Safety Harness Tether

01
of 08

Simple Straight Tether

Single Straight Tether
Photo © Tom Lochhaas.

A safety tether is a strong strap that connects between the sailor’s safety harness and a strong point on deck, such as a leg of the compass binnacle, a U-bolt installed in the cockpit expressly for the tether, a stanchion base, or a jackline.

The safety harness is worn around the chest and shoulders and has two D rings to which the tether connects. Most sailors now use inflatable PFDs with a built-in safety harness like that shown here.

A standard tether, as shown in this photo, is 6 feet long and has a shackle at each end. Typically the breaking strength of a commercial tether is over 5000 lbs. Different kinds of shackles are used, as described in the next pages.

02
of 08

Snap Shackle

Snap Shackle
Photo © Tom Lochhaas.

Here’s a close-up view of a standard snap shackle on the end of the tether that attaches to the boat. It is easy and fast to connect to a ring or other fixture.

The standard shackle, while the least expensive, is not considered the most secure choice. If the tether strap is twisted back around the shackle under force, there is a small chance that the shackle could open.

When a standard snap shackle is used, clip it directly to a strong metal fitting. Do not wrap the tether around an object and clip the shackle back on the tether itself, because this arrangement might result in a twisting motion that could open the shackle.

03
of 08

Quick-Release Shackle

Quick Release Snap Shackle
Photo © Tom Lochhaas.

Here’s a close-up of the quick-release shackle on the end of the tether that connects the safety harness D rings. This kind of shackle is opened by pulling on the cord with the red beads—it cannot be “snapped” into place like a snap shackle.

The quick-release shackle is considered secure and is used on the harness end of most tethers. It is unlikely that any unusual or twisting forces would be applied at this end of the tether.

04
of 08

Quick-Release Shackle Open

Quick Release Shackle Open
Photo © Tom Lochhaas.
The quick-release shackle is designed to open with a jerk on the release cord even if the tether is under great strain. A sailor who falls halfway off the boat, for example, may have to release the tether (once he or she is secure) in order to move into a safe position.
05
of 08

Double Elastic Tether

Double Elastic Tether
Photo © Tom Lochhaas.

Tethers are also available with double connections for the boat. Most double tethers have a 6-foot length and a 3-foot length. When it is necessary to move about the deck in dangerous circumstances, you can clip onto a new position with one shackle without having first to release the other shackle. This way, there is no vulnerable moment when you are not clipped in at all.

Both single and double tethers, in addition, are available with elasticized straps, such as shown here. The advantage of an elastic strap is that the tether does not droop down where it may snag on equipment or get in the way.

06
of 08

Gibb Shackle

Gibb Shackle
Photo © Tom Lochhaas.

The tether shown here has a Gibb shackle for attaching the tether to the boat. This kind of shackle is more secure than the standard snap shackle shown earlier. It should not open accidentally under any circumstance.

The disadvantages are that it costs more and that it is slower and more difficult to use until you become familiar with it. The next pages show the steps for opening a Gibb shackle.

07
of 08

How to Open a Gibb Shackle

Gibb Shackle Partly Open
Photo © Tom Lochhaas.
Opening the Gibb shackle requires two different finger maneuvers. First, move the inner lever bar downward as shown here, against the action of an internal spring. (Continued next page.)
08
of 08

Opening a Gibb Shackle Part 2

Gibb Shackle Fully Open
Photo © Tom Lochhaas.

After pushing the inner lever bar open with one finger (and holding it open against the spring), then open the shackle jaw with your thumb as shown here (against the resistance of a second spring).

When this thumb pressure is released, the shackle snaps closed with the action of both springs and is then very secure against any risk of accidentally opening.

In Conclusion

The most important thing about a safety harness and tether is to use it. Usually this means using it before you think it’s necessary. Almost all sailors who have fallen off a boat thought they were safe at the moment they fell. They didn’t expect the boat to suddenly lurch, they thought their nonslip shoes wouldn’t slip on a wet deck, they thought they had a secure handhold on the rail as they walked forward, they never thought the boom would hit them in the head and knock them overboard.

Even a tether is no guarantee, however. It’s still important to wear a PFD—preferably the inflatable offshore type with safety harness built in.

Read more about other Sailing Safety topics.

Format
mla apa chicago
Your Citation
Lochhaas, Tom. "Safety Harness Tether." ThoughtCo, Feb. 29, 2016, thoughtco.com/safety-harness-tether-2915411. Lochhaas, Tom. (2016, February 29). Safety Harness Tether. Retrieved from https://www.thoughtco.com/safety-harness-tether-2915411 Lochhaas, Tom. "Safety Harness Tether." ThoughtCo. https://www.thoughtco.com/safety-harness-tether-2915411 (accessed November 22, 2017).