As some factories grew too large and complex to be powered by a single steam engine, a system of "sub divided" power came into use. This was also important when a wide range of speed control was necessary for a sensitive operation such as wire drawing or hammering iron. Under sub divided power, steam was piped from a central boiler to smaller steam engines located where needed. However, small steam engines were much less efficient than large ones. The Baldwin Locomotive Works 63-acre site changed to sub divided power, then because of the inefficiency converted to group drive with several large steam engines driving the line shafts. Eventually Baldwin converted to electric drive, with a substantial saving in labor and building space.