The Precursor class was the first locomotive class to be designed wholly by F. W. Webb. He had previously ordered further examples of his predecessor's Samson and Newton classes.
The class featured enclosed wheel splashers and cabs from new, but no brakes were initially fitted; some received steam brakes and others vacuum brakes. They were also fitted with 1,500-imperial-gallon (6,800 L; 1,800 US gal) tenders.
Webb's Precursors performed well enough, but it didn't take long before these engines (as well as the Ramsbottom Samson and Newton classes) were superseded by his Improved Precedent Class and, being viewed as weaker than these newer engines, it wouldn't take long before they were on the line of withdrawal, with the first going out in 1892 and the last one holding on until 1895.