Mule tape for tree straps

[Joe L]

I own about a hundred more feet of mule tape than I need. It is free. You could reimburse me for the postage on the envelope, it that suits you. The bad news it that it is 2500# 5/8" or 3/4" size NYLON. A tree strap length of nylon with that strength will not stretch much after the initial load. When I washed it, the printing washed off of it and it seems thicker now and slightly more narrow at 5/8". The soft hand helps it grip the rough bark in my locale. It is heavy at about 7 grams per foot. A tree strap amount will easily fit in a tyvek envelope. My preference is to share with several hangers, not to send the whole lot to one, so ask for what length you want.

jlongbotham(AT)cybertrails(DOT)com

[Tim Marshall]

I have some 1/2" (1250#) MULE Tape and can hang my 300# from it with no worries. However after tying a truckers hitch with some found that the weave had been destroyed by the over hand loop. If you use mule tape be sure not to use any knots and to inspect it between hangs. It is very strong but because of the loose weave it is more delicate than polyester webbing.

-Tim

[Joe L]

The Neptco (mule tape manufacturer) website has a diagram of a "mule knot" that maintains the strength, but the complicated knot looks like one for tying thick monofilament fishing line. The knot function is more of a one time splice, not tying, untying, then retying use.

In industry, mule tape is designed as a disposible, single use item.

[Keith Selbo]

Incensed by the high price of a longer Hennessy tree hugger, a friend of mine went to the Home Depot and bought one of those webbing straps with a ratcheting tensioner. The webbing was rated to 1500lb. He removed the hardware and had 16ft of webbing to play with. It was more than enough for two straps.

He wasn't sure how to sew loops in the ends or what thread was suitable so he went with bowlines. Anybody know about loop making?

[Lynn Richard]

Stitch strength matches the tension strength of the thread used. I us 40lb polyester. Number of stitches = 5 * Maximum expected load * lb. strength of thread (includes industry approved human support safety factor). Brush up on your trig. Expected load has more to do with angles of suspension than with weight of person in hammock. Shoot for a 2,000 lb load and you'll be in the ballpark for the averag American with a versital hang.

[Lynn Richard]

Oh yeh- with 1/2" web, let's make sure we strap enough to properly distribute the load (without compressing and killing the circulatory system of the tree). Wrap x's 3, then secure to 2.

Peace.

[Keith Selbo]

My hennesy web is 1". The tie-down web looked to be wider.

It looks to me like if we use the angle (theta) between the support line and the horizontal for our calculations then the formula for the static load on each line is:

0.5 * weight/sin(theta)

At least it comes out right at the extremes of 0 and 90 degrees. Hennessy states a 200 lb limit for my Hyperlite, so for a 20 degree sag (I've never measured it but it looks like 20 – 30 degrees) it comes out to 292 lb per line. Each line is secured to two strap loops, each one taking up half the load, or 146 lb.

I don't dive into my hammock, so I'll double it for dynamic load (don't be afraid to chime in if that seems bogus) so we're back to 292 times 5 per Lynn or 1460 lb. add another 500 for a fitful night of tossing and turning and that's about 2000 lb. Works for me!

Based on what Lynn said, I think his equation has a typo in it:

he had: Number of stitches = 5 * Maximum expected load * lb. strength of thread

should be: Number of stitches = 5 * Maximum expected load / lb. strength of thread.

Thanks Lynn, very useful info!

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