Can I attach my lifeline to any of the D-Rings on my harness?
This week we are going to discuss the D-Rings on harnesses and which ones are safe to attach my lifeline to.
What are D-Rings?
D-Rings get their name from the fact that they are generally D-shaped, although their exact shape can vary. These D-Rings are sewn into the harness webbing and serve as loops to which other components, such as lanyards and self-retracting lifelines (SRLs), attach.
How to Use Harness D-Rings Safely
It is important to know how to use each D-Ring that you might encounter on a full body harness. In this section, we’ll introduce the most common types of D-Rings and ways to use them correctly and safely:
· The Occupational Safety and Health Administration (OSHA) requires all fall protection safety harnesses to , also known as a dorsal D-Ring. This is the required safety harness attachment point for a fall arrest harness. Connecting a personal fall arrest system to a back-ring harness helps keep the body upright during a fall and lets the harness do what it was meant to — distribute the forces of a fall arrest throughout the body.
· A personal safety harness may include extra D-Rings on the sides by the hips. These are not attachment points used in fall arrest, but rather useful points to connect devices to during work positioning. When an employee is held in suspension, common in tower applications and rebar construction, a positioning device can be attached to the side D-Rings. These positioning systems give more flexibility to workers in suspension, although they must be used together with — and cannot replace — standard fall protection connected to the dorsal D-Ring.
· A fall arrest body harness sometimes comes with chest D-Rings, which can serve as points of attachment for climbing applications. Again, these are not proper points of connection for fall arrest systems. Some other harnesses, such as those used for confined spaces or rescue operations, may feature shoulder D-Rings, which are excellent for safely lowering or hoisting a worker but are not meant to arrest an uncontrolled fall.
Proper D-Ring Usage
D-Rings not only act as the connection point to a fall protection harness, but help ensure the body stays in an upright position during a fall. Other situations that require the use of specific D-Rings include:
· Like with fall arrest, you must use the dorsal D-Ring.
· Use the D-Rings on the chest, hips, or waist.
· D-Rings on the waist and chest should be used.
· The D-Rings on the waist and chest should be used.
· Use the shoulder or dorsal D-Rings.
Top Misuses of Fall Protection Equipment and D-Rings
As fall protection equipment contains lots of parts, this leaves room for many mistakes, especially when you’re not fully versed on the basics of using body harnesses and D-Rings for safety harnesses. However, there are a few particularly common mistakes we’d like to mention so you can avoid them. These include:
1. Misusing Rebar Snap Hooks
The most effective method for mitigating possible misuse of the rebar snap hook is to make sure the anchorage connector D-Ring is bigger than the snap hook to prevent side loading of the hook. As this is hard to achieve, we encourage users to utilize a smaller anchor snap for attaining the right geometry.
If an employer chooses to use these hooks, they should know the hooks’ gate strength and be aware that certain hooks have two stress points aligning with the hook’s strongest points.
2. Anchoring Below the Dorsal D-Ring
Another common mistake regarding anchorage is people anchoring under their feet. When they do this, it increases free fall, which may exceed the equipment’s permissible limits. If a worker pushes a piece of equipment to its limit, this may cause the anchorage or lanyard to fail or exceed the permissible force on the body, which will increase the chances of a severe injury.
It’s critical to remember that, even if the fall is arrested, the longer the fall, the more forces on the body. In turn, serious injuries could occur. For this reason, it’s a good idea to avoid anchoring under the dorsal D-Ring. If you have no choice but to do so, use an SRL rated for extra free fall or a 12-foot free fall energy-absorbing lanyard. Keep in mind these lanyards have an arresting force greater than that of standard versions, so you must design the anchorage accordingly.
To mitigate the problem, do the following:
- Avoid standing if it isn’t necessary.
- Ensure your center of gravity remains low, thereby reducing the free fall distance.
- Use the appropriate equipment for the right application.
3. Mixing up Self-Retracting and Twin-Leg Energy-Absorbing Devices
While these two devices look alike and function similarly, many workers make the mistake of assuming they’re interchangeable. These two devices are tested in different conditions and applications, meaning you shouldn’t use them for things they haven’t been tested for.
Furthermore, people tend to misuse both lanyard types by anchoring under the dorsal D-Ring, which can increase the arresting force by several thousand pounds.
To avoid this problem, follow these tips:
- Ensure the device has been tested specifically for your application: Make sure self-retracting and twin-leg energy-absorbing devices have been tested in the way you intend to use them. For instance, if you attach below the dorsal D-Ring, make sure the device has been tested for extra free fall.
- Avoid connecting both legs to an anchorage:Attach the unused leg to the part of the harness that isn’t load-bearing by using the breakaway tab.
- Avoid anchoring both legs of the lanyard at the same height: Doing this could increase the arrest forces.
4. Not Ensuring the Equipment Fits Properly
Even if the harness’s condition is good, wearing it improperly can be hazardous. For instance, wearing a harness loosely creates a higher level of potential energy, which converts to kinetic energy when a fall occurs.
Other problems, like the position of the chest retainer strap or back D-Ring, could be seriously hazardous. A back D-Ring that’s too high could hit a worker’s head when falling, and one that’s too low could cause the worker to face the ground following the arrest, which increases the risk of suspension trauma. A chest retainer strap that’s too high could choke a worker, and one that’s too low could pull apart, allowing the worker to come out of the harness.
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