Hydraulic rescue tools

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A hydraulic spreader in use

Hydraulic Rescue Tools are used by emergency rescue personnel to assist vehicle extrication of crash victims, as well as other rescues from small spaces. These tools include cutters, spreaders and rams. They are popularly referred to in the United States as Jaws of Life, a trademark of Hale Products Inc.

Hydraulic rescue tools are powered by a hydraulic pump, which can be hand-, foot-, or engine-powered, or even built into the tool itself. These tools may be either single-acting, where hydraulic pressure will only move the cylinder in one direction, and the return to starting position is accomplished using a pressure-relief valve and spring setup, or dual-acting, in which hydraulic pressure is used to both open and close the hydraulic cylinder.

[edit] History

Previously rescuers often used circular saws for vehicle extrication, but these suffered from several drawbacks. Saws can generate sparks, which could start a fire, create loud noise, which could stress the victim, and are often slow cutting. Alternately, rescuers could try to pry open the vehicle doors using a crowbar or halligan bar, but this could compromise the stability of the vehicle, further injure the victims, or unintentionally activate vehicle airbags.

In comparison, hydraulic spreader-cutters are quieter, faster, and more versatile: they can cut, open, and even lift a car. Jaws of Life is a trademarked line of tools originally developed by Hurst Performance for use in auto racing. A hydraulic spreader was originally developed in 1972. Hurst later developed a cutter and a hydraulic ram

[edit] Tool types

[edit] Spreader-Cutters

A combination spreader-cutter with a built-in, manually operated pump

Detail of a combi-tool's blades.

In operation, the tips of the spreader-cutter's blades are wedged into a seam or gap — for example, around a vehicle door — and the device engaged. The hydraulic pump, attached to the tool or as a separate unit, powers a piston that pushes the blades apart with great force and spreads the seam. Once the seam has been spread, the now-open blades can be repositioned around the metal. The device is engaged in reverse and the blades close, cutting through metal. Repeating this process allows a rescuer to quickly open a gap wide enough to pull free a trapped victim. The blades can spread or cut with a force of several tons or kilonewtons with the tips of the blades spreading up to a meter.

This operation can also be performed by dedicated spreading and cutting tools, which are designed especially for their own operations and may be required for some rescues.

[edit] Rams

An Amkus Ram

Rams are used far less than spreader-cutters in auto rescues; nonetheless, they serve an important purpose. There are many types and sizes, including single-piston, dual-piston and telescopic rams. Sizes commonly vary from 20" to 70" (extended). Rams use more hydraulic fluid during operation than spreader-cutters, so it is essential that the pump being used have enough capacity to allow the ram to reach full extension.

A ram used to push the forward block (motor and dashboard) away from the driver. In this photo the driver's seat can be seen at the right. The steering wheel has been bent upwards, and the driver's door has been removed. The front driver's-side wheel can be seen at left. Driver and front passenger airbags have deployed, and can be seen as piles of white fabric. The ram is seen in the lower portion of the picture; it is labeled "holmatro".