Straw-Burning Portable Steam Engines

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A California threshing scene with a Heald steam engine, probably taken in the early 1880s.
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The 1880 J.L. Heald 20 hp portable straw-burning steam threshing engine.
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Agricultural historian F. Hal Higgins took this photo of pioneer equipment operator B.B. Brown (left) and Pierce Miller inspecting the J.L. Heald straw-burning engine at Pierce’s California Ranch Museum, Modesto, Calif., in 1958.
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This drawing by F.J. Howell, titled “The Steam Thresher of Benjamin Ely,” depicts harvest activities on Aug. 5-6, 1884, at the 1,600-acre ranch owned by Benjamin Ely, Winters, Calif. Equipment shown in the drawing includes a 20 hp 1883 J.L. Heald engine, an 1881 Jackson derrick and feeder, and an 1881 Bronson-Pitts separator. Note that all crew members are identified.
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Clip from Pacific Rural Press promoting Enright's patent straw-burning portable threshing engine.
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Heald's patent portable straw-burning engines.
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Heald engine specifics.
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The Heald straw-burning portable steam engine on display.

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.

Putting the Heald to work

Heald’s straw-burner must have seemed custom-designed for William Butcher’s needs. Owner of 1,000 acres near Vacaville, Calif., Butcher was fast building a reputation as a progressive operator. In its July 23, 1880 issue, the Solano Republican identified Butcher as one of just two persons in Solano County to own a grain cleaner. Eager to find a faster, less expensive way to harvest his wheat, Butcher discovered a ready solution in Vallejo, roughly 20 miles southwest of Vacaville. There, in 1880, he purchased a 20 hp portable straw-burning engine manufactured by J.L. Heald.

For reasons unknown, Butcher left Vacaville in 1883; five years later, he sold his ranch. His Heald engine essentially disappeared from view – until 1948, when it resurfaced at Barrett’s Boiler & Welding Works in Modesto, Calif. The Heald was parked outside of Barrett’s for years, as a sort of advertisement. In 1948 the engine was completely refurbished, including installation of new boiler tubes, and made ready to be part of an upcoming California state centennial celebration of historic agricultural equipment.

The Heald engine subsequently became part of the Pierce E. Miller Transportation Museum collection near Modesto, where it was stored outside for years. In the 1960s, the engine was rediscovered by California agricultural historian F. Hal Higgins, who wrote several articles about the Heald. He was particularly concerned about preserving what he referred to as “the only one left.” The engine remained outside, unprotected. By 2000, three of its wooden wheels had rotted away, causing the engine to fall onto its side.

Back from the brink

In 2001, I purchased the Heald engine from the Miller museum and started researching its history, tracing it back to William Butcher, the engine’s original owner. In the process, I learned about one of the Heald’s interesting features.

The engine’s boiler safety valve is of a very early design. It uses a piston valve located in the top of the boiler’s steam dome, held down by a lever connected to an adjustable Chatillon spring balance. The spring balance also acts as a boiler pressure gauge, and is calibrated in boiler pressure with a scale of 0 to 240 PSI.

That safety valve’s design was flawed, according to one early steam engine engineer: “The one great objection to the use of piston (safety) valves, namely, that they are likely to become clogged by the accretion of matter around them (unless in constant operation), as to prevent them from operating until a large excess of pressure is attained …”

Restoring a rare engine

In 2010, replica wooden wheels were installed on the Heald, after their reconstruction in Pennsylvania was arranged for by wheelwright Bill Melton, Porterville, Calif. A replica smokestack was constructed by the Walter Mork Co., Berkeley, Calif. In business since 1909, that company is managed by Fred Mork, a third-generation sheet metal fabricator and grandson of company founder Walter Mork (whose sheet metal tools were used in construction of the Heald engine’s new smokestack).

Future plans call for replacement of missing items, like firebox doors and grates (which are drawn to scale in the boiler patent drawings). The brakes, controls and the tongue to pull the engine can also be replicated. The engine is in remarkably good shape for its age and having been left outside for so long. It does not appear to have been worked very hard when it was operated in the 1880s.

The first public viewing of the refurbished 1880 Heald straw-burning portable engine was at the Best Harvest Show in July 2011 at the Wallace family’s pioneer ranch, Woodland, Calif. The show was sponsored by the Golden State Farm Education Center and the Antique Caterpillar Machinery Owners Club. FC

Interested in reading more about John L. Heald? Check out his patents:
No. 179,191: Improvement in furancaces for steam boilers
No. 200,453: Improvement in stop-cocks for steam boilers
No. 203,253: Improvement in steam boiler furnaces
No. 242,639: Grain thrashing and separating machine
No. 242,640: Grape elevator, crusher and stemmer
No. 305,816: Engine governor
No. 372,146: Device for separating almonds from hulls
No. 424,646: Steam boiler
No. 509,082: Combined harvesting and thrashing machine
No. 554,340: Controlling mechanism for engines

Jack Alexander is the author of several books on antique farm equipment, including the California Combined Harvester (2010). Contact him at

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