[2] From 1864 to 1883 he was Locomotive, Carriage and Wagon Superintendent of the Great Southern and Western Railway of Ireland at Inchicore.
[2] From 1 November 1882, McDonnell was Locomotive Superintendent of the North Eastern Railway (NER) in England; he succeeded Edward Fletcher, who had retired.
[4] His only other design for the NER, the '59' class 0-6-0, were also unpopular; in this case, the engines were of similar size to Fletcher's most recent 0-6-0, but were less powerful.
[5] As a consequence, McDonnell resigned from the NER in September 1884, receiving a year's salary as severance pay.
[4] McDonnell was not replaced immediately, the NER's locomotive department then being managed by a committee chaired by Henry Tennant.