The preparation and construction of the III stage of the Sofia Metro Extension started in the beginning of 2013, including the extension of Line 1 Eastwards – Lot 1 in the section Tzarigradsko Shosse – Druzhba residential district – Sofia Airport and Lot 2 – Mladost 1 – Business Park, with a total length of 7,6km and 7 metro stations.
Start Engineering JSC is one of the already established electrical engineering companies, whose teams have participated in each separate stage of the metro construction, from the first stations to the newly inaugurated stations in April and May this year. Start Engineering has been participated as a main contractor on metro stations Druzhba, Iskarsko Shosse and Business Park Sofia, while for the duration of the project they had successfully performed complete engineering, including the following: Electrical power supply of TPS/SS (Traction Power Station/Sub-Station) from urban substations – construction of new pipeworks for MV cables and equipment for fields in the urban substations, power supply of traction and non-traction utilities in the TPS/PS and the metro stations – 10kV MV and 0,4/2,3kV LV, power supply of the 825V DC catenary. Complete furnishing and electrical systems have been constructed with an equipment of Siemens, including Sitras Pro relay protections and Siemens 7SY61 and 7SY62 Switchgear.
The electrical engineers of Start Engineering have completely constructed a TPS/SS local control system – delivery of materials, equipment, software and commissioning of the signaling and control systems at three levels. A fiber optical network for data transmission has been constructed, working on the basis of programmable controllers, subordinated to a SCADA system. Entire communication and signaling system, including transportation automation, dispatcher control and monitoring system, transportation communication system, telephone system, train radio links system, public address system, CCTV, clock system, fire alarm system, automated ticketing system and others.
The company’s activities include execution of structural, architectural and building works, including water supply and sewerage of internal and external connections of the metro stations, heating and tunnel ventilation and water drainage systems. Alongside with that the teams of the company have also participated in the execution of all temporary and permanent reconstructions of existing utilities – power supply grid, street lighting of all boulevards above the metro lines, telephone networks etc.