Snatch/yarding block differences?

CBs / FRS / GMRS / MARS, radios, stereos, computers, tools, etc. The stuff you use to support wheeling or use of your PW.
Post Reply
User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Snatch/yarding block differences?

Post by Low_Sky » Thu Aug 11, 2016 7:10 pm

Does anyone know if there are any differences in the China-made cast-style, fixed-bail blocks that are available from various sources?

Warn's 33,000 lbs block, $165 (https://amzn.com/B0002Z9SWE)

looks identical to

Smittybilt's 36,000 lbs block, $99 (https://amzn.com/B004XG3KT0)

looks identical to

This painted yarding block, $73 (http://www.westechrigging.com/block-imp ... pin-6.html)

looks identical to

This galvanized yarding block, $53 (http://www.riggingwarehouse.com/default ... tlist=4434)

They all appear to be the same, but I suppose there could be minor differences that aren't readily apparent in pictures (bearings, finish/smoothness of the sheave). As far as I can tell, these are the only blocks rated for our trucks/winches that aren't $$$ professional rigging equipment. The "HD" snatch blocks from the off road companies with flat side plates are rated by ultimate strength, and don't give enough of safety factor to have a place on my truck. I'm looking to put together a recovery kit with two blocks, and I don't want to waste money shipping and returning crappy blocks to/from Alaska.
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Cactus Red
Moderator
Moderator
Posts: 1862
Joined: Sun May 20, 2012 6:43 pm
Location: Chino Valley, AZ.

Re: Snatch/yarding block differences?

Post by Cactus Red » Thu Aug 11, 2016 8:35 pm

I've been using 20K pulleys for years. That's a very decent safety factor for a 15K winch. No point on a pull will exceed the capacity of the winch if rigged properly, and 20K exceeds the strength of the cable in any respect.
I'm just along for the ride...

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Thu Aug 11, 2016 10:07 pm

Cactus Red wrote:I've been using 20K pulleys for years. That's a very decent safety factor for a 15K winch. No point on a pull will exceed the capacity of the winch if rigged properly, and 20K exceeds the strength of the cable in any respect.
Cactus Red, I'm not a rigging or recovery expert, but I am a mechanical engineer with too much time to read and think about this stuff. I'm sure that you have put more feet of cable through 20k pulleys than most anybody, but I just can't get on board with the math.

A block needs to be rated to twice the winch capacity, because a doubled pull (assuming 15,000 lbs for the PW winch getting enough current) can transmit up to 30,000 lbs through the block to the anchor. A safety factor would then need to be applied to that 30,000 lbs maximum pull. The off-road industry doesn't seem to have a standard for how safety/design/fudge factors are applied to recovery gear, but it appears that ARB and Warn use approximately 2.0 SF. In the case of Warn's "33,000 lbs" block, it's clearly a 6.5T WLL yarding block (it's actually cast into the housing).

6.5T * 2000 (lbs/T) * 5.0 SF (rigging industry standard) = 65,000 lbs ultimate rating

65,000 lbs / 2.0 SF = 32,500 lbs (Warn's rating, I wonder if it's a coincidence that they re-brand and sell a block rated to a doubled pull from their strongest winch?)

Granted, a rig will never see the winch's maximum pull unless the load is so badly stuck that the winch motor stalls out with the winch line paid out to the last layer, but I believe the recovery gear should still be rated for that worst case scenario.

As a hypothetical worst-case recovery scenario, an 8000 lbs PW mired up to the frame (3.0 resistance factor), pulling up a 45-degree slope (0.75 resistance factor) needs a 30,000 lbs pull to get out (or so says the Army's recovery field manual).

(3.0 + 0.75) * 8,000 lbs Loaded Weight = 30,000 lbs Pull

*EDIT* I corrected "last wrap" to "last layer". Pulling from the last wrap makes for a very bad day!
Attachments
Winching.JPG
Last edited by Low_Sky on Fri Aug 12, 2016 1:41 am, edited 1 time in total.
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Cactus Red
Moderator
Moderator
Posts: 1862
Joined: Sun May 20, 2012 6:43 pm
Location: Chino Valley, AZ.

Re: Snatch/yarding block differences?

Post by Cactus Red » Thu Aug 11, 2016 11:10 pm

Again, the load can't exceed the rating of the winch at any attachment point. The physics are straight forward. You do get a theoretical 30K of load, but it"s split between two points, the pulley and the anchor point. That's just the way it works. Here's some mathematics that show it better than I can explain it.

http://www.engineeringtoolbox.com/pulleys-d_1297.html

Socialism: A stage of society in Marxist theory transitional between capitalism and communism and distinguished by unequal distribution of goods and pay according to work done.
I'm just along for the ride...

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Thu Aug 11, 2016 11:15 pm

Take a closer look at the page you posted, under the "moveable pulley" header ;)


Sent from my iPhone using Tapatalk
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Thu Aug 11, 2016 11:24 pm

Cactus Red wrote:Again, the load can't exceed the rating of the winch at any attachment point.
If this is true, then crane companies have been wasting money on all those expensive blocks and way too much wire rope.
ImageUploadedByTapatalk1470972246.835648.jpg

Sent from my iPhone using Tapatalk
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Cactus Red
Moderator
Moderator
Posts: 1862
Joined: Sun May 20, 2012 6:43 pm
Location: Chino Valley, AZ.

Re: Snatch/yarding block differences?

Post by Cactus Red » Thu Aug 11, 2016 11:58 pm

So, the load on each line is no more than the rating of the winch pulling in the cable, but the load at the moving hook is higher. In our case, the pulley is fixed to a tree or PulPal. The moving load is the truck itself with only one point fixed as it were.

Socialism: A stage of society in Marxist theory transitional between capitalism and communism and distinguished by unequal distribution of goods and pay according to work done.
I'm just along for the ride...

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Fri Aug 12, 2016 1:29 am

Try thinking about it as if nothing is moving. Imagine that the truck is fixed too, and is just using the winch to exert tension on a static rig. I'm bored tonight, so I drew pictures :D

Anchors are black dots, Power Wagons are blue dots, and single blocks are red dots. The winch exerts W pounds of tension. For easy math, all winch lines are parallel except for the last example. No friction from the blocks.

1. The first diagram is a straight pull. The Power Wagon is experiencing a pull of W, and the anchor is experiencing an equal and opposite pull of W.

2. The second diagram is also a straight pull. This is the scenario that people sometimes "think" gives them a double advantage, but does not. The only benefit to this rig would be to get line off the drum to get down to the last wrap. The Power Wagon is experiencing a pull of W, the anchor right next to it is also experiencing a pull of W in the same direction, and the anchor with the tree strap and block is experiencing an equal and opposite pull of 2W to keep the system in equilibrium.

3. The third diagram is a double pull. The winch line goes through the block, and back to a tow hook on the Power Wagon. Two connections to the winch line means the Power Wagon experiences a pull of 2W. The anchor experiences an equal and opposite pull of 2W.

4. The fourth diagram is a redirected single pull. The placement of the anchors just happened to work out for really easy math. Lucky me! The Power Wagon experiences a pull of W. The right anchor, connected to a single leg of the winch line also experiences a pull of W. The anchor connected to the block is connected to two legs of winch line at 45-degree angles and feels a pull of 1.4W. The higher the angle between the two winch line legs, the less pull the block anchor would feel. The lower the angle between the two legs, the more pull the block anchor would feel. If the angle between the two legs was zero, we'd be back at scenario 2. If the angle was 180, we'd be back at scenario 1.

In every scenario except #1, the block, tree strap and shackles between the two need to be rated for more than the winch rating. You get more rating out of your tree savers if you rig them with a basket hitch versus a choker hitch. I won't even get started on rigging for triple pulls, especially since that would be done using more hardware rated for double pulls. No need to go shopping for 1" shackles :)
Attachments
winching.PNG
Last edited by Low_Sky on Fri Aug 12, 2016 2:02 am, edited 1 time in total.
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Fri Aug 12, 2016 1:30 am

And if anybody knows anything about yarding block quality, or where to get the cheapest 6.5T WLL yarding block if they're all the same, I'd love to hear about that too!
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

Colibri
1000_Posts
1000_Posts
Posts: 1611
Joined: Mon Jun 08, 2015 5:44 pm
Model Year: 2009

Re: Snatch/yarding block differences?

Post by Colibri » Fri Aug 12, 2016 9:18 am

Not necessarily the cheapest, but certainly competitively priced, and very good quality and customer service

http://www.awdirect.com/snatch-blocks-and-accessories/

Been using them for years for commercial quality rigging equipment and other hard to find stuff.
Central Texas and Houston area
2009 5.7 auto quadcab
Carli 3” coils deaver leafs 3” kings with 4 tube bypass rear and fr/rr hydro bumps
Howe steering pump and gear with hydraulic ram assist
Custom tube bumpers and white knuckle sliders
Creative fab trussed axle. rem polished and cryoed 5.13 gears with arb lockers fr/rr
Sharadon stage 2 545rfe with 3000 stall edge converter
Lots of other stuff lol

Ducky's Dad
1000_Posts
1000_Posts
Posts: 1469
Joined: Thu May 24, 2012 10:55 pm

Re: Snatch/yarding block differences?

Post by Ducky's Dad » Fri Aug 12, 2016 11:16 am

No need to go shopping for 1" shackles :)
Interesting. I was just shopping for 1" shackles before I read this post. Since I now have a Pull-Pal RW14000, I was planning to hang a 1" shackle on it and just leave it there rather than packing with the other recovery gear.

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Fri Aug 12, 2016 11:47 am

I'll be getting 7/8" 6.5T WLL shackles when I finally pull the trigger on building a recovery gear kit. If you never intend to rig a triple pull or don't think the pull pal or ground would stand up to a 45,000 lbs triple pull, a 1" shackle would be overkill. A 1" shackle also has a 1-1/8" pin, how big is the shackle pin hole at the end of your pull pal?
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Cactus Red
Moderator
Moderator
Posts: 1862
Joined: Sun May 20, 2012 6:43 pm
Location: Chino Valley, AZ.

Re: Snatch/yarding block differences?

Post by Cactus Red » Fri Aug 12, 2016 8:37 pm

This is my kit. All three pulley's are 20K rated, the shackles are (5) 3/4" and (3) 7/8", all rated at 6.5T. Don't over think it - these have done multiple double line pulls, dozens of single line pulls, and many redirected pulls. The snatch blocks are: Smitty Built 20K, ARB 9000 20K, Warn 88899 20K. If I'm going to load the system really heavy, the ARB is my #1 choice. Two ARB tree savers, one WinchLine.com 50' extension, one 10' rigging strap, two rope bones, one ARB 3" x 30 tow strap, and a couple safety vests. If we know we're heading into really bad conditions, I take the gear out of the JKUR which doubles what's shown here.
Attachments
IMG_20160812_135553479.jpg
I'm just along for the ride...

Ducky's Dad
1000_Posts
1000_Posts
Posts: 1469
Joined: Thu May 24, 2012 10:55 pm

Re: Snatch/yarding block differences?

Post by Ducky's Dad » Fri Aug 12, 2016 8:41 pm

A 1" shackle also has a 1-1/8" pin, how big is the shackle pin hole at the end of your pull pal?
Good point. The hole in the RW14000 is 1-1/8", but I thought it was larger until I went out and measured it.

User avatar
nts007
2000_Posts
2000_Posts
Posts: 2287
Joined: Wed Dec 11, 2013 10:01 pm
Model Year: 2008
Location: Sask, Canada, Earth

Re: Snatch/yarding block differences?

Post by nts007 » Fri Aug 12, 2016 10:35 pm

Low_Sky wrote:I'll be getting 7/8" 6.5T WLL shackles when I finally pull the trigger on building a recovery gear kit. If you never intend to rig a triple pull or don't think the pull pal or ground would stand up to a 45,000 lbs triple pull, a 1" shackle would be overkill. A 1" shackle also has a 1-1/8" pin, how big is the shackle pin hole at the end of your pull pal?
Keep in mind because even though you've created this amount of pull force you will still only pull as much as you need to get unstuck. A single snatch lock will cut the load on the winch by half. That's more the point not increasing the pull force. If 12k lbs isn't pulling you out then 24k is just gonna break things. For example if your axles are so buried that it takes more than the 12k winch you're likely gonna bend your control arms or something else. Not saying that increasing the pull with a snatch is bad but a person needs to have good knowledge of the situation. I know most of you guys aren't dumb enough pull your truck apart but you know what I mean. Part of the reason the cranes use a multi block system is to allow more force with a lighter hydraulic motor. But keep in mind every loop doubles the amount of cable on the drum. If they had an unlimited amount of winch power they could do it with a single line because the total weight the boom can handle doesn't increase just because there are more snatch loops.

I always wanted to hang my old PW on a big aframe by its winch. Woulda been awesome. Just not sure how well the fluids woulda liked that lol
08 ctd--mini max--thuren 3" coils and LT Leaves--4.56 gears and lockers in pw axles--some lights--afe intake system--bd super b turbo--Banks w/m Injection--Dynatrac Balljoints--king 2.5"s--37" Hankook Dynapro MT--DOR Long arms--Custom emf track bar--Manual T-case swap--Full PW Under armor--PSC Hydro Assist and so much more

Colibri
1000_Posts
1000_Posts
Posts: 1611
Joined: Mon Jun 08, 2015 5:44 pm
Model Year: 2009

Re: Snatch/yarding block differences?

Post by Colibri » Fri Aug 12, 2016 10:51 pm

I would pay to see that shit lol. It would be epic
Central Texas and Houston area
2009 5.7 auto quadcab
Carli 3” coils deaver leafs 3” kings with 4 tube bypass rear and fr/rr hydro bumps
Howe steering pump and gear with hydraulic ram assist
Custom tube bumpers and white knuckle sliders
Creative fab trussed axle. rem polished and cryoed 5.13 gears with arb lockers fr/rr
Sharadon stage 2 545rfe with 3000 stall edge converter
Lots of other stuff lol

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Fri Aug 12, 2016 11:39 pm

If you look hard enough you can find videos of people dumb enough to do this on YouTube, usually with jeeps. Getting the jeep in the air is the easy part. Getting it down is harder because almost any way you do it the jeep wants to come down on its roof.




Sent from my iPhone using Tapatalk
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Low_Sky
500_Posts
500_Posts
Posts: 797
Joined: Fri May 01, 2015 7:12 pm
Model Year: 2015
Location: Eagle River, Alaska

Re: Snatch/yarding block differences?

Post by Low_Sky » Sat Aug 13, 2016 1:50 am

https://youtu.be/YD5uAJPKasI

This is part one of a two-parter. It's not worth watching the whole thing. Just skip ahead a few minutes at a time and you'll get the gist of it :)


Sent from my iPhone using Tapatalk
John
Alaska
2015 PW on 2.5" Thuren Kings
My build thread

User avatar
Bill2014
1000_Posts
1000_Posts
Posts: 1027
Joined: Fri May 09, 2014 9:03 pm
Model Year: 2014
Location: Northern NY

Re: Snatch/yarding block differences?

Post by Bill2014 » Wed Oct 19, 2016 8:08 pm

Low_Sky wrote:https://youtu.be/YD5uAJPKasI

This is part one of a two-parter. It's not worth watching the whole thing. Just skip ahead a few minutes at a time and you'll get the gist of it :)


Sent from my iPhone using Tapatalk
I knew what was going to happen before they even activated the winch - one way trip
2014 Power Wagon Laramie
Titan V5 2.5" Receiver Pintle Hook
Warn wireless winch controller
.188" DOM White Knuckle Rock Sliders
Locker Bypass & Nanny Kill Switch

Moab 2006

User avatar
Reloaderguy
2000_Posts
2000_Posts
Posts: 2067
Joined: Tue Feb 09, 2016 8:06 am
Model Year: 2016
Location: Central Oregon

Re: Snatch/yarding block differences?

Post by Reloaderguy » Fri Oct 21, 2016 3:33 pm

Low_Sky wrote:https://youtu.be/YD5uAJPKasI

This is part one of a two-parter. It's not worth watching the whole thing. Just skip ahead a few minutes at a time and you'll get the gist of it :)


Sent from my iPhone using Tapatalk
Image
Best Year Power Wagon

Hammerballs
50_Posts
50_Posts
Posts: 129
Joined: Mon Dec 19, 2016 5:30 pm

Re: Snatch/yarding block differences?

Post by Hammerballs » Thu Jul 19, 2018 12:51 pm

I'd like to bring up an oldie here as I'm looking for a snatch block to add to my recovery gear. I'm looking at this guy:

Ranger 6" Bail Snatch Block Hoist Rigging Shackle Pulley with Grease Fitting by Ultranger (Max 16 Tons 36,000 LBs) https://www.amazon.com/dp/B072JPFG9R/re ... uBbR7MFCES

What I am not understanding is if the block is going to have double+ the trucks weight on it in a double pull configuration (16,000lb+), how can we use a snatch block with a WLL of 13,200lbs (6 tons)? This block is similar to the biggest Warn and ARB blocks. Get that the blocks max rated over double our winches max capacity but I thought your WLL should be what maches your pulling capacity.

Thanks for the help.

Sent from my Moto G (5) Plus using Tapatalk


TwinStick
2000_Posts
2000_Posts
Posts: 4148
Joined: Mon May 28, 2012 7:58 pm
Model Year: 2008

Re: Snatch/yarding block differences?

Post by TwinStick » Sat Jul 21, 2018 4:52 pm

Cactus Red wrote:
Thu Aug 11, 2016 11:10 pm
Again, the load can't exceed the rating of the winch at any attachment point. The physics are straight forward. You do get a theoretical 30K of load, but it"s split between two points, the pulley and the anchor point. That's just the way it works. Here's some mathematics that show it better than I can explain it.

http://www.engineeringtoolbox.com/pulleys-d_1297.html

Socialism: A stage of society in Marxist theory transitional between capitalism and communism and distinguished by unequal distribution of goods and pay according to work done.

Meaning: if you are pulling a 30,000lb load with a 15k winch & using 1 snatch block, then 15k at each point not 30k at 1 point. It is distributed by the snatch block. Exception being the attachment point.
In WNY State. 2008 Red QC PW G56. No lift yet, stock size tires. It pulls an 18' 2016 Starcraft AR One Extreme, 3500 lbs.
Load Pro 35 helper springs. 2015 A.R.E. MX Series custom cap. PCP front diff cover protector. Mag-Hytec 6 qt rear diff cover. K&N replacement air filter only. Dual grounded throttle body. Winch TPC bypass. Fab Four rear bumper. DURA BAK lined rocker protection. And a bunch of new front end stuff.

G-56 Gear ratios: 1st) 6.29:1 2nd) 3.48:1 3rd) 2.10:1 4th) 1.38:1 5th) 1.0:1 6th) 0.79:1 Rev 6.29:1 --- = 78.01613:1 Crawl Ratio
-------------------------5.94:1--------3.28:1-------1.98:1-------1.31:1-------1.0:1-------0.74:1-----5.42:1 ---- = 73.675:1
545RFE----------------3.0:1---------1.67:1--------1.0:1--------0.75:1-------0.67:1------------------3.0:1 -------=37.21:1

2013+ 32.47 crawl ratio...............Can you see the trend ??????????????

TwinStick
2000_Posts
2000_Posts
Posts: 4148
Joined: Mon May 28, 2012 7:58 pm
Model Year: 2008

Re: Snatch/yarding block differences?

Post by TwinStick » Sat Jul 21, 2018 4:56 pm

I have used my 2-20,000lb snatch blocks from Tractor Supply with no issues. I have made some heavy ass pulls too. Take em apart, clean & regrease em every few years too. Made in China. :roll:
In WNY State. 2008 Red QC PW G56. No lift yet, stock size tires. It pulls an 18' 2016 Starcraft AR One Extreme, 3500 lbs.
Load Pro 35 helper springs. 2015 A.R.E. MX Series custom cap. PCP front diff cover protector. Mag-Hytec 6 qt rear diff cover. K&N replacement air filter only. Dual grounded throttle body. Winch TPC bypass. Fab Four rear bumper. DURA BAK lined rocker protection. And a bunch of new front end stuff.

G-56 Gear ratios: 1st) 6.29:1 2nd) 3.48:1 3rd) 2.10:1 4th) 1.38:1 5th) 1.0:1 6th) 0.79:1 Rev 6.29:1 --- = 78.01613:1 Crawl Ratio
-------------------------5.94:1--------3.28:1-------1.98:1-------1.31:1-------1.0:1-------0.74:1-----5.42:1 ---- = 73.675:1
545RFE----------------3.0:1---------1.67:1--------1.0:1--------0.75:1-------0.67:1------------------3.0:1 -------=37.21:1

2013+ 32.47 crawl ratio...............Can you see the trend ??????????????

Hammerballs
50_Posts
50_Posts
Posts: 129
Joined: Mon Dec 19, 2016 5:30 pm

Re: Snatch/yarding block differences?

Post by Hammerballs » Fri Aug 03, 2018 1:46 am

I ended up buying the big ARB snatch block. I like knowing I have the right gear for the job if a situation arises. Thanks for the help here guys.

Sent from my Moto G (5) Plus using Tapatalk


Post Reply