Fiddle Block

[Climber020]

Well I just recieved my fiddle block from Sherril and was a little worried about the no locking Kong carabiners that come with it. They are rated at 22 kN which I would guess is somewhere around 4,700 lbs breaking strength. Now the tensile on the fiddle block is 10,000 lbs.
I normally will not rig anything just from habit without at least a rating of 30 kn, but usually 50 kn. First question, Ditch the carabiners and get locking ones with a higher tensile?

Ok here is part 2.
Now about 2 months ago I first concidered buying this but just wasn't quite sure what it could do and couldn't. But now having a portarap more possiblities arise. But one thing has been puzzling at a demo that Mark and Mahk did with it. After setting the fiddle block up as normal they attached an additional pully to rope of the fiddle block and ran a rope tied to the tree on through the pully. This would create a 10:1 MA. But when the applied force is usuall 200 pounds the output would be 2000 lbs. Now this would be double the safe working load. Would doing this be recommened? I know my rigging knowledge is not all that vast (I feel like I am reading another language trying to read what glen and spider write) but it wouldn't seem right to show something that isn't deemed safe.

And final question, what other uses have you found for the fiddle block?

 

[Eric_E]

Who is the manufacturer of the Fiddleblocks? Are they the Wichard blocks? I have a set of Wichards, I think the same as Sherril is selling. Safe Work Load Limit (SWL) is somewhere around 2750 pounds I think. I personally prefer the steel locking biners over the Kongs that come with the sherill set-up. The Kongs 22kn are suitable for the SWL of the fiddleblocks if they are the same Wichard block that I purchased from Sherrill a number of years ago.

Very rough calculations: 2 persons @ 200 lbs each = 400 lbs, 400x5 (5:1) = 2000lbs on the system

Tom turned me on to running the FB parralel to the ground which is much better than vertical from the PAW.

 

[Kevin]

[ QUOTE ]
They are rated at 22 kN which I would guess is somewhere around 4,700 lbs breaking strength

[/ QUOTE ]

closer to (tensile only) 4945 lbs.

your blocks are rated at wll 594 lbs., ... 5,940 tensile.(re sherrill)

 

[Kevin]

[ QUOTE ]
This would create a 10:1 MA.

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How is the extra block placed to acquire double the force in your system?
By going through a single anchored block you wll onle achieve the same pull.

 

[Climber020]

Yes each block is that so together they are about 11,000. You attach pulley to the rope from fiddle block not tree. THe tree would only add direction. You ancor the rope to tree then pass through the additional pully. You create twice as much pull adding the one pulley which double the force creating a 10:1 MA.

 

[huggybear]

[ QUOTE ]
[ QUOTE ]
This would create a 10:1 MA.

[/ QUOTE ]

How is the extra block placed to acquire double the force in your system?
By going through a single anchored block you wll onle achieve the same pull.

[/ QUOTE ]

you able to pull five times your power off the tail of the 5:1. then if you take a block and attach it to that tail, anchor one side and pull on the other you've doubled the force on the tail, making your 10 to 1.

I've used the fiddle block many times with the kong set-up and wondered about them being non-locking, but in a straight lime pull it should be fine. I tried to open the gate while it was under load and there was no way that was happening. If you were to angle the set up some way there is the possibility that it might come undone.

Steve

 

[Kevin]

Sorry to be a pain but I want to get some clarity on this change in MA.
The attachment is what I think I'm hearing but it doesn't change the force.

 

[Kevin]

Now this second attachment would do it ...

 

[glens]

That's correct.

I reiterate again, if you originally save the sketch in PNG it will not only be a smaller file, but it will suffer no degradation with subsequent edits.

 

[STLTreeclmbr]

U cant pull enough!

 

[Kevin]

The advantage comes with the force required to pull the load.

Even though at 10:1 you could exceed the WLL your actual pull is still less than the WLL but the force required is less at 10:1 so that's the advantage.
You still need to know what forces you're pulling ...as usual.

 

[RogerM]

[ QUOTE ]


Tom turned me on to running the FB parralel to the ground which is much better than vertical from the PAW.

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Could you explain (or anyone) as to how this works. I can't help but think this takes more parts in the system and an additional anchor point. THanks in advance for sharing.

 

[Eric_E]

Seeing how Tom ain't been round much...

...I shoulda claimed the idea as mine.

Since Tom is probably up to his elbows in boxes I'll try to explain.

Roger, Yes more parts, one block and choice of a sling. Use this at the base of the tree being worked on as a redirect to another anchor point at the roughly the same height. This way the FB is run parralel to the ground or some what horizontal.

The advantage of easy operation far out ways the disadvantage of additional parts in the system. Plus now there is a bit more rope in the system which is an advantage sometimes.

If I were half way capable with drawing I would post a diagram but I'm not.

Hope that helps.

 

[glens]

The verbiage produces a perfect mental image. It would be easier to put the same amount of tension on the line by hand the way you describe because you'd be pulling somewhat upward rather than somewhat downward. I know I can pick up a bit more weight than I can pull down

 

[RogerM]

Thanks for the quick response. My confusion was where to put the port-a-wrap. The second anchor point, behind the fiddle block set up(right?) just like on the vertical set up. Eric, your explanation was crystal clear. I'll share it with my crew and we'll give it a try. On a side note... They are always asking where I come up with this stuff. My answer is always the same "www.treebuzz.com" Thanks fellas and ladies. /forum/images/graemlins/guitarist.gif

 

[Eric_E]

[ QUOTE ]
My confusion was where to put the port-a-wrap. The second anchor point, behind the fiddle block set up(right?) just like on the vertical set up.

[/ QUOTE ]

That's correct. Attach the FB directly to the PAW.

I'm glad that you guys could "see" what I was saying. Sometimes things get lost in the translation from my head to the keyboard.

 

[Mahk_Adams]

Climber020;

Sorry for the confusion. We were limited for time and were trying to show as many options as possible while minimizing setup time. I put the extra pulley on the fiddle blocks rather than taking the time to take the fiddle blocks off and replace them with something heavier. We should have clarified that when adding the extra pulley to create additional MA (or when setting up any MA system) the WLL of the whole system has to be considered.

RogerM;

The attachment shows the horizontal setup for an MA system. Hard to see in the photo, but one end of the pulley system is attached by means of a carabiner directly to the nose of the P-A-W.

 

[RogerM]

Thanks Mahk, That is exactly what I envisioned. Pictures are ALWAYS appreciated. The fiddle block setup with a double whip technique ought to be all I'd ever want without the help of a crane. One day I'll have a GRCS...one day /forum/images/graemlins/boohoo.gif /forum/images/graemlins/biggrin.gif

 

[Mark Chisholm]

That pic reminds me of a tree I did once /forum/images/graemlins/smirk.gif

 

[RogerM]

[ QUOTE ]
That pic reminds me of a tree I did once /forum/images/graemlins/smirk.gif

[/ QUOTE ] Double whip technique photo courtesy of Mark Chisolm