The inauguration ceremony of India’s first under-river metro tunnel in Kolkata by Prime Minister Narendra Modi showcased a remarkable feat of engineering and collaboration. One of the critical components ensuring passenger safety in emergency situations within the tunnel is the installation of Danfoss VLT FC-102 Variable Frequency Drives (VFDs). These VFDs, supplied by Danfoss, are strategically placed on trackway exhaust fans and tunnel ventilation fans. The tunnel, which traverses under Kolkata’s iconic Hooghly River, is set to revolutionize transportation in the city by connecting Howrah Maidan to Esplanade.
Understanding the unique requirements of this project was paramount. With the length of the tunnels considered, along with the necessity for specific braking mechanisms in emergency or fire modes, Danfoss provided tailored solutions. The bidirectional nature of the fans required careful consideration, particularly in scenarios where the fan operates both as a supply and exhaust unit during fire emergencies.
In the event of an emergency, the VFDs are designed to swiftly activate braking, dissipate additional heat via brake resistors, and reverse fan direction, all within a mere less than a minute window. This rapid response ensures the safe evacuation of passengers and staff, underscoring Danfoss’s commitment to safety and efficiency.
Mr. Ravichandran Purushothaman, President, Danfoss India, expressed his admiration for the project’s innovative solutions, particularly highlighting Danfoss’s contribution. “The successful integration of Danfoss drives in the historic Kolkata under-river metro tunnel project signifies a remarkable leap in safety and operational efficiency within metro networks. This endeavor sets a new benchmark for technological advancements in ensuring passenger security during emergencies, solidifying Danfoss’s commitment to pioneering solutions for critical infrastructure needs. It’s a moment of pride for Danfoss to be an instrumental part of this transformative project, demonstrating our unwavering dedication to delivering tailored solutions that prioritize safety and operational excellence”
The contract, valued at 1.3 crores, was secured through a contractor, with Danfoss supplying a total of 82 VFDs solely for the fans. The breakdown of the supplied VFDs includes 28 units of 200kW, 48 units of 75kW, and 6 units of 22kW.
This project stands as a testament to Danfoss’s expertise and commitment to meeting customer needs while prioritizing passenger safety and energy efficiency. As the first underground water tunnel in which Danfoss drives have been implemented, it sets a precedent for future metro projects worldwide.