scare with pigtail on GRCS

treebing

Been here much more than a while
Location
Detroit, Mi.
This event occured about a month ago while I was using a newly puchased GRCS. We were in the proccess of removing a large silver maple and on the last phases of butt hitching down the top and stem.

The first mistake that we made was not switching out the GRCS for the aluminum bollard as no raising was neccesary.

Due to the shape of the tree I could not see how many wraps my groundsman was taking. The second mistake was not communicating with him prior to every cut how many wraps etc.

Now, when I chunked over the top and said "let her run" My groundman found that it was easier, naturaly to "let her run" if he used less wraps.

By doing this however he was inadvertantly transferring wieght on to the pigtail. He was probably standing at about a 60 degree angle from the GRCS and about 20 feet away. the rope was passing through the pigtail at this angle as well.

We continued chunking down the stem and consequently with each piece we took, we were loading the pigtail, which is held on by a simple weld and NOT meant to be taking loads of any sort.

The last chunk was fairly large. probably in the vicinity of 300+ pounds. the piece came over, and my groundman had only one wrap because he had been decieved by the friction in the pigtail that there was enough. I still fail to understand how his computer was calculating this one, but ultimately I am to blame for not communicating with him and not making sure all things were in place before making the cut.

What occured thanks to god, did not do any damage to person or property but the pigtail broke and the log flew my groundman into the air. He let it go and the log hit the only small piece of lawn in the vicinity.

We did several things wrong on this project. The number one thing was not communicating prior to every cut what was going on with the GRCS.

Being a new tool, it was a bit different than a small diameter port a wrap which my groundsman had become quite profficient and understanding of. I think he felt the larger diameter bollard required less wraps. During the course of the job, in which we were using a new rope that was quite sticky he found that for fluidities sake less wraps worked better. Through experimenting he discounted the effect that the pigtail had on the friction.

This whole incident also would not have occured if we had placed the aluminum bollard and replaced the winching device. That is what is was there for. We did not I thinkbecause we were on such a roll, and the GRCS was in a location where I was not worried about nailing it with logs. I also liked the ability to get the rope nice and tight before making the cut.

I post this because I want to put out there the danger that the GRCS device has if used improperly. The pigtail can decieve the user into thinking that there is more friction than there actually is. This is something to always be aware of.

Thinking of bad scenarios, my groundsman could have not let go of the rope and been pulled directly under the falling log. The pigtail could have flown off and struck someone. The log could have went through the pavement or through a roof.

The main thing however is to clarify communication throughout the proccess. It is easy to become complacent and assume or trust that your team members are doing the right thing. This is especially important when using a new tool. We had not been working on the same page and were unaware of this until things went wrong.

Anyway, the pigtail was easily welded back on, the job was completed with no damage to anyone or anything (besides the GRCS). And life goes on.

The aluminum bollard from now on will be used in likewise lowering situations where lifting is not required. It runs a lot smoother besides.

Thats all. Lessons learned.
kevin
 
I don't see how the pigtail could add a significant amount of friction.

It's good to hear no injuries or property damage resulted.
 
Wouldn't have happened with a Hobbs!

(Ooh, I just couldn't resist! /forum/images/graemlins/parry.gif /forum/images/graemlins/laughing.gif /forum/images/graemlins/lildevil.gif)

Lesson learned I suppose - luckily no damage to any one or thing.
 
I cant see how the pigtail would make any appreciatable difference, however, if he was at a good enough angle when the pigtail broke, it could cause the wraps to come off the drum.

300lbs isnt much, I would use the winch if it was on there, 300 lbs can be rigged on standard 1/2", plenty of friction potential there on either drum or winch.

I would write it off to being unfamiliar with the equipment and how to use it effectively? Glad noone and nothing was hurt!

I had a similar scare when I first used mine, nearly stuffed a worker up good with a 700lb tip of a limb with brush. Use it as a learning experiance /forum/images/graemlins/grin.gif
 
I'm not clear exactly what happened? The line comes in from the top or side through the fair lead (which can bend when winched or loaded if the line comes in at an angle to it), around the head, and out the pigtail. I think it would be nearly impossible to bend the pigtail if it's set up properly, because it only gets as much force as whoever is holding the end can exert, and your ground dude would have to be pretty huge to bend it. Even if it's not made to really take a big load, it's not that wussy. Maybe it had a bad weld? Maybe I'm totally wrong. I've lowered very heavy and also under-wrapped logs at a pretty good angle off the pigtail. For lowering, we actually go through the first loop of the pigtail only, and bend it out a little, so it is less likely to wrap over itself. May be particular to that unit, though.
 
Did groundie not tail the rope off the winch, through the pigtail and away, perpendicular to the axis of the winch? If so, I could see that a turn of rope might jump off the winch drum leading to less friction even in free running mode. It is surprising how much friction there is in one round turn.

I give you a chuck on the shoulder for taking responsibility for the mishap. Too often blame is shuffled onto undeserving shoulders. Taking the time to post here is a good way to share a close call, thanks!
 
The pig tail on mine is a bit bent but ok. I think the important thing is not to angle the rope through the PG while catching the load. Keep it perpendicular to the bollard, and let the bollard do all the work.

When the load comes near to the ground THEN the groundie can move wherever necessary to maybe catch the load and help direct it to where it needs to go.
 
[ QUOTE ]

It is easy to become complacent and assume or trust that your team members are doing the right thing.

[/ QUOTE ]

Boy, ain't that the truth.
Communication is KEY. Kudos to you for posting this and accepting the blame. Glad no one was injured and property wasn't damaged.
We often have the GRCS and a Port-a-Wrap anchored to the base of the tree just for that reason. After tightening the winch frame to the tree base, the frame is often cocked so we can't remove the winch without loosening the strap.
The GRCS does have a learning curve. The pigtail won't add any additional friction. It's there to keep the rope on the winch or drum. You are fortunate that the rope didn't come off the winch and your groundspeerson had the foresight to let go of the rope.
 
There is a great video of the GRCS & Hobbs tested to destruction on this board:

http://www.treebuzz.com/forum/showflat.php?Cat=0&Number=42912&an=0&page=3#42912

In it, the first thing that goes wrong with the GCRS is the pigtail bends out. They weld it back with stouter steel I belive, and it works better. It appears to be the weak point of the system and judging from the above comments, this fact is not at all obvious and could probably only be discovered through destructive testing.
 
Guys,

in my opinion there is actually a bit of a misunderstanding going on here.

The pig tail is intended to guide the line when using the Harken and only that. It's not load bearing, as the case above illustrates. Jerry and Frans's drop test comparing the GRCS and the Hobbs - a brilliant job they did, too - highlighted various problems with the two devices. The pig tail was not one of them. The parts bent were the top fairleads above the drum. These are essential in keeping the line and the load close to the base plate and by doing so avoiding nose loading of the friction device.

When using the friction bollard the line should be running around the bar on the front of the bollard, as opposed to the pig tails. This is made to withstand such loading and also the lever arm is very short. On the euro version of the GRCS the bollard has been modified (see attachment), by adding a cross bar and curved ends, making the device more versatile and increasing the positions you can assume relative to the bollard when holding the line. Unlike the 90° you have with the straight bar design. Also you can take 1/4 wraps adding even more control when lowering.

So: Pig tails and Harken good, friction bollard and pigtails bad.
 

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Paolo,

unnecessary jibe at the GRCS.

This is not about GRCS vs Hobbs. As Jerry and Frans clearly showed both devices have their Achilles' heel. At the end of the day it all comes down to the way they are used and configured in the system.

So, let's keep this objective and try to avoid over-simplifying the matter.
 
Strange remark mark? /forum/images/graemlins/confused.gif

I don't ever remember slagging off the GRCS? I do realise its limitations as much as the Hobbs though. I used both devices and various other incarnations before most could possibly have in Europe (and of course continue to on a routine basis).

Tree work can be a serious business, but not so serious as not having a sense of humour.

You're coming across a bit too all powerful and scary /forum/images/graemlins/bur2.gif

/forum/images/graemlins/listen.gif (shhh......it was a joke!)
 
Powerful and scary... I doubt it /forum/images/graemlins/bud.gif

Maybe the difficulty of picking up on jokes is one of the limits of this form of comunication methinks, despite Graemlins and all.
 
You guys are too funny! /forum/images/graemlins/fish.gif /forum/images/graemlins/icon1.gif /forum/images/graemlins/icon3.gif /forum/images/graemlins/icon2.gif /forum/images/graemlins/icon320.gif /forum/images/graemlins/trulies.gif /forum/images/graemlins/texy.gif /forum/images/graemlins/windycat.gif

That's some I've never used, until now! /forum/images/graemlins/grin.gif
 
Let me introduce my hired help Claud /forum/images/graemlins/iq.gif

His Hobbies are small animal care and listening to opera /forum/images/graemlins/hisboids.gif

His favourite tasks are dealing with on site complaints and stopping traffic /forum/images/graemlins/shocked.gif - nobody has ever tried to run a stop or got in our way, since he joined the gang.

He's so good at public relations, I gave him the job of hand delivering invoice statements. Late payments are down 80%. /forum/images/graemlins/aaa.gif /forum/images/graemlins/giveup.gif

I'd recommend Claud to any tree gang! /forum/images/graemlins/cool.gif
 

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