Harnesses are used by climbers, cavers, rescue personnel, window cleaners and anyone who works or plays where they are at risk of falling. They are the link by which a person is connected into the system. There is no one all‑purpose harness which will fill everyone’s needs. Careful deliberation and time spent examining and using harnesses are your best guides. When selecting a harness, keep the following in mind. The tie‑in point should be low enough so that descenders or ascenders can be used effectively, but high enough that you hang in an upright position. Hanging upside down is no fun and there is nothing as frustrating as discovering that the tie‑in point puts your descender out of reach when on rappel. Look for wide webbing at the load supporting points. This will provide for a much higher degree of comfort. If the webbing is thin, it will tend to restrict circulation making the user very uncomfortable in a short period of time. People who are in pain may rush about and take short cuts which could endanger all involved in the situation. Freedom of movement is important. If the harness is restrictive when just walking around, think what it will be like when you are hanging 2150 feet in the air. The harness should stay up on your body when walking around. It should not be hanging down around your knees or ankles. Harnesses must fit snugly and the design must not allow the wearer to fall out of the harness even when suspended upside down. The stitching must be of good quality and be protected from abrasion. Make sure that all stitching is a synthetic thread such as nylon to prevent rot and mildew.
There are a number of prime harness applications. Following is a brief rundown of these applications and important points to consider for them.
RESCUE: The harness should be comfortable to hang in for long periods of time. It must be robust in design and capable of withstanding high stress and adverse conditions. The harness should have gear loops or provisions for them so that you can carry the tools of the trade with you. It should be quick and easy to don on yourself or on the subject you are there to rescue. The wearer should feel secure and not have to expend a lot of energy to maintain an upright stance.
CAVING: Harnesses that are suitable for rappelling or ascending are important. It must not interfere with motion when crawling or climbing in tight passages. The stitching must be resistant to abrasion. Caving harnesses should have a minimum of attachments such as gear loops to prevent snagging in tight areas.
MOUNTAINEERING AND CLIMBING: The harness should allow good freedom of movement. The stitching and webbing must hold up under wear and abrasion. It must direct the forces in a fall to the stronger more massive portions of the body and it must bring the user to a stable upright position after stopping a fall. For simple rope climbing, a seat harness may be adequate, but for lead climbs, we and UIAA recommend the use of a full body harness or a seat harness with a chest harness.
TACTICAL: Harnesses for police or tactical work must be quick and easy to put on even under stress. It should allow great freedom of motion at all times. The harness must remain comfortable at all times and allow access to weapons or other tools.
INDUSTRIAL SAFETY HARNESS: Must be of rugged construction to withstand heavy use. The harness must be capable of being worn without interfering with tools or materials. It must be comfortable when worn for long periods of time and one which holds the wearer in a stable position after a fall or in case of an emergency.
Many harnesses have gear loops, tabs or D rings which are designed as a handy place to hang the tools and equipment the climber/rescuer may need. Some have gear loops made of accessory cord covered with plastic protector sleeves. Others have two forged D rings which can function as gear loops. DO NOT use the gear loops, tabs or D rings as a critical life supporting clip‑in point. When on rappel, DO NOT clip your rappel device into them. When ascending DO NOT clip in a life supporting ascender into the gear loops, tabs or D rings. And of utmost importance, never clip a belay line into gear loops, tabs or D rings. These lightweight attachment points are designed to carry light loads of non‑critical nature. They are not designed to support the weight of a person and will not withstand any shock loading. A belay line tied or clipped into a gear loop, tab or D ring is a deadly situation, as they will rip out under heavy or shock loads. Always remember, gear loops are a good place to hang your tools, but they are a terrible place to hang your life.