Dean had worked under Armstrong on and off for 22 years before becoming his successor and he perpetuated his locomotive policy for some time. He later produced standardised 0-6-0 and 2-6-0 goods locomotives (the 2301 and 2600 "Aberdare" classes), and 0-6-0STs of various sizes (the 2021 and 2721 classes). For express trains he initially developed the 2-2-2 type, culminating with the elegant 3031 class. He later moved on to the 4-4-0 type, producing the Badminton and Atbara classes with wheels, and the Duke and Bulldog classes with wheels. For branch line and suburban trains he built 31 3600 class 2-4-2T locomotives.