Rope rescue techniques are the dominant skill set needed to effect a rescue in most technical rescue scenarios. As with any rope operation, organization of the rescue operation combined with rope proper systems will play a major role in a successful rescue. As with any rescue operations, proper planning and foresight throughout the operation will play a key role.
As with any operation a good size-up is needed. There are a lot of factors that will go into a confined space rescue size-up, but for purposes of this article we are going to focus on the rigging operation.
Confined spaces can be put into two categories:
- vertical - such as a storage tank
- horizontal - such as a large drainage pipe systems
Sometimes you will be faced with a rescue operation that encompasses both a horizontal and vertical space, such as a sewer system. It has a vertical entry point that transitions into a horizontal run. All confined spaces will present different and unique challenges however a solid skill set of rigging principals and the ability to adapt them to various spaces will allow you to perform these operations safely, efficiently, and effectively.
When performing a rigging size-up there are a few key things we're looking. One being anchor points and the second being the direction we want our rigging systems to travel. The anchor is going to be the most important aspect of your operation. Without it your rigging is useless. Bombproof anchors are our first choice but in the event bombproof is not a possibility thoroughly inspect your questionable anchor and be sure to back it up with an anchor of equal or greater size and strength.
The direction our rigging systems will travel ideally should always be in a straight line. In the event a straight line is just not possible simply utilize directional pulleys to redirect your system in the desired location. In other words, before you jump the gun and move your anchor point, steer your system with directional pulleys to its desired location. As with any system, changes in direction will create inefficiency's do to friction created by the bends in the rope. However the bigger picture, that being the victim, takes precedence. The minor friction loss you'll inherit by using directionals will in no way compromise your operation.
Let's take some time now to look at rigging techniques for these operations.
Let's first look at vertical rescue operations. All vertical operations will need to utilize an overhead anchor preferably directly in-line with the entry hatch. These overhead anchors can be attained several ways. The first being an I-beam. If you look at Figures 1 and 2 you will see a single point anchor system as well as a load sharing anchoring anchor system. Both were created by using an I-beam(s) as the anchor point. Rope, webbing, or anchor straps will all do the trick. Just remember when utilizing a load sharing anchor system be sure to keep the angle created in the neighborhood of 45 to 60 degrees.
We can also use what's called a beam clamp, a device that clamps onto an I-beam creating a point to anchor from. This application would be beneficial when the I-beam sits flush against the roof decking or provides little space to pass rope, webbing, or an anchor strap through.
The last means of overhead anchoring that we will examine is a tripod (see Figure 3.) A tripod is what can be considered a mobile overhead anchor. This is based on the fact that it can be easily moved from one location to another. There are however some limitations. The tripod needs a surface over the entry point to stabilize it's legs on. It is versatile in the sense that the legs can be at different heights and still maintain a level overhead anchor point.