Features December 1, 1999 Issue

Safety Harness Tether Test

Of 19 tethers tested, fully 47% of the tethers failed the test. None of the tethers met the Safety at Sea Committee’s criteria of an ‘ideal’ tether, although there are several on the market which come close.

In 1998, the Safety at Sea Committee embarked on a program to evaluate common safety harnesses and tethers used in sailing. Most testing for this study was based on the ORC regulations. Our testing consisted of subjective and objective criteria.

Tethers tested were the Captain Al’s Single and Three-point, Forespar Passagemaker, Holland Yacht Equipment, Helly-Hansen Three-point, Jim Buoy, Lirakis, Raudaschl, SOSpenders Three-point, Survival Technologies Single and Shock Arrest, West Marine (four different models), Wichard (two different models), along with the Miller Industrial 216 M. (Ed. Note: A three-point tether is one with two tethers, with three total attachment points, one at each end and one at the harness.)

Test Methodology
We rented a test facility to do a dynamic load test. Each harness was attached with a tether to a 220-lb. dummy and dropped 6.6'. When testing the tethers, we used the same type of harness to eliminate it as a variable. Each harness and tether was soaked in water before the test, per the ORC regulation. It should be noted that this improves the shock absorbing qualities of nylon webbing. Failure criteria include “flaws, defects, or deterioration after testing that would jeopardize the safety of the wearer.” There were some harnesses and tethers that either had bent or slightly deformed hardware and one instance where the webbing was shredded, but the equipment still held.

Test Results
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.

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.

As with the harnesses, we leave it to readers to decide whether they consider something like a quick release shackle with a bent pin to be a failure, even though the shackle didn’t open. 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 Three-point tether
• Forespar Passagemaker tether
• Holland Yacht Equipment tether
• Helly-Hansen Three-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 that did not endanger the wearer:

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

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

The following tethers passed without failures:

• Jim Buoy
• Lirakis
• SOSpenders
• Survival Technologies ShockArrest
• 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

We tested only one industrial tether, the Miller 216M, which passed.

Our Ideal Tether
Our ideal tether would have a quick release snap shackle at the inboard end, and both a 3' and 6' leg. The 6' leg may have some shock cord built into it to help keep it from getting in the way while working on deck. One skipper in the 1998 Sydney-Hobart race thought it ridiculous that his crew had to unhook from a windward padeye, and drop knee-deep into water on the leeward side before finding a padeye and then easing a sheet. A dual tether would have solved that problem. The boat end of the tether would have either the new Wichard patented locking snap hook or the Gibb snap hook with locking gate, which is preferable to a snap shackle that may take two hands to attach. The stitching would be at a minimum 2" or 3" long, and a contrasting color to the webbing for easy inspection. The snap shackle would have a very substantial cotter ring, and the release line would have an easy-to-grip feature such as a plastic ball. None of the tethers tested have all these features.

Some tethers have quick release hardware, others do not. When wearing a tether without a quick-release, crew should always have a knife within easy reach in case they get trapped and need to release themselves.

Captain Al’s Single Point Tether
This is a 6' tether with two locking aluminum carabiners, rated at 2,000 kgs (4,400 pounds) on the ends. This tether has a very short amount (less than 1" long) of stitching holding the carabiners in place. Also, the stitching is black on a dark blue webbing, making it hard to inspect without very good lighting.

When subjected to the dynamic load test, the stitching parted, allowing the test dummy to come free.

Recommendation: We cannot recommend this tether.

Captain Al’s Three Point Tether
This is a three-point tether with one leg of approximately 3' and one leg approximately 6'. The outboard ends are anchored by two of the same locking aluminum carabiners that are used on the single point tether, while the inboard end has a quick release shackle. This unit also had very short, black stitching holding the hardware.

When subjected to the dynamic load test, the stitching parted, allowing the test dummy to come free.

Recommendation: We cannot recommend this tether.

(Ed. Note: Capt. Al’s president, Alan Byer, responded to the SailingFoundation that as a result of the findings, it had “instituted the use of a secondary fastening effective immediately” and that in tests of them all passed.

Forespar Passagemaker Tether
This is an approximately 5-1/2' tether with a locking hook on the outboard end, and a snap ring on the inboard end. There is a small button on the locking hook used to unlock the gate, which is an improvement over the standard snap ring without a locking gate. We found the button to be somewhat difficult to actuate, because it was small. The stitching is done in yellow on yellow webbing, making the inspection of stitching very difficult even in good light.

When subjected to the dynamic load test, the inboard snap ring bent straight, allowing the test dummy to come free.

Recommendation: We cannot recommend this tether.

(Ed. Note: Following these tests, Forespar conducted their own tests, informing us that their shackle withstood 4,900 lbs. before deforming. As a possible explanation for the failure, Forespar measured the stretch in various tethers, finding that theirs stretched just 5/8" where others, such as the West Marine tether, stretched as much as 5-5/16".)

Holland Yacht Equipment Single Tether
This is a 6' tether with two locking stainless steel snap hooks, rated at 2,200 kgs (4,800 pounds) on the ends. This tether has a very short amount (about 1-3/8" long) of stitching holding the snap hooks in place. Also, the stitching is black on dark blue webbing, making it hard to inspect without very good lighting. Due to an ordering error we had two tethers.

When subjected to the dynamic load test, on the first tether the stitching parted, allowing the test dummy to come free. When the second tether was tested the stitching at both ends gave way, allowing the test dummy to come free.

Recommendation: We cannot recommend this tether.

Helly Hansen Three-point Tether Model K-947
This is a 6', three-point tether of somewhat unusual design. Instead of having one leg of 3' sewn into another leg of 6' (which is fairly common in the industry), this tether has a loop sewn into its middle to attach the second snap hook. There are three identical snap hooks. The stitching is yellow on yellow webbing, making it hard to inspect without very good lighting.

When subjected to the dynamic load test, the stitching parted where the intermediate (3') snap hook was attached, although the webbing kept its integrity and the test dummy didn’t come free. However, one of the snap hook gates bent open, which might allow the tether to come unhooked. We consider this type of defect to be a failure.

Recommendation: We cannot recommend this tether.

Jim Buoy 922 Tether
This is a 6' rope tether with a single gated snap hook on one end and spliced eye at the other. This tether comes as a package with the Jim Buoy harness. It is attached to the harness by snaking the hook end through the D-rings and the eye at the end of the tether, making a “permanent” attachment at the inboard end. The locking gate used for this product was the only one to fail the ORC requirement of being able to pass a .500" dowel through its opening. The splice is apparently well done and the white whipping on a gold and white rope sheath is not too bad for inspection. When subjected to the dynamic load test, this tether had no failures.

Recommendation: This tether will work, although the harness it comes with failed the dynamic load test (see November 1, 1999 issue).

Lirakis Newport Tether
This is a 6' tether with a forged Wichard snap hook on one end and a loop in the webbing at the other. This tether comes as a package with the Newport harness. It is attached to the harness by snaking the hook end through the D-rings and the loop at the end of the tether, making a “permanent” attachment at the inboard end. The stitching is white on red webbing for good contrast, however the stitching is spaced somewhat far apart, making inspection a little tougher than it could be.

When subjected to the dynamic load test, this tether had no failures.

Recommendation: This is a good tether.

Raudaschl Tether
This is a 6' tether with what appear to be cast snap rings on the ends. The stitching is black or dark blue on a medium blue webbing, making inspection difficult.

When subjected to the dynamic load test, the snap ring deformed from a D shape to a straight I shape, allowing the test dummy to come free.

Recommendation: We cannot recommend this tether.

SOSpenders Three-point Tether with Snap Shackle
This is a three-point tether with one leg of approximately 3' and one leg approximately 6'. The outboard ends are anchored by two of the same type of gated snap hook, while the inboard end has a quick release shackle. The stitching is white on medium blue webbing, making inspection relatively easy.

When subjected to the dynamic load test, this tether had no failures.

Recommendation: This is a good tether, which allows crew the freedom of either a long or short tether length.

We would prefer to see either the Wichard or Gibb locking gated snap hook on the outboard ends.

Survival Technologies 6' Tether with Snap Shackle
This tether has a gated hook/carabiner on one end and a snap shackle on the other. The locking gate is easy to actuate with one hand. The stitching is red on black webbing, making inspection relatively easy.

When subjected to the dynamic load test the pin on the snap shackle bent slightly, although if the release cord was tugged, the shackle would release. The test dummy did not come free even with the bent pin.

Recommendation: This is a good tether.

Survival Technologies Shock Arrest Tether
This is a 6' tether of unusual design. Instead of using webbing, it uses a spliced braided line. Woven into or around one end of the line is a piece of shock cord to help absorb the load of a fall. One end has a snap shackle and the other a snap hook.

The splicing appears good, but the whipping is black on a black sheath so inspection requires good eyes and good light.

When subjected to the dynamic load test there were no failures.

Recommendation: This is a good tether of interesting design to help absorb shock loads.

West Marine 6' Tether with Snap Shackle
This tether has a gated hook/carabiner on one end and a snap shackle on the other. The locking gate is easy to actuate with one hand. The stitching is white on medium blue webbing, making inspection relatively easy. When subjected to the dynamic load test, this tether had no failures.

Recommendation: This is a good tether.

West Marine 6' Basic Tether
This tether has a snap hook on each end. The locking gate is easy to actuate with one hand. The stitching is white on medium blue webbing, making inspection relatively easy.

When subjected to the dynamic load test, this tether had no failures.

Recommendation: This is a good tether.

West Marine 6' Tether with Snap Shackle and Gibb Hook
This tether has a locking Gibb snap hook on one end and a snap shackle on the other. The locking gate is easy to actuate with one hand, and doesn’t suffer from the ability to open when twisted around a padeye (the single wire sprung snap hooks will open when twisted around a padeye in a not too unusual manner, causing them to open inadvertently). The stitching is white on medium blue webbing, making inspection relatively easy.

When subjected to the dynamic load test, this tether had no failures. We used 25 of this model for our harness testing, and none failed.

Recommendation: This is a good tether.

West Marine 6' Tether with Dual Snap Shackles
This tether has a snap shackle on both ends. The stitching is white on medium blue webbing, making inspection relatively easy.

When subjected to the dynamic load test, one of the pins on the snap shackle bent slightly, although if the release cord was tugged, the shackle would release. The test dummy did not come free even with the bent pin.

Recommendation: This is a good basic tether. However since it is sometimes necessary to use two hands to secure the snap shackle, we don’t recommend the use of snap shackles on the boat end of the tether.

Wichard 7015 Tether
This tether has a patented locking gate hook on the ends. The locking gate is easy to actuate with one hand. The stitching is multicolored on medium blue webbing, making inspection relatively easy.

When subjected to the dynamic load test, this tether had no failures.

Recommendation: This is a good tether, although it does not have a quick-release shackle on the end.

Wichard 7001 Tether
This is a 6' tether with forged snap rings on the ends. The stitching is multicolored on medium blue webbing, making inspection relatively easy.

When subjected to the dynamic load test, one of the gates on a snap ring came unsprung. While the test dummy did not come free, we consider this type of defect to be a failure.

Recommendation: We do not recommend this tether.

Contacts- Cal-June (Jim Buoy), 5238 Vineland Ave., North Hollywood, CA 91601; 818/761-3516. Captain Al’s, PO Box 370153, West Hartford, CT 06137-0153; 860/232-9065. Forespar Products (Passagemaker), 22322 Gilberto, Rancho Santa Margarita, CA 92688; 949/858-8820. Helly-Hansen (US) (K-947 Tether), 17275 N.E. 67th. Ct., Redmond WA 98073, 425/883-8823. Holland Yacht Equipment, PO Box 452, San Carlos, CA 94070; 650/595-2009. Lirakis Safety Harness, 18 Sheffield Ave., RI 02840; 401/846-5356, 800/USA-SFTY. Navtec Norseman Gibb, 351 New Whitfield St., Guilford, CT 06437-0388; 203/458-3163. Raudaschl Sails, 3140 Lakeshore Blvd. W, Toronto, ON, Canada M8V 1L4; 416/255-3431. Sporting Lives (SOSpenders), 1510 N.W. 17th St., Fruitland, ID 83619; 208/452-5780. Survival Technologies, 1803 Madrid Ave., Lake Worth, FL 33461; 800/525-2747. West Marine, 500 Westridge Dr., Watsonville, CA 95077-5050; 800/262-8464. Wichard, 507 Hopmeadow St., Simsbury, CT 06070; 860/658-2201.

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