General John T. Thompson developed the Thompson Submachine Gun. He originally envisioned an "auto rifle" (semi-automatic rifle) to replace the bolt action service rifles then in use, but he came across a patent issued to John Bell Blish in 1915 while searching for a way to allow his weapon to operate safely without the complexity of a recoil or Gas-operated reloading mechanism. Blish's design was based on the adhesion of inclined metal surfaces under pressure. Thompson gained financial backing from Thomas F. Ryan and started the Auto-Ordnance Company in 1916 for the purpose of developing his "auto rifle". It was primarily developed in Cleveland, Ohio, and the principal designers were Theodore H. Eickhoff, Oscar V. Payne, and George E. Goll. By late 1917, the limits of the Blish Principle were discovered; rather than working as a locked breech, it functioned as a friction-delayed blowback action. It was found that the only cartridge currently in service that was suitable for use with the lock was the . 45 ACP round. Thompson then envisioned a "one-man, hand-held machine gun" in . 45 ACP as a "trench broom" for use in the ongoing trench warfare of World War I. Payne designed the gun and its stick and drum magazines. The project was then titled "Annihilator I", and most of the design issues had been resolved by 1918; however, the war ended two days before prototypes could be shipped to Europe.