Third Rail System & Areas of Usage :

There are two types of voltage lines that lie through the railways. First of them is generally placed on the line that lies above the train called as “Catenery Line” which is used mostly at intercity railways. Other one is placed beside one of the rail as a third rail and this type of voltage lines are used mostly at domestic railways.

Catenery System :

There are two types of “Catenery Line”:

1. Convensional Catenery System

2. Rigit Catenery System

Third Rail::

As the name implies, the third rail is a rail that be placed beside one of the rail. The train is energized by this third rail. Rarely, third rail might be placed in the middle of the two of the rails.

One of the advantages of the third rail is low voltage. It decreases the opening height of the tunnel since the electric poles are builded at the edge of the rails. This situation leads to decrease the cost and the construction time, at the same time. The electric voltage that we rectified by using diodes is 750 Volts. This voltage is transfered from third rail to train via current wedges. These wedges must be placed both sides of the train. One of the wedges must be contacted with the train in order to move the train. Otherwise, train will not move since power will not be transfered to the train.

Advantages of the third rail:

► The construction cost of the third rail system is cheaper than the aerial transmission lines. It is more appropriate to use this system on environments that have more favorable weather conditions like tunnels, bridges etc.

► Third Rail Lines are not in public sight. Aerial Lines are lead to visual pollution. The Aerial Lines that include electric poles and cables constitute seamy avenues and streets. Because of this reason, Singapore government banned the usage of Aerial Lines in public areas.

► The continuity of electric transmission on Third Rail System is much higher than the Aerial Line counterparts.

► It is more difficult to reach Aerial Lines. Therefore, the maintenance processes are easier on Third Rail Lines.

Disadvantages of the third Rail:

► Third Rail Systems may yield safeyt problems since they are placed near the rails. In case of “Rail Landing” of human factor might result in serious problems.

► Third Rail Systems are appropriate to use on metro lines that completely underground or have closed lines. It is not applicable to use on pedestrian areas, even if it is partially open.

► For İnfo : Murat KAYA

► Contact : info@yagizlastik.com.tr