This wheel arrangement came to be known as the Pacific type after the voyage the completed locomotives had to make across the Pacific Ocean to New Zealand. A few instances of the 4-6-2 wheel arrangement are known to have existed prior to 1901, but these were all reconstructions of locomotives that were originally built with a different wheel arrangement, thereby making the thirteen members of the Q class the first "true" Pacifics in the world.
The term "Pacific type" refers to a specific wheel arrangement used on locomotives. This particular arrangement was named after its journey across the Pacific Ocean to New Zealand, where it was first implemented. The thirteen members of the Q class are considered the first true examples of this wheel arrangement in the world.