Transactions of the American Society of Civil Engineers, vol. LXVIII, Sept. 1910 The New York Tunnel Extension of the Pennsylvania Railroad, The North River Division. Paper No. 1151

"Transactions of the American Society of Civil Engineers, vol. LXVIII, Sept. 1910" by Charles M. Jacobs is a technical record from the early 1900s, chronicling the ambitious project to extend the Pennsylvania Railroad into New York City. It details the many considerations needed to connect the Pennsylvania and Long Island Railroads into the area, serving as a robust overview of the planning, engineering problems, and construction solutions. It's a look at the history of this huge project, from evaluating whether the railroad was feasible to the choices that advanced the project. Jacobs touches not only on the engineering strategies but also on the ways they overcame challenges. He sheds light on achievements, like the planning of routes and engineering breakthroughs needed for underwater tunnels. Furthermore, Jacobs gets into the techniques used in building the tunnel, highlighting the use of hydraulic shields to tunnel and different supplies to keep the structure solid under unsteady land.