Horizontal Lifelines – An Introduction

“But there’s nothing to tie-off to!”

It’s a common refrain in the world of safety. The safety professional informs a worker that they need fall protection to work in the location they intend to work and the worker comes up with every reason in the book why that is not possible. Some of those reasons are legitimate. Some aren’t. So, in which category does the above excuse belong?

Obviously, without knowing every detail of every scenario, it’s impossible to say for sure, but often what “There’s nothing to tie-off to” means is “Nobody bothered to plan for my fall protection” or “I don’t know how to select a proper anchor point.” Even in the most difficult of situations there is a possible solution. One solution that gets overlooked (probably because it takes pre-planning) is a horizontal lifeline (HLL). It isn’t always the simplest solution, but it is a very effective one.

What is a Horizontal Lifeline?

A horizontal lifeline is exactly as it sounds – a horizontal, linear anchor point that can be composed of either wire rope cable or rigid steel. Each has its pros and cons. However, the line is anchored at both ends, and possibly at locations in between (depending on which material and the length of the line). A worker properly secured to this lifeline can travel its length, remaining protected the entire time. These anchors allow the user the flexibility to move to a number of different work locations without having to be unprotected or without constantly having to move an anchor around.

The problem is that a company cannot just grab the nearest wire rope, loop it around a piece of steel and go to work. A horizontal lifeline, according to OSHA, “shall be designed, installed, and used, under the supervision of a qualified person…” The definition of a Qualified Person here is one who is recognized by extensive experience, degree, or other education that is able to, in this case, design a horizontal lifeline system, recognize problems with it, and recognize hazards associated with its use. If questioned by OSHA, you will need to be able to demonstrate why you considered this person to be a Qualified Person. One way to eliminate a portion of this burden is to purchase a designed horizontal lifeline system. These can usually be installed by the manufacturer or distributor. You’ll still need a Qualified Person to inspect it, but it eliminates the design and possibly install portions which may have necessitated a higher level of qualification.

Wire Rope vs Rigid Lifelines

If you do your research, you’ll find there are pretty much two types of systems: wire rope and rigid rail. Each comes with its own pros and cons. Both, installed correctly, will protect your workers. However, which is best for you?

There is no easy answer.

Wire rope systems could be a little less expensive, but because of sag and deflection you may need to allow for more fall distance than if you were using a rigid rail system. Because the rigid system doesn’t have that give, there is also a reduced chance of secondary injuries that occur when an employee swings into a structure or object (the sag in a wire rope will force the trolley – the device that attaches the lanyard to the rope and travels along the length – to move, causing a swing). A rigid rail may need more room for its anchors and may have less flexibility in where those anchors get placed, but you will also most likely need fewer of them. Finally, with a wire rope, when one falls, any other people on that line will be affected. The sudden jarring force could cause other people to fall. That does not occur with a rigid system.

Travel Restraint vs Fall Arrest

There are two distinct aspects of active fall protection: travel restraint and fall arrest. While the same personal protective equipment will be required for both, there is a key difference: fall arrest slows a person’s descent after a fall has taken place, while travel restraint keeps a person from falling in the first place by preventing them from reaching an edge. Given that injuries can occur from a fall even if the person is properly tied-off (including internal injuries or suspension trauma), any opportunity you have to prevent a fall in the first place should be taken.

If you are using a horizontal lifeline, travel restraint can be achieved by ensuring that your lanyard does not allow you to reach the edge of the roof or platform on which you are working. 10 feet to the edge? A 6’ lanyard will prevent you from getting there. At least on a rigid system. When dealing with wire rope, it is important that you take into account any stretch, sag, or deflection that system has. If your edge is 7’ away and you are using a 6’ lanyard, you may believe you’ve achieved fall restraint when, in reality, the rope has a 3’ deflection and your worker can fall. A false sense of security is often worse than no security at all.

Fall Clearance

Fall clearance is a fairly simple concept that turns into a big problem because people are not aware of how it works. When selecting fall protection, it is important to know that the equipment you are choosing will actually prevent you from hitting a lower level. In order to do this, you must factor in all of the necessary information: length of lanyard, length of deceleration device (if any), length of person’s body, stretch of harness, and – most important to this article – sag in the anchor system. When all is said and done, and with the obvious caveat that this number could be different in each situation, you normally need to allow 18.5’ before you can use a 6’ lanyard with a deceleration device. This number accounts for 2-3’ of sag. If you are using a rigid lifeline, then you can eliminate the sag in the anchorage system, meaning you need less room to make your solution acceptable. If you are using wire rope, you can’t just count on the amount of slack you have from tugging on the rope, but rather how much slack you’d get if thousands of pounds of force were suddenly imposed upon the system (talk to that Qualified Person!).

In the end, horizontal lifeline systems are an effective fall protection solution that could be more cost effective than other options like surrounding a roof with guardrails. The key is making sure the system is designed, installed, and used under the supervision of a Qualified Person and making sure your personnel are properly trained to use the system correctly. Using it wrong could result in unexpected falls, swing hazards, or even failure to actually tie-off. With a horizontal lifeline in place, workers will no longer be able to say, “But there’s nothing to tie-off to!”