953 nut 55,297 #1 Posted January 20 The Nebraska Tractor Test Laboratory The Nebraska Tractor Test Laboratory (NTTL) is a program operated by the University of Nebraska in accordance with Nebraska law to test the performance of agricultural equipment that is to be sold in the United States. The NTTL has operated since 1920 as the common standard reference for tractor performance in the United States. Impetus for the Nebraska Tractor Test Act of 1919, or Nebraska Tractor Law, came from a Nebraska farmer, Wilmot F. Crozier, who had been disappointed with the performance of several tractors he had bought. One had been marketed as a Ford tractor, but the Ford Tractor Company of the time was completely unrelated to the Ford Motor Company, and its products were of poor quality. The new law was enacted to address problems of false advertising of tractor features and capabilities, requiring that all agricultural tractors sold in Nebraska must have their performance verified by three engineers. The laboratory was established in 1920 at the University of Nebraska as a central location for tractor testing. The first tractor to be tested at the NTTL was a Waterloo Boy, which passed the test. 4 3 2 Share this post Link to post Share on other sites
ebinmaine 67,589 #2 Posted January 20 Very interesting Share this post Link to post Share on other sites
JoeM 7,874 #3 Posted January 20 that tractor dynamometer caught my eye and looked around a bit on the net. I went down the rabbit hole on this one and really didn't find out how it was made, Richard may expound on this later, IDK But I found a whole bunch of interesting stuff. From gear selection testing, exhaust testing, and some vibration testing. All modern testing tho. How about this location for a vibration test sensor? 2 Share this post Link to post Share on other sites
953 nut 55,297 #4 Posted January 20 In the process of gathering information I did find a few more pictures of the early days of tractor testing. The BELT HORSEPOWER rating was done in the laboratory with a flat belt driving a dynamometer at a specified RPM as shown below. I presume that the cart being towed by a tractor in the picture in my post above was a ground driven dyno. but wasn't able to find any proof of that. The Larsen Museum has a great deal of historical information on the Nebraska Tractor Test history. This visitors guide is a tractor trivia treasure chest. https://tractormuseum.unl.edu/larson-tractor-museum-visitors-guide 3 1 Share this post Link to post Share on other sites
8ntruck 7,016 #5 Posted January 20 Early tractors were rated for draw bar horsepower and belt horsepower. Been a long time since I played with a brake dynamometer in the lab sessions for my thermodynamic class, so I'm working from deep in my memory. Force, time, and distance need to be measured to determine horsepower. For the belt horsepower, the tractor is connected to an instrumented shaft with a brake to generate the data needed to calculate horsepower. Draw bar horsepower data was measured with an instrumented wagon with some sort of brake to load the tractor. Notice the big lugged steel wheels on the right side of the picture. I suspect that they were connected to a brake to supply the load. There appear to be wires hooked up to some sort of box on the rear hubs of the tractor being tested - rpm sensor maybe? I also suspect that there is some sort of calibrated spring built into the hitch between the dynamometer car and wagon to tell how hard the tractor is pulling.. Soil conditions would introduce a bunch of variables in a rig like that. 2 Share this post Link to post Share on other sites
953 nut 55,297 #6 Posted January 21 21 hours ago, 8ntruck said: Soil conditions would introduce a bunch of variables in a rig like that. It would be impossible to accurately measure the power exerted if the wheel on the dynamometer hasn't got good traction. 1 Share this post Link to post Share on other sites
Horse Newbie 7,074 #7 Posted January 21 Great idea- to start testing tractors… Probably squelched a lot of those outlandish claims concerning a certain brand of green and yellow tractors… 1 2 Share this post Link to post Share on other sites
