The Barco Jackhammer

Development of an earth-shattering tool.

By Glenn Thompson and Ed.D.
Updated on October 28, 2022
article image
by Glenn Thompson, ED.D.
The Barco jackhammer, as found under a pile of boards on an abandoned farm site. The design includes substantial handles for the operator and the spring-loaded starting rod.

Thanks to the Industrial Revolution, we have an unbelievable amount and variety of machines that assist us in our personal lives, ease the burden of our vocations, and serve as sources of recreation. Although perhaps not as soul-stirring as a Harley Davidson Knucklehead or a Porsche 911, one such invention is the jackhammer. To our ancestors who quarried stone, mined coal, or undertook demolition with a sledge hammer and a chisel, the jackhammer was a momentous invention. Like most things mechanical, it went through a period of development.

Early innovation

The first jackhammers, dating back to the early 1800s, used steam to raise the drill and gravity plus the force exerted by the operator to drop it. Further development incorporated steam to propel the drill downward. Although successful, this design was time consuming because steam pressure had to build up and often the boiler had to be some distance from the drill, such as in a mine. A later and more practical development was the pneumatic jackhammer, which operated using a vacuum. Changes during the late 1800s and into the 1900s resulted in jackhammers that functioned using compressed air, electricity, hydraulic fluids, and gasoline. A noteworthy improvement was a drill bit that rotated slightly between blows.

Barco Manufacturing Company

The Barco Mfg. Co. was based in Chicago. It was founded in the early 1900s and remained in business into the 1950s. The company sold a wide variety of products, including gasoline jackhammers, drills, and tampers; plug valves; flexible ball joints; sand dryers; railroad car connections; swivel joints; railroad engine tender connections for steam, air, oil, and water; power reverse gears; direct steaming systems; and the Cleveland low-water alarm for locomotives. For a short period the company also made stoves for cabooses.

Pickin’ pays off

Although he doesn’t consider himself to be a collector of any one thing in particular, Allen Becker of Boerne, Texas, has managed to accumulate a variety of interesting things during his fourscore years on this earth. His collection includes a number of antique tractors, old engines and a Barco jackhammer.

During the mid 1970s, Becker was invited to go with an acquaintance named Wimberly to explore an abandoned farm site north of Georgetown, Texas. Wimberly made a living purchasing items at garage sales and auctions and reselling them to people he thought would be interested. He was always on the alert for possible sites where interesting things might be found such as abandoned home sites. At the farm site, Wimberly and Becker drove through a field of tall grass to the farm’s “dump” in a grove of trees in the middle of a field. There, they found an old kitchen range in good condition and a number of small items they deemed collectible. While leaving the farm site, they stopped to investigate a pile of boards that had once been a shed. From under the boards, Becker retrieved the Barco jackhammer. Since he invited Becker to go to the farm site, Wimberly only charged his usual fee – a cheeseburger with fries and a tank of gas for his pickup.

At first glance, most people probably wouldn’t consider Becker’s Barco jackhammer to be a gasoline engine, but in fact it is a 2-cycle engine consisting of a cylinder and a free-floating piston, along with a fuel tank, a carburetor, an intake manifold, a spark plug, a kill switch, and all the other essential components of a gasoline engine. A separate battery and buzz coil are needed to run the Barco. There is neither a tag on the jackhammer nor evidence that there ever was one. The only numbers on the machine are casting numbers for individual parts.

The Barco’s operation

To start the Barco, the operator pushes down on a spring-loaded rod at the top of the cylinder that, in turn, pushes down the piston and compresses springs below the piston. When the rod is released, the springs push the piston upward. As it moves upwards, the piston creates a vacuum that draws an air/fuel mixture into the combustion chamber. When the starting rod is pushed again, the piston compresses the air/fuel mixture, and as the piston moves upward, the fuel is forced through holes in the piston into the intake port on the side of the cylinder and from there into the combustion chamber above the piston where it is ignited. After combustion, the spent fuel is vented out through an exhaust port in the side of the cylinder as the piston moves downwards.

As the piston nears the top of the cylinder during the compression stroke, ignition is caused by a cam on the bottom of the piston that activates a roller in the side of the cylinder, opening and closing points that determine the timing of the electrical charge leading to the spark plug. Insulated wires lead from a separate battery and buzz coil to the ignition points. A condenser mounted on the air cleaner is also part of the ignition circuit.

Combustion forces the piston downward where it strikes an anvil and then strikes the upper end of the drill, the chisel, or whatever other tool is inserted into the jackhammer. When the piston rebounds from the anvil, the force of the rebound plus the expansion of the springs push the piston upward. The cycle is repeated over and over.

Although compact and portable, at approximately 90 pounds the jackhammer is not light and it requires a sturdy operator. It is not unusual to have two individuals take turns running it. The jackhammer also is extremely loud due to the engine’s lack of a muffler and the sound of the tool hitting the object being struck. Individuals operating the jackhammer for extensive periods can expect to suffer hearing loss, joint and back problems, and nerve problems such as carpal tunnel syndrome.

Because the Barco is a 2-cycle engine, the fuel consists of a mixture of oil and gasoline. One pint of SAE No. 70 oil is mixed with one gallon of gasoline. The amount of oil would need to be increased in extremely hot weather. To start the engine, the operator must first prime the engine by verifying that the needle valve on the carburetor is backed off approximately 1-1/4 turns. A check valve on the bottom of the fuel tank is opened to allow fuel to drain into the carburetor. With fuel in the carburetor, the operator must promptly push down on the starting rod – four to six times – until the engine starts. A kill button on one of the handles stops the engine.

The Barco jackhammer is an interesting relic of a past era. Although noisy, heavy, and challenging to operate, it was a vast improvement over the crude hand tools it replaced.

Sources:  Trade Catalogs from Barco Mfg. Co., americanhistory.si.edu


Glenn Thompson is a retired university professor and regular contributor to Gas Engine Magazine. He and his wife live on acreage in the Texas Hill Country where they maintain a wildlife management program. Much to his wife’s chagrin, Glenn has a cherished collection of some three dozen riding lawnmowers, garden tractors, and compact tractors cluttering up the place. He can be reached at 830-997-5738 or uffda@beecreek.net.

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