A steering brake is a device that allows an operator to turn or steer a vehicle by applying a brake. Typical vehicles that employ a steering brake system are bulldozers, tractors and airplanes. The steering brake works by applying the brake on the side of the vehicle corresponding with the direction the operator wishes to turn. By applying the left brake, the vehicle's right side will continue pushing the vehicle around to the left and a left turn will occur. By applying both brakes, the vehicle will come to a stop.
This type of system was first introduced on the Caterpillar track-driven tractor because it prohibited conventional steering components. The principal is based on the same mechanics as steering a boat. By placing resistance to one side of the craft, it is forced to pivot around the resistance, resulting in a turn.
The steering brake was employed on conventional wheeled tractors in an effort to turn the machine's when pulling a plow. The force of the plow digging into the ground made it difficult to turn the tractor with the front tires. By applying pressure to one wheel at a time, the operator could control the direction of the tractor while keeping the throttle applied and the plow in the ground. This resulted in much straighter furrows and better looking fields.
Many aircraft use a steering brake to turn when maneuvering on the ground. The pilot applies the brake on the wheel representing the direction that the plane needs to turn and pushes the throttle ahead. The plane rotates around the braking wheel and the turn is completed. This can be an extremely difficult and dangerous procedure at take off and landing speeds. Pilots work hard to achieve the smooth application of the brakes which results in smooth turns.
Many race car builders design a brake cut-off switch into oval track cars resulting in a type of steering brake. By eliminating the right front brake, the car is much easier to turn into the left-hand corner. The driver has the ability to adjust the brake bias between the front and rear of the race car as well as to cut the right front brake off. This application is particularly common on dirt track cars where the driver pitches the car into the corner in a controlled drift or slide. The downside to this steering brake is that it causes many cars to spin out when the brakes must be applied suddenly to avoid a mishap.