The EMD GT22 Series were first introduced in 1972 after the rise in popularity of six axle locomotives. The GT series now carried a turbocharger that increased the horsepower depending on customer input. The GT series also utilized six axle HTC Trucks, which allowed the locomotive to haul heavier loads at slower speeds with minimal wheelslip. These designations could apply to any kind of export locomotive design of EMD or another licensee of EMD as long as the electrical & mechanical gear was left unaltered.