The 720 That Goes “chuff, chuff, chuff”.


“There is something about steam that gets in your blood.”


That’s one of the reasons why, more than five years ago, C.B. Cliburn decided that he wanted to build himself a steam engine. Not just any old steam engine, though. He wanted to build one based on a two cylinder John Deere tractor.


C.B. said that at the time, a friend of his had built a one-third scale working model of a Case steam engine. “I asked him why he didn’t build another one and use a John Deere tractor, the 88-year-old central Missouri farmer said. “He said to me, ‘Well, why don’t YOU build it?’”


With a challenge like that, the die was cast.


C.B.’s sons even tried to talk him out of it. “We told him, ‘Dad, if you want a steam engine, why don’t you go out and buy one?’” son R.L. said.


C.B., though, wanted one with some special features. “I wanted one with power steering, live power, three-point and live hydraulics,” he said. One way to get all that was to take a later model two cylinder John Deere tractor and convert it to steam power. The question—was such a thing possible?


“One of my boys called up John Deere back east somewhere and talked to one of their engineers,” C.B. said with a chuckle. “The engineer said it couldn’t be done.”


That was in 1996 and the project got started when R.L. backed “Ol’ Smoky,” one of three 720s that C.B. owns, into the one-car garage-size farm shop and began taking it apart. The front sheet metal, fuel tank, radiator, front wheels and cylinder head were removed and stored away. A boiler was made from a large tank from a heavy-duty air compressor and a local welding shop fabricated a firebox. To support the 2,800 pound weight of the 180 gallons of water in the boiler and the other heavy steel parts, the front half of a 1951 Ford farm truck frame was bolted into place. Piece by piece, with many of them useful bits and pieces from other machines and the farm iron pile, the steamer took shape.


From the engine block rearward, mechanical components are stock John Deere 720. All transmission gears are operable and the stock crankshaft, flywheel, block, pistons and rods are used. The cylinder head is a simple plate of half-inch steel with a rubber gasket bolted to the engine block. A cam, bell crank and rod arrangement attached to the flywheel end of the crankshaft operates the ball-type steam valves, which direct the steam to each of the two cylinders at the proper time. Timing the valves to work correctly was the biggest challenge of the project, C.B. said.


With all the weight out front, steering also posed a problem. Obviously the stock steering rod couldn’t go through the boiler and firebox, so an arrangement was worked out using universal joints and a triple reduction gearbox to direct steering effort to the Ford front axle.


For those who might be concerned that “somebody butchered a nice 720,” fear not. The whole thing is a bolt-together job. “You can take out eight or 10 bolts on this thing and take this tractor out and put another in,” said C.B. Since none of the original parts were discarded, the steamer components could be removed and the tractor put back to a stock 720 diesel, if one were so inclined.


C.B.’s experience in steam power and basic mechanical engineering goes way back. As a teenager in 1927, he hauled water with a team and wagon for the steam engine during several threshing runs on which he worked. “We would sometimes haul water four miles,” he said. “People didn’t have farm ponds around like they do now.” Also, accommodations were primitive at times for the threshing crew members. He said that there were times that they slept in the straw pile or on the farmer’s front porch and were rousted out at 4 a.m. to build a fire in the engine and start getting things ready.


Somewhat later, in 1934, C.B. and his father began working on river projects along the Missouri, Mississippi, Arkansas, Tennessee and Sacramento rivers. Many of these projects involved stabilization of the riverbanks to prevent erosion. To do this, the banks were cut down or built up to a certain grade slope, pilings were driven with steam-powered pile drivers and then mats were fastened to the pilings. At first the mats were woven from willows growing along the riverbank, but later board mats were used. C.B.’s father, who worked as a mechanic, invented a machine that was used to cut and twist lengths of wire that were used to tie the mats together. Then the mats were covered with man-size rocks for riprap. The work was hard, for everything was done by hand, but in those Depression-era times, any job was a good one. “Railroad jobs paid nine cents an hour. River jobs paid 10 cents,” C.B. explained. “You didn’t dare get sick and you hoped you didn’t get hurt. If you did, there were 20 guys over there waiting on the riverbank for your job.”


After traveling around the country on various river and construction jobs for many years, C.B. got a job in an ammunition plant in St. Louis when World War II broke out. In 1942, he returned to the farm where he now lives to farm and continued to do construction work. One of the dozers that he used in the early days, a Holt Caterpillar four ton that he bought in 1936, is still on the farm today.


In addition to the Cab, C.B. owns three 720s (including the steamer), a 730, a 1948 John Deere “A” and a 1943 “B” that he bought new. He also has an IHC 15-30 that he used with a John Deere thresher for 14 crop seasons after he returned to the farm.


In its present form, the 720 steamer has quite a few unique features. For one thing, it is one of few steam engines that are stoked from the front; in other words, the boiler and firebox are reversed from traditional steam engine design and the flue stack runs through the center of the full-length canopy. “We didn’t have much choice,” said C.B. Once a head of steam is built, the 720 will move under its own power at 40 pounds of pressure, but they have run it at up to 100 pounds. Two pop-off valves are set at 120 psi. The water induction pump used on the tractor came from a turn of the century steam locomotive.


Operation of the steamer is almost the same as driving a regular 720. The stock throttle control serves as throttle for the steam engine. Forward is on, back is off. The hand clutch sets things in motion just like a regular 720, although ground speed is a bit slower to allow proper RPM for the live PTO. C.B.’s 720 is also one of the few steam engines that has independent rear wheel brakes.


Even though C.B’s 720 steamer works well, and was used to bale straw with a John Deere 214 PTO-driven pickup baler as a demonstration in early 2001, C.B.’s mind is already working on more improvements. Plans are to add an oil burner to the firebox to give multiple fuel capability. “We’ll be able to burn used oil, kitchen grease or what have you,” he explained. This is in addition to the wood, straw or coal it can use now. He also plans to add an extra water tank over each rear wheel and the induction pump will be used as a transfer pump between the auxiliary tanks and boiler. Safety has also been taken into consideration. The induction pump can provide the engine with its own firefighting ability via an outlet plumbed into the water line if the need should arise.


As for the future? C.B. says he and his sons plan to be taking his creation to shows and intend to do some plowing with it. He also plans to build a steam-powered pile driver like those that were used on the river projects in the 1930s. It just goes to show what someone willing to put forth the effort can do with enough determination. With luck, C.B. and his 720 steamer will be chuffing and puffing along for many years to come.