"Extreme Rigging"

Re: \"Extreme Rigging\"

3000lbs standing still - probably 20,000lbs with 6ft of fall = WLL 40,000lbs 0n block sling x SF5 (minimum for a sling knotted) = sling tensile 200,000lbs! Which would explain why I see so many mangled 10 tonne blocks.

Then we have to tie it and set it snug to stop it taking off down the trunk, providing it doesn't fuse fail first.

Then we have to cut the face - how do we stop that big chunk from causing damage?

Then we have to wrestle the big fat bull line into place round 4ft of girth. With moss round here in the North West, thats a lot of fricion to overcome!

I'm tired just thinking about it, but the thought of the rigging or tree failing will keep yours eyes open -trust me!

I reckon the lag technique isn't as slow as all that. Especially considering nothing to ring up on the ground. But thats irrelevant, because its easier and safer and controlled. If someone wants to underbid it - great, take some time to sit there with your camera and stop watch
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. Might end up a not so good advert for professional tree work.
 
Re: \"Extreme Rigging\"

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I'd like to see a vid of this

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That makes 3 of us.
I would highly discourage using this method. The forces generated at the lag catching the wood would be phenominal.
 
Re: \"Extreme Rigging\"

[image]http://aolpictures.aol.co.uk/galleries/regcoates1/[/image]

Hello gentlemen, am new to the site but have followed this disscussion with intrest. 12' lag system with steel rods as rollers probably works but just sounds a little weak. Must involve a helluva lot of sawing and time stood on the irons. Personally I use the 'block driver' with 3 foot long/deep notchless pieces which mitigates the momentum (sliding effect as explained by Paolo) but at least allows me to dislodge a decent size sections and make good progress.I put the flip line below the split tail/pulley to further shorten the distance of initial fall, this also allows me to leave some 'edge holding wood'to prevent saw trapping and the tearing effect further slows down the section momentum. You might think oh, the flip line should always be above the split tail! So long as the split tail and not the pulley traps the flip line, your self and equipment come to no harm. Also bails of straw make exellent impact barriers when free falling. Cheap, robust and abundant. Check out the pictures if their viewable, not sure Ive linked them correctly. Keep it simple fellas.
 
Re: \"Extreme Rigging\"

I tried it with some smaller stuff. the lag bolts bent a bit if they weren't all the way into the heart wood in oak. I used a makita battery drill, which ate batteries like nobodys business. a petrol drill would be better.
it is a verasaile system and does work well when you get the hang of it, as clipping the pulley into an eye is infinitely easier than moving a sling around, and the groundies job is really easy.
small (relatively) pieces is the key though. and put in your hooks on the way up!
 
Re: \"Extreme Rigging\"

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OK - Now I'm going to have some fun:

Time consuming compared to what?

What exactly are your safe and controlled options?

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had some lags, had an open area today so we tried it. using a bucket truck.

It was a big silver maple, trunk was 36" at about 35' so we screwed some lags cut 1' pieces as suggested. did it 3 times.

my safe and controlled method is drop crotching using a tenex eye sling and a CMI stainless with a 3/4" stable braid. We knock out 3-4' sections. Using a clove hitch rather than a bowline. ( I am sure I will get knocked for this but I have been doing it this way 4 ever, I trust it)

Final opinion? I am sure there is a learning curve to it, but it did seem time consuming,and I felt uncomfortable with it. I plan on trying it again, maybe it will grow on me, but It wont replace drop crotching in my playbook.
 
Re: \"Extreme Rigging\"

Silver Maple - definitely not my fav tree. Clove hitch is strong, but can roll out. You could try a cow hitch instead. But if one of the loops pops off a short section, you've lost the piece. A half hitch and running bowline is just as strong but more secure in that respect. I'll run the Math on your rigging alternative and see how it shows up. Good news that your lags didn't snap. Who makes them please? what size?

Thanks for taking the effort to try this guys. Like Xman says, clip the line to a lower bolt as well while you're experimenting, just in case.

Using bales is a great alternative to tyres - easy to thrash apart and carry back instead of a truck load of rubber. The wires in the tyres can mark indents into asphalt surfaces. The discs can be left to crash into the bales with the rope and lags attached to stop the rebound. But use shackles here not karabiners. I attach a shackle to the lag, then a krab to the pulley, so it sits side on - less chance of bending.

Good to hear from you Simon. Cordless drills are a waste of time, you need a serious one which isn't much lighter than a petrol one. I use the Stihl - expensive but impressive! Just blasts in. Setting the lags with a proper spinner is also easy. The drill bit should be the same diameter as the lag under the thread for smooth and safe results. Its very important to set the lags to the hilt to reduce levergae. I've got a job for you carving on the channel islands if you fancy a working holiday? Love your signature.

Welcome contract climber, thats a good way to introduce yourself. Thanks for re-posting the pics Kevin. Its doesn't look like you're using lags, sections that small can throw the rope. The technique is for shorter lengths and wider discs than that really.

My main concern is lags snapping. It doesn't take much time to set lags. Having spent so much time talking with Denny Moorhouse on metals, I appreciate there is a big difference between forging processes and metals. Once we've designed something suitable I'll give it a good bashing. Nylon ropes should buffer nicely rather than polyester. Consider nylon for all topping down with the drop distance required; let it run and it won't come into play, mess up and you'll be forgiven.

Care to tell us your alternative Norm? Trees this size over here are normally protected, so they are always on the verge of collapse by the time they have the go ahead to come down - not the situation to start shock loading big pieces. Your comment on 'phenomenal forces makes me think you are mis-understanding the technique
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Re: \"Extreme Rigging\"

if all the lags are put in at one time, i wonder if the dropping slice will bash into some of them, knocking them a little loose for possible pull out when they are used later.

maybe 3 lags should be put in at a time. holes could already be drilled. bag of lags on your belt with a spinner.

i would think lag pull-out would be the failure if any, instead of breaking them. haven't seen them break, just pull out under extreme forces.

jonserbred, cool you tried it so fast.

still don't know if i like this. but what other choice would you have in this rare situation?
 
Re: \"Extreme Rigging\"

2 lags initially, then one at a time would work.

In sherrills catalogue, it states 5/8" lags have a holding capacity of 4,200lbs from a 1936 study.

It was the alloy 5/8" j lag sold by Sherril that snapped. Hardly what it was designed for. But forged steel should cope. Is that what you used jonsered bred?
 
Re: \"Extreme Rigging\"

It sounds like your trying to 'force' this technique to appear feesable. If your discs aren't long enough to safely secure by rope, make them longer. Compensate for the extra weight by making them notchles and push offset from the pulley block' which keeps the rope taught at all times throughout the procedure. 3-400 kg is fine. Attatching ropes and slings to 3 ft long pieces is pretty staight forward as you can lower your half hitches over the top of the section as opposed to trying to flick it round on long pieces when notch cutting, abit like you would with chains when craning timber. Never lost one yet and have done some whoppers over the years U.K, Aus, NZ.

The sherril lag that broke may have been 1 in 100 of a good batch, perhaps you were unlucky with the one but why take that chance anyway with so little to gain?

I'd only consider this method if I was under equipped some how by lets say, not having a strong enough rigging system, the finising cut on a pollard type job (still need a sling and pulley though), being less than 10 feet from the floor with the need to still arrest the section, or not having the ground staff that can move the bigger peices when needed (It would be as easy though to get down and help out, dont mind having a break from the harnness and irons anyway).

Your relying on lags that aren't purpose built, questionable wood integrity and very a limited loading capacity. Sure the system can work but that doesn't make it practical and economical enough to be justified.

My objective as a contract climber is to utulise my skill and experience to make as much money as as possible for whoever has hired me for that particular day. This mind-set helps me to maintain a healthy balance between risk manage ment and actual progress. In other words, the fact that I'm not hired to conduct on-site experiments keeps me realistic and in the right frame of mind to be most effective. Its easy to go off on a tangent in your own time and is something one must be aware of. Sorry if that was all abit long winded.
 
Re: \"Extreme Rigging\"

Just because you don't have a notch and keep the rope taught doesn't mean you aren't incurring dynamic forces; a 3 foot lump still has at least a 3 foot fall distance. The fall is measured from the centre of mass, not where the rope is tied.

A 3 foot long by 4 foot wide piece of hardwood is one helluvva lump with a corresponding helluvva shock load. Say that lump weighs 1,500lbs static = more like 6,000lbs of force = 12,000lbs WLL on pulley sling X SF5 = 60,000lbs tensile, which is a big sling and a 7/8" double braid rigging line @ SF 5:1. Thats an expensive rope to abuse at low safety factors. You're still going to have to ring it all up to get it out. I'd sooner spend the money taking a little more time with a powerful sharp saw and less risk, effort and time with heavy rigging.

Such short lumps = more slinging.

In terms of time, effort and safety, at the end of the day, I'd say the lag technique comes out on top.

You're entitled to your opinion, and I'm sticking to mine.
 
Re: \"Extreme Rigging\"

Give me all the equations you want Laz but it doesn't change the fact that Ive never lost one. My eyes alone tell me that forces do incur but also recognise momentum between notchless(dependant on direction when roped) and notched pieces is different, so less force old mate. Opinion based on experience not ignorance, sincerely. I'm aware its your personal job to pioneer and investigate new methods but there appear to be too many compromises in this one, and the other feedback suggests thats this is not just my opinion alone, no offence. If you have some footage please take the time to display 2-3 'sections' clip, un-edited, sawing included. Dont want to harp on again about time spent sawing in the tree but sawing and dealing with sections on the 'ground' has to be easier and safer, common sense surely! show us or try to attain some footage, after all sometimes seeing is believing, though I'm just not seeing this one at the moment. Good luck all the same
 
Re: \"Extreme Rigging\"

"Give me all the equations you want Laz but it doesn't change the fact that Ive never lost one."

As I've witnessed many times, lack of an accident may only prove luck's hand. Accident prevention is being pro-active. Accident investigators look at the numbers, they don't care how often someone 'got away with it'.

My risk assessment looks at the physics, the ergonomics, the repurcussions. I choose the controls accordingly for long term safety and efficiency for myself, my team, my equipment, my client, the public and surrounding property.- not the expediency of getting just one job done for someone else. I undrstand your position entirely, I contracted out for many years, but only now to those who have the same approach to risk assessment and effective controls as myself.

We obviously aren't both assessing the same long term risks and consequences of our actions.

the lag technique may have drawbacks, but what is certain, is the technique you explain doesn't work safely for the situation explained for the lag technique on 4ft diameter hardwood.

Its natural to resist a challenge to what is held dear. Forget about opinions and look at the numbers. I prefer not to bury my head in the sand - necessity is the mother of invention (not that I invented this technique, i wrote the article years ago for rigging students to grasp limitations of current systems. There were very experienced riggers using this technique before I thought about it).Its interesting that no one has mentioned where this technique really is advantageous.
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Re: \"Extreme Rigging\"

'Accident investigators look at no's they don't care how often someone gets away with it' - I dont 'get away' with anything. I use manipulation and experience to control things.

'I choose controls accordingly for long term safety ect, not the expediency one job done for someone else'- I agree, good one. I treat all jobs the same whether mine or someone elses. Varied exposure though keeps me 'in touch' with the reality of the job ie workers,their strengths/weaknesses, limitations, potential hazards. keeps me out of the comfort zone and on high alert, which hopefully allows me to co-ordinate more effectively.

'Its natural to resist a challange to what is held dear' - a little bit patronizing and inapropriate if aimed in my direction considering you only no about me what I've told you

'Forget about opinions and look at numbers'- Quite happy with my numbers thankyou

'I prefer not to bury my head in the sand' - never said you did, your obviously a tryer and I commend you for it.

'Its interesting that knowone mentioned where the technique really is advantagous' wonder why!

If I ever end up using the technique and it turns out to be a winner I'll hold my hands up and conceed that my instinct/intuition/logic was wrong. I'm 'grown up' enough to do that. However, I think more than likely, the day I start driiling holes on the way up a big tree I'll be laughed and ridiculed off the site and relegated into the 'he's lost the plot' category.

I'm no mathamatician but have just thought of an equation

Drill+lags+reality= fannying about when you should be working. thats a joke laz, just trying to lighten things up abit. emails are interpreted subjecively, I hope that myne are read in the johovial manner of which they are meant, are meant to be constructive not argumentive. Get the footage sorted Laz, whether its your idea or not, your probably the best person to present a viewing of its application. Think Laz and I should bow out now and invite some other opnions. goodnight
 
Re: \"Extreme Rigging\"

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my safe and controlled method is drop crotching using a tenex eye sling and a CMI stainless with a 3/4" stable braid. We knock out 3-4' sections. ...

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Umm...that would be 'butt hitching' or 'blocking' (or, in some parts of the world, 'chogging'), not 'drop-crotching'. 'Drop-crotching' is an older term for 'reducing' which is a type of pruning.

See ISA's "Glossary of Arboricultural Terms".
 
Re: \"Extreme Rigging\"

[ QUOTE ]
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my safe and controlled method is drop crotching using a tenex eye sling and a CMI stainless with a 3/4" stable braid. We knock out 3-4' sections. ...

[/ QUOTE ]


Umm...that would be 'butt hitching' or 'blocking' (or, in some parts of the world, 'chogging'), not 'drop-crotching'. 'Drop-crotching' is an older term for 'reducing' which is a type of pruning.

See ISA's "Glossary of Arboricultural Terms".

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Sorry, we have called it drop crotching for 20 yrs. proper definition or not thats what we know it by.
 
Re: \"Extreme Rigging\"

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It was the alloy 5/8" j lag sold by Sherril that snapped. Hardly what it was designed for. But forged steel should
cope. Is that what you used jonsered bred?

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we used some old lags out of the cabling box, round eye lags and we welded the ends together. Like I said we tried it out in the middle of a back lawn
 
Re: \"Extreme Rigging\"

Today I was tubgrinding and had alot of idle brain time. I was one of the early ones to become a naysayer on both boards regarding your rigging idea's.

Having tried and still not (yet) being a believer, I do have to say the more posts I read that you put out there, the more I realize how well you understand your technique.

If it wasnt for guys like you thinkin, we would still be climbing with axes and handsaws huh??
 
Re: \"Extreme Rigging\"

This is all quite interesting, but frankly it scares the h--- out of me! The only place I have ever heard of, or personaly used lags for, is to lower a large notch (too big to safely toss down). And even then it's a pucker moment.
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