Spider leg length (?)

Chris Schultz

Member
Location
Minturn
I’ve got a 30’ piece of 3/8” tenex I picked up for a spider leg. I intend on cow hitch or running bow, coupled with taughtline hitch onto primary rigging line. Before I cut mine I’m curious about how long are peoples spider legs for limb balancing? I rarely have a need to deploy this, but I figured for the cost of the tenex it couldn’t hurt to have in my rig bag...My only real life experience is the piece we have in the tree service truck which is annoyingly long, and it’s not mine to cut..... thanks
 
Last edited:

Reach

Well-Known Member
Location
Atglen, PA
We use a set of 20’ and 25’ spider legs for lifting and balancing, we’re using 3/4” Ultrex now, but we still have some 3/4” double braid as well which we use for smaller picks.
 

Jehinten

Well-Known Member
Location
Evansville
I bought one from Wesspur a few years ago at 20' long. It works pretty well, although doesn't get used often. It's a bit long for short trees where the friction hitch gets into the rigging point, but the excess tail can make for a short tagine to help it around obstacles
 

TheTreeSpyder

Well-Known Member
Location
Florida>>> USA

090 spread is 45degrees spread each leg from centerline .
120 spread is 60degrees spread each leg from centerline.
2 support legs to centerline is 50% load each.
As support legs deflect from centerline
>> they are less efficient support columns require more tension for same load.
>>they also incur inwardly crushing side force, that leverages harder against weakness and deformity.

Deflection
Load​
Per leg/cosine=tensionX sine=side
451000500.707707.707500
601000500.5001000.866866

Above finds tension from support column needed per leg divided by cosine, then finds side compression by multiplying tension X sine.
.
Below shortcuts from support column needed per leg X tangent to find side compression without going thru tension calculation.
Deflectionloadper legskipskipX tangent=side force
4510005001500
6010005001.73866

Side force escalates very rapidly flatter than 120 spread benchmark, more than doubling at 150 to 1866!!
 
Last edited:

Chris Schultz

Member
Location
Minturn
I don't have much intelligent to add other than it's super easy to splice an eye onto the end that'll connect to your rigging line and use a klemheist to attach instead of using a tautline. A tautline is super easy too though.
I kinda dislike the klemheist ONLY because the whole tail needs to be fed through your wraps.... But if I do splice an eye in it, what dimension do you recommend? Rigging line 1/2”-5/8”. Tenex sling 3/8”
 

tek9tim

New Member
Location
Winthrop, WA
I kinda dislike the klemheist ONLY because the whole tail needs to be fed through your wraps.... But if I do splice an eye in it, what dimension do you recommend? Rigging line 1/2”-5/8”. Tenex sling 3/8”

Yeah, that’s a definite downside. I don’t recall what I spliced mine up at. IIRC, I just doubled it up and wrapped it around my rigging line and came up with an eye length that worked. And I don’t have my rigging gear handy at the moment to measure.
 

New threads New posts

Kask Stihl NORTHEASTERN Arborists Wesspur TreeStuff.com Kask Teufelberger Westminster X-Rigging Teufelberger Tracked Lifts Climbing Innovations
Top Bottom