Therefore the bore, and often the stroke, are increased in low pressure cylinders resulting in larger cylinders.

Unlike the other locomotives, both high and low pressure cylinders had the same piston stroke.

Their spent steam is then fed to the larger low pressure cylinders that drive the front set of coupled wheels.

The low pressure cylinder was said to be larger and heavier than any other fitted to a paddle steamer.

To start the locomotive, the low pressure cylinders could be supplied with low pressure steam.

With a fully open regulator, live steam was supplied to the low pressure cylinders by an automatic throttle.

The high and low pressure cylinders were mounted in vertical line with each other, with the piston rods in parallel.

Usually the low pressure cylinder was on the bottom, but clearance issues sometimes caused it to be put on the top.

Without this, the low pressure cylinders would have to actually work against atmospheric pressure.

This eliminated the connections between sides characteristic of cross-compound engines, where the low and high pressure cylinders were on opposite sides.