Their most remarkable feature was perhaps the arrangement of the two low-pressure inside cylinders en echelon so as to accommodate the very large bore.

The low-pressure cylinder on the right was set at an angle due to its large size.

Opposing sides of the high- and low-pressure cylinders were cross-connected to each other.

Also, the engines were constructed with the high-pressure cylinder aft and the low-pressure cylinder forward.

The two low-pressure cylinders drive the rack wheels.

The locomotive had one high-pressure and one low-pressure cylinder, coupled to four driving wheels in a 4-4-0 configuration.

Smith improved on this by developing a three-cylinder compound system with one high-pressure cylinder inside and two low-pressure cylinders outside.

Also in this space was a reheater for the high-pressure exhaust before it was fed to the forward low-pressure cylinders.

The low-pressure cylinders drove the first coupled axle, and the high pressure cylinders the second set of axles.

Each had one high-pressure and two low-pressure cylinders connected to a crankshaft.