Straw-Burning Portable Steam Engines

The short-lived sustainable harvest: Straw-burning portable steam engines utilized the byproduct of threshing machines

| November 2011

A California threshing scene with a Heald steam engine, probably taken in the early 1880s.

A California threshing scene with a Heald steam engine, probably taken in the early 1880s.

Although portable steam engines that burned coal or wood were used for threshing in California in the 1860s, in the 1870s California manufacturers began to experiment with straw as a fuel source for portable steam engines. Their motivation was simple: Using a horsepower to power a threshing machine was both slow and expensive. Elsewhere in the U.S., steam engines were fueled by coal or wood, costly (and cumbersome) commodities in California. 

Inventors there focused instead on straw burning; utilizing straw that was the byproduct of threshing. They were not alone; similar experiments had been conducted in Europe and in other parts of the U.S. None proved successful. Steam could be generated easily enough in straw-burning engines, but as soon as the steam was drawn on to furnish power to drive the thresher, steam levels plunged to levels insufficient to drive the machine. Straw-burners were also prone to choked boiler flues and clogged grate bars.

Into that arena stepped Harvey W. Rice of Hayward, Calif., who tweaked the return-flue boiler, adapting it to use as a straw-burner, and mounted it on wheels, making it portable. By 1878, one writer suggested that as many as 200 straw-burning return-flue boilers were in use in California.

Roots in Vallejo Foundry

The source of at least some of those straw-burners was originally known as the Vallejo Foundry, established in August 1869 by Thomas McCormick. In 1871, machinist John L. Heald (born in Maine in 1835) joined forces with McCormick, and the business became known as the Vallejo Foundry and Machine Works. By 1874, Heald had bought out his partner.

In 1875, Heald began building portable straw-burning threshing machine engines. By 1879, the enterprise employed a staff of 20. Two years later Heald began construction of a new facility in Crockett, Calif., where he’d relocated his foundry, machine shop and agricultural works. At the new facility, he manufactured boilers, stationary and movable engines, threshing machines, separators, grape crushers and pressing machinery, roller-crushing barley mills and, in 1889, a steam traction engine. In 1891, Heald sold his plant to Dunham, Carrigan & Co., San Francisco.

Heald won his first U.S. patent (no. 179,191) June 27, 1876, for a straw-burning boiler. That patent was challenged by H.W. Rice as an infringement on straw-burning boiler patents he’d been awarded in 1874-75. In January 1877, a jury decided in favor of Rice. Heald and Joseph Enright of San Jose, Calif., subsequently developed a straw-burning boiler that did not infringe upon the Rice patent. Their boiler was patented March 11, 1878 (no. 203,253). Production ramped up quickly. Within a year, the Pacific Rural Press reported that Heald was building 15 of his improved straw-burning portable steam engines at his Vallejo shop.