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Electricity, which had been discovered back in the 18th century but had never amounted to more than a scientific curiosity, became a source of mechanical force in the early 19th century when Samuel F. B. Morris invented the telegraph. This instrument makes use of a coil winding which, when charged by closing the circuit with the telegraph key, pulls a metal plunger down to make a "click" noise. Telegraph communication was one of the early essentials that made railroads practical. So it soon became widespread both in the industry and for commerce in general.
By the late 19th century, many people were experimenting with both making and using electricity. It wasn't long before the linear motion of the telegraph sounder coil was translated into a circular motion by putting several coils on a rotating armature. This, it was found, allowed one to either create electricity by driving the armature from an external power source, or to use electricity by allowing the current flow to turn the armature. Thus were born both the generator and the electric motor.
By the 1890s, the better trains were "electric lighted" from an auxiliary power plant carried in a "baggage-dynamo" car. Electric power was turning fans, running ventilators, and providing light both inside (for passenger's comfort) and outside (headlights and running lights). Power supplies quickly advanced: storage batteries, steam- and later gasoline powered dynamos, locomotive mounted generators (using boiler steam), then generators mounted on the carbodies.
However, all these power sources are limited and the demand small. Electricity, while providing many conveniences in the Varnish age, lacked the kick needed for heavy industrial applications. (At the turn of the century, heavy industrial tools such as lathes and milling machines were driven by leather belting from a network of drive shafts hung from the factory roof - the origin of the 16' high industrial building. These shafts were driven, in turn, by a stationary steam engine.)
However, this situation could not last. George Westinghouse (inventor of the air brake) took an early interest in electricity and crafted the first successful light bulbs. This created a consumer industry in electric lighting - which created a staggering demand for electric power.
This lead, in short order, to building the first large scale commercial power plants. Now electricity was available in bulk quantities which could do useful heavy work. It was not long before the first experimental electric powered railroad cars were fielded by Frank Sprague on his Richmond, Virginia transit line. The railroad industry, lead by the large locomotive builders, derided the idea - until people began to notice one peculiar trait of electric trains: they produce no smoke.
Enter the Baltimore & Ohio railroad.
In the 1880s, the B&O had a problem that was becoming increasingly common in the urbanized East. At that time, their tracks terminated in Baltimore and through traffic had to be ferried across the Patapsco River. Rival Pennsylvania Railroad had laid through tracks in the 1870s before the area got built up and before locomotive exhaust became a political issue. In order to compete, the B&O had to build through and make rail connections with its northbound partner, the Reading Railroad.
However, the City Fathers were not willing to allow a new line to carve a swathe through the middle of town, nor could the B&O afford the land acquisitions this would entail.
There was another alternative: build a belt line around the core of the city. The problem here, however, was that the right of way approaching Mount Royal Station, Baltimore, had to run through a mile long tunnel. The proposed Howard Street tunnel featured a fairly stiff grade, which would make locomotives work hard, which would produce choking clouds of exhaust smoke. Conditions in the tunnel would obviously be unbearable.
When Frank Sprague's trolley line began turning in respectable performance and reliability figures, the Baltimore management took notice. Something had to be done and this new electric power might be just the ticket. After some debate and a feasibility study, the newly formed General Electric Company received a contract to electrify a short stretch of the right-of-way through the tunnel and into Mount Royal Station.
This lead to a bit of a quandary. There was almost no body of experience in electrification, so the engineers had to dream this stuff up as they went along. First off, the Virginia trolley line seemed - well - insubstantial by steam road standards, so some new form of distribution had to be developed.
Third rail was considered and rejected for fear of it being shorted out by a derailment with who-knows-what kind of result. An overhead trolley was the answer, but unlike the Virginia catenary, what GE developed was a cumbersome rigid overhead third rail.
These third rails were offset to run parallel down the center of the two track main, with the locomotive pantograph reaching up to one side to make contact. The rails are supported by a series of girderwork gantries which - it was discovered - are also a convenient place to hang the interlocking wires and signals.
Power would be brought in by a scissors pantograph which has a small wheeled trolley on its end to run on the power rail (thus the name "trolley car"). This pantograph would later serve as the prototype for the popular Westinghouse and General Electric pantographs used on most heavy electrics and MU cars.
What sort of power to use was another problem. The great bulk of the thus-far limited electric experience was with Direct Current. DC from batteries had been around for years and the primitive motors and switching gear of the time were designed for it. Alternating Current, a fairly new evolution, was still a largely unknown commodity.
The Virginia trolley line had settled on 600 volts DC. This voltage has the advantage of being very easy to work with. Early commercial power was produced at 600 volts (and stepped down in pole top transformers for each group of customers) so no special circuitry was needed. As the line voltage is the same as that used by the motors, no transformers are needed in the locomotives. The principal disadvantage of DC power, line loss, is not a significant factor. The B&O operation only covers a few miles.
These matters settled, work began on building the first ever main line electric "motor" (electric locomotives are called "motors" because they do not have their own power supply - the "loco-" part of the term). The result - appropriately numbered "1" - is a remarkable creation.
Number 1 is actually a pair of 4 wheel stub units permanently coupled back to back. The carbody halves are bolted onto main frames of cut steel plate and the lower parts filled with cement for ballast. The 62" drivers are rigidly mounted (the entire carbody pivots on curves).
GE designing what, at the time, was state-of-the-art in electrical motors. These motors are huge, sitting on top of each power axle and protruding up into the carbody. This is a gearless drive in which the axle serves as the motor armature and the field coils are rigidly mounted to the frame. From this would come a host of early designs, including the famous Milwaukee bi-polars, providing an alternative to the Baldwin / Pennsylvania Railroad jackshaft drives. They produce 360 HP each, for 1440 HP total. This allows #1 to maintain a steady 35 mph upgrade with a locomotive and 15 cars in tow.
To avoid complex turning moves, the design is bidirectional. The two half-cabs create a protected area in the center with windows all round: adequate for a unit spending most of its time under ground. On either end are two sloping cowls that hold the air pump, sand boxes, etc. As these take up little room, the cowls sit well below the cab line for great visibility: a design we know today as a "steeple cab".
Despite all the misgivings, it works. One of the motors meets incoming trains at the entrance to the tunnel, the road engine banks its fire (mostly eliminating the exhaust fumes) and the electric hauls the entire train - locomotive and all - through to Mount Royal.
Typically, each unit handles about a dozen trains a day.
Two additional units, #2 and #3, were built and, with a few early bugs
ironed out of them, have proven both capable and reliable. The one area
which has proven a problem is the early rigid trolley system. This was replaced
by third rail in 1902.
Time marches on and these first units were soon technologically dated. In 1912, the B&O ordered three larger and more modern motors to replace them. At that time, #2 and #3 were scrapped while #1 remained on the roster as a reserve motor. In 1927, it was duded up and put on display at the "Fair of the Iron Horse" celebrating the B&O's centennial. That assignment completed, #1 was ignominiously scrapped.
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