Above is the 1364 with the original compound cylinders.

Below is the 1364 with the  simple single cylinder configuration.

The idea behind the vauclain compound cylinder system is to take full advantage of the steam pressure energy by using it a second time.  The second cylinder being bigger required less pressure to get the same energy output.  This proved to be very economical as it took less coal to generate the same horsepower.  However despite the best math one or the other cylinder pushed harder in a given moment putting stress on the yoke that joined the 2 cylinder's pushrods.   The cost of maintenance exceeded the savings on coal therefore in 1924 simple cylinders were installed on the 1364 at the cost of $79.06.



To the right is the patent for the vauclain compound.