Old Maude, Preface - Virtual Railroader

itself at the cutting edge of railroad electrification technology),
the Central planned instead to eventually extend its Hudson
Division electrification as far north as Albany with low-voltage
d.c. (The superiority of a.c. as a distribution system ultimately
discouraged any serious expansion of the Central's
electrification. The New Haven, after experiencing early
difficulties to the point of nearly abandoning its a.c. system,
extended its electrification to New Haven and set the standard
to be followed decades later by the Pennsylvania Railroad in its
electrification of what is now Amtrak's Northeast Corridor. As
of this writing, that system is expected to be extended all the
way to Boston.)
S-motor 110 at North White Plains, NY, 13 November 1966. Photo by Francis J.
Goldsmith, Jr.
A paper presented by Sprague at a meeting of the American
Institute of Electrical Engineers on May 21, 1907, provides some
insight into the Central's choice of system and the design of the
S-motors, so integral a part of the overall plan. What is
interesting is that by 1907 many of the claimed advantages of
d.c. over a.c. were discounted by at least some engineers, as was
evident by the comments of those attending the meeting. Yet
Sprague's approach to electrification remained unchanged.
Foremost in Sprague's approach was the assertion that the
locomotive's motor (Sprague's forte) is the starting point, the
key element, the first variable in the design process to be fixed.
For Sprague, this pointed to the d.c. motor because of its