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10th January 2011, 04:41 PM
#11
I am he, fear me
Firstly, what a great Post Darren,
I am also a Driver Trainer and Rescue Systems Instructor with the S.E.S. which brings a heap of personal satisfaction which I am sure you get as well doing similar with your Club.
If I may be permitted to make an observation in the interests of accuracy tho. The figures for two snatch blocks IE triple line pull are incorrect. A standard triple line pull provides a 3:1 mechanical advantage not 4:1 reduces the load on the cable to 1/3rd not 1/4.
25 Degrees = Load (2,800kgs) + 45% = 4,060kgs X 300% for mud = 12,180kgs
PLUS the wieght of the Organic mass out the front (About 3m3) and we were up around the 15,000kgs!!
Put in a Snatch block and that is halved to 7,500kgs, and what is the Hi Mount rated at? 3,632kgs!
Should have done a triple line pull...Even a Triple Line pull would be 3,250kgs!,
In that example the "triple line pull" cable load will be 1/3rd or 5,000 Kg's hence the "triple" in the M.A. rig name.
Whilst on the subject... There is one other factor in M.A. rigs for everyone to keep in mind as well, the load on the snatch block is the sum of the loads on the cable so again to use the same example whilst the load on the cable is 5,000 Kg's the load on the strap or shackle securing the snatch blocks to the vehicle and tree (or whatever) is 10,000 Kg's.
Here is a cracking good article on M.A. Rigs and loads to illustrate.
Figure 7 Rig C shows a standard or "triple" line pull 3:1 M.A. rig most people are familiar with and utilise (2 Snatch blocks, 3 anchors)
Figure 8 Rig A shows how to get a 4:1 M.A from only 2 Snatch blocks and 3 anchors with the lowest load on the Shackles and Rigging using a compound rig which would indeed reduce the line load to 3,750 KG but is no longer a "triple pull". This method needs another rope or cable tho for the 2nd 2:1. In my case I carry a length of Dyneema for this and other uses.
http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf
Again, my compliments on a top shelf amount of info. The more we get the info out there and the simpler it is then the safer it is for everyone and hopefuly the tragedies will diminish
Last edited by the evil twin; 10th January 2011 at 07:07 PM.
Dolphins are so smart that within a few weeks of captivity, they can train people to stand on the very edge of the pool and throw them fish.
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The Following 8 Users Say Thank You to the evil twin For This Useful Post:
AB (10th January 2011), Bigrig (10th January 2011), Black Rock (12th April 2012), damianovdd (11th February 2011), Just A Troll (31st October 2015), MudRunnerTD (11th January 2011), rusty_nail (27th January 2012), Waza (15th December 2013)
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10th January 2011 04:41 PM
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10th January 2011, 08:08 PM
#12
Patrol God
You could put a short info night in on the 2012 meet,as an up date on gear and technique
cheers roofy
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The Following 2 Users Say Thank You to Sir Roofy For This Useful Post:
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10th January 2011, 08:11 PM
#13
Banned
Originally Posted by
roofy
You could put a short info night in on the 2012 meet,as an up date on gear and technique
cheers roofy
Not a bad idea to have training sessions of some description if we are going to have some qualified lads and ladettes out there ... nothing too over the top/time consuming, but you get the gist ... good call roofy!!
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10th January 2011, 08:13 PM
#14
Bitumen Burner
Thanks for bumping this thread.
I've been looking for it for days.
Ross
Winner of 'Best 4 x 4 ' at the 2017 Albany Agricultural Society Inc - Town n Country Ute Muster.
Ex Telstra - 2005, 4.2 TDi ute -with pod and more fruit than a grocery shop.
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10th January 2011, 08:41 PM
#15
Administrator
Originally Posted by
roofy
You could put a short info night in on the 2012 meet,as an up date on gear and technique
cheers roofy
That's a great call Roofy, that would make a good night learning more about the fundamentals and facts for sure.
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10th January 2011, 09:21 PM
#16
I am he, fear me
Originally Posted by
AB
That's a great call Roofy, that would make a good night learning more about the fundamentals and facts for sure.
It's amazing how popular things like that are yet how little most of us do them... Our Club put a weekend together 2 yaers ago that had some 4WD trips and fun plus a heap of 1 to 2 hour presentations on the two evenings.
Invited a couple of other Clubs along and the presentations covered things like, Camp Cooking, GPS, Radio Comms, Photography, Local Ranger, etc plus had some Nav Runs, Poker Run etc.
Everyone reckoned it was FAT.
Dolphins are so smart that within a few weeks of captivity, they can train people to stand on the very edge of the pool and throw them fish.
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The Following 2 Users Say Thank You to the evil twin For This Useful Post:
Bigrig (11th January 2011), Woof (10th January 2011)
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10th January 2011, 09:26 PM
#17
Administrator
Especially you too ET, I hope Doggy and Rossco can convince you to come over for the meet up.
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10th January 2011, 10:04 PM
#18
I am he, fear me
Originally Posted by
AB
Especially you too ET, I hope Doggy and Rossco can convince you to come over for the meet up.
Hmm... Well, someone is going to have to go along to recover 'em or they'll never make it across the Nullarbor... Bwaahahaha.
I have LSL in 2012 so me and the missus are heading for Tassie... tentatively via the Great Central, Coober Pedy, Wilpena and coming back via the Great Ocean Road then Streaky Bay etc... I'll post up over in the Forum Meet. thread.
Dolphins are so smart that within a few weeks of captivity, they can train people to stand on the very edge of the pool and throw them fish.
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10th January 2011, 10:05 PM
#19
Administrator
Originally Posted by
the evil twin
Hmm... Well, someone is going to have to go along to recover 'em or they'll never make it across the Nullarbor... Bwaahahaha.
I have LSL in 2012 so me and the missus are heading for Tassie... tentatively via the Great Central, Coober Pedy, Wilpena and coming back via the Great Ocean Road then Streaky Bay etc... I'll post up over in the Forum Meet. thread.
haha, sounds good, might be able to pop in if we ever decide where we are going that is!
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11th January 2011, 10:06 AM
#20
Moderator
Originally Posted by
the evil twin
If I may be permitted to make an observation in the interests of accuracy tho. The figures for two snatch blocks IE triple line pull are incorrect. A standard triple line pull provides a 3:1 mechanical advantage not 4:1 reduces the load on the cable to 1/3rd not 1/4.
25 Degrees = Load (2,800kgs) + 45% = 4,060kgs X 300% for mud = 12,180kgs
PLUS the wieght of the Organic mass out the front (About 3m3) and we were up around the 15,000kgs!!
Put in a Snatch block and that is halved to 7,500kgs, and what is the Hi Mount rated at? 3,632kgs!
Should have done a triple line pull...Even a Triple Line pull would be 3,250kgs!,
In that example the "triple line pull" cable load will be 1/3rd or 5,000 Kg's hence the "triple" in the M.A. rig name.
Whilst on the subject... for everyone to keep in mind as well, the load on the snatch block is the sum of the loads on the cable so again to use the same example whilst the load on the cable is 5,000
Kg's the load on the strap or shackle securing the snatch blocks to the vehicle and tree (or whatever) is 10,000 Kg's.
Figure 7 Rig C shows a standard or "triple" line pull 3:1 M.A. rig most people are familiar with and utilise (2 Snatch blocks, 3 anchors)
Figure 8 Rig A shows how to get a 4:1 M.A from only 2 Snatch blocks and 3 anchors with the lowest load on the Shackles and Rigging using a compound rig which would indeed reduce the line load to 3,750 KG but is no longer a "triple pull". This method needs another rope or cable tho for the 2nd 2:1. In my case I carry a length of Dyneema for this and other uses.
http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf
Again, my compliments on a top shelf amount of info. The more we get the info out there and the simpler it is then the safer it is for everyone and hopefuly the tragedies will diminish
Thanks for the correction Evil, you are correct 3:1 is the outcome.
Nice link mate, i have saved that to my computer, really sorts out the science of it.
http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf
EVERYONE SHOULD READ THE LINK ABOVE.
Its a Nissan! =====> Its a Keeper!! ....... Got a TD42 in it BONUS!!
....... I'm a lucky bugger! I've got 2 of em!
Check out my Toy -->
MudRunnerTD's GQ From the Ground Up
Originally Posted by
Rogue Dung Beetle
Wish it was Nissan though, Toyotas just can't keep up with the Pootrol pace.
The only good thing about an 80 series is..... the front end?? Wrong!!, the Engine?? Wrong!! the Full Time 4WD system?? Wrong!! Its the NissanPatrol.com.au stubby holder fitted over the transfer lever.
WARNING: Towballs used for recoveries can, and do kill people and damage property.
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