Test Summary
Dynamic Testing - Tethers

Test Setup
In this test, a harness was placed on a 220 pound dummy. Each tether to be tested was attached to the harness and the dummy was raised up to a quick release shackle such that when the shackle was released, the dummy would free fall 6.6 feet. Failure criteria include "flaws, defects, or deterioration after testing that would jeopardize the safety of the wearer".

 
Test Results

General Comments on the Tethers:
We were somewhat surprised that there were so many tether failures. 47% of the tethers failed in such a way as to endanger the wearer.  Failures were both in the hardware, stitching, or sometimes both. Build quality of the tethers varied considerably from company to company.

We generally consider a tether with a quick release shackle at the inboard end to be an important feature; however, we tried to test as broad a spectrum of hardware as possible to see if there might be any lessons learned. We did come to this conclusion: quick release snap shackles are robust, as are the locking, gated snap hooks (the Wichard and Gibb hooks). Snap hooks without a gate, even the well-respected Wichard forged models, and most of the other non-locking hardware have too high a failure rate to trust your life to them. Also, snap hooks have been known to pick up a lazy jib sheet while walking along the deck, and can come undone if twisted on a padeye in a not uncommon manner.

As with the harnesses, we will leave it to the reader to determine whether they consider something like a quick release shackle with a bent pin to be a failure, even though the shackle didn't open and let the dummy free. However we do consider it a failure when a gated snap hook fails in such a way that the gate remains open. It appears that the weak link in the whole system generally comes down to the tether.

The following products failed in a way that could have caused the wearer to lose contact with the boat:

• Captain Al's single tether
• Captain Al's 3-point tether
• Forespar Passagemaker tether
• Holland Yacht Equipment tether
• Helly-Hansen 3-point tether
• Raudaschl tether
• Wichard Model 7001 tether.

The Captain Al's, Holland Yacht Equipment, and Helly-Hansen products all had failures of the stitching. All the other failures were due to hardware bending or breaking.

The following tethers had some damage to them that did not endanger the wearer:

• Survival Technologies single point tether
• West Marine 6' tether with dual snap shackles

In both instances, the damage was a slightly bent pin on the quick release shackle. In both cases the shackle remained closed, and could be opened by tugging on the release lanyard.

The following tethers passed the dynamic test without failures:

• Jim Buoy
• Lirakis
• SOSpenders
• Survival Technologies Shock Arrest
• West Marine 6' tether with snap shackle
• West Marine 6' basic tether
• West Marine 6' tether with snap shackle and Gibb Hook
• Wichard Model 7015 Tether

It should be noted that the Jim Buoy tether passed the dynamic test, however the opening in the snap shackle is too small according to ORC regulations (it must be greater than 1/2").

We tested only one industrial tether, the Miller 216M. It passed the dynamic test, but its most interesting feature was a small flag sewn into the tether material. When the tether is stressed beyond a certain point the stitching holding the flag breaks, allowing the flag to unfurl and giving you an indication that the tether has been overstressed.

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