When introduced they had the then new style of 12 in (300 mm) letters for the company's initials on the tank sides.

They were fitted with saturated "Precursor" class boilers with lagged ends, round-top fireboxes, and sloping coal bunkers.

Lever actuated Joy reversing gear appeared in-lieu of the normal Ramsbottom screw system.

[1] During the Depression years many of the class spent time in store for want of work and almost half were scrapped.

47884, achieved the highest calculated service mileage of 732,425 mi or 1,178,724 km.