Monorails

The Singular Monorail

A railroad transportation system based on a single rail acting as its sole support and guide way, a monorail system is often but not exclusively elevated and can be both manned and unmanned. Several designs of monorails are divided into straddle beam and suspended monorails. The straddle beam monorail, which has a train straddling a steel or reinforced concrete beam within the range of 2 to 3 feet wide, is the most common type of monorail. A carriage with rubber tires connects the beam on the top and both sides for traction and stability. The German company ALWEG popularized the straddle beam. A suspended monorail features a train with cars suspended beneath the wheel carriage with the carriage wheels riding inside the single beam. The French company SAFEGE offers a suspended monorail system. In the 1880s, German inventors Nicolaus Otto and Eugen Langen developed the suspensed monorail which opened in the twin cities of Barmen and Elberfeld in the Wupper Valley in 1901, and it is still operating.

Monorail cars can come in a singular rigid format, articulated single units, or as multiple units linked into trains with cars that are wider than the guiderails that support them. Monorails are powered by linear induction motors and their cars are connected to the beam by bogies, which are wheeled wagon or trolley systems that allow the cars to safely negotiate curves. In contrast to some tram and light rail systems, modern monorails are separate from other traffic and pedestrians and, unlike other guided railroad systems, they are guided and supported with the same single beam. They also do not use a pantograph, a single overhead wire on the roof with return current running through the track.

Monorail Systems

Metropolitan monorail systems are in operation in 178 cities around the world, with 20 in Asia. Ten monorail systems are located in Japan with the longest operational monorail line in the world, a 15-mile corridor in Osaka. The Chinese government is constructing a crisscrossing network of monorail corridors to expand the 28-mile Chennai, China monorail system that it estimates will be 186 miles long if it is completed according to plan.

Monorail systems have been operating since the 19th century, but in their pioneering years they were primarily short line systems that moved small amounts of freight and passengers. On June 25, 1825, the Cheshunt Railway in Cheshunt, England celebrated its grand opening, earning its place in history as the first passenger-carrying monorail. In 1876, the Sonoma Prismoidal, a 7-mile wooden monorail, was planned to be the first rail line built to connect Sonoma in northern California with a steam ship landing at the San Pablo Bay. Only 3.5 miles of the line with a 15-inch-high track were built between Norfolk and Sonoma, at a cost of $4,500 per mile, half of the cost of contemporary narrow gauge railroads. Although the railroad operated from November 23, 1876, to May 5, 1877, promoter Joseph S. Kohn never realized his plans to extend the monorail to Sonoma Landing on the Petaluma River or build an elevated prismoidal rail along Market Street in San Francisco.

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