Postcard depiction of Mammoth Cave Railroad steam dummy engine Hercules 3.
(Curt Teich, Kyle Company, Louisville, KY, via W. Lenheim Collection)
DUMMY ENGINE
A dummy engine or steam dummy was a steam locomotive enclosed in a box structure made to resemble a passenger railroad car. Steam dummies had some popularity in the first decades of railroading in the U.S., from the 1830s but eventually passed from favor.
An early postcard depiction of the Dinkey Train led by a dummy engine at Mammoth Cave, ca. 1910.
(Unknown, Mammoth Cave, via W. Lenheim Collection)
Overview
It was thought that the more familiar appearance of a coach presented by a steam dummy, as compared to a conventional steam locomotive, would be less likely to frighten horses when these trains had to operate in city streets. Later it was realized that it was actually the noise and motion of the operating gear of a steam engine that frightened horses, rather than the unfamiliar outlines of a steam engine.
This steam passenger car operated on the Moshassuck Valley Railroad in Rhode Island in 1916. The car carried passengers and mail; the windows were not just for show. Nonetheless, the term "steam dummy" was sometimes used to describe these cars.
Baldwin Locomotive Works manufactured steam dummies or steam motors for many American tramways. Baldwin exported to places such as Sydney, Australia - where they were known as 'steam tram motors' - and New Zealand, where two, both built in 1891, survive at museums today.
(Walter Fogg, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
Production
H. K. Porter, Inc. preferred the term "noiseless steam street motor" in their 20th-century catalog, although they used the term "dummy" (in quotes) in the 19th century. In the 20th century, they offered 0-4-0 and 0-4-2 wheel arrangements. In the 19th century, they also offered a double-ended dummy with a 2-4-2 wheel arrangement. Porter recommended using anthracite or coke as a fuel in order to avoid smoke. Side flaps to hide the mechanism were optional. Operating speeds between 15 and 25 miles per hour (24 and 40 km/h) were reported by 19th-century users.
Mammoth Cave Railroad dummy steam engine No. 4 as it appeared on April 18, 2008.
(Doug Coldwell, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons, cropped)