Monorail Car

Overview

A monorail car is a passenger rail vehicle that runs on a single elevated concrete beam rather than a pair of rails. This is a straddle-beam type: the car sits astride the guideway beam on two bogies whose load tires roll on top of the beam while guide and stabilizing tires grip its sides. Rubber tires give a quiet ride and good grip on grades, AC traction motors drive the car, power comes from beam-side third-rail bus bars, and a train control and management system runs the vehicle.

The car is built from a Carbody Shell shell carried on two Straddle Bogie assemblies, with Traction Equipment for power, four Sliding Door door sets, the Interior, LED Lighting System, the Train Control & Management control system, Auxiliary Power for low-voltage loads, two Automatic Coupler couplers, a Emergency Evacuation System for emergencies, and the Vehicle Wiring Harness harness tying it together.

Carbody

The Carbody Shell is a welded aluminium-extrusion shell. Because the car straddles the beam, the Underframe (Beam Tunnel) includes a central beam tunnel that the guideway passes through. Two Side Wall Panel panels and a Roof Structure form the box, fourteen Side Window units glaze it, and a Fastener Set holds the structure.

Bogies and traction

Each Straddle Bogie wraps around the beam. Four Load/Drive Wheel units ride on top of the beam carrying the car weight and driving it; eight Guide Wheel units press the beam sides to steer; four Stabilizing Wheel units bear on the lower beam flange to resist roll. Each wheel is a Tire on a shared Wheel Rim with Ball Bearing supports. The bogie carries two Traction Motor units, each a Stator Assembly and Rotor Assembly with Copper Winding and bearings, geared down through a Final Drive Gearbox. Four Air Spring bellows form the secondary suspension between bogie and carbody, on a welded Bogie Frame.

Power and control of the motors live in the Traction Equipment. A Third-Rail Power Collector runs spring-loaded carbon shoes along the beam-side bus bars to pick up traction current. The Traction Inverter (VVVF) is a VVVF drive built from IGBT Power Module switches and DC-Link Capacitor capacitors that vary voltage and frequency to control motor speed, which also lets the inverter feed braking energy back into the supply. A separate Auxiliary Inverter (SIV) steps the line voltage down to run the lighting, HVAC and control loads.

Doors and interior

Each Sliding Door is a bi-parting electric sliding door: two Door Leaf panels driven by a Blower Motor operator under a Door Control Unit that carries a Bare PCB, an Microcontroller and Connector units. The Interior holds twelve Seat Assembly units, fourteen Grab Pole poles, Floor Covering, and two Roof HVAC Unit roof units, each with Blower Motor fans, a HVAC Compressor, control electronics and Relay contactors. The LED Lighting System system runs sixteen LED Light Fixture fixtures off a Wire Bundle and many Connector joints.

Control, power and safety

The Train Control & Management is the train brain. A TCMS Computer coordinates vehicle systems, a ATO / Signaling Board handles automatic train operation and signaling, four LCD Panel displays show passenger information, and a Public Address System drives announcements. Low-voltage loads are backed by Auxiliary Power, an 12 V Battery kept charged by a Battery Charger. Each Automatic Coupler joins cars mechanically through a Coupler Head & Draft Gear and electrically through a large Connector block. Because the car runs on an elevated beam, the Emergency Evacuation System provides a Deployable Walkway Panel that deploys to the side and a Emergency End Evacuation Door at the car end so passengers can reach a walkway in an emergency.