How the Jaws of Life Work

Have you ever wondered what the Jaws of Life actually are? The Jaws of Life are a lifesaving device that firefighters use to extricate people out of crashed vehicles and other emergency situations. They’ve played a vital role in rescue procedures for years now with their simple but effective design. Today, we’ll be looking into how this miraculous tool functions in its many forms.

How Do the Jaws of Life Function?

The Jaws of Life are hydraulic tools, meaning they rely on fluid to help create the great amounts of force they need to function. There are three types of Jaws of Life tools, which we’ll be covering in a later section. Whatever the type though, the Jaws of Life require hydraulics to work as well as they do.

The head of the tool is attached to a gasoline or electrical power source via a set of hydraulic lines. The power source drives a compressor, which creates pressure in the hydraulic lines. The pressure in the hydraulic lines then feeds into the tool head. The tool head uses this pressure differently depending on its design and function. 

Cutters and spreaders feed the pressurized hydraulic fluid into a piston cylinder through one of two hose ports. This either closes or opens the tool head. It depends on which of the two hose ports the fluid flows though. An operator can flip a valve switch to change which port the hydraulic fluid pushes through, thus changing whether the tool opens or closes. Rams, meanwhile, use the hydraulic fluid to move the piston head inside a cylinder, extending and retracting it as needed to produce the ramming effect.

While oil is the typical hydraulic liquid in these types of tools and equipment, it’s unfortunately highly flammable. Because the Jaws of Life are often used in emergency situations where open flames or intense heat aren’t uncommon, Jaws of Life usually have phosphate ester fluid in their hydraulic lines instead. This fluid doesn’t conduct electricity and is nonflammable. Jaws of Life typically need about a quart of this fluid to work. Some systems can use electricity or pneumatics instead of hydraulics. 

Jaws of Life Machine Types

As we’ve mentioned, the Jaws of Life have different tool heads for various purposes. We’ve outlined these machine types in this section for easy reference.

Spreaders

Jaws of Life spreader heads spread compressed car frames and other collapsed structures. They begin in a closed position and apply force outward as they open, placing a great amount of pressure on anything in their way, like fiberglass frames and steel body panels. This allows firefighters to free victims who are trapped in or behind the pinched metal. Spreader heads have two pincerlike, aluminum alloy arms with heat-treated steel tips. Jaws of Life spreaders can exert about 60,000 pounds of spreading force, which is enough to lift about 10 elephants. The amount of force varies depending on the spreader’s size and design.

Cutters

Jaws of Life cutter heads also have a mouth that opens and closes, but they have larger claw-like pincers to bite through metal and other materials. They work similarly to spreaders and have aluminum-alloy housing with heat-treated steel blades. Cutter heads are best used when removing vehicle roofs or doors to get to the people inside after an accident makes the doors unusable. They work fast and are more precise than other metal cutting tools. This precision is exactly what makes them perfect for rescue operations. Other cutting tools like blow torches and saws are too risky in close quarters.

Rams

As we’ve explained, Jaws of Life rams use hydraulics to apply force through a piston rod. As the rod extends, it pushes against a surface. These tools are best for situations when a victim is trapped under a dashboard or other part of the vehicle. They can be positioned in such a way that they lift up the crashed part, allowing rescuers to remove the victim without anything collapsing on them.

Combination Tools

Jaws of Life combination tools are exactly what they sound like. These tools often incorporate both a spreader and a cutter into their design, allowing rescuers to save time on setup and switching heads. It also adds convenience to the process since rescuers can go from cutting to spreading easily. The precious seconds saved can be the difference between success and disaster.

Jaws of Life Tool History

The Jaws of Life have saved innumerable lives since they entered the rescue scene. But who invented the Jaws of Life in the first place? A race car parts manufacturer by the name of George Hurst first created these hydraulic rescue tools in 1961. When he saw how long it took for rescue crews to free a driver from a crashed car, Hurst was inspired to create a tool that could quickly and efficiently cut through the vehicle’s body. He named this first model the Hurst Power Tool. After a decade, Hurst improved the design, making it lighter and easier to manage. By the 1970s, it became popular with firefighters and eventually, after saving many victims from the jaws of death, the tool became known as the Jaws of Life.

The Jaws of Life have been an invaluable tool for rescuers since its release in the ’60s. Its simple but useful hydraulic design continues to prove itself in emergency situations. Now you know more about this brilliant invention, and can appreciate all it can do if you ever find yourself in a nasty accident.