An Engine for Every Engineer

From 1878 through 1914, Gaar-Scott Offered an Impressive Array of Engines


A later Class E coal- and wood-burning engine threshing. 

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During the early winter of 2005, my fiancée, Revonda, and I paid a visit to Joe Graziana's shop in Wood River, Ill. We came to drop off the governor from my 22 HP Gaar-Scott engine for Joe to repair and in the course of visiting with Joe, I asked if he had a Gaar-Scott parts book. I had been hankering for one for a while, as I figured it could help me in the search for parts for my engines. Joe actually had two of them and was kind enough to sell me one.

Upon opening the parts book and examining the vast number of different styles and sizes of engines offered by Gaar-Scott from 1887, I was absolutely amazed. I have a few of the company's yearly catalogs from the early 1900s, and I knew they built quite a few different engines. As the company stated in its 1912 yearly catalog, “You can not look at the many and varied types of engines shown in this catalog without being impressed by our success in supplying power for the widest range of service and to meet the special conditions of different agricultural regions.” The variety was even wider than I had previously known, and I felt compelled to research and write a summary of the different engines produced by Gaar-Scott from 1887 to the end of the company in 1914.

I began researching earlier engines built by Gaar-Scott by contacting other enthusiasts and museums, and came up with at least some information on Gaar-Scott's earlier traction engines. I later found and bought an older parts book, which listed parts for traction engines dating to 1878. I would like to encourage anyone with additional information on the older engines built by Gaar-Scott to provide this information for readers of Steam Traction.

Early Days

Sometime around 1878, Gaar-Scott began building traction engines, in addition to the company's portable engine and threshing machine production. By studying the patents issued to Gaar-Scott's design team of Horatio Land and Howard Campbell in the early to mid-1880s, one can see the evolution of the traction engines that followed.

On July 6, 1880, patent no. 229,715 was assigned to a spiral steering roll, which helped take slack out of the steering chains. On Feb. 28, 1882, patent no. 254,223 was granted for a continuous rear axle, which wrapped around the underside of the firebox. On May 2, 1882, patent no. 257,444 was assigned for Land and Campbell's design of a water tank with braces that mounted to the sides of the smokebox and that attached to the top of the steam dome. On May 12, 1885, patent no. 317,722 was issued for a spring-mounted platform, which helped take the jarring and shaking out of the operator's platform. In addition to the patents issued to Land and Campbell, in 1881, Gaar-Scott obtained re-issue no. 9,819 of an earlier patent (no. 144,467, issued in 1873), assigned to one Nathan M. Mendenhall, for a strange steering system that employed a system of locking differentials and a tiller-type steering wheel. Unless Gaar-Scott intended to use part of the details of the differential, it is unclear which features of this patent they felt were pertinent to the firm's engine design.

By 1885, Gaar-Scott was building engines in sizes including 8, 10, 12 and 15 HP. Gaar-Scott's 1885 catalog referred to “The Great Atlanta Test Trial of Engines” of December 1881, where apparently the company's traction engine made quite a showing by towing an 11-ton load through several different tests. Within a few years, Gaar-Scott added a friction clutch, which landed Gaar-Scott and several other engine builders in a long, drawn-out court battle. (For more information on the lawsuit, see Robert T. Rhode's “The Mystery of the Lehmer Model,” Iron-Men Album, November/December 2002, “Lehmer Update,” Steam Traction, March/April 2003 and “Update on Isaac Lehmer,” Steam Traction, May/June 2003.) Though a few details, such as the axles under the firebox, were later dropped, in place were most features that for many years characterized Gaar-Scott's first style of engines.

Single-cylinder Wood- and Coal-burning Engines

These engines (Table 1) were built by Gaar-Scott from around 1878 to 1912, when the line moved towards exclusively rear-mounted engines (with a few exceptions). All classes of these engines were side-geared engines with wet-bottom boilers. Class E engines used locomotive slides with the flywheel on the left-hand side and with the cylinder mounted toward the rear of the engine. Class E engines were the earliest named style of engines introduced by Gaar-Scott.

Class F engines were identical to Class E engines with the sole difference that the cylinder and flywheel were mounted on opposite sides. In 1892, all Class E engines except the tiny 6 HP model were phased out, replaced by Class F engines. The Class G engines replaced the Class F engines themselves. The exception was the 10 HP Class F engine, which was not phased out until almost all side-geared engine production was discontinued at the end of 1912.

Class G engines were the later model side-geared, single-cylinder engines with bored Corliss-style crosshead guides. The rear-mounted cylinder was on the left-hand side; the flywheel, on the right-hand side. An alternative to the rear-mounted cylinder Class G was Class H, which was identical to Class E, with the exception of having a forward-mounted cylinder. Class E, F and G engines were also offered as portable engines.

Class J engines were compound-cylinder variations of the Class G models. By the early 1900s, Gaar-Scott reached the decision to build compounds in only the company's larger model sizes and only on Universal, dry-bottom boilers. One parts book indicates that at least a few 30 HP Class J models were built in 1903 and 1904, before engines of this size were switched to Universal boilers.

A curious fact about Class J is, from 1895 through 1896, various Class J engines (13 HP and 18 HP) used what Gaar-Scott called the “Wolfe” reverser. These engines were referred to as “Wolfe Compounds.” After trying out the Wolfe on only the Class J models for a few years, Gaar-Scott returned to the link reverse on all the firm's models.

Another noteworthy feature of Class E, F, G, H and J engines built during 1880-1899 was the use of a water-lined smokebox. According to steam historian Jim Jake Templin of Texas, the water-lined smokebox was intended to make use of waste heat from combustion to help heat the water in the boiler. In reality, the short smokebox on a traction engine had insufficient surface area to contribute much heat to the water, the added expense in construction was hardly justified, and it gave scale and rust a place to collect. According to steam historian Thomas Stebritz, whose family owned a 13 HP Gaar-Scott Class H, “ … in a number of cases, the bolts burned off and the engine was no longer good because of the lack of a welder to fix it up.”

Other interesting engines built with coal- and wood-burning boilers were the Class R portable engines, a number of which were the biggest engines Gaar-Scott built. Most were constructed in a style similar to that of the standard portable or semi-portable engine produced by various manufacturers of farm steam engines. Others were built in a special undermounted style that permitted the engine to be detached and set up beside the boiler for stationary applications.  

  The parts book indicates Gaar-Scott stopped production of almost all of its side-geared engines in 1912, but later catalogs continued to list side-geared engines. Gaar-Scott probably offered the remaining inventory of such engines for sale after the style was discontinued. In 1913, Rumely Products, which had bought Gaar-Scott in December 1911, offered a beautiful yearly catalog depicting the Gaar-Scott and Advance lines side by side. This catalog still featured the newer rear-mounted engines and older side-mounted engines built by Gaar-Scott. By 1914, the yearly catalog depicted only the single- and double-cylinder rear-geared Gaar-Scott engines.

Single-cylinder, Return-flue Engines

Along with building its standard Class E engines, Gaar-Scott built engines with a return-flue boiler for burning straw. These engines (Table 2) were produced at least as early as 1885 in a “7-1/2-by-11-inch size only,” but, by 1891, a 16 HP model was added. The line was successful, and, by 1892, Gaar-Scott was offering separate classes of return-flue engines. Such engines were quite popular in the 1880s and 1890s, especially those designed to burn straw. Because of its double-pass design, a return-flue boiler was slightly more efficient than a standard locomotive-style boiler. Also, the standard Scotch Marine type (referred to by Gaar-Scott as the Cornish-style boiler, though it was not a true Cornish boiler in the strictest sense) had the added plus of being relatively simple and inexpensive to build, due to the lack of stay bolts that were used in a standard locomotive firebox. Gaar-Scott designated its simple, single-cylinder engines on Cornish boilers as Class K and its compound engines on Cornish boilers as Class L.

An inherent problem of the standard Cornish boiler proved to be insufficient grate area when used to burn fuels besides straw or coal. Long grate bars enabled these engines to burn long material (such as slabs), but these boilers lacked the deep firebox needed to burn bulky material, such as wood. On an engine that burned only straw, this would not have been a problem, but Gaar-Scott advertised these engines as being able to burn other materials after changing the fire grates.

To cope with this problem, in 1897 to 1898, Gaar-Scott phased out the Class K and L engines and replaced them with the Class P and Class M engines. These boilers were return-flue but had a deeper firebox more like that of a standard locomotive boiler. Besides retaining the large central fire flue for carrying most of the flue gases, Gaar-Scott used four to six additional 2-1/2-inch diameter flues to carry the initial pass of gases. Several 2-1/2-inch diameter flues were used for the return pass, the number varying with the size of the engine. The Class P was a simple, single-cylinder model, Class M a compound-cylinder model. After building its Class P and Class M engines for only a few years, Gaar-Scott phased these engines out between 1904 and 1905, replacing them with the firm's standard Universal boiler engines with a firebrick arch that could be added for burning straw.

Apparently, no examples of the older Cornish boilers have survived, but at least one complete Class P engine survives: a 22 HP model that sold at the Danny Roen auction in September 2004. The buyer, Robert Holp of Ohio, is currently giving this rare machine the careful restoration it deserves. There are also two incomplete models of return-flue Gaar-Scott engines in a Canadian collection.

Universal Boiler, Single-cylinder Engines

Gaar-Scott introduced its Universal, dry-bottom boilers (Table 3) in the early 1900s. These boilers were designed so a firebrick arch and a straw chute could be mounted to burn straw. The arch and straw chute could be removed and other fuels burned. These engines replaced the earlier return-flue engines as Gaar-Scott's straw burning models. The locomotive-style boiler was simpler to build than a return-flue boiler with an added firebox.

Class S included side-geared, simple-cylinder engines. At first, the Class S engines were built only with standard gearing and cast wheels. As steam plowing became more popular, Gaar-Scott began offering these engines with what were referred to as “Plowing Gear Features.” Plowing-gear engines sported larger diameter (6-foot 4-inch diameter vs. 5-foot 6-inch diameter) rear wheels, made of steel and with riveted cleats that could be replaced when worn. The gearing was made wider and stronger, and constructed of steel and semi-steel. Greater water carrying capacity was an important feature, and, in addition to the standard tank on top of the boiler, an extra tank was added to the operator's platform. Occasionally, engineers deemed this water capacity inadequate, and customers could special order an engine with a tank on the platform, the standard tank between the steam dome and smokestack, and another large tank in front of the smokestack.

Gaar-Scott plowing engines proved themselves quite readily in the fields and in contests. In the September 1909 issue of The Canadian Thresherman and Farmer, the results of the Brandon Motor Contests showed that a 25 HP Gaar-Scott engine out-plowed a larger 32 HP Case and 30 HP Avery. The 25 HP Gaar-Scott pulled a 14-bottom, 14-inch breaking plow at a depth of 4 inches in 20-1/2 minutes for a total of 1.98 acres plowed. The Case 32 pulled a 12-bottom, 14-inch breaking plow at a depth of 4 inches in 18 minutes for a total of 1.454 acres plowed. The Avery pulled a 12-bottom, 14-inch breaking plow at a depth of 4 inches in 29 minutes for a total of 1.454 acres plowed. The smaller Gaar-Scott engine definitely showed its worth, even though it failed to rack up enough points to win the contest. Another intriguing aspect of the contest, and one that the Gaar-Scott excelled at, was the turning-radius test. The Gaar-Scott had a 21-foot turning radius; the Avery, a 29-foot turning radius; and the Case 32, a 35-foot turning radius.

Class SR featured the later model rear-mounted, single-cylinder engines. Class TR was the designation for the big rear-mounted 30 HP compound. This engine was not shown in Gaar-Scott's later catalogs, but parts were offered in the parts book. The rear-mounted singles were the last style of engines introduced by Gaar-Scott. These later rear-mounted engines were built with plowing-gear features only.

Double-cylinder Engines

Around 1904 to1905, Gaar-Scott began producing double-cylinder engines (Table 4) with either Universal boilers or coal- and wood-burning boilers. Class DZ was the firm's designation for its coal- and wood-burning double engines; DY, its designation for its Universal double engines. Class DR was the designation for the rear-mounted axle engines offered by Gaar-Scott. These engines were the last style introduced by the company.

As steam plowing became even more popular, the company desired to build an engine bigger than its 30 HP or 32 HP side-geared models. In 1906, Gaar introduced the Big Forty, a new engine designed for the heaviest traction work. This massive machine boasted 6-1/2-inch-by-10-inch-by-11-inch tandem-compound cylinders, a rear-mounted axle design, steel wheels and gearing, and a positive locking pin clutch. This last device was quite handy for an engine designed for traction work and did not require the adjustment that friction clutches demanded from time to time. Even though the pin-type clutch was standard, various pictures exist that show a 40 HP engine with a friction clutch. Oddly enough, the friction clutch is not listed in either parts book I own. I would be curious to hear if any readers have any information on the 40 HP with a friction clutch.

The rear-mounted axle was much stronger than the short stub axles featured on the firm's side-geared engines, and, within a few years, Gaar-Scott was offering all of the company's plowing engines with rear axles. Another fascinating departure for Gaar-Scott with the Big Forty was placing the crankshaft at the rear of the boiler with the cylinder facing forward. (Though the older Class H engines used a forward-mounted cylinder, the crankshaft was placed in approximately the middle of the boiler as on Class G engines.) For some reason, this engine was down-rated in Canada to 33 HP.

Though the Big Forty was not officially introduced until 1909, the company's 1908 catalog included pictures of a Big Forty engine plowing. It is worth noting that Gaar-Scott adopted the practice of building new engines for a few years before adding them to the firm's yearly catalog. It was probably a wise decision – one that gave Gaar-Scott ample time to get the bugs worked out of a new design before it was offered to the public.

In 1910, Gaar-Scott began building the Montana Special, a 25 HP engine based on the Big Forty. It had many of the same features as the Big Forty, such as steel gearing and wheels, and cylinders mounted toward the front. Instead of having compound cylinders, it merely used 7-inch-by-11-inch double-simple cylinders. Another departure from the Big Forty design was the pin-type clutch was replaced by a friction clutch with four shoes, instead of the two clutch shoes used on other Gaar-Scott engines. The clutch, though, could be locked in place with pins if intended for heavy traction work only. By 1912, demand increased enough for this engine to be officially added to the firm's yearly catalog. Also on offer were 20 HP and 22 HP doubles, based closely on the Montana Special.

In 1912, the annual Gaar-Scott catalog contained a large variety of engines: the rear-geared single- and double-cylinder engines, the older side-geared single- and double-cylinder coal- and wood-burning engines, and Universal boiler side-geared plowing engines. Nonetheless, the diversity of the Gaar-Scott line was about to be decreased dramatically, and the 1912 catalog hinted at this sad fact by stating “the old Gaar-Scott line and the Advance Line of Battle Creek, Mich., have become part of the well known Rumely line. Through our united efforts each of the old lines is strengthened and a broader, and more standardized line created with increased facilities for manufacture, sale and distribution.”

After 1912, Gaar-Scott dropped all production on its older side-geared models with the exception of a few Universal boiler engines, and concentrated efforts on building the rear-geared plowing engines only. From surviving examples of later model engines, it appears the rear-geared plowing-gear engines sold quite well.

Unfortunately, it was not long before Rumely Products, which had purchased Gaar-Scott at the end of 1911, began reeling from the effects of becoming too large too quickly. B y 1915, Gaar-Scott engine production ceased for good. Though Rumely Products ended production of the Gaar-Scott line, engines and machinery were still offered in 1916 advertisements in The American Thresherman. I have heard there were still advertisements depicting Gaar-Scott equipment as late as 1918. It must have taken a while to sell off the remaining stock of Gaar-Scott inventory.


I would like to extend my thanks to the following people who provided help and information to make this article possible: my wife, Revonda, for putting up with the many hours I have spent working on and running my Gaar-Scott engines and studying old parts books; my father-in-law, Ronnie Blurton, for his help in scanning the images used for illustrations and in studying the U.S. patents; Robert Rhode, for his valuable help in editing; the staff at the Reynolds Museum (in particular Anne Shepherd) in Alberta, Canada, for providing information from their 1880s and 1890s catalogs; Thomas Stebritz, for providing many photocopies and much technical insight; Jim Jake Templin, for his technical insight on return-flue boilers; Gary Yager, for his insight on the 40 HP engines; Robert Holp, for information on Gaar-Scott's later firebox-style return-flue boilers; and, last but not least, Joe Graziana, for selling me the parts book that gave me the initial motivation to write this article.   

Contact steam enthusiast Mike McKnight at (901) 849-2185;