4 elements of shore-based water rescues
Match the parameters of your water rescue with the appropriate shore-based rigging or deployment of motorized watercraft
Water rescue scenarios in which the environment does not cooperatively line up with your primary capabilities seems to be the norm in my experience. In basic terms, let's qualify what type of water environment might guide our decision to deploy motorized watercraft or a simplistic shore-based approach, such as a two or four line tether.
A shore-based approach usually involves current that is too swift for our watercraft to safely and efficiently motor up river; and may involve down river conditions and current that would be considered high hazard due to strainers, objects or other significant water hazards.
This picture we have just painted would imply that a motorized watercraft deployment would be extremely high risk. If the watercraft lost power and failed to perform a critical maneuver, it would be swept down river into significant hazards and may not have the ability to power up into a safe position.
When performing a risk benefit analysis of this scenario, the victim presentation will initially drive the rescue decision, followed by the safety, skill level and resources of the rescue team. I am still a big believer in risking a lot to save a lot for a viable victim, provided the rescue team is adequately prepared for the task at hand.
For the purpose of this article, we will focus on analysis resulting in a decision to switch gears and go to a secondary rescue approach during a water rescue. These approaches usually take more time to develop, but provide more safety and a higher probability of a successful rescue.
Moveable control point water rescues
The rescue approach we are working our way up to here has many names. This system is commonly referred to as a movable control point, tyrolean traverse or high line with reeving system. Although these terms may reflect some subtle nuances between the systems, the general premise and application is the same. It involves a tensioned line positioned perpendicular to the current and has control lines integrated with a watercraft or buoyant rescue platform that can traverse across the line as well as up and down river.
These measures are implemented through shore-based personnel who manage the system with minimal rescuers out on the water in the craft. One of the biggest challenges with these systems is developing the ability to deploy and operate them with limited manpower in a timely fashion.
We recently worked with a group overseas comprised of very advanced practitioners in operating this type of the system. However, they rarely used it in scenarios because it was too manpower intensive and took too long to build. On average, they were using 12 rescuers and the system would require approximately 45 minutes to put in place and operate. Most of these resources were used due to what I would consider overkill.
Their system utilized twin track lines or two tensioned lines and required shore-based personnel to be located on opposing shores to operate the system. They were also using hardware that was somewhat elaborate to rig and operate, resulting in delayed development of the tensioned lines and slowing the entire operation down.
We dedicated two training days to a more minimalist approach to the system. At the end of the two days, this team was launching from the staging point by motorized watercraft, identifying the victim, building the system and retrieving the victim with six rescuers in less than 15 minutes. The restructured approach and techniques used in the movable control point now made it a usable option for the team.
Align rescue techniques with mission parameters
The rescue techniques we elect must always match the parameters of our mission objectives. Here are four elements of water rescue we shared with our fellow rescue professionals across the pond:
1. Eliminate twin track lines.
Although these systems mimic the design of vertical high line systems, they do not mimic the loads produced. Twin lines, in my opinion, are over engineering when being utilized in a horizontal loading configuration on water.
2. Have a well mapped out plan for carrying and deploying your resources.
If a rescue system requires a special requisition of gear, the likelihood of it being used in a real scenario in a timely fashion is slim to none. Conversely, carrying a massive quantity of hardware and software on your watercraft is also not a recommended practice. Hence, a more minimalist approach is advised.
3. Know your bodies of water, and pack versatile rope on your watercraft.
Have a variety of methods at your disposal for transferring the line from one shore to the other. Options can include pneumatic line guns; mechanical messenger systems, such as sling shots; or line ferrying via watercraft. Watercraft ferrying is an important technique to train on because many river bodies in these conditions may not be accessible from both shores.
Also, the rivers may be swollen and raging, and the trees that you may be selecting for anchors may be in the current. In this situation, a boat crew may need to deploy the line to the anchor and pin the craft against the anchor while the line is secured. There are several approaches to configure and stretch the line, but this is the way I believe works the best:
- Place a three-man crew in the motorized craft. Select a launch point slightly up river from the objective anchor if the craft cannot effectively power up river. Take the rope (preferably ½ inch life safety low stretch rescue rope), and place it in the bow of the craft. Evaluate the diameter of the tree across the river and pull out an appropriate length of rope to perform a high strength tie off or tensionless wrap on the anchor. Pre-rig this end of the rope with an appropriate G-rated carabiner and knot (typically a figure eight on a bight).
- Then place a crew member in the bow with the rope bag, a crew member in the middle of the craft and a craft operator. Take the opposite end of the rope then and give it to the crew on the near shore before launching. When ready to launch, the pilot sets a good ferry angle and motors toward the objective.
- While traversing the river, the middle crewman holds the rope up from the center of the craft while the bowman feeds rope out of the bag. The near shore crew also works to keep the rope up and out of the water. This deployment technique allows the craft to maintain control of its ferry angle and simply play out rope as needed. It also prevents the crew members in the craft from holding onto the end of a rope which they will be reluctant to let go of – which often results in a crew member swimming.
4. Develop support elements on the near shore.
The shore crew should be working diligently to develop the support elements on the near shore. The first objective is to establish an anchor and rig the tension line through a progress capture device with tensioning capabilities. The CMC MPD is an ideal piece of hardware for this application. Initially, the end of the tension line is simply rigged into the MPD, which is secured to an appropriate anchor. Once the watercraft crew has the far side anchor established with a high-strength tie off, the near shore crew can then pull all of the excess rope across by manually pulling through the MPD. Once the slack is all pulled through, the line can then be tensioned.
It is important that rescuers do not over-tension the line. There are formulas for tension in a vertical application, but for horizontal applications that are less than 300-foot stretches, a compound 3:1 ratio with a single rescuer tensioning the line is adequate to apply appropriate tension. Once the line is tensioned, the far side watercraft crew can secure a glide connection to the tension line from the bow of the craft if necessary, set a motorized ferry angle and work their way back across to the support crew.
Once the primary line is tensioned, the support crews should lay out three control lines: one line for river right movement, one line for river left movement, and one line for river up and down movement. To connect all of these lines into the system, follow this progression:
- Set a gibbs style ascender on the line with the direction of travel facing the far shore. Rig in a pulley and pass one control line through the pulley. Place one end of this control line on the near shore, oriented slightly up river from the tension line. Now place a rock exotica side click style pulley with integrated swivel on the tension line. This pulley will be referred to as the movable control point. This MCP should be placed between the near shore and the ascender. The other end of the control line that was fed through the ascender pulley can now be tied into or connected into the swivel on the MCP pulley. This control line can now control river left movement.
- Now take another control line, place it on the near shore slightly down river from the tension line and tie it or connect it into the swivel of the MCP. This should be an opposing line to the one already established on the swivel. We now have our river right line.
- The last line to be established is the river up and down line. The most simplistic approach is to rig an additional pulley into the bottom of the swivel on the MCP. Simply pass the up and down line through the pulley and connect it to the bow of the craft, resulting in a 1:1 MA to the craft. This may not be adequate for hauling the craft up river. If more mechanical advantage is expected to be necessary and manpower is minimal, placing a pulley on the bow of the craft and redirecting the line back up to the MCP results in a 2:1 MA at the craft. If additional advantage is required, a 3:1 piggyback can be established off of an anchor at the near shore. This supplemental anchor should have an MPD or other appropriate device to control the lowering of the craft, convert to hauling the craft, and capture the progress of the movements. This is an important safety element for this system.
- Deployment of the craft is the next step. This system is designed to be totally managed from the near shore because of the COD pulley on the ascender that we have applied on the tension line. This COD has to be set at the appropriate position on the water and it is imperative that the set point is accurate.
Another absolute key to success is the placement of the pick off strap or adjustable anchor strap between the craft and the MCP. The purpose of this attachment is to maintain proximity of the craft to the tension line while the craft ferry’s out into position. If this fixed connection is not established, then the crews will have an incredibly difficult time managing the control lines. To set the COD, a crew member in the bow reaches out over the bow and hooks the MCP with his or her arm. The craft operator then sets a ferry angle and motors across the river until the COD is at the furthest possible operating boundary for the evolution. This can also be accomplished without a motorized advancement by pulling the craft down the tension line.
Once the boundary for the COD is established, the fixed safety tether can be disconnected and the craft can be lowered down river and maneuvered river right, bringing the craft to the victim. Once the victim is secured, it is advised to pull the craft back up to the tension line and reconnect the safety tether before hauling the craft back into the near shore with the river right control line. Avoid river left movement when the craft is not connected with the safety tether. If the craft is deployed down river and crews want to move the draft river left, this is in essence a mechanical disadvantage of a 1:2. When the crews pull on this control line, the craft will be attempting to come up river and travel river left. This is a very challenging maneuver for the support crew and can quickly overwhelm their hauling capability.
There are numerous ways to approach, design and operate these systems. Whatever technique you choose, remember the importance of training on that technique to the point of mastery. Always keep a realistic timeframe in mind and choose the approach that works best for your crews.
Give this one a try and give us some feedback on your challenges or success with it. Train hard and be safe!