>>1600408For the direct drive turbines, they often didn't have a transmission that could change gears. So the designers would have to choose a compromise between a high gear ratio for starting and a low gear ratio for high speed running. This is what did the PRR S2 in as the turbine used huge volumes of steam to get enough torque to start.
The Jawn Henry and the C&O turbines tried to get around this by using an electrical transmission. Unfortunately, electrics are a bad combination with coal dust, ash and water.
The Swedish locomotives had a low enough gearing for starting trains along with never needing a higher gear ratio due to their slow speed usage. This allowed them to shine as they have a smooth torque output, which is great for hill climbs and adhesion.
