PIONEERING THE FARM TRACTOR


| March/April 1978



1902 Hart-Parr No. 1

1902 Hart-Parr No. 1

1021 F Street, Schuyler, Nebraska 68661

I'm enclosing an article written by W. H. Williams in 1927, which may be of interest to G.E.M. readers.

In going through the article, it seems that Mr. Williams guessed at the weights of the parts he mentions. I looked up the parts he mentions. In my book, the 220 pound crankshaft is listed at 368 pounds for the early number and 350 pounds for the later number. Next he mentions a 500 pound flywheel. The flywheel of the 45 and 60 horse engines, of which Mr. Williams writes, is listed at 1124 pounds. The belt pulley isn't mentioned. The pulley had a 40' diameter and a 12' face. Within this pulley was contained a planetary gear set to provide a reverse gear plus the belt and traction clutch. This conglomeration weighed nearly as much as the flywheel and had to be removed when the crankshaft had to be replaced. No doubt, the service man erected a tripod from which to suspend a block and tackle for this heavy lifting. I was looking at a Hart Parr '60' in Saskatchewan, noticing that the key had split a piece out of the hub and an iron band had been shrunk on to the hub to hold the broken out piece in place. I said it would be a calamity if that flywheel came off while the engine was running. The owner said it did while they were threshing. It rolled past the rack and the wagons and into the 'bush.' They had an awful time getting it out of the bush and then it took 16 men to get it back on the crankshaft. Those 16 men must have been crowded like ants on an ant hill.

Twenty-five years ago there was no such thing as the farm tractor. For the past ten years it has been a commonplace in agriculture. Mechanical inventions develop very rapidly in the twentieth century, whose first years saw many experiments in the tractor building. Several of the large builders of gasoline engines took part in these experiments, but all these designs consisted simply of a stationary gas engine mounted on a truck and when put to field tests failed because they lacked special features to adapt them to this different class of service.

In 1902 the Hart-Parr Company of Charles City, Iowa, put its first farm tractor in the field. The results were valuable chiefly in showing what features their design lacked, and some of the features it should contain. The next twelve months were spent in an entire re-designing of the first model; in the spring of 1903, the first successful model of a gasoline tractor was put in the field. They were purely threshing engines, but could propel themselves and pull a separator around the country. Fifteen of these were sold that first fall, and so well were they designed and built that all of them remained in the field from five to twenty-five years, and six were still in operation as late as 1925. The year 1903, therefore, marked the successful beginning of what is now known as the farm tractor. But the real farm tractor was not to come until after many moons of trials had passed over the heads of the early designers.

In 1905 the Hart-Parr Company re-designed the transmission gears of their 1903 model, making them much heavier, and using an enclosed 'spur differential.' This enabled them to pull plows as well as threshing machines, and marked another step in the right direction. In 1906 they abandoned the old pushrod type of valve gear, and used a rotary valve gear, with removable valve cages and high-tension ignition. These changes did away with most of their ignition troubles. During the next four years most of the weak spots in this 1906 model were worked out through field experience and showed the world that the farm tractor had come to stay, although still far from perfect.