A couple of questions about the Port-a-wrap

[tree md]

I am looking over the port-a-wraps in a couple of catalogs and notice that the WLL is only 2000# on the large model. I'm not sure I would be too comfortable using a porty when I'm blocking down big wood. I don't normally block 2000# chunks when I am butt hitching and it produces some shock but I have before and I will tip tie large pieces, over 2000 pounds often when lowering big chunks. If I am butt hitching a 1500# piece and it drops 1 foot I am looking at 3000#. That's a thousand over what the porty is rated for. I block 1500# chunks all day long. I know that that is not breaking strength but I'd still be going over the recommended WLL. Don't get me wrong, I can see where the porty would be a huge advantage in a lot of situations but I'm not sure it would be the best option for blocking big chunks down?

Also, The mini port-a-wrap looks like it would be really slick to use in the tree. I will often take a wrap up top to control the load from above while the guys on the ground maneuver the limb where it needs to go or cut it up as I lower it. Anyone ever use the mini in the tree or would it be more trouble than it's worth to set up topside?

 

[tree MDS]

I think they are made to work with 3/4" max diam rope max, wich is (DB) rated @ 19500 or 2150 (I think, close enough) depending on wich DB you chose, SWL is about ten percent of that, so you should be fine.

A couple of months ago I took an elm log (from the bucket) that was like 36" x 8' or better - one of the bigger pieces that I remember - and had no problems other than the timber hitches sliding up a bit more than usual. Probabaly a little big that one was, lol.

The pieces you took in mary rotten crotch (risky oak, bad tree) would not be any problem for a large porty. I've been using them for probably 8 years or better now - and yes I've been known to go large. You will love it

 

[TreeClimber57]

Go for it, don't like to admit it publicly, but my porti has had over WLL on it a few times I think.. the only thing you notice is a bit of rope strain. The porti never flinches.

 

[Mikecutstrees]

I am looking over the port-a-wraps in a couple of catalogs and notice that the WLL is only 2000# on the large model. I'm not sure I would be too comfortable using a porty when I'm blocking down big wood. I don't normally block 2000# chunks when I am butt hitching and it produces some shock but I have before and I will tip tie large pieces, over 2000 pounds often when lowering big chunks. If I am butt hitching a 1500# piece and it drops 1 foot I am looking at 3000#. That's a thousand over what the porty is rated for. I block 1500# chunks all day long. I know that that is not breaking strength but I'd still be going over the recommended WLL. Don't get me wrong, I can see where the porty would be a huge advantage in a lot of situations but I'm not sure it would be the best option for blocking big chunks down?

Also, The mini port-a-wrap looks like it would be really slick to use in the tree. I will often take a wrap up top to control the load from above while the guys on the ground maneuver the limb where it needs to go or cut it up as I lower it. Anyone ever use the mini in the tree or would it be more trouble than it's worth to set up topside?

It's a 2,000lb WLL so you can drop a 2,000 lb piece into it and it will be fine. WLL is rated usually at 10% of the breaking strength. So it probably has a 20,000lb breaking strength. I wouldn't snub off a 2,000 lb piece that fell 20 ft though. A 2,000 lb piece tip tied should be no big deal. The sling or rope will probably be the weak link in the system though..... Mike

 

[John464]

you will be fine. have 2 small and 4 large porty. hardly use the small unless we are running two lowering lines at once, the small porty will get the secondary line, which is usually on there as a stop line, or a spider leg rig. the large porty is what you want to use for most 3/4" and 1/2" applications. use ours everyday

I saw that pic of your guy wrapping around a tree, that man is slowing you up bud. Get a porty pronto!

 

[pdqdl]

Ignoring the working load for just a moment, I think the loops of a large port-a-wrap are made with 3/4" high strength steel? And then that strength is doubled for both sides of the loop?

On just that basis alone, you can bet that port-a-wrap is much stronger than the 3/4" rope you are tying to.

I have never heard of a port-a-wrap failure; has anyone else EVER hurt one with a rope?

 

[StihlRockin']

I don't often push the limits of the WLL, but have no problems going over it because I often think these measurements are brought up on the merits of liability than real world circumstances. Like always, use good judgment and prior experience dictate what you think is best.

StihlRockin'

 

[outofmytree]

I usually don't rope down big blocks I prefer to bomb them onto bags. In the rare cases where that is too risky my crew are slick enough to allow the rope to run and limit shock loading. One of the precautions they take is to wear a pair of welding gauntlets to prevent friction burns where lighter gloves might tear.

 

[tree md]

I have never seen a porty fail either. I have seen the sling jerked up the tree a little bit. My guess is the sling or knot in the sling and/or rope would be the weak spot. I just wonder how real world these WLL's that some of this stuff is rated at is. My block is rated at 5000# and I know I have put more on it than that. I will try to use a natural crotch when I am hanging a large fork to another or I am hanging a whole tree and cutting it from the bottom as I lower it because I don't like to exceed the WLL on the block but I know it can handle it in most cases. I know the porty can withstand more than 2000# because I have seen it and anyone who has blocked down a 1500 pounder with a butt hitch has likely seen it as well. I guess there is a reason for the 10:1 safety margin but I really don't think that most people use it as gospel in real world applications.

Anyway, thanks for all the input. I am planning on buying a port-a-wrap later this week.

 

[Raymond]

I'm about to make a port-a-wrap purchase soon myself.
Maybe not this week but soon.

Last time I was looking at'em, I was looking for a little booklet
of instructions or something to go with it...NOTHING.
But yet you can find directions on a box of cereal..Go Figure!

 

[Treetom]

tree md, i run the big porty with 9/16" bull rope with great success with some big tops. but when shock loading heavy trunk sections i opt for the hobbs and a 3/4" stable braid: these are chunks i'd normally crane down if i could reach them. often i've wanted a mini up in the tree for the same reason you described. just bought one along with a whoopie. haven't used it yet but it will offer great versatility over braking the rope by wrapping around a short limb or nub.

 

[tree md]

tree md, i run the big porty with 9/16" bull rope with great success with some big tops. but when shock loading heavy trunk sections i opt for the hobbs and a 3/4" stable braid: these are chunks i'd normally crane down if i could reach them. often i've wanted a mini up in the tree for the same reason you described. just bought one along with a whoopie. haven't used it yet but it will offer great versatility over braking the rope by wrapping around a short limb or nub.

Yeah, I really want a GRCS and plan to get one this year (if the market ever picks back up). The GRCS or Hobbs is really where it's at as far as large removals go. I am thinking I will go with a porty and a couple of fiddle blocks until I can afford one. Let me know how that mini works out for you in the tree. Looks like it would be really slick.

 

[Treetom]

Yeah, I really want a GRCS and plan to get one this year (if the market ever picks back up). The GRCS or Hobbs is really where it's at as far as large removals go. I am thinking I will go with a porty and a couple of fiddle blocks until I can afford one. Let me know how that mini works out for you in the tree. Looks like it would be really slick.

i've used the big porty in the tree and it works great, just a bit of overkill for most jobs. the mini will be quicker and slicker.

 

[outofmytree]

I'm about to make a port-a-wrap purchase soon myself.
Maybe not this week but soon.

Last time I was looking at'em, I was looking for a little booklet
of instructions or something to go with it...NOTHING.
But yet you can find directions on a box of cereal..Go Figure!

Look inside the barrel.

 

[Raymond]

Look inside the barrel.

REALLY? So it's rolled up and put where it wouldn't get lost?

I knew I could look it up and all but always thought it was weird, they could charge some silly money
for something that didn't cost #### to make and at less come up with a couple pics and instructions.

Maybe even on a laminated card, hanging off one corner out of the way. :monkey:

 

[Bigus Termitius]

I busted a medium sized porty last summer "experimenting" with a rather large Hackberry. The guy next door welded it up and we moved on to a conclusion. A couple actually.

~Just because the guy who made it said that it has held half of hell, doesn't mean it actually will. That's an expression.

~A good ground guy can be worth his weight in gold.

~Communication. Communication. Communication. If you can't get that with your goundie, get a new one.

~Don't experiment(esp. not on main street)...know what you are doing. An idea doesn't cut it...you have to know. Plenty of info available.

~Know how much that piece weighs.

~Keep shock loading to a minimum.

~Always inspect your equipment.

~Do not paint a used homemade porty for visability on backwoods ROWs. (We found where it had been cracked a bit for a while.)

~Buy factory made Porties.(Also worth their weight in gold) And go large.

~Overkill can be a good thing.

That's more than a couple.

Nothing was damaged save the porty, thankfully.

Here are some instructions I take with me in my field books.

http://www.wesspur.com/Info/portawrap-instructions.html

 

[TheTreeSpyder]

Also, look at factors that reduce the impacting load to the Porty; like the length and the elasticity of the line, running to a snubbing out of force, frictions etc. To reduce shocking, can also leverage over load on hinge (into wide face) slower and farther before line takes loading. this can be by jacking up with wedge or prybar(preferrign semi trailier tire spoon as short lever that fits in kerfing and doesn't bend) from behind or pulling over with rope on front, this forces a stronger hinge, by placing more force on it to fold earlier/thicker. Must realize that vertical loads have about no cosine force on them, so they force weakest hinge; that they then fall farther on; giving more force potential and less hinge strength to control. So the idea would be (if the mount could take the slower, outward reaching loading) to pivot load on hinge/ working it earlier, rather than line. If it is slow enough to seem hydraillically smooth and buffered, loading will be less on line,then less transmitted on to Porty.

More force from a 2000 load in impact of drop, impact of stop, short, static line vs. soft impact, graduated stop, long line, elastic line etc. Also realize to use lines in their range of elasticity. A 2000 load will have more impact force on a 32,000 test line than a same manufacture and material 20,000 test line; thus the Porty will take more shock from the 32,000 because it is more static to the loading. for as the SWL goes up, the elastic response goes down!

One place to tweak more elastic length into line is the point between block and first hitch on load. Note the Center of Gravity doesn't change; by where that hitch is placed, only the length of line that takes initial hit- before the friction of block reduces any of the hit/impact to rest of line. So this short leg of line, has the least elastic length to buffer impacting, but the fullest (other than the 2xPotential of the block position) raw force loading. Of curse you can take this too far to where it means it's own paradigm/inversion of theory (kinda throwing forces to the opposite side of the yin-yang) so keep first hitching before the CG of the load, so load doesn't flip to correct. But, still watch for loads that are wider than tall, short/stubbies, that i think line should be bedded or dogged at imperfections or small humboldts maid for same. i think in terms of these having more flip leverage, because being wider than tall gives less leverage from htich to CG (to pull straight) than leverage from side to CG); orrrrrrrrrrrrr sumetin like'dat!

 

[bonker81]

It's a 2,000lb WLL so you can drop a 2,000 lb piece into it and it will be fine. WLL is rated usually at 10% of the breaking strength. So it probably has a 20,000lb breaking strength. I wouldn't snub off a 2,000 lb piece that fell 20 ft though. A 2,000 lb piece tip tied should be no big deal. The sling or rope will probably be the weak link in the system though..... Mike

Per OSHA overhead rigging is designed to a 5 to 1 safety factor which would be 20% of breaking strength. I'm not sure if portys fit this description, I don't see why they wouldn't, so be careful.

If you need something bigger try consulting a local structural engineer to have him design something similar. It would be a fairly easy design for any professional engineer. Although now you have to consider the capacity of the timber you're securing to.

 

[squad143]

As per the mini. I occasionally take one up for use with a speedline system when I have to control the descent of large pieces.

 

[tree md]

Also, look at factors that reduce the impacting load to the Porty; like the length and the elasticity of the line, running to a snubbing out of force, frictions etc. To reduce shocking, can also leverage over load on hinge (into wide face) slower and farther before line takes loading. this can be by jacking up with wedge or prybar(preferrign semi trailier tire spoon as short lever that fits in kerfing and doesn't bend) from behind or pulling over with rope on front, this forces a stronger hinge, by placing more force on it to fold earlier/thicker. Must realize that vertical loads have about no cosine force on them, so they force weakest hinge; that they then fall farther on; giving more force potential and less hinge strength to control. So the idea would be (if the mount could take the slower, outward reaching loading) to pivot load on hinge/ working it earlier, rather than line. If it is slow enough to seem hydraillically smooth and buffered, loading will be less on line,then less transmitted on to Porty.

More force from a 2000 load in impact of drop, impact of stop, short, static line vs. soft impact, graduated stop, long line, elastic line etc. Also realize to use lines in their range of elasticity. A 2000 load will have more impact force on a 32,000 test line than a same manufacture and material 20,000 test line; thus the Porty will take more shock from the 32,000 because it is more static to the loading. for as the SWL goes up, the elastic response goes down!

One place to tweak more elastic length into line is the point between block and first hitch on load. Note the Center of Gravity doesn't change; by where that hitch is placed, only the length of line that takes initial hit- before the friction of block reduces any of the hit/impact to rest of line. So this short leg of line, has the least elastic length to buffer impacting, but the fullest (other than the 2xPotential of the block position) raw force loading. Of curse you can take this too far to where it means it's own paradigm/inversion of theory (kinda throwing forces to the opposite side of the yin-yang) so keep first hitching before the CG of the load, so load doesn't flip to correct. But, still watch for loads that are wider than tall, short/stubbies, that i think line should be bedded or dogged at imperfections or small humboldts maid for same. i think in terms of these having more flip leverage, because being wider than tall gives less leverage from htich to CG (to pull straight) than leverage from side to CG); orrrrrrrrrrrrr sumetin like'dat!

This is why I am a big fan of tip tying larger pieces and lowering from a high rigging point. Tip tying naturally lends itself to cutting bigger pieces because you have to get low enough on your cut to make the chunk butt heavy. On spar pieces, the heaviest pieces are at the lowest points and allow you to use the rope's elasticity when you rig from a high fork or another tree. The elasticity of the rope absorbs much of the shock when rigged from a high point. I think it is much safer and less shock (less weight overall) than butt hitching much smaller pieces.