Owing to the length of the locomotive , the tender was kept to a short 6 - wheeled pattern , rather than the existing 8 - wheeled designs of the 0 - 8 - 0 locomotives .
The overall locomotive would still fit onto existing turntables .
Owing to the length of the locomotive , the tender was kept to a short 6 - wheeled pattern , rather than the existing 8 - wheeled designs of the 0 - 8 - 0 locomotives , so that the overall locomotive would still fit onto existing turntables .