This is a really quick look at one of the many ways a tracking skate-block can be built and run. We often hear of folks looking for a easy way to get people from “top to bottom” without having to deal with the headaches of “the math”. And so while you’ll never be able to escape being responsible for safety margins and staying within them, there are systems that are easier to deploy than others; A track line skate-block is one of those systems.
Equipment to pay attention to...
- An artificial high point like an Arizona Vortex, TerrAdaptor or SMC Vector
- Rock Exotica Omni Pulleys
- An Anchor Plate
- Bi-Vocational lowering and progress capture type of device for the control center… like the Petzl I’d
In a trackline skate block system, the working line is the trackline in that the raise and or lowering system are all applied to the same system. Our AHD (here a monopod/gin-pole) was placed at the top of the cliff in order to gain the necessary height to get past the edge and away from cliff face.
The monopod/gin-pole was guyed appropriately with a quad-guy pattern and the AHD was errored forward appropriately (following the guy plane and applied force angles).
The skate-block shown here a classic setup where the twin tracklines (TTRS) begin at the base where the tensioning/lowering systems are deployed and run up through change of direction pulleys and back down to the patient… there by completing the circuit and becoming “the skate block”.
Advantages to a skate block as the working line (as opposed to a hybrid system) are a few folds:
- Only two ropes are needed… granted, they need to accomplish the length of the angled drop (2x the length plus another 15 meters minimum).
- Very few personnel are needed.
- Well suited for SAR teams and fire service teams alike.
A concern and something to remember is the pulleys at the AHD are part of the overall tensioning system, so caution needs to be placed with tensioning the trackline to much.
Key points here:
- High directional pulleys at the AHD
- AHD angle
- Guying patterns
- Gin-pole / Monopod
- Tensioning/lowering system
- Rope length
Peace on your Days…