Belaying for Firefighter Escape Training: Researching Best Practices

The purpose for this testing is to try to determine the “best practices” when it comes to providing belays for firefighters who are performing escape systems training. Motivation for the testing comes from both documented cases and word of mouth reports of injuries to firefighters who were practicing survival techniques such as escape systems and head-first ladder bailouts. In many of these cases a “belay” was in place and often we hear that there was a “belay system failure”.

These reports however likely did not involve a full investigation which would encompass identifying root and contributing causes as well as review the training of the instructors and working with the manufacturers of the various components used in the setups. Proper investigations such as these should either be led by a qualified independent technical investigator/subject matter expert, or at least consult these people on the technical matters of the investigation.

It is highly likely that these incidents had a large contributing human factor and not a failure of a piece of equipment. To prevent these injuries a belay or safety system must be selected and proper training on the system must be conducted by a qualified instructor. This training must include a practical belay competency test before someone is permitted to belay an actual student performing a firefighter survival skill.

Why not use a typical fire service belay such as tandem prussiks, Petzl I’D, or CMC MPD? Why are people not being caught on belay in escape system training? What’s the big deal?

The big deal is that typical escape system training is done out of a second or third story window, with a “main line” that may have an unsecured anchor. This means that we do not have much time to react and not a lot of distance to go before the feet of a firefighter impact the ground. So if a typical 2nd story window sill height is 12’ above the ground and we have a 6’ firefighter performing the skill, we only have 6’ of distance to the ground. Add any slack in the belay system, rope stretch, harness stretch and we don’t have much of a safety factor left.  

Some departments and academies use landing mats, like the stunt and gymnastics type. They are designed for high impact landings and rolls. There have been reports of injuries from the impact landing and slips and falls when transitioning off the mat to the ground, especially if used outside. These are an option and it should always be a best practice to have a landing pad of some type to minimize a potential injury during a landing from a controlled descent. This could be a thin gym mat or a mattress.  

Fire service belays do not typically allow us to operate the belay without either introducing significant slack into the system, or so little slack that it hangs up the firefighter performing the escape. The end result is that the belay line is almost the main line or that the firefighter never gets to fully experience their escape system. So what are the desired capabilities of the firefighter escape system belay?  

Here is what we believe are the desired capabilities of the firefighter escape system belay:

• Reusable
• Safe
• Effective
• Easy to train on
• Ability to independently lift / lower
• Low impact forces
• Provide realistic feel (minimal interference with primary system)

Here are some of the different types of belay devices and techniques we have found people using or we have tested:

Typical Fire Service belay

• Tandem prusik belay
• MPD

Assisted Braking

• GriGri
• GriGri 2
• Petzl ID
• Mad Rock Lifeguard

Automatic belays

• DEUS 7300 (aka Big Brother)
• ISC ALF
• 3MCapital Safety Lil' Buddy R520

We have discussed most of these items however, we have not touched on the ability to independently lift / lower. Why is this important? There are times when performing an escape maneuver that the low pressure hose coming off the firefighters MMR, a gloved hand, or portion of gear get trapped under the escape system line and we have to raise the firefighter up to free them. There have also been instances where firefighters with previous injuries perform an escape maneuver and then are unable to operate their device. This has happened with firefighters with previous should injuries that cannot bring their arms up to operate the device. As with any rope based training there should always be a rescue plan in place. Some departments will keep a ladder nearby to put under the firefighter, but we find that takes time. With a proper rope based system you can lift the firefighter within seconds and have them free of the problem and then either lower them to the ground with the belay system or allow them to operate their escape system.

With all of this in mind, we decided to start testing a system that we have used and which some escape system manufacturers use as well as an alternate method that is used by some manufacturers, departments and training companies. There are so many things we could possibly test, but we had specific areas we wanted to measure or test. Also, we wanted to ensure that the test was as realistic as possible when someone was operating the belay device within manufacturer’s instructions. This meant that a belayer would be required to just hold the braking end of the rope and maintain no slack between the anchor and the belay device.

Testing Setup

• 300lbs test mass
• Dynamometers (Enforcers - 500 samples per second) located at test mass and each anchor/redirect
• Rope construction comparison - Static (Sterling 10mm and 10.5mm Safety Pro) - Dynamic (Sterling 10.1mm Marathon Pro)
• Distance from overhead anchor / belay redirect to ground
• Belay Type - Assisted (GriGri 2) w/blayer holding baking end, Top-Bottom Belay, Top Belay
• Belay Considerations - Distance from window to belay anchor, Effects of longer distances, Belay Redirects / Change of Direction, Various slack amounts in belay system
• Rope Stretch
• Fall Distance

Initially this test was done at Sterling Rope headquarters in Biddeford, Maine, then has been repeated at Capital Technical Rescue & Safety Consultants in Albany, NY and again at the New York State Academy of Fire Science in Montour Falls, NY at their technical rescue conference.

The results were similar at all locations, with each test being repeated 2 – 4 times.

Conclusion

These tests are not exhaustive and only tested a single rope manufacturers brand new ropes, so results can certainly vary. The first major point is that Top Belays generate a lot more force on the anchor and the test mass (firefighter) due to a higher fall factor. Even though the anchor is directly overhead, there is very little rope in-service which means the rope cannot stretch or absorb much of the forces generated. In certain situations, without slack in these situations forces were generated that could injure a firefighter who is caught on belay (>5kN). Maximum arresting force should be under 4kN on the firefighter to ensure there is no injury created by catching them on belay.

Secondly, when using dynamic rope it is imperative to ensure there is minimal slack in the system. The fall distance increased significantly with the use of dynamic rope and with just 2’ of slack in the system the load fell just over 8’.  

The more slack introduced into a system, whether dynamic or static rope, increased fall distances impact forces. It was clear that belayers in escape system training must understand how important it is to minimize slack as much as possible.

Forces generated at the belay device and the change of direction anchor were all within acceptable limits for the equipment and anchorage used. The highest force generated at a COD anchor was 12kN when we put 4’ of slack in a system where the slack was between the COD and the test mass, instead of between the belay device and the COD anchor. It should be emphasized that if there needs to be slack in the system it should be between where the belay device can help absorb the shock by allowing some slippage and is likely to have more rope in-service than between the firefighter and the change of direction anchor.

Typically we hear that training facilities are building their anchor points to fall protection standards of 5000 lbs. That is perfectly acceptable, but with testing such as this we may be able to show that worst case scenarios will generate much less force than 5000 lbs.

After these tests the belay device was also operated to ensure it still worked as intended. There was never an issue where the belay device would not operate like it was designed.

Moving forward, we would like to test other belay devices and rope types. Some options will be the new GriGri +, additional testing with the MadRock Lifeguard, and semi-static ropes, as well as looking more at the effects of location of slack in the system, and how the distance from the change of direction anchor to the belay anchor impacts all the other factors.