In "Transactions of the American Society of Civil Engineers, Volume LXVIII, September 1910: Tunnel Extension of the New York Pennsylvania Railroad. Tunnels Through the City. Report #1158," authors Brace, James H. and Mason, Francis examine the enormous construction program undertaken by the Pennsylvania Railroad in New York at the beginning of the 20th century. This work is a detailed review of the technical challenges and innovations associated with the construction of a tunnel and branches in the center of the metropolis. The authors trace the history of the project from concept to implementation, consider the design and construction processes, and establish technical requirements and conclusions. Through the prism of this report, the reader can learn a lot of interesting things about engineering solutions to the needs of a big city and the transport system.