week to operate a railway system. Voltages over 66 kV are not desirable, as it raises construction costs.
It will be extremely difficult to change the location of a substation after the system has been commissioned. Therefore, the plan for the location of substation shall incorporate projected load distribution. The plan below assumes that trains composed of four cars are operated at intervals of 120 seconds in the final stage of the project and takes into account extension of the Green and Red lines and construction of the Blue and Yellow lines.
(2) Contact Rail
(a) Construction
Contact rails are simple in structure, have large current capacity, and are used to economize on construction and maintenance costs of structures.
There are two types of contact rail construction :.Upperside of Contact Rail and Underside of Contact Rail. Bangalore ELRT is recommended to adopt the top sliding construction that has been proven in Calcutta and Japan. It is also effective to reduce maintenance costs. Contact rail adopted by Tokyo Metropolitan Transit Authority (TMTA) in Japan is shown in Fig 7.4.1
