Northern Pacific 3-cylinder 4-10-4

During the height of experimentation with 3-cylinder engines in North America, the Northern Pacific railroad was in search of a new passenger locomotive to replace their aging Pacifics. ALCO proposed a small line-up of locomotives of varying wheel arrangements to the NP. One of the engines in the line-up was a 3-cylinder 4-10-4. Very little is known about the design of the locomotive other than what is on the surface. It most likely would've used a cylinder arrangement similar to what was on other contemporary 3-cylinder engines at the time, such as the SP 4-10-2s and the UP 9000 Class.
What we do know is that management on the Northern Pacific was skeptical of the 3-cylinder concept. They wanted the Chicago, Burlington, & Quincy railroad to try out a 3-cylinder locomotive first, and if it worked over there, then they would have a look into it. However, while they didn't accept a 3-cylinder 4-10-4, this did lead to the creation of the first 4-8-4s in the world.