Cutters The cutter is a pair of hydraulically powered shears that is designed to cut through metal. Cutters are most commonly used to cut through a vehicle's structure in an extraction operation. They are sometimes specified as to their capacity to cut a solid circular steel bar. Cutter blades are replaceable, and blade development progresses as vehicle technology progresses in order to be able to cope with the new car protection technology.
Spreader A spreader is a hydraulic tool that is designed with two arms that come together in a narrow tip, and that uses hydraulic pressure to separate or spread the arms. The tip of the tool can be inserted into a narrow gap between two vehicle panels (such as between two doors, or between a door and a fender), then operated to create or widen an opening. Spreaders may also be used to "open" vehicle doors from their hinges.
Combination spreader While a cutter or spreader tool is designed for a particular application, a combination tool (also known as a combi-tool or spreader-cutter) combines cutting and spreading functions into a single tool. 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. Spreader-cutters sometimes have lower capabilities when compared to the dedicated tool (e.g. a smaller spreading range) but may be useful where space is at a premium on
fire and rescue vehicles, or when the budget does not allow for a separate cutter and spreader tool. Many manufacturers utilize the body of their dedicated cutting tool for the combination tool. Specially engineered combination blades that are designed to spread and cut are used on the cutter body. If the end user decides later to add a separate cutter and spreader, the blades of the combination tool can be changed to make it a cutter only.
Extension rams An extension ram consists of a piston or telescoping cylinder that extends under hydraulic pressure to exert force on vehicle structures. Rams are used less often than spreader-cutters in auto rescues, but serve an important purpose of creating space in compacted vehicles. Rams can extend and apply directed force much farther than the arms of a spreader, making them ideal for reaching deep into crushed vehicle compartments. For example, a ram may be used to push away the dashboard to free a trapped occupant’s legs. There are many types and sizes of rams, including single-piston, dual-piston and telescopic rams. Sizes commonly vary from to (extended). Rams use more hydraulic fluid during operation than spreader-cutters, so it is essential that the pump being used has enough capacity to allow the ram to reach full extension. ==Power==