PartⅢ Passage
Metro Vehicle
In China，there are only two types of metro vehicles，named motor car and trailer，but vehicle structure and technology are very different from each other for different cities.Motor car can obtain power from current collector，but trailer can't do it.
A metro train includes the following parts：body and door；bogie；coupler buffer connecting device；brake device（air brake，rheostatic brake，regenerative brake，electromagnetic rail brake）；current collector，conductor rail collector，shoe gear，collector shoe；interior equipment（electricity，ventilation，heating，air conditioning，seat，handle，accumulator box，relay case，main control box，motor air compression unit，power source transformer，electrical switch，contactor box）；electrical system（power circuit，main circuit，auxiliary circuit，control circuit），etc.The main subway equipments on vehicles include coupler buffer devices，bogie，door，body.
A six-car train comprises two three-car units.These units are coupled by a semipermanent bar coupler
Each three-car unit comprises：
—A Driving trailer（Dt）；
—A Motor vehicle，equipped with a pantograph（Mp）；
—A Motor vehicle-intermediate（Mi），without a pantograph.
The body shell is a welded aluminium fabrication with a stainless steel fire barrier in the floor.
The passenger areas are laid out to achieve maximum standing areas while providing 50 seats arranged along the sidewall.Two rows of ceiling mounted fluorescent lights extend the length of the saloons，with emergency lights positioned above the doors and gangways.Both the normal and emergency lighting are powered by two independent circuits.This split circuit reduces the risk of total lighting failure.
Passenger comfort is maintained by a ventilation and air-conditioning system and a comprehensive communications system provides audio information.
Access to the train for disabled passengers is facilitated by level boarding between the platform and the train floor.Two seats have been removed in each Mp car to provide a secure location for wheelchair bound passengers.
New Words and Expressions
地铁车辆
在中国，地铁车辆虽然只分为动车和拖车两大类，但各城市地铁车辆的技术与结构形式仍存在较大差异。动车是指有动力来源的车辆，而拖车则没有动力来源。
地铁列车包括以下几个部分：车体和车门、转向架、车钩缓冲装置、制动装置（空气制动、电阻制动、再生制动、轨道电磁制动）、受流装置、第三轨受电器、汇流装置、集电靴、内部设备（电、通风、采暖、空调、座椅、扶手、蓄电池箱、继电器、主控制盒、电机空气压缩机、电源变压器、电气开关、接触器箱）、电气系统（电源电路、主电路、辅助电路、控制电路）等。地铁车辆的主要设备包括车钩缓冲装置、转向架、车门和车体。
六辆编组列车由两个三节车辆单元组成。这些单元通过半永久牵引杆而连接。
每个三节车辆单元的构成：一节拖车为驾驶室；一节动车，安装有受电弓；一节中间的动车，不带受电弓。
车架采用焊接铝型材为原材料，地板面采用防火的不锈钢制成。
乘客区域沿车体侧墙设有50个座位以保证最大的站立面积，配有两列沿天花板全长布置的两列日光灯，以及安装在门体上方和过道的应急照明灯。正常照明和应急照明分别由两个独立的电路进行供电。这种分开式供电电路能够减少整车照明失效的风险。
乘客的舒适性由通风系统、空调系统和提供音频信息的综合通信系统来保证。
在站台和列车地板面之间设有水平踏板，以此为残障乘客提供进入列车的便利条件。每节带受电弓动车上都拆除了两个座位，用来为乘坐轮椅的乘客提供安全位置。