Technical Rescue: Old School & New School

Dec. 1, 2015
Bob Duemmel covers different techniques in rope rescue training.

The fire service is constantly evolving, and the rope rescue arena is no exception. At most departments, the training provided is based on the department’s desired skill level for its members. That means for many firefighters, the rope rescue educational path ends there. This situation presents a couple of significant challenges:

  • Skill atrophy: If you do not embrace ongoing education in rope rescue (or any response area that you deal with), your skills will drop off to a point where you can become ineffective when working an incident with other responders.
  • Conflicting training levels: Not staying current with training can create a situation where members of the same department have been training in different methods, leading to division among the ranks.

Both skills atrophy and conflicting training levels can create a difficult situation at the department. Consider a scenario where a new department member goes for training in a specialty area. The course consists of the most advanced and up-to-date methods being practiced at the time, which do not correspond with the training that the more senior department members previously received on the same area. Upon returning from training, the new member is full of energy and enthusiasm, and when they attempt to share the new information, they are met with resistance by those senior members who hold on tightly to their version of training. These types of responses have a negative impact on the recently trained member’s motivation and morale.

With this in mind, let’s take a look at some segments in the rope rescue arena to see how old school and new technologies can work together.

Safety knots

When I first began my training for rope operations, it was pounded into our heads that a knot is not a “proper” knot without a safety on it. This concept still holds true for some of the knots we use, including the Bowline and Square Knot. However, knots like the family of 8s really do not require a safety. When they are tied properly, the knot is very sound and actually locks down on itself.

Our state curriculum was recently updated to reference tail length on the family of 8 knots as being the critical aspect in the safety and accuracy of the knot. Now the spoken standard is a 6-inch tail or approximately a hand’s length of tail to be acceptable for rope. For webbing, a hand’s width or 4-inch tail is now accepted.

So why did the rope rescue community decide “all” rope end knots needed to have safeties? One answer jumped to the top of the list the most often: “If the responder puts a safety on everything, he or she will not forget when there should be one in place.” Fortunately, user responsibility prevailed, and the safety knots are now used in the specific applications where they were always needed and have been removed from those that do not have a need for them.

Load release hitches

First, we all have to agree that we need to have some type of device within your system to release a load in a controlled manner when needed.

The original system I was introduced to utilized the Mariner’s hitch as the release device on a progress capture system. The Mariner’s hitch was used on both the main line as well as the belay line. This provides some benefits but also has some limitations.

Once activated, the Mariner’s hitch has to be fully retied or replaced prior to the continuation of the operation. Through third-party testing, the Mariner’s hitch was determined to be Not Capable (NC) in the areas of release distances and in withstanding rescue-sized shock force and post-drop release capability.

Along came the British Columbia load release hitch or “BC Hitch.” This hitch became the go-to release hitch for the belay line, while the Mariner’s hitch remained the choice for main lines. During third-party testing, the BC hitch received an acceptable overall rating in most of its testing combinations.

Many times release lengths for any load release hitch come into the conversation. One thing we must focus on is properly rigging the device we are adding to the system. The device being added to the operation is usually a system rack (U rack) or a rappel rack. Make an effort to remove the maximum amount of slack between the rack and the progress capture device to minimize the distance required to transfer the load. This will allow for faster changeovers.

Our third generation of load release hitches is the 3:1 Radium hitch. During testing the Radium hitch received compatible ratings in all categories and an overall rating of “Recommended.”

The Radium has similar release capabilities as the BC hitch and is considered to be both easy to tie as well as to release. Another of its advantages is the ability to reset when activated, which eliminates the need to have multiple hitches on hand or to take the time to rebuild the hitch once utilized.

One of the biggest advantages we have found with the 3:1 Radium Hitch is the ability to use it on both the main line and the belay line.

The toughest part of each of these transitions was getting all of our responders on the same page. No matter if you are making changes in a single department, a county or within an entire state, the training and implementation time will be significant. This again reinforces the need for all responders to constantly train so that their skill levels are fresh and the methods being utilized are a part of their current skill sets.

New technologies

For many years our systems were a direct reflection of the limited types of equipment available to the responder. Over the past decade, we have experienced a major growth spurt with new equipment available to the rope rescue community.

One of the latest technologies to hit our market is the multi-purpose device, such as CMC Rescue’s MPD (Multi-Purpose Device) and the Petzl I’D. A key advantage that these new technologies bring to the table is their safety features. If the operator makes a mistake, or is not properly prepared for the task at hand, the devices will lock down, preventing movement.

Note: There should always be a backup system in place no matter what level of technology you are using to keep the operation safe for all involved. I know that there are agencies that use single-line systems due to specific applications within their home environment. Those are the exceptions to this theory.

So what do the multi-purpose devices provide the responder? They accomplish the work of multiple pieces of equipment in one device. You can control a descent, belay a line, function as a progress capture device, and quickly establish various haul systems with these devices.

Both of the devices mentioned can be used in pairs to create a mirrored system, which we will cover later in this article.

When these devices are placed in the main line system, you can effectively eliminate the:

  • Descent device
  • Progress capture device: load release hitch and attachment (Prusik, Ascender or Rope Grab)

This lightens your equipment load when working in remote locations that require packing your gear to the scene. Additionally, the setup time is much quicker due to the minimal number of equipment pieces required to accomplish the task.

When these devices are used as the system belay device, you can eliminate any other devices and/or systems you previously used. One of the primary systems used for the belay position is the Tandem Prusik Belay, which consist of:

  • Two Prusik cords
  • A load release hitch of choice
  • And (many times) a Prusik-minding pulley

Once again we have decreased the number of pieces of equipment required and provided for a quicker setup time once on scene.

With our traditional systems, setup time is a major factor in getting your operation in motion. We often have our rescuer dressed and waiting on the edge for their systems to be assembled. With these new technologies, the opposite is becoming the norm; the systems are waiting at the edge when the rescuer completes their preparations.

New technologies will never replace training and preparation; however, by using these devices, you are able to affect a more timely response for those in need.

Pre-rigging has been a part of the rope rescue community for some time. Setting up prebuilt 4:1 systems—or having the components for RPMS (rack, pulley, Mariner’s and system) or RPRS (rack, pulley, Radium hitch and system) on a rigging plate—all work to enhance your efficiency on a call.

You can do the same with these new technologies. We have standardized our primary go-bags with the following:

  • MPD or I’D, depending on the vehicle.
  • One single Prusik-minding pulley with swivel and pivoting side plate (this eliminates the need to open and close carabineers once the system is set up and safety checked).
  • One double Prusik-minding pulley with all of the features of the single pulley we use.
  • A rope grab device. We utilize an ascender for this position; however, you could use a Prusik or commercial rope grab with equal success.

These systems can be carried in pairs so we can work mirrored systems, or they can be split up to support multiple operations when paired with traditional systems.

No matter what you chose for you primary application, you still must practice with all of the pieces in your inventory. You never know when you will look for one system to accomplish the task and find it already in use and have to revert to another option to complete the task.

Mirrored systems

The term “mirrored” references systems that are capable of performing as the main line and belay at the same time. In this case, if either of the two ropes were to fail, the other rope in the system would become the belay line. The mirrored system provides a more streamlined operation, as the responder now has to be proficient in one operational setup.

The difference between a traditional two-line system with a main line and a belay line is that the main line is at full tension with all of the rope’s designed stretch applied to the rope due to the load it is carrying. The belay line, however, is run in a slack mode, meaning the rope has not experienced designed stretch when loaded. The farther your rope system is deployed, the farther the “stretch” or elongation of the belay will be in the event of a main line failure. (For more about rope elongation and its impact on a system, visit Firehouse.com/xxxxxxxxx and see a side-by-side comparison of both systems.) Even with a textbook belay operation, you cannot overcome this additional travel distance and resultant forces being generated on the line.

With the mirrored system, both lines are at (or close to) their designed elongation limits. In theory, the load is being shared between both ropes. In this case, if there is a failure of either line, the resulting “belay line” will have minimal or no stretch taking place, which will capture the load sooner and in a less violent manner.

Conclusion

There are many variations of the systems mentioned in this article, and in many cases, they are very safe methods to use. Take some time to review your own programs to ensure that all of your responders are ready when called into service.

Online Exclusive Content: Traditional Rope Rescue Systems vs. Mirrored Systems                                  

Rope is designed to stretch; this is a good thing. However, it can have a major impact on your rope rescue operation in the event of a main line failure with the load being caught by the belay line.

NFPA 1983: Standard on Life Safety Rope and Equipment for Emergency Services defines elongation as “the increase in length, expressed in a percent of the original gauge length that occurs in a sample of new rope when tested as specified herein.” Chapter 7.1.1 states, “The minimum elongation shall not be less than 1 percent at 10 percent of the breaking strength, and the maximum elongation shall not be more than 10 percent of breaking strength.” Further, General Use “G”-rated rope is defined as rope that will have a minimum diameter of 11mm and a maximum diameter of 16 mm.

After reviewing multiple brands of rope, I found the general elongation percentages to fall between 6 percent and 7.7 percent. For the sake of the following example, we will use 6 percent as our constant.

Comparing the traditional main and belay to the mirrored system, we see the following results as related to potential arresting distances during a main line failure.

Traditional main line and belay setup

The main line is out 150 feet when there is a catastrophic failure of the system. The belay device is activated immediately and the arresting process of the rescuer and victim begins.

  • When the main line failed, the belay line first had to have all slack taken up for the device to activate and capture the load. (Remember, the belay is not loaded, so upon the failure of the main line, the belay is not instantly activated due to the lack of pressure on the device of choice.) This is a secondary factor in the travel distance prior to the load being properly arrested.
  • The belay line then has to reach its rated elongation once it is activated. With 150 foot of rope being used and an elongation of 6 percent, the additional distance of travel would be approximately 9 feet.
  • When you add the 9 feet of elongation to the existing slack in the rope, you will have 10 or more feet of travel on the belay line before the system is fully arrested.

Mirrored systems

With the main line and belay line out 150 feet in a mirrored system, both of the lines will have been elongated to near or at their designed percentages as both are carrying the load.

  • When the main line failed (could be either line as both are under load), the belay line (or remaining line) had already been elongated to equal or close to its designed percentage of stretch.
  • The new technology devices (either the MPD or I’D) activate into a break mode much faster than some of the traditional belay systems, such as the tandem Prusik belay, which is dependent on the operator’s ability to have all components positioned for a quick capture of the load once it begins to flow through the system.
  • The arresting distances will be minimal using the mirrored system.

By eliminating as much of the distance of travel once a main line fails, we have provided the rescuer and victim with a safer system. We have also decreased the chances of component failures within the system by eliminating much of the impact force on these components.

About the Author

Bob Duemmel

Bob Duemmel was the technical rescue editor for Firehouse Magazine and Firehouse.com. A deputy coordinator for Special Operations in Monroe County, NY he recently retired as a captain with the City of Rochester Fire Department. Bob's involvement in technical rescue is very diverse. He is the Plans Manager for New York Task Force-2 USAR Team, a member of the Western New York Incident Management Team and a member of the New York State Technical Rescue curriculum development team. He is a nationally certified instructor with a focus on technical rescue programs. He has delivered training to fire service, industrial, military and international rescue teams and has assisted with exercise evaluation for the United Kingdom and the European Union's USAR program. Bob has also participated in numerous USAR exercised as both a participant and evaluator. He hosted “The Buzz on Technical Rescue” podcast.

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