1949 Allis-Chalmers Model U

“You know me, Barney Oldfield.” And in 1933 what you probably knew about the Allis-Chalmers Model U tractor was that Oldfield had set a world speed record for tractors driving one. Of course it didn’t just happen because Barney thought it would be fun to ride a tractor going over 64 miles per hour. His comments afterward indicated that it was anything but fun. One of the greatest self promoters of the Twentieth Century, Oldfield was well aware of the value of name recognition. He had been doing product endorsements since his days on the bicycle racing circuits in the 1890’s. Harry Merritt Tractor Division General Manager at Allis-Chalmers also knew the value of celebrity and had hired big names from auto racing to promote the rubber tires that A-C introduced with the Model U in 1929.

The Model U had the misfortune of hitting the market about the same time the hedge fund managers of the day pulled the rug out from under Wall Street and that market hit the skids. In a classic example of trickle down economics small farms across the nation were soon biting the dust by the thousands. The prospects for selling new tractors were bleak indeed. Merritt knew it would take some special selling points to move some tractors in the existing market. It’s not clear exactly who came up with the idea of putting rubber tires on tractors but the engineers at Allis were soon delving into the possibilities. Harvey Firestone provided some of his company’s aircraft tires and they were quickly adapted and installed. The test they conducted suggested that there were significant advantages in horsepower output and fuel economy to using rubber instead of steel wheels.

At first Merritt staged demonstrations at county fairs and such that pitted a steel wheeled Model U against one on rubber in plowing demonstrations. The farmers who stayed to watch were impressed but this proved to be too academic to generate much excitement. Back at the factory he had his engineers modify the gearing of the U to develop the maximum speed possible. His next move was to hire a team famous race car drivers that included names like Oldfield and Ab Jenkins and send them out on a barnstorming tour of the nation’s dirt racetracks. These events were an instant sensation and hugely popular with race fans but unfortunately it didn’t translate into tractor sales. The first year of production ( 1929 ) netted only 1,974 units sold. The U would remain in production until 1952 but sales remained lackluster throughout, usually between 300 to 1,400 units sold per year. 1946 proved to be the best year with 2,458 sold. Ian and Sheila McIntyre brought this 1949 vintage U to the Foothills Antique Power Association 2017 show. They list its serial number as 22143. Manufactured near the end of the U’s production run it gives you an idea of the total number of these tractors produced.

The Model U was sent to the University of Nebraska and evaluated in Tractor Test number 170 from Oct. 21 to Nov. 7 1929. The tractor tested had a 4 cylinder L head Continental engine with 4 ¼” bore and 5” stroke running at 1200 rpm. It was equipped with a 1 ¼ “ Schebler carburetor and an Eisemann Mod. G-4 magneto. Brake rated load horsepower for 1 hour was listed at 30.27. Drawbar HP for 10 hours in intermediate gear was 19.28. Speed was recorded as: low 2 ⅓ mph. Intermediate 3 ⅓ , high 5 mph. The tractor tested had 42” drive wheels and weighed 4821 pounds.

While the speeds recorded at Nebraska fell short of those reached by Merritt’s barnstormers, they were more in line with what the average farmer would find useful. Records are made to be broken and it wasn’t long before Ab Jenkins topped Oldfields speed record. In 1935 on his home turf at the Bonneville Salt Flats in Utah he clocked 67.877 mph. A record that would stand for 81 years. In May of 2016 Jack Donohue blew Jenkin’s doors off ( ok, would have if Model Us had doors ) when he clocked 101 mph with his 8NCredible at the E.C.T.A. Ohio Mile event. See the May 1, 2016 Ironmule post for more about the 8NCredible. So why did it take so long to beat Jenkin’s record? Probably because there just aren’t many people who feel a need for speed on a tractor.

You can see a collection of entertaining photographs that cover Barney Oldfield’s exploits at www.thehenryford.org/explore/blog/our-collection-on-barney-oldfield/ . For more about Ab Jenkins visit https://bangshift.com and search for an article on the 2014 Bonneville Speed Week. Want to find out what Jack Donohue has been up to? Visit: http://jackdonohue.com .

Additional Resources:

https://www.agriculture.com look for an article on the Allis-Chalmers Model U by Dave Mowitz 3/24/11

articles.aberdeennews.com/2012-10-19/farmforum/3459180_1_allis-chalmers-tractor-production-expert-on-vintage tractors



UNL Tractor Test #170 Report