 McDonnell decided that in future, locomotives would use shared standard parts where possible, and that locomotive design and construction would utilise the practices which he had used at Inchicore.His first locomotive design for the NER, the '38' class 4-4-0, incorporated a number of unpopular features; and some popular features of Fletcher's engines were omitted.Worse, although the new locomotives were larger than Fletcher's most recent designs, they were no more capable.