation to the block, not where the piece is tied in relation to the block. I believe that there is a good diagram of such in the Art and Science of Practical Rigging. Some people try to get it (or think that they have to get it) tied as close to the butt of the piece as possible. So long as it is not above the COG, it shouldn't matter.

 

[tophopper]

Exactly what I was getting at. It doesnt matter where its tied if its below the COG.

 

[Burnham]

Right. The distance from COG of the piece to the block is the fall. Whether you tie it off one foot from the bottom of an 8 foot piece or 3 feet from the bottom of an 8 foot piece, the fall is the same. Tie off at 3 feet, and you have the opportunity to reel some of that in as the piece tips...less so if tied off at one foot. Which in the end reduces the dynamic load the rope man has to manage with letting it run. And that makes for easier treatment of your rigging.

IMO....

 

[sotc]

The sooner you can begin to slow your piece, the more room you have to decelerate, the less stress on the rigging. Thats what plays through my mind. Like skidding to a stop at the white line or smoothly braking for 45' to stop at the same place.

 

[bonner1040]

Man.. If we all got together it would be like captain planet.

 

[emr]

I pull the slack out when anything is getting rigged from above. I do it because I think it's a smoother transition from free falling to letting it run. I have never been too considered with the shock loading aspect but it's a pride thing with me. I want every piece that I run rope on to be as smooth as possible.

Several years back we went to a rigging class put on by NATS and the instructor said that if you are blocking down wood, you get less force at the block if you pretension your rigging line. He had a dyno and it was less, not much less but less. I have pretensioned the line before when blocking down wood in a super tight area. We were taking 2' long pieces and snubbing them off. This was the only way we could think to do it because below the tree was an insane slope down to a river and on the other side was a 100 year old retaining wall, patio, and boxwood hedge. I was not the climber on that tree but I was scared sh¡+ less on the ground. I am sure there eat less force at the block but it sacked having that piece of wood swinging around right by the climber.

 

[Jack]

The proof would be in the dynamometer. Could all be theoretical, without real world gains.

Some good info (with test results) here: Evaluation of current rigging and dismantling practices used in arboriculture

Looong PDF! But, good read!

 

[stig]

The snugging up tecnique works particularly well if you are blocking a tree down, using the tree next to it as rigging point.
When you take pieces out that are abovr the rigging point, you can ratchet in line as they are falling towards the block.

I don't use the bollard on my GRCS, I wish it was optional, so one didn't have to pay for it, just to have it sitting around.
On the fairly rare occasion that we lower pieces that we feel are to big for the GRCS, we bring out the Hobbs.
Since I don't make a habit of throwing Volvos out of trees, the Hobbs will handle anything.

 

[Bushwackertree]

Wow guys alot of good info and thought, just placed the order and cant wait for it to get here. I'll keep ya posted once I get it and how it works.

 

[Jake Andrews]

Used my first rc-3002 today and thought it was awesome. Really enjoyed it and was a real treat being able to pre tension before cutting. Lowered some pretty large, long stems and was a nice feeling when they swung away from me like planned.
I also believe this particular job saved us a huge amount of time, job was priced for 3 for a day, someone called in sick but we still got it done with two men.
Was this because of the bollard making it easier or was the job over quoted.............open for debate I guess.
What I will say is that it was very easily used with one operator and I think I made around 2/3rds less cuts than using a porty.
Very impressed.
J

 

[CurSedVoyce]

I think you answered your won question... Bigger cuts and better control make the job go smoother and smooth is fast.
Also.. I have noticed when we are short on the crew, everyone there just seems to flow better to make up the difference.
Then again, one less body to communicate to speeds things up as well sometimes.

 

[Oldmilltreecare]

I've had a RC3002 for about four years and we love it. So easy, so much control, never wished i had spent 4x more money on a GRCS and theres no way it will break, ever!