Tetracycline has been studied extensively in clinical trials, with thousands of people worldwide having been evaluated. In these studies, side effects occurring in a group of people taking the drug were documented and compared to the side effects that occurred in a similar group of people not taking the medicine.
Steel ties are utilised in nearly all sectors of the worldwide railroad systems including heavy-haul, class 1s, regional, shortlines, mining, electrified passenger lines (OHLE) and all manner of industries.
Railroads in the 1800s for kids: Timeline of the Trains, Inventors and Innovators. The timeline of the famous men, innovators and inventors who developed the railroads and the steam locomotives: 1814: George Stephenson constructed a locomotive that could pull 30 tons up a hill at 4 mph. 1  Stephenson called his locomotive, the Blutcher. He is considered to be the inventor of the first steam locomotive engine for railways.