The most dramatic incident in the ESC's rationalisation programme was the ending of steel-making and steel-rolling at Penistone. The facts of the case highlighted the deficiencies of past thinking and practice in British basic industries, the powerful impact of more effective commercial criteria and the issue of the social responsibility of major industrial companies.

The plant installed at Penistone in the war had reduced hand labour, but the new open hearth shop and the concentration there of operations from three tyre plants into one new mill had led to an increase in employment before recession cut the total back again. The Bessemer converters, only dating from 1914, were not used after 1922; from then on Penistone output was rolled from open hearth steel. Tyre manufacture and billet production was important, but the staple trade had always been rails. There were rail mills with better locations and lower process costs.

Much Penistone plant was good. Cammell Laird's brochure for the 1924 Empire Exhibition described it as ‘recently remodelled and extended to meet the most modern requirements’. In the mid-1920s a new rolling mill ‘with all the most up-to-date handling devices’ was reckoned ‘one of the most efficient in the country’. Even the ‘old’ works had been ‘practically’ rebuilt during or shortly after the war, ‘so as to bring them in every respect up to date and to make them comparable with the most efficient works in any part of the world’.