Lombard Steam Log Hauler

The Lombard Steam Log Hauler, patented 21 May 1901, was the first successful commercial application of a continuous track for vehicle propulsion. The concept was later used for military tanks during World War I and for agricultural tractors and construction equipment following the war.

Alvin Orlando Lombard was a blacksmith building logging equipment in Waterville, Maine. He built 83 steam log haulers between 1901 and 1917. These log haulers resembled a saddle-tank steam locomotive with a small platform in front of the boiler where the cow-catcher might be expected. A steering wheel on the platform moved a large pair of skis beneath the platform. A set of tracked vehicle treads occupied the space beneath the boiler where driving wheels might be expected. The locomotive cylinders powered the treads through a gear train. The log haulers mechanically resembled 10- to 30-ton snowmobiles with a top speed of about 4.5 miles per hour (7.2 km/h).

While the ground was covered with snow and ice, a log hauler could tow a string of sleds filled with logs. Each sled train required a crew of four men. An engineer and fireman occupied the cab behind the boiler, and a steersman sat on the platform in front. A conductor rode on the sleds with a bell-rope or wire to signal the crew in the cab. The earliest log haulers pulled three sleds, and later models were designed to pull eight sleds. Each train carried 40,000 to 100,000 board-feet of logs. The record train length was said to be 24 sleds with a total length of 1,650 feet (500 m).

The greatest operational difficulty was on downhill grades where ice allowed the sleds to accelerate faster than the engine. Jack-knifing sleds pushed many log haulers into trees, and most photos of log haulers show rebuilt cabs and bent ironwork on the boiler and saddle tank. Hay was spread over the downhill routes in an effort to increase friction under the sleds, but hungry deer sometimes consumed the hay before the train arrived.

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