Got my GRCS

[irish93stang]

Been usin it mainly to pull trees on this job in kansas... my question is ... It has safe working load stickers sayin 2000lbs is that for shockloading or pulling? ive got a big elm to pull over and im hoping this will be able to do it... anyone crank over big trees with their GRCS?

 

[tree md]

Dude, Treebot came down here from Lawrence, KS back in 07 to help me with the ice storm here. We used his GRCS to pull over a massive Oak. It was around 36 DBH and sprawled over the house, pool and deck. Treebot trimmed a little weight off of the side that was over the house and pool and we anchored it with my 2 ton dump and pulled it over with the GRCS. The tree was held together with a logging chain at the first fork where it had split from ice.

It is amazing what you can do with the the GRCS.

 

[dieselcutter]

THey will pull amazing things over. Just put a block above the grcs to fairlead it in. Another way to get even more power out of it is anchor the end of your line close to you that will double the power. Not that it's lacking. We've stood blown over trees back up with it, single line. 16-18dbh or so!

 

[treeman82]

I've used mine to pull over big trees, no problem. Just have to keep in mind how much weight you are pulling... small trees, or ones with no lean I'll do with a straight pull. Once the trees start getting larger, or more back weight I'll start putting pulleys into the system.

 

[pdqdl]

There is a very good Youtube video showing a "test-to-destruction" comparison of the GRCS and a Hobbs device. I am pretty sure Beranek narrated the film.

If you can find it, it will give you a real good idea what you can and cannot get away with. They dropped big logs on the devices until they tore them up.

Perhaps someone else can find that video?

 

[pdqdl]

Found it. My mistake, it was not a YouTube video. Now will I be able to post the link?

http://www.#########.info/f7/grcs-vs-hobbs-drop-tests-destruction-1248.html

Nope. type in t r e e w o r l d without the spaces where crossed out by this site, that will get you there.

 

[cory nicols]

With My GRCS, i did a dead lift with a maple log to see just what the straight lifting power is. With no mechancal advantage i could get the log off the ground ( 1,000lbs ) and that was the max. I hope this helps you, this is not the safe working load, just some info on the power output i got.

 

[pdqdl]

Only 1000lbs?

There is supposed to be a 44:1 mech. advantage built into the high power crank. That should translate to easily picking up 1k.

Was the rope slipping on the capstan or was it too hard to turn?

 

[tree md]

I read the specs on it when Treebot brought his down from KS. I was thinking it was like 2200# lift and 4400# pull but I am going on memory of what the bot told me. The documentation should have the specs in there or the DVD that comes with it. I was pretty sure you have twice the pulling capacity as lifting capacity on the thing though.

 

[John Paul Sanborn]

The ratios are meant for yacht use, they are not true output doing what we do. eg 100# in = 4400# out.

I've never did a test on output, but have never really had the need to do a straight pick on a huge log. Everything i do involves applying the force of the winch to a leveraged pick or pull. So the limb may be huge, but I'm cutting it hinged with a tip-tie so it cranks up easy in low gear.

One thing to remember on the 44:1 high gear is that you are cranking like mad to pull a short bit of rope. I'll bull into the low gear as much as possible just to get on with it.

 

[cory nicols]

Yes it is not very often you need to actually straight dead lift something, but seemed to be a popular question and i wanted an answer for myself. Yes you can lift a large branch on an angle with a back notch but any way you slice it the max power i could produce was about 1,000lbs and that was 165lbs of all my weight to turn the handle, and there was no slipping of the rope. Trust me when i say to you it is a great piece of equipment i use it allot but don't let the specs confuse you it will NOT pick up much more than 1,000lbs with the length of the crank handle! Bigger handle... Bigger power. And yes this was in low gear.

 

[pdqdl]

That is very good information. I don't think I get that much straight line pull out of my gas powered capstan rope winch. Quite frankly, I have never hooked to a known weight and lifted it.

How did you weigh your log?

 

[John Paul Sanborn]

Trust me when i say to you it is a great piece of equipment i use it allot but don't let the specs confuse you it will NOT pick up much more than 1,000lbs with the length of the crank handle! Bigger handle... Bigger power. And yes this was in low gear.

Was your lift with a single pulley in the tree?

If i see Greg Good at the WAA convention next week I will have to ask him.

I remember reading a kinesiology paper many moons ago that said that most people can only get around 75% of thier bodyweight into a push/pull. So for a 200# man that is 150# of force...

 

[cory nicols]

Yes the lift was with a single pulley in the tree. As far as the log weight, it was a log i had just lowered, it was quite large so i thought this would be a good time to test the lift power. Once to the ground i tried to lift it back up and it was all i could do to raise it. When we dumped the log at my house later i cut a one foot section from the log which was about seven foot long, i then stood on some scales with the chunk. The chunk weighed about 140 lbs. Hope this helps.

 

[pdqdl]

ONE foot was 140#? Either that was green and heavy, or you were picking up a pretty big diameter chunk.

My home scale wouldn't weigh a 140lb chunk with me holding it.

 

[cory nicols]

It was green... i had just lowered it from the tree, and yes it was heavy. My scales go to 300lbs, and as i said in a previous post i weigh about 165.
When holding the chunk the scale barely read 300lbs and thats the most it will read. The log was Sugar maple.

 

[rogert906]

any comments on a device called a maasdam rope puller? i use one all the time for pulling and they work nice. 9:1 mech advantage. kind of a pain threading it but a nice tool. cost about $45. weighs about 10#

 

[rbtree]

The latest Harken is a B46...

so it is 46-1 mechanical advantage.

I dunno if I agree with Cory. We've had ours since 2004 and done some massive work with it...including hanging whole trees that weigh way over 10,000 pounds....not that the winch ever held all that much, as these would be storm scenarios where we are cutting a hung tree off at the ground and then cutting slabs off the butt....

To be fair to ya, cory, we've never actually known the exact weight we've lifted.

There is a handle that has room for two sets of hands....and there may be one with a longer arm, which would increase the lifting power. I'm sure we've lifted in the neighbor hood of 2000 pounds with it....without using mechanical advantage, which I've never done, but have it in my bag of tricks.

For one thing, lifting is best done with a double braided full spectra core 9/16th line....5/8th might be OK, but there's only room for 4 wraps..... 3/4 is not an option. As I've written about many times, the GRCS and HMWPE full static lines are a match made in heaven..but it has to be a jacketed line. single braid spectra is way too slippery.

 

[John Paul Sanborn]

Good Rigging lost a suite where the users were cranking as two man had a failuer with severe injury. This is the reason they have the 2000# swl stickers. My experaince says that there is a lot of "Jesus factor" in that number.

I do not know what part failed, or the injuries involved, but I do know that substituting the handle will void warentee. I'm sure tht Rog does not care about that, but people should know.

heck even with picking big chunks you can use your hinge to add MA for moving the log. I've rarely ahd to put two men on the crank, and usually that is on a pull where I had to do a lower then desirable tie-in because of decay issues.

On the Massdam question...it is a good cheap tool for doing pulls in backyards and woodlots. I know a number of GRCS owners who have one because in many situations it is impractical, or impossible, to set up The Winch.

One good way to use it is to have two ropes, the long one for tie in and the shorter one conected to a prussick, this allows you to load it without having to manage the overhead line. You can anchor the masdam with a loopie on almost any small tree.

I've dne this where we have pulled several trees over using different anchor points. One guy is setting pull ropes while the others are doing the real work.