TBM S-639B, nicknamed Vidyarthi, is an Earth Pressure Balance machine manufactured by Herrenknecht. Commissioned in January 2024, it is the fourth TBM for Kanpur Metro Phase 1. TBM Vidyarthi's primary task is to construct a tunnel on the 23.78 km-long Line-1, linking IIT Kanpur to Naubasta.

In June 2024, TBM Vidyarthi completed its first assignment by constructing an underground tunnel about 1,250 meters long (down line) between Kanpur Central Station and Nayaganj Station. Following this, the machine undertook its second assignment, completing a 331-metre-long tunnel from the ramp near Swadesh Cotton Mills to Transport Nagar Station in November 2024. Currently, TBM Vidyarthi is working on its third assignment, constructing an underground tunnel from Transport Nagar Station to Kanpur Central Station via Jhakarkati.

The Afcons-Sam India consortium secured the underground Package KNPCC-06 from the Uttar Pradesh Metro Rail Corporation (UPMRC) at a value of Rs 10.87 billion. The contract, which has a 36-month deadline, involves connecting Nayaganj Station and the Transport Nagar Ramp through three underground stations: Kanpur Central, Jhakarkatti, and Transport Nagar Station.