Brake Introduction

Roller Coaster Brakes are placed in specific areas along the track.  Normally there are several brake segments that form a barrier or block.  This is where the track’s block zones are formed.

The brake segments are either a Master or Check.  Check brakes are a slave to the Master’s Emergency Stop Air that is used to “cage” the E-Stop Spring.  With that exception, the brake segments operate independently.

 

     Brake Operation

The Brakes require air pressure to “cage” the E-Stop Spring, as seen in the following diagram.  Additionally, there is air pressure applied to the opposite side of the bladder which applies the stopping force for normal operation.  When the brake is commanded to open, the air pressure is released from the larger cans and applied to the smaller, opening cans.  The idea is that during a malfunction of the relase of air from the small can, the larger cans will overpower the smaller one.

     Fail Safe

The brake segments should be fail-safe.  Fail-safe means that when a failure occurs, the brakes will fail in a closed and compressing state.

 

     Sensors

The Ride Control System, if designed correctly, should monitor the “adequate” air pressure used to apply stopping pressure to the brakes and “vented” air pressure used to “cage” the Emergency Stop Spring.  Additionally, there should be a proof of closure proximity sensor mounted on the

brake segmentBe specific. If you know exactly what the system will be, say it here.

 

       “Adequate” Air Pressure Switch

This sensor monitors the air pressure coming from the compressor that is used to apply pressure to the brake therefore squeezing the train’s brake fin.

       “Vented” Emergency Stop Air Pressure Switch

This sensor monitors the absense of air pressure in the Emergency Stop can where the Emergency Stop Spring is located.  The air pressure actually “cages” the spring so the brakes are allowed to operate with the supply air pressure.

 

 

       Brake Position Proximity Sensor

This sensor is an inductive sensor that is able to detect metal such as steel, brass, copper and aluminum.  Typically this sensor is mounted so it detects a piece of the movable part of the brake caliper when it is in a closed position.  The sensor will confirm that the brake is closed and in a safe state.  With the sensor in this position, any failure of the sensor will be detected prior to it being needed to stop a train.  If the sensor fails OFF when it should be detecting a closed brake, then the Ride Control PLC will cause an E-Stop.  If the sensor fails ON, the Ride Control PLC will detect it during its next normal operation.

     Trim vs. Stopping Brake Solenoids

Some applications may require that the brakes be used for two functions.  The first being Trim or to trim some of the speed off of the train at specific points along the track.  It may be at the Block Brake or at the Slowdown Brake.

This is accomplished by having two separate air regulators set to different operating pressures.  The Trim pressure would be set to ½ or ¾ of the stopping pressure regulator.

     Ride Control System

During each cycle the Ride Control System PLC verifies that the brake is functioning properly.  If there is any disagreement between air supply pressure and the position of the brake (open or closed) the Ride Control System can post an alarm message or cause an Emergency Stop to prevent train cycling until the brake can be fixed.