The first examples of this wheel arrangement were built in 1909 for the
Southern Pacific. They were experimental Mallet type locomotives with
the boiler split into two sections. The front section was more of a
feedwater heater than a boiler. These locomotives later evolved into
the now famous cab forward design.
Although most railroads did not have a specific name for this wheel
arrangement, the C&O called them "Chesapeakes" while the SP called
them "Mallet Consolidations".
Norfolk & Western made this design famous by spending many years putting a
lot of effort into perfecting the compound design. The N&W ended up with
the ultimate stump-puller in their 2-8-8-2s with unsurpassed pulling ability.
Fortunately, two of these impressive steam locomotives survive today.