Torque

In the case of a fire, a firefighter would hook up a hose to the valve of this hybrid fire hydrant. He/She would then turn the red wheel to allow the pressurized water in the hydrant to be pushed through the hose and onto the fire. This task would be very difficult without special tools since the wheel's diameter is very large, it is pulled tightly to prevent pressurized water from bursting out of the valve, and is rusty. To turn the wheel, the firefighter would have to exert a significant torque. If the firefighter could not exert enough torque, he/she could increase the lever arm by attaching a clamp to the wheel with a bar attached. The firefighter could then push on the extended bar to turn the wheel, as the force necessary to exert a specific torque is inversely affected by the length of the lever arm.