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Miniature Locomotive for War Work, 1915

Reported in Scientific American, this Week in World War I: August 14, 1915

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Whole economies during the First World War were geared to mass manufacturing supplies for armies engaged in the desperate struggle. A complex infrastructure developed to move materiel from factory to front line: guns, ammunition, water, rum, boxes of biscuits, tents, barbed wire, timber, medical supplies, more ammunition, and so on. Heading in theopposite direction, of course, were troops on leave, prisoners, the wounded and the dead.

The last segment of shipping, from military base to front-line trench, was difficult: trucks, horses or exhausted soldiers hauled supplies over pitted roads, dirt tracks or endless mud. One transportation solution was the narrow-gage railway (“gauge,” for our British readers). These railways used a diminutive locomotive—perhaps a tenth the size of standard locomotives—pulling small wagons along narrow trackways. They were called “trench railways” but electric or gasoline versions were also used inside massive fortifications to move shells and other necessities.

An early military narrow-gage railway constructed by the British, using French locomotives, in 1885 in Balochistan.
Image: Scientific American, August 15, 1885


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The issue of August 14, 1915, reports on one model of locomotive, 107 of which were ordered in February 1915 by the French military authorities from a U.S. manufacturer, the Baldwin Locomotive Works in Philadelphia.

“The driving wheels are 25.5 inches in diameter and are mounted in swiveling bogie frames placed outside the wheels. As all the wheels are drivers and the wheel base is articulated, these engines have great hauling power with extreme flexibility.  The springs are of special design, having rubber washers to absorb shocks, so that these engines are very easy riders, there being practically no jar or lurching when traversing curves with an uneven track. These peculiar locomotives are of the Pechot type. They were originally introduced in 1888 and reflect great credit on their designer. The track gage is 1 foot 11 5/8 inches [60 centimeters] and the engines in working order weigh 28,100 pounds. The cylinders are 6.88 inches in diameter by 9.44 inches stroke. The valve gear is the Walschaert motion.  These engines were built to very rigid specifications prepared by the French engineers, and they were finished in a remarkably short space of time. The order was received February 1st, 1915; forty engines were shipped on March 31st, and the last one left the works on April 24th.”

Such light railways, designed by military engineers and laid by troops or labor battalions, already had a long and useful history. The other illustration here is from an article about a British military light railway built in 1885 in the Bolan Pass in what is now Pakistan. For that railway the British used locomotives and tracks made by the Decauville company in France. The most efficient way of transporting locomotives and track material up the narrow mountain passes was on the backs of elephants.

For a look at these railways in use, there’s a short film on YouTube (note: film is preceded by a short advertisement) with a compilation on building and using various trench railways during World War 1: https://www.youtube.com/watch?v=F3s01i3aa7w

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Our full archive of the war, called Scientific American Chronicles: World War I, has many articles from 1914–1918 on supply and transport during the war. It is available for purchase at www.scientificamerican.com/products/world-war-i/