It seemed like a good idea. The articulated locomotive was being developed in the early 1900s, basically two engines under a single boiler, and was eliminating helper engines on heavy trains and steep grades.
The Erie Railway was using 0-8-8-0s to successfully haul coal and
so upped the ante by ordering this triple-engine locomotive from Baldwin in 1914, incorporating the third engine under the tender. Power was good, but the boiler could not generate steam as quickly as 6 cylinders could use it. It was sent back for grate enlargement and other mods. Two more were ordered to the new specifications for use on the hill from Susquehanna PA to Gulf Summit NY. They also were not a success, having to stop halfways up the eight mile hill for water and time to build steam. These huge monsters rarely broke 10 mph while working but must have been something to see.
The last one, #5016.