Pysäytysjarrulla

Pysäytysjarrulla is a Finnish term that refers to the emergency brake mechanism used to stop a vehicle quickly in a situation where normal braking may be insufficient or unsafe. The term combines pysäytys (stopping) and jarru (brake) and, with the adessive suffix -lla, indicates the device or means by which stopping is achieved. It is typically distinguished from regular service brakes and is designed to provide a rapid, independent means of halting motion.

In practice, pysäytysjarrulla is activated by a person in need of immediate stoppage, or by a safety system triggered by an operator. Activation commonly involves a dedicated control such as a red handle, lever, or button located at accessible points on the vehicle or vehicle interior. Once engaged, the brake system applies heavy braking force to halt the vehicle as quickly as safely possible and may initiate automatic safety procedures, such as bringing all units to a stop or isolating traction.

The use of pysäytysjarrulla is most common in rail and public transport contexts, including trains and trams, but the concept can apply to other transport and safety-critical equipment where an emergency stop is required. After an emergency stop, authorized personnel typically inspect and reset the system before normal operation can resume, ensuring that the vehicle and braking system are functioning correctly and that any fault conditions are addressed.

Etymologically, pysäytysjarrulla derives from pysäytys (stopping) and jarru (brake), with the binding meaning of the instrument or mechanism used to stop. The exact design, location, and procedures associated with pysäytysjarrulla may vary by vehicle type and era.